chapter 5 results and discussion -...

55

CHAPTER 5

RESULTS AND DISCUSSION

This chapter has following four parts that deals with the results obtained during

present investigation.

1. Standardization of Chhana jalebi

2. Shelf life enhancement by using two following preservatives

a. Sodium benzoate

b. Potassium sorbate

3. Shelf life enhancement by using following four packaging materials

a. Low barrier packaging materials

i. Polystyrene cups covered with aluminum foil

ii. Cardboard box lined with butter paper (generally using for

packaging of sweets)

b. High barrier packaging materials

i. Metalized polyester (MET)

ii. Low density poly ethylene (LDPE) pouches

4. Shelf life enhancement by using following two packaging techniques

a. Modified Atmospheric Packaging (MAP) technique in MET and LDPE

materials with following three modified atmospheric conditions

i. 100% CO2

ii. 100% N2

iii. Combination of 50% CO2 and 50% N2

b. Vacuum packaging technique

56

PART –I: STANDARDIZATION OF CHHANA JALEBI

5.1 STANDARDIZATION PROCEDURE FOR CHHANA JALEBI

PRODUCTION

Standardized procedure for the preparation of Chhana jalebi has not been

available so far. Preparation of Chhana jalebi involves making batter, coil formation and

frying and dipping in sugar syrup. This method is highly variable as followed by small

scale manufacturer or halwais.

In order to produce uniform quality product various processing parameters such as

i. Fat content in milk

ii. Combination of Chhana maida ratio

iii. Level of water addition

iv. Frying time and temperature

v. Sugar Syrup concentration, temperature and time of soaking are needed

to be optimized.

5.1.1 Optimization of fat levels in milk

Fat plays a significant role in determining the quality of Chhana in terms of

consistency, texture and flavor. Increasing of fat level in milk is desirable character for

Chhana making for soft end product. Soft Chhana is preferable for manufacture of

jalebi.

Chhana prepared with milk containing different fat levels such as 1.5%, 3%,

4.5% and 6% was used in batter making by mixing with other ingredients such as

Chhana, maida, baking soda, corn flour and water.

For comparing the effect of fat, all other factors such as level of Chhana- maida

ratio (1:1), hydration time (3 hr), baking soda (0.25%), corn flour (4%), water, sugar

syrup concentration (60°Brix) and soaking time (1 min) and soaking temperature (50°C)

were kept constant whereas frying temperature and exposure time was determined based

on change of desired color of the product through visual observation [65]. The Chhana

jalebi prepared was evaluated through sensory quality such as color and appearance,

57 flavor, body and texture, overall acceptability using 9-point hedonic scale. Ideally good

quality Chhana jalebi should have a golden to yellow color, crispy texture, rich flavor

and sweet taste. The comments of evaluators was recorded and expressed as a mean

value of sensory scores of jalebi on 9 point hedonic scales in Table 5.1.

Table 5.1 Effect of fat level in milk on sensory score *(max 9.0) of Chhana jalebi

Level of fat percentage

Parameters 1.5% 3.0% 4.5% 6.0% CD(P≤0.05)

Colour and appearance 7.31±0.51a 7.33a±0.59a 7.38 ±0.744a 7.36 ±0.74a -

Flavour 7.08±0.44a 7.70±0.46b 7.89±0.45b 8.19±0.50c 0.23

Body and texture 6.6±0.77a 8.12±0.74ab 7.52±0.98a 6.71±0.72a 0.98

Overall acceptability 7.11±0.63a 7.70±0.62d 7.47±0.66c 7.28±0.67b 0.16

*Average three trials; Note: Values with different superscripts are differ significantly at

P≤0.05

Table 5.2. Statistical report (ANOVA) of milk fat level effect in Chhana jalebi

based on the sensory score (max 9.0)

Source dfCA FL BT OA

MSS F MSS F MSS F MSS F

Judges 4 1.570 29.641 1.015 37.233 1.121 2.200 1.663 117.652

Fat level in milk

3 0.005 0.103NS 1.116 40.959* 2.382 4.673* 0.325 23.037*

Error 12 0.052 - 0.027 - 0.509 - 0.014 -

Total 19 - - - - - - - -

* Significant at 5% level; CA-Color and appearance, FL-Flavor, BT-Body and texture,

OA-overall acceptability; NS-Non significant

58 i. Color and appearance

The color and appearance scores for fat levels 1.5%, 3%, 4.5% and 6% were

7.31, 7.33 7.38, 7.36 respectively. Jalebi prepared from 1.5%, 3%, 4.5% and 6% of milk

fat have given same color development. The color of jalebi varied from light yellow to

brown; however, fat level in milk did not show any impact on color and appearance

scores whereas frying time and temperature plays vital role on the same. Brown colour

development during frying is attributed to derivatives of proteins and their interaction

with carbohydrates [75]. The fat content in milk had no significant influence on color

and appearance of the product (Table 5.2). The brown color development of jalebi was

mainly due to frying. The products are mainly protein derivatives and interact with

carbohydrates and developed colour. Hence, fat content showed only less effect on the

colour and appearance of the product.

ii. Flavor

The flavor scores for 1.5%, 3%, 4.5% and 6% milk fat were 7.08, 7.70, 7.89,

and 8.19 respectively and it’s contributes less, optimal, strong and very strong flavors to

the products respectively. The flavor of Chhana jalebi was partly dependent on fat level

in milk as indicated by significantly higher flavor scores (P<0.05). This could be

attributed to the optimal fatty acid balances in butter fat. Milk fat contributes for the

desirable flavor of milk [76]. It observed that the flavor scores were increased when

increases the fat content in milk. It means the product prepared with high fat content

milk had high flavour than that prepared with low fat content milk. Based on our

observation, concluded that milk fat significantly contributes to the flavor of milk

products, the mean value and significantly difference are represented in Table 5.2. For

example the flavor score was 7.08 which significantly increased to 8.2% in case of 6%

fat milk product whereas there was no significant difference among 3 and 4.5% fat milk

samples.

iii. Body and texture

The body and texture of the product was also influenced by fat level in milk. The

jalebi became firmer to more chewy as fat level in the milk increased. The fat generally

contributes to the soft texture to the product; but in the present study the product

prepared with higher fat milk exhibited chewy body. This may be attributed to

59 interaction of proteins (specifically casein) and fats during frying at high temperature

[77]. The body and texture score of the product prepared from 1.5% was 6.69 which

statistically increased to 8.12 for 3% fat milk. When the fat level in milk increased to

4.5%, the scores significantly decreased to 7.52 and thereafter to 6.71 (P≤0.05). There

was no significant difference between 1.5%, 4.5% and 6% of fat milk products in the

body and texture scores (Table 5.1). Because 1.5% fat milk jalebi samples were firmer

and 4.5% and 6% fat milk jalebi samples were chewier. There was significant difference

between 3% fat milk jalebi samples from other fat level samples. The jalebi samples

prepared from 3.0% fat milk showed crispier than other samples.

iv. Overall acceptability

According to evaluators the flavor of the product prepared from 6% fat milk was

better. However, overall acceptability of these product scores was less due to more

chewy body and texture. The overall acceptability scores of jalebi were significantly

different from each jalebi samples prepared from 1.5%, 3%, 4.5% and 6% fat milks.

The highest score was noticed in 3% fat milk jalebi as a 7.70. The overall acceptability

score of the product prepared from 1.5% was 7.11 which increased to 7.70 from 3% fat

milk samples whereas the scores was significantly decreased in 4.5 and 6% milk fat

samples as 7.47 and 7.28 respectively (P≤0.05). As can be seen from the Table 5.1, the

effects of fat on flavor, body and texture there by overall acceptability are statistically

significant (P≤0.05) (Table 5.2). Based on the sensory report, concluded that 3% fat

milk jalebi had a desirable color, body and texture. Hence, further trials were continued

with 3% fat milk.

5.1.2 Water content of batter for Chhana jalebi

Water plays a key role in food preparation. It helps to distribute the particles like

starch and protein to produce a smooth texture. The quantity of water in food creates

impact on texture, consistency and makes comfortable feeling in mouth during chewing

process. In case of jalebi manufacture, water level in batter is very important because it

affects the integrity of coils formed for deep fat frying. The initial study was undertaken

to estimate the optimum water level in the batter for making jalebi coils. The extrusion

behavior of batter was also recorded using plastic container for making jalebi coils.

Hence, the water content used for batter making has been optimized.

60

Water content in the batter has impact on the formation and retention of shape,

size, frying qualities, as well as jalebi quality. During studies different levels of water

was added in to other ingredients such as Chhana and maida for making batter. For

comparing the effect of water level in batter, all other factors such as level of Chhana-

maida ratio (1:1), baking soda (0.25%), corn flour (4%), hydration time (3 hr), sugar

syrup concentration (60°Brix) and soaking time (1 min), soaking temperature (50°C),

were kept constant [65] whereas, frying temperature and time determined based on

color change of the product through visual observation.

In order to optimize the water level, five different levels of water ranges 35%,

40%, 45%, 50% and 55% percent were taken. There was no impact of water level in

batter on color, appearance and flavor of the product, but the body and texture of the

product was highly dependent on water level in the batter. Initially, when 35% of water

was added in the batter, more force required to extrude it through the plastic container.

The batter consistency was found very thick. The final product after dipping in sugar

syrup was showing hard body, very closed texture, firmer texture.

Added 55% of water level showed the batter became thinner. This batter was

easily passed through an aperture of the plastic container but the retention of shape

and size was found to be complex. The final products were not in uniform size,

breakage of coil during extrusion, too soft and sticky in texture, absorbed more oil and

sugar syrup. Hence two extreme levels of water have been rejected due to above

unacceptable batter and end product. Therefore, it was confirmed that water level may

be within 40% to 50%.

At the water level of 40% of batter was observed discontinued flow from an

aperture due to hard batter consistency with application of moderate force. The fried

Chhana jalebi coils were little hard and firmer body and texture. In water content of

50% batter were flows very easily from the aperture, non-uniform shape and breakage

of coil during extrusion. The end product of fried Chhana jalebi was found disintegrated

coils during frying and more sugar syrup absorption during soaking. Both 40% and 50%

water levels are given little better results than the 35% and 55% of water levels, even

though batter and product characteristics were not up to the acceptable level. However

these studies are given more assurance that optimal level water would fall between 40%

and 50%.

61 In batter, 45% of water was added and again tried to make Chhana jalebi. At this

time, the batter passed easily through the plastic containers aperture with application of

very less force and formed the desired shape and as well as retained the shape. The fried

Chhana jalebi coils were sufficiently expanded. They were shown uniform shape,

uniform frying and crispy in texture.

The prepared Chhana jalebi was evaluated for sensory quality such as color and

appearance, flavor, body and texture, overall acceptability using 9-point hedonic scale.

The comments of evaluators was recorded and represented in Table 5.3.

i. Color and appearance

The color and appearance scores for water levels in batter 35%, 40%, 45%, 50%

and 55% were 7.04, 7.06, 7.06, 7.06 and 7.06 respectively (Table 5.3). The results

indicate that the water level in batter had no significant influence on color and

appearance. The color of jalebi was mainly because of the browning products formed

during frying and those products are mainly derivatives of proteins and interaction with

carbohydrates. But the brown color was observed in 35%, 40%, 45%, 50% and 55% of

water level in batter as same. Hence, it is clearly showed that there was no impact of

water level in batter on color and appearance of the product.

Table 5.3 Effect of water level in batter on sensory score *(max 9.0) of Chhana jalebi

Water level in batter* (%)

Parameters 35 40 45 50 55 CD(P≤0.05)

Colour and appearance 7.04±0.26NS 7.06±0.19 NS 7.06±0.19NS 7.06±0.13NS 7.06±0.18NS -

Flavour 7.1±0.29NS 7.14±0.24NS 7.18±0.22NS 7.10±0.28NS 7.12±0.25NS -

Body and texture 6.80±0.14a 7.06±0.19b 8.24±0.18c 7.08±0.19b 6.80±0.20a 0.23

Overall acceptability 6.80±0.14a 7.06±0.19ab 7.24±0.18b 7.00±0.14a 6.88±0.17a 0.20

* Average three trials; ml water for 65 g of batter; Note: Values with different

superscripts are differ significantly at P≤0.05; NS-Non significant

62

Table 5.4 Statistical report (ANOVA) of water level effect in batter based on

sensory score (max 9.0) of Chhana jalebi



Judges 4 0.025 0.599 0.224 7.652 0.052 1.813 0.055 2.529

water level in batter

4 0.000 0.009NS 0.005 0.190

NS 1.794 62.089* 0.144 6.593*

Error 16 0.042 - 0.029 - 0.028 - 0.021 -

Total 24 - - - - - - - -

* Significant at 5% level; CA-Color and appearance, FL-Flavor, BT-Body and texture,

OA- overall acceptability; NS-Non significant

ii. Flavor

The flavor scores for water levels in batter 35%, 40%, 45%, 50% and 55% were

7.10, 7.14, 7.18, 7.10 and 7.12 respectively (Table 5.3). The ANOVA report indicates

that the water level in batter had no significant influence on flavor (Table 5.4). In our

pervious analysis concluded that flavor scores increased as fat content in milk was

increased. However, in this study 3.0% of fat milk was taken for all water levels of

dough making. Hence, it is clearly showed that there was no impact of water level in

batter on flavor of the product.


The average body and texture scores of different water levels such as 35%, 40%,

45%, 50% and 55% in batter were 6.80, 7.06, 8.24, 7.08 and 6.80 respectively. Jalebi

samples were shown very hard, crispy, very firm and soggy texture based on the water

content in batter. Product became firm and soggy as water content increased in the

batter. This is attributed to gelation and water absorption during batter making. The

crust thickness of the product increased with respect to decreasing moisture content

during frying. The mean values of sensory scores obtained from 9 point hedonic scale

are presented in Table 5.4. The sensory score of body and texture of product prepared

from 35% to 45% moisture batter ranged from 6.80 to 8.24, whereas further increase of

63 water level in batter to 50% and 55% decreased scores to 7.08 and 6.80 respectively,

which was statistically significant (P≤0.05). This was due to interaction of water and

protein during frying [75]. There was no significant difference between 35% and 55%

as well as 40% and 50% water level products but there was significant difference in

45% water level products from each other (Table 5.4). Because pour ability of this water

level batter was optimum and the product was crispy in texture compared to other

samples. Hence 45% water level in batter content was given good score of 8.24 on body

and texture of the product.


It was observed from the sensory report that the average overall acceptability

scores for water levels in batter 35%, 40%, 45%, 50% and 55% were 6.80, 7.06, 7.24,

7.00 and 6.88 respectively. According to evaluators, the body and texture of the product

prepared from 45% water level in batter was better. The overall acceptability scores of

jalebi were significantly different from each other among 35%, 40% and 45% water

level in batter. The highest score of Chhana jalebi was noticed in 45% water content

batter as 7.24. There was no significant difference between 35% (6.80), 50% (7.00) and

55% (7.29) water level of batter. The mean value presented in Table 5.3 and 45% water

level in batter product was significantly different from each other. The Table 5.4

represented that when water content increases, overall acceptability scores was also

increases upto 45% water level and there after decreased. The results indicate that 45%

of water level in batter gave a desirable body and texture in Chhana jalebi.

Thus, it was concluded that a batter prepared with 45% water level was found to

be optimum for Chhana jalebi preparation which not only facilitates in shape formation

but also yields best quality Chhana jalebi. Therefore, remaining trials were continued

with 45% of water content for making batter. Role of water content in Chhana as well as

dough on the quality of the product has also been reported by several Researchers.

Nawale Pratik (2010) [13] reported that 45 to 50% water level in khoa jalebi was found

to be optimum which not only facilitated shape formation but also yielded good quality.

Chakkaravarthi et al., (2009b) [78] reported that maida jalebi prepared with 53 to 57%

of water content needed additional force to push the batter through an orifice while

gravity flow was possible when water content was between 57 and 61%.. Nath (1992)

[27] reported that pantua made from Chhana with about 58% water level possessed all

64 desirable sensory attributes. Desired water level of 60% in gulabjamun dough has been

reported by Prajapati et al., (1992) [39]. Rajhoria (1989) [54] reported that the softness

of gulabjamun could be increased by increasing the quantity of water content from 60 to

65% in dough preparations. In case of rasagulla, about 55-58% water level was found

to be optimum for good quality and acceptable product which showed a round shape,

soft body and maximum spongy texture reported by Bhattacharya and Des Raj (1980)

[55].

5.1.3 Effect of frying temperature and time combination for Chhana jalebi

Frying temperature determines the nature of the fried product, especially in deep

fat fried foods. Foods fried at the optimum temperature and time which have golden

brown color, crispy and optimal oil absorption [79]. However, under fried foods at

lower temperature or shorter frying time have white or slightly brown color at the edge

and have un-gelatinized or partially cooked starch at the center. Over fried foods at

higher temperature and longer frying time have darkened and hardened surfaces and a

greasy texture due to the excessive oil absorption [80].

In order to optimize the frying temperature and time combination, Chhana

jalebi was made with Chhana obtained from 3% fat milk mixed with other

ingredients such as maida and water (45%). For comparing the effect of frying

temperature and time, all other factors such as level of Chhana-maida ratio (1:1), baking

soda (0.25%), corn flour (4%), hydration time (3 hr), sugar syrup concentration

(60°Brix) and soaking time (1 min), soaking temperature (50°C), were kept constant.

Four different ranges of temperature such as 120-130°C, 140-150°C, 160-170°C and

180-200°C were selected. Development of golden brown color on the product was

taken as the end point and time taken to the end point was recorded for each

temperature ranges. Fried units were then transferred to hot sugar syrup at room

temperatures. The Chhana jalebi prepared was evaluated for sensory quality such as

color and appearance, flavor, body and texture, overall acceptability using 9-point

hedonic scale.

In the preliminary trial, it was found that frying at 120-130°C required 5 min.

The product obtained from frying at this temperature range was prolonged frying time,

hard product, less sugar syrup absorption. It needed more time to fry and the end

product also showed not satisfactory results. Thus 120-130°C of frying temperature was

65 not selected for the further studies. At the temperature range of 140-150°C, the product

obtained optimum color at 4 min. The product became firmer body, chewy texture and

less sugar absorption in this frying temperature range. Hence the frying temperature of

140-150°C was discontinued. At 180-200°C for 40 sec, the dark brown in color was

developed rapidly in the product and very difficult to maintain the color at this

temperature, case hardening and poor sugar syrup absorption. This frying temperature

range also showed not satisfactory results.

However, frying at 160-170°C for 2 min produced a final product with crispy in

texture, good sugar syrup absorption, optimum body and texture and pleasant flavor.

The product obtained from this frying temperature range showed acceptable outcomes.

Consequently, it was concluded that frying at 160-170°C for 2 min found to be optimum

for Chhana jalebi preparation which not only facilitates in golden brown color as well as

produced the best quality of Chhana jalebi. The prepared Chhana jalebi was evaluated

for sensory quality such as color and appearance, flavor, body and texture, overall

acceptability using 9-point hedonic scale. The average sensory scores for color and

appearance, flavor, body and texture and overall acceptability are expressed in Table 5.5

and statistically analysis of the sensory scores is presented in Table 5.6. The comments

of evaluators was recorded and presented in Table 5.5.


It was observed that the color and appearance scores for frying temperatures at

120-130°C, 140-150°C, 160-170°C and 180-200°C were 7.78, 7.88, 7.98 and 7.88

respectively. In this study, jalebies were taken based on the development of golden

brown color and time was noted. It was found that at lower temperatures. i.e, from 120-

130°C the product used to get the optimum golden brown color gradually. As the

temperature increased upto 180-200⁰C the product became dark brown in color within

short time and at this temperature it was very difficult to maintain the color. This is

evident from the ANOVA presented Table 5.6. Color and flavor changes in product

were due to increased rate of non-enzymatic browning (Maillard) reactions between

proteins and reducing sugars during frying [75]. Higher temperature gave dark brown

color and cooked flavor to the product; lower frying temperatures resulted in whiter

color.

66 Table 5.5 Sensory characteristics* of Chhana jalebi fried at different frying

temperatures

Frying temperatures (°C)

Parameters 120-130 for 5min

140-150 for 4min

160-170 for 2min

180-200 for 40sec

CD(P≤0.05)

CA 7.78±0.29NS 7.88±0.16 NS 7.98±0.35 NS 7.88±0.13 NS -

FL 6.80±0.57a 7.10±0.72ab 7.70±0.57bc 6.56±0.84a 0.52

BT 6.30±0.44a 6.95±0.377ab 8.11±0.36bc 6.60±0.54a 0.44

OA 6.50±0.50a 6.95±0.37a 8.00±0.58b 6.60±0.54a 0.5

* Average three trials; Note: Values with different superscripts are differ significantly at P≤0.05; NS-Non significant

Table 5.6. Statistical report (ANOVA) of frying temperatures effect on sensory score (max 9.0) of Chhana jalebi



Judges 4 0.130 3.070 1.446 10.091 0.466 4.555 0.643 4.983

Frying temperatures 3 0.033 0.784NS 1.212 8.454* 3.140 30.693* 2.353 18.217*

Error 12 0.042 - 0.143 - 0.102 - 0.129 -

Total 19 - - - - - - - -

* Significant at 5 % level; CA- Color and appearance, FL- Flavor, BT- Body and texture, OA- overall acceptability; NS-Non significant

ii. Flavor

The flavor scores showed a variation from 6.80 to 7.70. The lowest score was

for the product fried at 120-130°C (6.80) and 180-200°C (6.56) [Table 5.5]. The flavor

profile showed a forward trend as temperature increased to 160-170°C whereas

increasing temperature caused a reduced sensory score due to core of Channa jalebi was

showed case hardening, poor sugar syrup absorption and crust got burnt flavor at high

67 temperature. The statistical scores of flavor revealed that there is no significant (P≤0.05)

difference in the product fried between 120-130°C and 180-200°C, while there was

significant difference between 140-150°C and 160-170°C from each other. Frying of

batter at 160-170°C (7.70) produced a final product which was superior quality of flavor

than those fried at 120-130°C, 140-150°C, and 180-200°C. Flavor changes in product

were due to increased rate of non-enzymatic browning (Maillard) reactions between

proteins and reducing sugars during frying [75]. It is well known that frying temperature

significantly contributes to the flavor of milk products. This could be also attributed that

the typical fatty acids balance in butter fat. During deep-fat frying the food is

completely surrounded by the frying fat or oil and different events occur within a few

minutes: dehydration of food surface, absorption of fat, formation of flavor compounds,

development of surface color, etc [81].


The average body and texture scores of different frying temperatures (120-

130°C, 140-150°C, 160-170°C and 180-200°C) were 6.30, 6.95, 8.11 and 6.60

respectively (Table 5.5). The texture of product is influenced by the type of oil used,

frying temperature and time. Crispiness is an important textural characteristic of fried

foods. Crispiness indicates freshness and high quality [82]. For example, a crisp fried

food should be firm and should snap easily when deformed, emitting a crunchy sound

[83]. Same case was observed in Chhana jalebi fried at 160-170°C. Lower temperature

(120-130°C for 4-5 min and 140-150°C for 3-4 min) of frying resulted in chewy texture,

more oil absorption, hard surface and higher frying temperature (180-200°C for 40-50

sec) resulted in case hardening. The optimal temperature of frying i.e. 160-170°C for 1-

2 min gave crispy texture, light golden color and pleasant flavor. The body and texture

score of the product prepared from 120-130°C, 140-150°C and 160-170°C were

statistically increased from 6.30 to 8.11 whereas further increase of frying temperature

such as 180-200°C was statistically decreasing score to 6.60 at (P≤0.05). Hence 160-

170°C frying temperature was giving good score on body and texture of the product.


The overall acceptability of the product was also changed according to frying

temperature. The average scores varied from 6.50, 6.95, 8.00 and 6.60 for 120-130°C,

140-150°C, 160-170°C and 180-200°C respectively. The pleasant flavor, crispy body of

68 the product was obtained at 160-170°C which resulted in maximum acceptability score

of the product. The Chhana jalebi samples fried at 160-170°C scored maximum

followed by the samples fried at 140-150°C, 180-200°C and120-130°C. It was also

observed that the scores differ significantly (P≤0.05) due to the variation of four

different temperatures of frying. However, the overall acceptability scores did not differ

significantly (P≤0.05) between the product fried at 120-130°C, 140-150°C and also

between the product fried at 180-200°C.

Considering the time taken for frying and sensory attributes, the temperature

combination of 160-170°C for 1-2 min was found to be better for the desired crispy

body and texture for frying of Chhana jalebi. Bajaj et al., (2002) [65] found that frying

of maida jalebi at 165-175°C for 2-3 min resulted in good product with uniform brown

colored surface. Nawale pratik (2010) [13] was found that frying of khoa jalebi at 160-

165°C for 2-3 min resulted in good flavor and uniform product.

5.1.4 Optimization of sugar syrup soaking conditions for Chhana jalebi

The concentration of sugar syrup not only provides taste and correct sweetness

of the product but also has an influence on soaking characteristics of sugar syrup, shelf

life and commercial value. In addition, effective soaking depends on temperature of

syrup and time of soaking. Therefore, an attempt was made to find out suitable soaking

conditions for uniform absorption of sugar syrup in a minimum time.

The Chhana made from 3% fat content of milk was used in batter making by

mixing with other ingredients such as maida and water. For comparing the effect of

sugar syrup soaking conditions, all other factors such as level of Chhana- maida ratio

(1:1), baking soda (0.25%), corn flour (4%), hydration time (3 hr), and frying

temperature 160-170°C for 1-2 min were kept constant. The fried units were kept

dipped in sugar syrup of 50, 60, 70 and 80°Brix with the constant time and temperature

of 1 min at 60°C. The product soaked in 50 and 80°Brix had showed less sweet, soggy

body and texture, poor sugar syrup absorption and too sweet, poor sugar syrup

absorption respectively. It was found that 60 to 70°Brix products gave good sensory

scores. Again, 63, 65 and 68°C Brix were taken to find out exact sugar syrup

concentration. It was found that 68°Brix concentrated sugar syrup was given slightly

low sweetness, medium sugar syrup absorption than the other sugar syrup

concentration.

69

Then soaking time was optimized by using 1, 2, 3 and 4 min for 68°Brix

concentrated sugar syrup with constant temperature of 60°C. It was found that 2 min

soaking time had showed optimal sweetness, desirable sugar syrup absorption, optimum

body and texture.

Then temperature was optimized by using 50, 60, 70 and 80°C with sugar syrup

concentration of 68°Brix and 2 min soaking time. It was observed that temperature of

60°C was given good sensory scores. Thus, it was concluded that concentration of

sugar syrup of 68°Brix with 2 min of soaking time at temperature of 60°C showed

optimum sweet and sugar syrup absorption.

The prepared Chhana jalebi was evaluated for sensory quality such as color and

appearance, flavor, body and texture, overall acceptability using 9-point hedonic scale.

Ideally a good quality Chhana jalebi should have a golden brown color, crispy texture,

rich flavor and sweet taste. The comments of evaluators also recorded. The results are

presented in Table no 5.7.


It concluded that the average scores of color and appearance of different

concentration (50, 60, 65, 68, 70, and 80°Brix) sugar syrup was 7.75 and there was no

statistical significant among them (Table 5.7). Based on the sensory score determined

that color and appearance of Chhana jalebi was not dependent on sugar syrup

concentration. The color of jalebi mainly due to browning of products during frying and

those products are mainly derivatives of proteins and interaction with carbohydrates.

The golden brown color was observed in 50, 60, 65, 68, 70, and 80°Brix sugar syrup

concentrations as similar. Hence, it indicates that there is no impact of sugar syrup

concentrations on color and appearance of the product.

ii. Flavor

The flavor scores for sugar syrup concentration 50, 60, 65, 68, 70, and 80°Brix

were 6.90, 7.34, 8.17, 8.70, 7.17 and 6.53 respectively (Table 5.7). It observed that the

sugar syrup concentration had significant influence on flavor of the product (Table 5.8).

The flavor score of the product prepared from 50°Brix was 6.90 which increased to 8.70

for 68°Brix sugar syrup concentration whereas sugar syrup concentration increased to

80°Brix, the scores significantly decreased to 6.53 (P≤0.05).

70

Table 5.7 Effect of sugar syrup on sensory score* (max 9.0) of Chhana jalebi

Sugar syrup concentrations (°Brix)

Parameters 50 60 65 68 70 80 CD

P≤0.05)

CA 7.75±0.36NS 7.75±0.23NS 7.75±0.31NS 7.75±0.23NS 7.75±0.36NS 7.75±0.47NS 0.23

FL 6.90±0.74a 7.34±0.55a 8.17±0.18bc 8.70±0.13c 7.17±0.74ab 6.53±0.84a 0.59

BT 6.96±0.84a 7.30±0.44a 7.34±0.47ab 8.12±0.45bc 7.50±0.50a 7.20±0.57a 0.4

OA 6.93±0.72a 7.10±0.74a 7.14±0.77a 7.92±0.68b 6.90±0.74a 6.80±0.75a 0.44

* Average three trials; Note: Values with different superscripts are differ significantly at P<0.05; CA-Color and appearance, FL-Flavor, BT-Body and texture, OA-Overall acceptability; NS-Non significant

Table 5.8 Statistical report (ANOVA) of the effect of sugar syrup on sensory score

(max 9.0) of Chhana jalebi

Source DfCA FL BT OA


Judges 4 0.589 24.348 1.186 6.002 1.300 14.147 2.734 24.415

Sugar syrup concentration 5 0.000 0.000NS 3.336 16.881* 0.843 9.176* 0.852 7.612*

Error 20 0.024 - 0.197 - 0.091 - 0.111 -

Total 29 - - - - - - - -

* Significant at 5 % level; CA-Color and appearance, FL-Flavor, BT-Body and texture, OA-Overall acceptability; NS-Non significant

Based on the observation, there was no significant difference between 60°Brix

and 70⁰Brix sugar syrup concentration for 1 min. But the reasons are 60°Brix had less

sweet, low sugar syrup absorption and 70°Brix had high sweetness, slightly low sugar

syrup absorption. But 68°Brix for 2 min had showed optimal sweetness, desirable sugar

syrup absorption, crispiness and more juiciness. Both increasing and decreasing of sugar

syrup concentrations resulted in less acceptable taste of the jalebi. Hence, in these study

68°Brix sugar syrup concentrations for 2 min was taken.

71 iii. Body and texture

The body and texture scores for sugar syrup concentration of 50, 60, 65, 68, 70,

and 80°Brix jalebi samples were 6.96, 7.30, 7.34, 8.12, 7.50 and 7.20 respectively. The

sugar syrup concentration had significant influence on body and texture. It observed that

the body and texture scores were increased as sugar syrup concentration increased. The

lower sugar syrup concentration of 50°Brix, 60°Brix and 65°Brix for 2 min gave soggy

texture, whereas the product prepared with higher sugar syrup concentration of 70°Brix

and 80°Brix for 2 min resulted in firmer body. The sugar syrup concentration of 50, 60,

65, 68, 70, 80°Brix for 1 min gave poor sugar syrup absorption whereas jalebi samples

of same concentration for 3 and 4 min, resulted high sugar syrup absorption, sweetness

and soggy body and texture.


It determined that the overall acceptability scores of jalebi prepared with

different sugar syrup concentration 50, 60, 65, 68, 70 and 80°Brix were 6.93, 7.10, 7.14,

7.92, 6.90, and 6.80 respectively (Table 5.8). It found that the sugar syrup concentration

had significant influence on body and texture. It may be also observed that the overall

acceptability scores increased as sugar syrup concentration was increased from 50°Brix

to 68⁰ Brix. The body and texture score of the product prepared from 50°Brix was 6.90

which increased to 7.92 for 68°Brix sugar syrup concentration when the sugar syrup

concentration increased to 80°Brix the scores significantly decreased to 6.90 and

thereafter to 6.80 (P≤0.05). Based on the observation, there was no significant

difference between 60°Brix and 65°Brix sugar syrup concentrations for 1 min. In

generally in milk products, the low sugar syrup contributes to the soggy texture whereas

in the present study the product prepared with higher sugar syrup exhibited hard body

that was due to interaction of proteins and fats specifically casein and fat during frying

at high temperature. Based on the observation it was concluded that 68°Brix sugar syrup

concentrations for 2 min selected for the jalebi preparation.

5.1.5 Optimization of Chhana maida combination

Maida plays a vital role in Chhana jalebi making by acting as binding agent. The

binding agents affect the composition, rheology and sensory attributes of the

product. It also influences holding capacity of dough with its ingredients taste

72 and binds with moisture. In Chhana jalebi preparation, maida was used as a binding

agent.

Table 5.9 Effect of Chhana and maida combination based on sensory score of Chhana jalebi

Mai

da (g

)

Sensory attributes scored on 9-point hedonic scale

Chhana (g)

Parameters 15 30 45 60

CD

(P≤0

.05)

=0.4

7

Colour and appearance

20 7.00±0.0b 7.44±0.48a 6.71±0.35a 6.80±0.44a

30 6.64±0.41ab 7.64±0.58a 6.86±0.45a 6.81±0.29a

40 6.47±0.33a 7.46±0.45a 6.90±0.54a 7.19±0.41a

50 6.47±0.33a 7.36±0.35a 6.96±0.44a 7.83±0.45b

60 6.14±0.31a 7.32±0.34a 6.77±0.47a 8.10±0.37b

70 6.14±0.31a 7.30±0.34a 6.54±0.33a 7.820.311b

Flavour

20 7.20±0.27bc 7.76±0.43a 6.51±0.36a 6.90±0.37a

CD

(P≤0

.05)

=0.5

4

30 6.60±0.49ab 8.13±0.41ab 6.79±0.35a 6.87±0.18a

40 6.43±0.40a 7.69±0.43a 6.83±0.43a 7.32±0.35a

50 6.42±0.42a 7.55±0.37a 6.91±0.47a 7.92±0.49b

60 6.09±0.35a 7.45±0.30a 6.75±0.51a 8.30±0.43b

70 5.94±0.60a 7.27±0.30a 6.44±0.32a 7.97±0.21b

Body and texture

20 7.18±0.69a 7.86±0.21a 6.47±0.31a 6.76±0.50a

CD

(P≤0

.05)

=0.4

1

30 7.33±0.84ab 8.08±0.51ab 6.71±0.41a 6.93±0.46a

40 7.22±0.89a 7.89±0.21a 7.00±0.58ab 7.19±0.41ab

50 7.18±0.87a 7.76±0.17a 6.83±0.32a 7.71±0.61bc

60 7.07±0.79a 7.59±0.30a 6.82±0.48a 8.10±0.37b

70 6.83±0.77a 7.51±0.40a 6.66±0.37a 7.82±0.31b

Overall acceptability

20 7.18±0.69a 7.84±0.23b 6.68±0.35a 6.90±0.54aC

D (P

≤0.0

5)=0

.24

30 7.02±0.72a 8.27±0.22bc 6.75±0.41a 6.99±0.52a

40 6.88±0.73a 7.98±0.10b 7.20±0.20a 7.23±0.41a

50 6.74±0.66a 7.82±0.10b 6.73±0.33a 7.82±0.67ab

60 6.74±0.66a 7.72±0.30ab 6.72±0.37a 8.31±0.33b

70 6.64 ±0.61a 7.64±0.40ab 6.60±0.34a 7.92±0.21b

Note: Values with different superscripts are differ significantly at P<0.05

In order to select the suitable ratio of binding agent for best quality product,

maida was added as a 20, 30, 40, 50, 60 and 70 g in Chhana obtained from 3% fat milk.

The desirable good quality of Chhana jalebi should have a golden brown color, crispy

73 texture, rich flavor and sweet taste. The comments of evaluators were recorded and

presented in Table 5.9.

i Overall acceptability

Addition of maida and Chhana ratio of 1:1 ratio resulted in best quality product

with crispy body and uniform texture. Addition of lower quantity maida and higher

quantity of Chhana produced a product which was more brittle and coil disintegration

during frying. Higher quantity maida and lower quantity of Chhana resulted chewy and

more firm product. It also influenced syrup holding capacity of fried dough along with

its ingredients during soaking process. It is evident from Table 2 that increase of maida

levels from 20 g to 70 g showed significant difference in scores and increase of Chhana

levels from 15 g to 60 g had also showed significant difference in them. It may be

observed that all the combinations of Chhana-maida ratio had significant influence on

overall acceptance of the product. The ANOVA revealed the same (P≤0.05). Maida is a

common binding agent used in dairy products like gulabjamun [84], Chhana podo [85]

and pantua [86] in which it helps in obtaining the typical shape and texture for which

the products are well known.

Table 5.10 Statistical report (ANOVA) of the effect of Chhana maida combination

on overall acceptance score (max 9.0) of Chhana jalebi

Source of variation SS df MS F P-value F crit CD

p<0.05

Chhana 22.498 3 7.499 33.220* 8.15 2.699 0.24

Maida 0.492 5 0.098 0.436NS 0.822 2.309 0.24

Interaction between Chhana and maida 9.590 15 0.639 2.831* 0.001 1.771 0.60

Error 21.672 96 0.225

Total 54.254 119

* Significant at 5 % level; NS-Non significant

74

The average sensory scores of overall acceptability scores are represented in

Table 5.9. These data were again statistically analyzed and ANOVA of sensory scores

is presented in Table 5.10.

The average minimum score of overall acceptance score was 6.60 and the

maximum score was 8.27. As per the Table, it was clearly showed that increase of

maida levels from 20 g to 70 g on the product had no significant difference. But

increase of Chhana levels from 15 g to 60 g on the product had significant difference. It

may be observed that all the combination of Chhana and maida ratio had significant

influence on overall acceptance of the product. The ANOVA also reveals that there was

significant (P≤0.05) difference between products made by using different combination

of Chhana and maida ratios are presented in statistical Table 5.10.

5.1.6. Optimized process of Chhana jalebi production

Chhana jalebi was manufactured based on the optimized specifications of

individual processing parameters. The flow chart is provided in Figure 5.1 and

photographs of the same are given in Figure 5.2. The optimized process includes

preparation of Chhana from 3% fat level milk (Figure 5.2 – 1), mixing of Chhana

(Figure 5.2 – 3) with equal quantity of hydrated maida, baking soda (0.25%), corn flour

(4%) and water to form a smooth and uniform consistency batter (Figure 5.2 – 5).

The well kneaded batter (Figure 5.2 – 4) was extruded through an aperture of

soft PET bottle to give a coiled shape (Figure 5.2 – 6). Extruded batter coils were fried

in hot refined sunflower oil for deep frying (Figure 5.2 – 7) at 160-170°C for 2 min.

Sugar syrup was prepared by boiling 1:1 ratio (v/v) of sugar and water (Figure 5.2 – 8).

The fried products were then soaked in sugar syrup with 68°Brix for 2 min of soaking

time at temperature of 60°C (Figure 5.2 – 9). Then the soaked jalebi coils were drained

out of sugar syrup and packed in packaging material followed by it (Figure 5.2 – 10)

was analyzed for its physico-chemical, microbial, textural and sensory characteristics..

75

* Parameters were standardized

Figure 5.1 Flow chart for optimized process of Chhana jalebi production

Filtration/Clarification

Packaging and Storage

Mixing of maida (25.5%) and water (44.75%)*

Deep frying(160-170°C for 2 min)*

Soaking in sugar syrup (68ºBrix at 60ºC for 2 min)*

Chhana jalebi

Extrusion through an aperture of a soft PET bottle*

Addition of Chhana (25.5%), corn flour (4%), baking soda (0.25%),

and formation of batter*

Hydration time (3 hr)

Chhana

Straining

Setting of coagulum (15 min)

Cooling to 80°C

Addition of citric acid (2%)

Heating to 90°C

Standardization of milk(3% fat and 8.5% SNF)

Reception of milk

76

Figure 5.2 Standardization of Chhana jalebi

1

6

2

3 4

5

77

Figure 5.2 (Continued)

Figure 5.2 Standardization of Chhana Jalebi

1. Milk (3% fat level)

2. Coagulation of milk

3. Chhana

4. Jalebi batter (After mixing of all ingredients and hydration time)

5. Batter consistency

6. Extrusion of jalebi coils through aperture

7. Frying in oil

8. Sugar syrup

9. Soaking of Chhana jalebi in sugar syrup

10. Chhana jalebi (Standardized product)

7 8

9 10

78 5.2 CHARACTERIZATION OF THE STANDARDIZED CHHANA JALEBI

PRODUCTION

After the production of optimized Chhana jalebi it was analyzed for various

physical characteristics such as weight, thickness, diameter, sugar absorption, oil

absorption, pH, acidity; Chemical characteristics such as moisture content, fat,

carbohydrate, protein, sucrose, ash and water activity; Textural characteristics such as

hardness, fracturability, cohesiveness, adhesiveness, springiness, chewiness,

gumminess; sensory characteristics such as color and appearance, flavor, body and

texture, overall acceptability; color determination by L*, a* and b* values etc. The

mean values of mentioned characteristics are given in Table 5.11.

5.2.1 Physical characteristics of standardized Chhana jalebi

Based on the results, it was concluded that the standardized Chhana jalebi

samples were golden yellow in color and coil shaped, crispy with porous core, slightly

juicy with syrup oozing out when chewed, having high protein and fat content, and

fracturability that is brittle in nature (Table 5.11). The overall acceptability score was

above 8.5, which indicates that the product was ‘liked extremely’ and highly acceptable

[87]. It consists of 2 coils with diameter of each coil being 0.81±0.09. The diameter of

each jalebi unit is 6.51±0.48. Weight of each Chhana jalebi unit before soaking in sugar

syrup after frying was 5.1±0.22g, whereas after soaking in sugar syrup each unit weighs

5.1±0.22g. The final product was crispy with porous core, slightly juicy with syrup

oozing out when chewed. Titratable acidity was found to be 0.310±0.01 expressed as

percentage of lactic acid and pH of Chhana jalebi was 5.05±0.07. It shows that Chhana

jalebi sample was acidic in nature. Similar observations were observed in khoa jalebi

and other jalebi samples [10, 14, 78].

79

Table 5.11 Quality characteristics of standardized Chhana jalebi

Quality characteristicsMean value with SD

Quality characteristics

Mean value with SD

Physical characteristics Proximate composition (%)

Weight of jalebi, g 5.1±0.22 Carbohydrate 67.11±0.19

Thickness of jalebi, cm 0.81±0.09 Protein 5.71±0.202

Diameter of jalebi, cm 6.51±0.48 Fat 12.53±0.17

Sugar syrup absorbed by each jalebi (g)

2.77±0.20 Ash 0.29±0.06

Oil absorbed by each jalebi (g) 1.57±0.04 Moisture 20.23±0.25

Chemical CharacteristicsSucrose 40.21±0.30

pH 5.05±0.07

Acidity (% of lactic acid) 0.310±0.01 Textural characteristics

Water activity 0.825±0.002 Hardness (N) 0.028±0.003

Sensory characteristics (9-Point scale) Fracturability (N) 1.38±0.584

Colour and appearance 8.98±0.16 Cohesiveness 0.438±0.109

Flavour 8.98±0.16 Adhesiveness (Ns) -0.012±0.008

Body and Texture 8.98±0.34 Springiness 0.694±0.101

Overall acceptability 8.98±0.23 Chewiness 0.008±0.003

Color characteristics Gumminess 15.82±1.416

L* 51.04±1.47 Microbial characteristics

a* 10.35±0.29 SPC (log 10 cfu/g) 3.26±0.81

b* 29.97±2.66 Yeast and mold(log 10 cfu/g)

0.41±0.89

80 5.2.2 Proximate composition of standardized Chhana jalebi

Chhana jalebi sample had shown the protein content of 5.71%, fat content of

12.53% and total carbohydrate content of 67.11%. The moisture content was estimated

to be 20.23%. The ash content and water activity was determined as 0.29% and 0.82

respectively (Fig 5.3). Same observations were obtained by Pagote et al., (2012) [10],

Rewa Kumari et al., (2012) [14] and Chakkaravarthi et al., (2009b) [78].

Figure 5.3 Proximate composition of Chhana jalebi

5.2.3 Texture profile characteristics of standardized Chhana jalebi

Textural characteristics analysis is one of the significant analyses for food

products in order to know consumption comfort ability of the food. Various textural

characteristics such as hardness, adhesiveness, springiness, cohesiveness and chewiness

were analyzed for Chhana jalebi (Figure 5.4) [88-90]. Gumminess and chewiness are

mutually exclusive characteristics since gumminess applicable for semi solid food and

chewiness is applicable for solid food. Since Chhana jalebi is considered as solid food,

chewiness was analyzed. Textural analysis was done for fresh samples on 0th day.

Hardness of the product was found as 0.028 ± 0.003 N. This indicates that, 0.028

Newton force is required to compress the Chhana jalebi in order to deform the product.

Protein5.71%

Fat12.53%

Carbohydrate67.11%

Moisture20.23%

Ash0.29%

81

Adhesiveness of the product was measured as –0.012±0.008 Ns and concluded

that -0.012 Newton-seconds energy is required to overcome attractive forces between

food and contact surface. This was due to sugar syrup coating on the product.

Springiness of the product was determined as 0.694±0.101. This denotes that, 0.694

elastic distance was recovered when the compressive force is removed. In other way,

15.82±1.416 was recovered in product’s original shape (gumminess) after the

deformation. It is not 100% recovery of product’s original deformation. It was because

of fried product and total milk solids, but 15.82 distances was recovered due to elastic

product in a maida which is gluten. Similar studies were carried out in khoa jalebi

samples by Pagote et al., (2012) [10].

Cohesiveness of the product was identified as 0.438±0.109. This indicates that,

strength of internal bonds in a Chhana jalebi was 0.438. It is actually very less

compared to other food products. It is due to consistency of batter. Since consistency of

batter was like gel in nature, weaker internal bond was formed during frying of the

product. Moreover, since sugar syrup was also percolated in to the product, strength of

internal bonds was reduced. Chewiness of the product was measured as 0.008±0.003.

This value reveals that, the energy required to chew a Chhana jalebi solid food in to

convert in the state ready for swallowing is 0.0.08. It is actually, energy required to

mellow the product to convert semi solid state from the solid state in order to swallow

the product [88-90].

Figure 5.4 Textural characteristics graph of Chhana jalebi

82

Based on textural characteristics it revealed that, fresh sample of final

standardized Chhana jalebi was little crispy, smooth and soft in nature. In overall

product was suitable and comfortable for human consumption.

5.2.4 Color characteristics of standardized Chhana jalebi

Table 5.11 shows the Hunter parameter (L*, a*, b*) for Chhana jalebi sample.

Color analysis of four jalebi samples was done and the average for ‘L*’, ‘a*’ and ‘b*’

was taken. From the analysis it was observed that all values are in positive .The mean

value of L* value was 51.04±1.47, it indicates that Chhana jalebi samples have bright

colour and a* value for all the samples were 10.35±0.29, which proves that the product

was little orange-ish and ‘b*’ value was 29.97±2.66, which proves that the sample was

brown in colour (Figure 5.5). Similar results were observed in maida jalebi [10, 88-90].

Hence we concluded from this analysis Chhana jalebi samples shown golden brown in

color.

Figure 5.5 Hunter color lab analysis for Chhana jalebi

5.2.5 Sensory characteristics of standardized Chhana jalebi

The final product was given to 15 panel members for sensory analysis according

to 9 point hedonic scale and the scores obtained showed that the final product has all the

desirable characters. The color of the product was golden yellow with the score of

8.98±0.16, taste of the product was also very good with score of 8.98±0.16 and flavor

was also pleasant with score of 8.98±0.16. Texture was crispy and juicy because of

83 syrup with a score of 8.98±0.34 [89-91]. The overall acceptability was good with a

score of 8.98±0.23. Table 5.11 shows the average sensory analysis score given by 15

panel members. The overall acceptability score was above 8.5 out of 9, it indicates that

the product was “like extremely” range and acceptable.

5.2.6 Microbial characteristics of standardized Chhana jalebi

Microbiological analysis for the standardized Chhana jalebi was done by

standard plate count and yeast and mold count. The Chhana jalebi had a standard plate

count of 3.26±0.81 log10 cfu/g and yeast and mold count of 0.41±0.89 log10 cfu/g (Table

5.11). Presently there is no microbiological standard for the products like Chhana jalebi;

however for Chhana (material used for Chhana jalebi preparation) standards are

available [21]. In this regard, the results obtained in this study may be helpful for the

formulating microbiological standards for the jalebi in future. These microbial results

were supported with another research carried out by Nawale Pratik (2010) [13] on khoa

jalebi. Dyuthi (2009) [25] also reported that similar results for Chhana jhili in his

Research work.

5.2.7 Shear thinning efficiency of batter

Shear thinning efficiency of batter was measured by using rheometer. Batter was

prepared and kept required sample on rheometer platform. It was operated, through

which graph with values was received from the monitor [93]. Same analyses were

repeated around 20 times and mean value with standard deviation was taken for arriving

final value. Resultant graph was accomplished by using final mean values. Based on the

graph following values were identified. Viscosity was 2.76±1.27 Pa.S; Shear rate was

55.05±28.01 1/S and Shear stress was 121.5±26.41. This graph was clearly showing the

indirect proportion relationship between viscosity and shear rate, i.e. shear rate increases

viscosity decreases. From these results, it is clearly indicated that the prepared jalebi has

shear thinning rate / shear thinning efficiency which gives exact batter consistency for

making jalebi coils.

84

PART-II: SHELF LIFE ENHANCEMENT BY USING PRESERVATIVES

5.3 PRESERVATIVE STUDIES OF STANDARDIZED CHHANA JALEBI

This part is discussing about shelf life enhancement by preservatives. Three

types of preservatives were utilized in this study viz., potassium sorbate, sodium

benzoate and potassium meta-bi-sulphite. Preservatives treated Chhana jalebi samples

were kept under two different temperature conditions such as ambient and refrigerated

temperatures. Sensory analysis, regression analysis and trend line model parameters

were analyzed in order to determine more suitable preservative.

5.3.1 Effect of preservatives on the changes in Chhana jalebi during storage

Chhana jalebi was manufactured based on optimized process as shown in Figure

1. It was observed that Chhana jalebi packed in low density polyethylene (LDPE) pouch

without preservative could stay in good condition and quality up to 4 days at room

temperature (28°±2°C), whereas it could be stored up to 15 days at refrigerated

temperature (4±2°C). Hence efforts were made to enhance the shelf life using permitted

preservatives. This will pave a way for commercial marketing. Chhana jalebi was

prepared with and without the preservative and packed in low barrier packaging

materials viz., LDPE.

During preliminary trials, three preservatives namely potassium sorbate [13, 25,

56], sodium benzoate [13, 25] and potassium meta-bi-sulphite [94] were tried. During

storage at ambient temperature, the staleness and lack of freshness were observed after

8 days in the samples which contained potassium meta-bi-sulphite (500 ppm) and after

12 days in the samples which contained sodium benzoate (500 ppm), whereas no

abnormal flavor was noticed in the samples containing potassium sorbate (500 ppm)

even after 12 days on the basis of sensory evaluation. This was attributed to the

differences in their mechanism of action. Sodium benzoate is active against yeast and

mold and bacteria at low pH levels, while potassium meta-bi-sulphite is not much

effective against yeast and mold whereas sodium benzoate and potassium sorbate shows

more effective against bacteria, yeast and mold at the low pH levels of Chhana jalebi.

Similar results were observed in other studies. [96-99].

Hence, potassium meta-bi-sulphite was excluded from this study among three

preservatives and remaining two preservatives with different levels were tried for

85 further investigations. Potassium sorbate with 600 ppm, 800 ppm and 1000 ppm levels

and sodium benzoate with 100 ppm, 200 ppm and 300 ppm levels were tried for

enhancement of shelf life of Chhana jalebi [95]. They were added in different

concentrations in sugar syrup. The low density poly ethylene (LDPE) packaging

materials were sterilized by exposing to UV light for 45 min before packaging Chhana

jalebi. About 50g Chhana jalebi was packed in LDPE pouches and stored at both

ambient (28±2°C) and refrigerated temperatures (4±2°C). At the interval of every

alternate day the packets were cut opened and evaluated for sensory acceptance. Finally

it would be determined that more effective and suitable preservative along with its

concentration for giving more shelf life to the product.

5.3.2. Effect of sodium benzoate on standardized Chhana jalebi

In order to enhance the shelf life, a commonly used permitted class II

preservative viz. sodium benzoate was used, which was dissolved in sugar syrup. This

concentration is well below the permitted levels of the preservative in milk based sweets

i.e. 300 ppm [21]. It acts against bacteria, yeasts and molds by alteration of cell

membranes, inhibition of transport systems and key enzymes, creation of a proton flux

into the cell, or more than one of these actions [101]. Hence sodium benzoate was

chosen for studying the preservative effect with three different levels viz. 100 ppm, 200

ppm and 300 ppm.


The color and appearance scores of the jalebi during storage as influenced by

benzoate level are presented in Table 5.12. It was clearly understood from the sensory

report that as storage day increased the sensory score of color and appearance was

decreased irrespective to the preservative level. Similar results were observed in other

Researchers [13, 99]. The means score decreased from the initial value of 8.96 to 1.83 at

the end of 14 days of storage at room temperature. In control without preservative the

score was 7.58 on 4th day and which drastically decreased to 2.2 on 6th day storage. This

was due extensive mold growth was observed inside the package. At 100 ppm, 200

ppm, 300 ppm preservative level the scores were 6.58, 6.53 and 7.2 at the end of 8, 10

and 10 days respectively. It is indicating that the shelf life was 8, 10 and 10 days for 100

ppm, 200 ppm, 300 ppm of sodium benzoate respectively. This was determined by

taking the minimum score of 6.5 as acceptable limit. It concludes that as preservative

86 level significantly increased the color and appearance scores when storage period

increased. The mean scores were 4.36, 5.69, 6.56 and 7.24 respectively for control, 100

ppm, 200 ppm, 300 ppm of benzoate. These scores were statistically significant from

each other. These may be attributed to the effect of benzoate on mold growth. The

ANOVA indicates the significant effect of preservative and storage period and their

interaction (P≤0.05).

Table 5.12 Changes in color and appearance score* of Chhana jalebi samples

treated with different concentrations of sodium benzoate at ambient temperature

(28±2°C)

Sodium

benzoate

Storage days at 28±2°C

0 2 4 6 8 10 12 14 CD=1.54

Control 8.97 8.52 7.58 - - - - - 4.36a

100 ppm 8.99 8.51 8.12 7.71 6.58 - - - 5.69a

200 ppm 8.92 8.82 8.53 8.50 7.21 6.53 - - 6.56ab

300 ppm 8.94 8.72 8.52 8.42 7.52 7.20 - - 7.24b

CD=2.17 8.96cd 8.64c 8.19c 6.71bc 5.88b 4.48ab

*Average three trials; Note 1: Values with different superscripts are differ significantly

at P≤0.05. Note 2: - indicates sample discarded.

The sodium benzoate is a common preservative used normally in high acid foods

to prevent the spoilage from yeast and mold [25]. The pH of Chhana jalebi was around

5.0 at which the benzoate may be effective though may not optimum.

87

Table 5.13 Changes in color and appearance score* of Chhana jalebi samples

treated with different concentrations of sodium benzoate at refrigerated

temperature (4±2°C)

Sodium benzoate


0 5 10 15 20 25 30 35 CD=1.04

Control 8.99 8.94 6.92 6.50 - - - - 4.66a

100 ppm 8.99 8.98 8.95 7.77 7.87 - - - 6.97b

200 ppm 8.98 8.92 8.9 8.59 7.93 6.69 - - 7.35b

300 ppm 8.97 8.96 8.95 8.79 7.92 7.85 - - 7.73b

CD=1.48 8.98b 8.95bd 7.93b 7.41bc 6.85b 5.58ab 4.49a -



Based on observation, the changes observed in the sensory score of color and

appearances of the product stored at 4±2°C are presented in table 5.13. In refrigerated

storage temperature (4±2°C) also, the effect of storage period, preservative level and

their interaction found to be significant as was observed at 28°C. The Color and

appearance score remained 6.5 and above for control, 100 ppm, 200 ppm, 300 ppm

products were 15, 20, 25 and 28 days at 4°C respectively these were observed higher

than at 28°C [13, 25].

ii. Flavor

The flavor scores of the jalebi during storage as influenced by benzoate level are

presented in Table 5.14. It concluded that as storage day increased the sensory score of

flavor was decreased irrespective of the preservative level. Similar reported by other

Researchers [13]. The means score decreased from the initial value of 8.96 to 1.85 at

the end of 14 days of storage at room temperature. The control (without preservative)

score of 4th day was 7.50 which drastically decreased to 2.3 on 6th day. This was due to

extensive mold growth observed inside the package. At 100 ppm, 200 ppm, 300 ppm

preservative level the scores were 6.55, 6.50 and 7.0 at the end of 6, 7 and 10 days

88 respectively. It is indicating that the shelf life was 6, 7 and 10 days respectively. This

was determined by taking the minimum score of 6.5 as acceptable limit. It can also

observe from the Table 5.13 that as preservative level significant increased the flavor

scores irrespective to storage period. The mean scores were 4.31, 5.53, 6.37 and 7.26

respectively for control, 100 ppm, 200 ppm, 300 ppm of benzoate. These scores were

statistically significant from each other. These may be attributed to the effect of

benzoate on mold growth [25]. The ANOVA indicates the significant effect of

preservative and storage period and their interaction (P≤0.05).

Table 5.14 Changes in the flavor score* of Chhana jalebi samples treated with

different concentrations of sodium benzoate at ambient temperature (28±2°C)

Sodium benzoate


0 2 4 6 8 10 12 14 CD=1.46

Control 8.98 8.57 7.50 - - - - - 4.31a

100 ppm 8.99 8.57 8.50 6.55 - - - - 5.53a

200 ppm 8.91 8.84 8.51 8.43 - - - - 6.37ab

300 ppm 8.95 8.87 8.52 8.47 7.51 7.00 - - 7.26b

CD=2.06 8.96c 8.71c 8.26cd 6.44bc 5.49b 4.31ab - -



Based on observation, the changes observed in the sensory score of flavor of the

product stored at 4°C are presented in Table 5.15. At this storage temperature also the

effect of storage period, preservative level and their interaction found to be significant

as was observed at 28°C. In that period within which the flavor score remained 6.5 and

above for control, 100 ppm, 200 ppm, 300 ppm products were 15, 20, 25 and 28 days at

4°C respectively these were observed higher than 28°C storage.

89

Table 5.15 Changes in the flavor score* of Chhana jalebi samples treated with

different concentrations of sodium benzoate at refrigerated temperature (4±2°C)

Sodium benzoate


0 5 10 15 20 25 30 35 CD=1.13

Control 8.98 8.95 6.91 - - - - - 4.54a

100 ppm 8.97 8.97 8.95 7.55 7.85 - - - 6.71b

200 ppm 8.95 8.93 8.92 8.68 7.71 6.69 - - 7.25b

300 ppm 8.96 8.92 8.95 8.60 7.96 7.82 - - 7.65b

CD=1.59 8.97b 8.94bcd 7.93b 7.26bc 6.76b 5.43ab - -




The body and texture scores of the jalebi during storage as influenced by

benzoate level are presented in Table 5.16. It is clearly understood from the Table 5.16

that as storage day increased the sensory score of body and texture was decreased

irrespective of the preservative level, some of the Researchers also reported similar

results in their studies [25]. The means score decreased from the initial value of 8.94 to

1.92 at the end of 14 days of storage at room temperature. Increase of control that is

without preservative the score of 2nd day was 8.53 which drastically decreased to 2.5 on

6th day. It may be due extensive mold growth observed inside the package. At 100 ppm,

200 ppm, 300 ppm preservative level, the scores were 6.50, 6.53and 6.50 at the end of

6, 7 and 10 days respectively. It is indicating that the shelf life was 6, 7 and 10 days

respectively. This was determined by taking the minimum score of 6.5 as acceptable

limit. It can also observe that preservative level significantly increases the body and

texture scores irrespective to storage period. The mean scores were 4.25, 5.52, 6.51 and

7.12 respectively for control, 100 ppm, 200 ppm, 300 ppm of benzoate and scores were

statistically significant from each other. These may be attributed to the effect of

benzoate on mold growth [13]. The ANOVA indicates the significant effect of

preservative and storage period and their interaction (P≤0.05).

90

Table 5.16 Changes in the body and texture score* of Chhana jalebi samples


(28±2°C)

Sodium benzoate


0 2 4 6 8 10 12 14 CD=1.32

Control 8.97 8.53 - - - - - - 4.25a

100 ppm 8.91 8.58 8.01 6.50 - - - - 5.52a

200 ppm 8.94 8.93 8.91 8.90 6.54 - - - 6.51ab

300 ppm 8.94 8.91 8.87 8.73 7.55 6.50 - - 7.12b

cd=1.87 8.94c 8.73cd 7.95c 6.65bc 5.51b 4.25ab - -



Table 5.17 Changes in the body and texture score* of Chhana jalebi samples



Sodium benzoate


0 5 10 15 20 25 30 35 CD=1.11

Control 8.95 8.93 7.02 6.90 - - - - 4.58a

100 ppm 8.98 8.98 8.95 7.79 7.89 - - - 6.64b

200 ppm 8.99 8.92 8.90 8.69 7.75 6.52 - - 7.20b

300 ppm 8.97 8.91 8.93 8.64 7.91 6.55 - - 7.48b

CD=1.57 8.97c 8.94cd 7.93b 7.26c 6.76bc 4.95ab



91

Based on observation, the changes observed in the sensory score of body and

textures of the product stored at 4°C are presented in Table 5.17. In that period within

which the body and texture score remained 6.5 and above for control, 100 ppm, 200

ppm, 300 ppm products were 15, 20, 25 and 25 days at 4°C respectively which was

higher than 28°C.


The overall acceptability scores of jalebi during storage as influenced by

benzoate level are presented in Table 5.18. If the storage day increased, the sensory

score of overall acceptability was decreased irrespective to the preservative level. These

findings are correlated with previous Researchers [13, 25]. The means score decreased

from the initial value of 8.96 to 1.77 at the end of 14 days of storage at room

temperature. The control without preservative the score of 2nd day was 8.54 which was

drastically decreased to 2.4 on 6th day due to extensive mold growth inside the package.

At 100 ppm, 200 ppm and 300 ppm preservative level, the scores were 7.21, 6.81and

6.50 at the end of 6, 10 and 10 days respectively and concluded the shelf life of product.

This was determined by taking the minimum score of 6.5 as acceptable limit. It was

observe that as preservative level increased significant level of overall acceptability

scores also increased irrespective of storage period. The mean scores were 4.32, 5.58,

6.66 and 7.01 for control, 100 ppm, 200 ppm, 300 ppm of benzoate respectively and

scores were statistically significant. These may be due to the effect of benzoate on mold

growth [25, 99]. The ANOVA indicates the significant effect of preservative and

storage period and their interaction (P≤0.05).

The changes observed in the sensory score of flavor of the product stored at 4°C

are expressed in Table 5.19. The effect of storage temperature (28°C), storage period,

preservative level and their interaction found to be significant In that period within

which the flavor score remained 6.5 and above for control, 100 ppm,200 ppm, 300 ppm

products were 15, 20, 25 and 28 days at 4°C respectively.

Based on the observation, it was concluded that control and 100 ppm,200 ppm,

300 ppm of sodium benzoate treated samples had 4, 6,10 and 10 days respectively at

28±2°C and 15, 20, 25 and 28 days at 4±2°C respectively.

92

Table 5.18 Changes in the overall acceptability score* of Chhana jalebi samples


(28±2°C)

Sodium benzoate


0 2 4 6 8 10 12 14 CD=1.40

Control 8.99 8.54 7.14 - - - - - 4.32a

100 ppm 8.98 8.58 8.19 7.21 - - - - 5.58a

200 ppm 8.92 8.97 8.93 8.90 6.81 - - - 6.66ab

300 ppm 8.97 8.85 8.50 8.41 7.55 6.50 - - 7.01b

CD=1.98 8.96c 8.73cd 8.19c 6.73bc 5.64b 4.37ab - -



Table 5.19 Changes in the overall acceptability score* of Chhana jalebi samples



Sodium benzoate


0 5 10 15 20 25 30 35 CD=1.30

Control 8.98 8.94 6.93 6.50 - - - - 4.07a

100 ppm 8.98 8.98 8.95 7.79 6.58 - - - 6.44b

200 ppm 8.97 8.94 8.95 8.65 7.53 6.70 - - 7.22b

300 ppm 8.96 8.95 8.95 8.77 7.98 7.55 - - 7.72b

CD=1.84 8.97c 8.95cd 7.95bc 6.93bc 6.07b 5.09ab



93 5.3.3 Effect of potasium sorbate on standardized Chhana jalebi

In order to enhance the shelf life, a commonly used permitted class II

preservative viz., potassium sorbate was used, which was dissolved in sugar syrup. The

concentration is well below the permitted levels of the preservative in milk based sweets

i.e. 1000 ppm [21]. It acts against bacteria, yeasts and molds by alteration of cell

membranes, inhibition of transport systems and key enzymes, creation of a proton flux

into the cell, or more than one of these actions [101]. Hence potassium sorbate was also

chosen for studying the preservative effect with three different levels viz. 600 ppm, 800

ppm and 1000 ppm.


The color and appearance scores of jalebi during storage as influenced by

sorbate level are represented in Table 5.20. The sensory score of color and appearance

was decreased when storage day increased irrespective to the level of preservative [13,

25]. The means score decreased from the initial value of 8.99 to 2.05 at the end of 22

days of storage at room temperature. In case of control that is without preservative the

score of 4th day were 6.45 which drastically decreased to 6.45 on 4th day due to

extensive mold growth inside the package. At 600 ppm, 800 ppm, 1000 ppm

preservative level the scores were 6.57, 6.71 and 6.78 at the end of 12, 14 and 16 days

respectively and it indicates shelf life of the product. This was determined by taking the

minimum score of 6.5 as acceptable limit. It can be also observed that as preservative

level, significantly increased the scores of color and appearance irrespective to storage

period. The mean scores were 4.08, 6.26, 6.95 and 7.54 for control, 600 ppm, 800 ppm,

1000 ppm of sorbate respectively. These may be due to the effect of sorbate on mold

growth [100-102]. The ANOVA indicates the significant effect of preservative and


The sensory score of color and appearance of the product stored at 4°C are

expressed in Table 5.21. The effect of storage temperature (28°C and 4°C), storage

period, preservative level and their interaction were found to be significant. Similar

results were obtained by other Researchers [56, 95]. In that period within which the

color and appearance score remained 6.5 and above for control, 600 ppm, 800 ppm,

1000 ppm products were 15, 30, 45 and 60 days at 4°C respectively which was higher

than 28°C.

94

Tabl

e 5.

20 C

hang

es in

the

colo

r an

d ap

pear

ance

scor

e* o

f Chh

ana

jale

bi sa

mpl

es tr

eate

d w

ith d

iffer

ent

conc

entr

atio

ns o

f pot

assiu

m so

rbat

e at

am

bien

t tem

pera

ture

(28±

2°C

)

Pota

ssiu

m so

rbat

eSt

orag

e da

ys a

t 28±

2°C

CD

=0.9

70

24

68

1012

1416

1820

22

Con

trol

8.99

7.57

--

--

--

--

--

4.08

a

600

ppm

8.99

8.98

8.92

8.95

8.55

7.80

6.57

--

--

-6.

26b

800

ppm

8.99

8.95

8.94

8.75

8.55

7.95

7.60

6.71

--

--

6.95

bc

1000

ppm

8.99

8.97

8.95

8.85

8.57

8.48

8.35

7.50

6.78

--

-7.

54c

CD

=1.6

98.

99c

8.61

c8.

31b

7.93

b7.

51bc

6.78

ab6.

23ac

5.75

ab4.

82a

*Ave

rage

thre

e tri

als;

Not

e 1:

Val

ues w

ith d

iffer

ent s

uper

scrip

ts a

re d

iffer

sig

nific

antly

at P

≤0.0

5. N

ote

2: -

indi

cate

s sam

ple

disc

arde

d.

95 Table 5.21 Changes in the color and appearance score* of Chhana jalebi samples

treated with different concentrations of potassium sorbate at refrigerated


Potassium sorbate


0 15 30 45 60 75 CD=2.03

Control 8.98 - - - - - 3.67a

600 ppm 8.99 7.34 6.67 - - - 4.77a

800 ppm 8.99 8.93 7.43 6.52 - - 5.98ab

1000 ppm 8.99 8.97 8.94 7.97 6.52 - 7.27b

CD=2.48 8.99bc 7.18b 6.36b 4.77ab 3.28a

*Average three trials; Note 1: Values with different superscripts are differ significantly at P≤0.05. Note 2: - indicates sample discarded.

ii. Flavor

The flavor scores of jalebi during storage as influenced by sorbate level are

represented in Table 5.22. It clearly understood from the Table 5.22 that as storage day

increased the sensory score of flavor was decreased irrespective to the preservative

level. Previous findings were correlated with our finding [13, 25]. The means score

decreased from the initial value of 8.98 to 1.92 at the end of 22 days of storage at room

temperature. Increase of control that is without preservative the score of 2nd day was

7.58 which drastically decreased to 1.70 on 22nd day. This was probably due to

extensive mold growth. At level, the scores were 6.58, 6.52 and 6.59 at the end of 12, 14

and 16 days respectively. The shelf life was determined by taking the minimum score of

6.5 as acceptable limit and determined as 12, 14 and 16 days for 600 ppm, 800 ppm and

1000 ppm preservative samples respectively. Based on the observation it concluded that

the preservative level significantly increased the flavor scores irrespective to storage

period. The mean scores were 3.96, 6.18, 6.91 and 7.49 respectively for control, 600

ppm, 800 ppm, 1000 ppm of potassium sorbate. These may be due to the effect of

potassium sorbate on mold growth [100-102]. The ANOVA indicates the significant

effect of preservative and storage period and their interaction (P≤0.05).

96

Tabl

e 5.

22 C

hang

es in

the

flavo

r sc

ore*

of C

hhan

a ja

lebi

sam

ples

trea

ted

with

diff

eren

t con

cent

ratio

ns o

f pot

assiu

m so

rbat

e at

am

bien

t

tem

pera

ture

(28±

2°C

)

Pota

ssiu

m

Sorb

ate

Stor

age

days

at 2

8±2°

C

02

46

810

1214

1618

2022

CD

=1.0

2

Con

trol

8.98

7.58

--

--

--

--

--

3.96

a

600

ppm

8.98

8.96

8.94

8.93

8.57

7.87

6.58

--

--

-6.

18b

800

ppm

8.99

8.96

8.92

8.71

8.57

7.96

7.62

6.52

--

--

6.91

b

1000

ppm

8.98

8.96

8.95

8.84

8.59

8.45

8.32

7.40

6.59

--

-7.

49bc

CD

=1.7

78.

98c

8.61

c8.

28ab

7.82

ac7.

48ac

6.72

ab6.

25ac

5.60

ab4.

66a

*Ave

rage

thre

e tri

als;

Not

e 1:

Val

ues w

ith d

iffer

ent s

uper

scrip

ts a

re d

iffer

sig

nific

antly

at P

≤0.0

5. N

ote

2: -

indi

cate

s sam

ple

disc

arde

d.

97


product stored at 4°C are presented in Table 5.23. At this storage temperature (4°C)

also, the effect of storage period, preservative level and their interaction found to be

significant as was observed at 28°C.

Table 5.23 Changes in the flavor score*of Chhana jalebi samples treated with

different concentrations of potassium sorbate at refrigerated temperature (4±2°C)

Potassium

sorbate

Storage days at 4±2°CCD=2.06

0 15 30 45 60 75

Control 8.97 6.57 - - - - 3.56a

600 ppm 8.98 7.35 6.68 - - - 4.77a

800 ppm 8.97 8.94 7.47 - - - 5.94ab

1000 ppm 8.98 8.97 8.95 7.97 6.53 - 7.23b

CD=2.52 8.98c 7.21bc 6.33c 4.68ab 3.18a -



These results are correlated with previous report [25, 56]. In that period within

which the flavor score remained 6.5 and above for control, 600 ppm, 800 ppm, 1000

ppm products were 15, 30, 45 and 60 days at 4°C respectively these were observed

higher than 28°C.

iii. Body and Texture

The body and texture scores of the jalebi during storage as influenced by sorbate

level are represented in Table 5.24. It was concluded that when storage day increased,

the sensory score of body and texture was decreased irrespective to the preservative

level. The means score was decreased from the initial value of 8.97 to 2.12 at the end of

22 days of storage at room temperature.

98

Tab

le 5

.24

Cha

nges

in th

e bo

dy a

nd te

xtur

e* sc

ore

of C

hhan

a ja

lebi

sam

ples

trea

ted

with

diff

eren

t con

cent

ratio

ns o

f pot

assiu

m so

rbat

e at

ambi

ent t

empe

ratu

re (2

8±2°

C)

Pota

ssiu

m

Sorb

ate

Stor

age

days

at 2

8±2°

C

02

46

810

1214

1618

2022

CD

=1.0

3

Con

trol

8.98

7.55

--

--

--

--

--

3.96

a

600

ppm

8.97

8.95

8.94

8.91

8.58

7.88

6.7

--

--

-6.

25b

800

ppm

8.99

8.97

8.95

8.72

8.58

7.95

7.61

6.63

--

--

6.94

b

1000

ppm

8.97

8.94

8.92

8.81

8.59

8.47

8.34

7.51

6.65

--

-7.

50bc

CD

=1.7

88.

97c

8.60

c8.

31b

7.76

b7.

38bc

6.67

ab6.

26ac

5.68

ab4.

69a

*Ave

rage

thre

e tri

als;

Not

e 1:

Val

ues w

ith d

iffer

ent s

uper

scrip

ts a

re d

iffer

sig

nific

antly

at P

≤0.0

5. N

ote

2: -

indi

cate

s sam

ple

disc

arde

d.

99

The control (without preservative) score was 6.43 on 4thday which was

drastically decreased to 3.8 on 8th day due to the extensive mold growth inside the

package. At 600 ppm, 800 ppm and 1000 ppm preservative level, the scores were 6.70,

6.63 and 6.65 at the end of 12, 14 and 16 days respectively. The shelf life was

concluded as 12, 14 and 16 days for 600 ppm, 800 ppm and 1000 ppm respectively. The

shelf life was determined through base score of 6.5 as acceptable limit. The preservative

level significantly increased the body and texture scores irrespective to the storage

period. The mean scores were 3.96, 6.25, 6.94 and 7.50 respectively for control, 600

ppm, 800 ppm, 1000 ppm of potassium sorbate and were statistically significant from

each other. These might be inhibition effect of benzoate against mold growth [56, 95].

The ANOVA report described the significant effect of preservative and storage period

and their interaction (P≤0.05).


product stored at 4°C are expressed in Table 5.25. At this storage temperature, also the

effect of storage period, preservative level and their interaction were found to be

significant as observed at 28°C. During the storage period, the flavor score remained 6.5

and above for control, 600 ppm, 800 ppm and 1000 ppm products were 15, 30, 45 and

60 days at 4°C respectively these were higher than the 28°C storage period. Similar

results were reported by other Scientists [100-102].

Table 5.25 Changes in the body and texture score* of Chhana jalebi samples treated with different concentrations of potassium sorbate at refrigerated


Potassium sorbate

Storage days at 4°CCD=2.00

0 15 30 45 60 75

Control 8.95 6.57 - - - - 3.69a

600 ppm 8.99 7.4 6.65 - - - 4.86a

800 ppm 8.98 8.89 7.46 6.51 - - 5.96ab

1000 ppm 8.97 8.97 8.94 7.96 6.52 - 7.21b

CD=2.46 8.97c 7.21bc 6.36b 4.72ab 3.33a



100 iv. Overall acceptability

The overall acceptability scores of jalebi during storage period which was

influenced by sorbate level are represented in Table 5.26. When storage day increased

the sensory score of overall acceptability was decreased irrespective to the preservative

level and also similarly reported by some Scientists [13, 25]. The score was decreased

from the initial value of 8.98 to 1.80 at the end of 22 days of storage at room

temperature. The score of control without preservative was 6.37 on 4thday which was

drastically decreased to 4.4 on 6th day which was due to extensive mold growth inside

the package. At 600 ppm, 800 ppm and 1000 ppm preservative level the scores were

6.74, 6.73and 6.77 at the end of 12, 14 and 16 days respectively. It is indicating that the

shelf life was 12, 14 and 16 days respectively. This was determined by taking the

minimum score of 6.5 as acceptable limit. It can also observe from the Table 5.26 that

as preservative level increased significant level of body and texture scores irrespective

of storage period. The mean scores were 3.86, 6.02, 6.87 and 7.53 respectively for

control, 600 ppm, 800 ppm, 1000 ppm of sorbate. These scores were statistically

significant from each other. These may be attributed to the effect of benzoate on mold

growth [100-102]. The ANOVA indicates the significant effect of preservative and


The changes observed in the sensory score of overall acceptability of the product

stored at 4°C are presented in Table 5.27. The effect of storage temperature and period,

preservative level and their interaction were to be obtained significant as observed as

28°C. In that period within which the flavor score remained 6.5 and above for control,

600 ppm, 800 ppm, 1000 ppm products were 15, 30, 45 and 60 days at 4°C respectively

these were observed as higher than 28°C and similar findings were reported by other

Researchers [56, 95].

101

Tab

le 5

.26

Cha

nges

in th

e ov

eral

l acc

epta

bilit

y sc

ore*

of C

hhan

a ja

lebi

sam

ples

trea

ted

with

diff

eren

t

conc

entr

atio

ns o

f pot

assiu

m so

rbat

e at

am

bien

t tem

pera

ture

(28±

2°C

)

Pota

ssiu

m

Sorb

ate

Stor

age

days

at 2

8°C

02

46

810

1214

1618

2022

CD

=1.

55

Con

trol

8.97

7.65

--

--

--

--

--

3.86

a

600

ppm

8.98

8.96

8.95

8.92

8.58

7.89

6.74

--

--

-6.

02a

800

ppm

8.99

8.97

8.95

8.72

8.58

7.96

7.62

6.73

--

--

6.87

b

1000

ppm

8.97

8.91

8.91

8.85

8.62

8.55

8.36

7.62

6.77

--

-7.

53b

CD

=1.9

98.

98c

8.62

b8.

30b

7.72

bc7.

35bc

6.70

b6.

26ac

5.69

ab4.

38a

4.15

ab2.

99a

*Ave

rage

thre

e tri

als;

Not

e 1:

Val

ues w

ith d

iffer

ent s

uper

scrip

ts a

re d

iffer

sig

nific

antly

at P

≤0.0

5. N

ote

2: -

indi

cate

s sam

ple

disc

arde

d.

102

Table 5.27 Changes in the overall acceptability score of Chhana jalebi samples

treated with different concentrations of potassium sorbate at refrigerated


Potassium sorbate

Storage days at 4°CCD=2.09

0 15 30 45 60 75

Control 8.97 6.60 - - - - 3.56a

600 ppm 8.98 7.45 6.67 - - - 4.80a

800 ppm 8.98 8.90 7.50 6.53 - - 5.85ab

1000 ppm 8.97 8.97 8.95 7.97 6.62 - 7.26b

CD=2.56 8.98bc 7.23b 6.33b 4.73ab 3.13a



Based on observation, it was concluded that control and 600 ppm, 800 ppm,

1000 ppm of potassium sorbate treated samples had 4, 12, 14 and 16 days respectively

at 28±2°C and 15, 30, 45 and 60 days at 4±2°C respectively.

Hence, among these two preservatives, potassium sorbate was assumed to be a

better preservative and selected for further investigation on the shelf life of Chhana

jalebi [13, 25, 56, 95]. This was attributed to the differences in their mechanism of

action [100-102]. Sodium benzoate is comparatively less active against yeast and mold

and bacteria at low pH levels. The spoilage of Chhana jalebi was mainly due to yeast

and mold, a preservative which is more effective against yeast and mold at the pH of

Chhana jalebi is needed, hence potassium sorbate was chosen as a suitable preservative

for Chhana jalebi (Figure 5.8-1 and Figure 5.8-2). Most of the other Research studies

were also suggested that potassium sorbate was a suitable preservative for dairy based

products [13, 25, 56, 95, 100-102]

Potassium sorbate contained samples of 800 ppm were showed 14 days without

any adverse effect on its body and texture, flavor, color and appearance. Despite the

longer shelf life (16 days) given by 1000 ppm of potassium sorbate was not preferred

due to the maximum permissible limit for the use of potassium sorbate in food materials

103 [21] and however the difference among the shelf life of 800 ppm and 1000 ppm of

product was just 2 days only. The control sample without preservative was also

analyzed in every 2 days interval and it gave shelf life of 2 days. Hence, 800 ppm of

potassium sorbate was selected for further investigation.

Related observations were found by Scientists that successfully employed the

potassium sorbate for preserving the khoa jalebi up to 15 and 25 days with a

concentration of 500 ppm and 1000 ppm at 30°C respectively [102]. Potassium sorbate

was also found to enhance the shelf life of another milk product, khoa [100].

5.3.4. Linear regression analysis for effects of preservatives on sensory scores of

Chhana jalebi samples stored for 10 days at ambient temperature (28±2°C)

Linear regression analysis was performed to identify preservative and

temperature effect among both sodium benzoate and potassium sorbate preservatives

under both ambient and refrigerated temperatures. Based on the above preservatives

analysis, it was determined that 800 ppm of potassium sorbate has given good

preservative effects than the other preservative and their levels. This was further

confirmed through linear regression analysis using Microsoft excel software and the

values are given in Table 5.28.

Table 5.28 Preservative effects based on linear regression with respect to sensory

scores of Chhana jalebi samples treated with sodium benzoate and potassium

sorbate stored for 10 days at ambient temperature (28±2°C)

Sensory attributes

Sodium benzoate (300 ppm) Potassium sorbate (800 ppm)

Slope value R2 value Slope value R2 value

CA 0.025 0.848 0.001 0.905

FL 0.024 0.863 0.001 0.863

BT 0.021 0.82 0.001 0.837

OA 0.0021 0.696 0.001 0.828

CA-Color and appearance, FL-Flavor, BT-Body and texture, OA-overall acceptability

104 Table 5.29 Temperature effects based on linear regression with respect to sensory

score of Chhana jalebi samples treated with sodium benzoate and potassium

sorbate stored for 10days at ambient temperature (28±2°C) and refrigerated


Sensory attributes

Sodium benzoate (300 ppm) Potassium sorbate (800 ppm)

28±2°C 4±2°C 28±2°C 4±2°C

Slope value

R2

valueSlope value

R2

valueSlope value

R2

valueSlope value

R2

value

CA -0.374 0.738 -0.121 0.749 -0.3 0.8 -0.108 0.895

FL -0.376 0.756 -0.128 0.738 -0.306 0.788 -0.11 0.895

BT -0.434 0.813 -0.136 0.82 -0.302 0.804 -0.107 0.911

OA -0.433 0.825 -0.121 0.781 -0.318 0.818 -0.114 0.879

CA-Color and appearance, FL-Flavor, BT-Body and texture, OA-overall acceptability

From the Table 5.28 and 5.29, it was clearly indicated that less slope value and

high R2 value for potassium sorbate than sodium benzoate. Similar results were

observed by Pang et al., (2001) [103], June chan et al., (2012) [104] and Lee et al.,

(2014) [105]. Based on the results, it was concluded that potassium sorbate was given

more effect against microbial growth on Chhana jalebi samples than sodium benzoate.

Similarly, same effect was observed in refrigerated temperature than ambient

temperature of storage conditions.

5.3.5 Trend line analysis for tyrosine values of Chhana jalebi on changes of flavor

scores during storage at ambient temperature (28±2°C)

A graph was drawn between tyrosine value and flavor scores of Chhana jalebi.

Based on the resultant curve, various trend line model parameters such as exponential,

linear, logarithmic, polynomial and power were drawn in order to identify suitable

model through which changes of flavor scores could be addressed. Based on the

analysis it was found that, 118.8, -5.382, - 30.3, 0.548 and 397.0 as ‘a’ values, -0.35,

50.27, 70.31, -11.92 and -1.93 as ‘b’ values and 0.953, 0.975, 0.995, 0.992 and 0.912 as

R2 values for exponential, linear, logarithmic, polynomial and power trend line

parameters respectively (Figure 5.6).

105

Figure 5.6 Model parameters for tyrosine value versus flavor scores of Chhana

jalebi

This analysis reveals that R2 value of logarithmic model parameter was found to

be higher than the other parameters. Moreover, this analysis discovers that logarithmic

model parameter was more suitable than the other model parameters to address the

changes of flavor of Chhana jalebi during storage. Hence it was concluded that, tyrosine

values of the product was increased in terms of one log cycle while increasing of

storage days.

5.3.6 Trend line analysis for tyrosine values of Chhana jalebi on changes of

overall acceptability scores during storage at ambient temperature

Similarly a graph was drawn between tyrosine value and overall acceptability

scores of Chhana jalebi. Based on the resultant curve, various trend line model

parameters such as exponential, linear, logarithmic, polynomial and power were drawn

in order to identify suitable model through which changes of overall acceptability scores

was expressed.

y = -30.3ln(x) + 70.31R² = 0.995

y = 0.548x2 - 11.92x + 67.51R² = 0.992

y = 397.0x-1.93

R² = 0.912

y = -5.382x + 50.27R² = 0.975

y = 118.8e-0.35x

R² = 0.953

0

10

20

30

40

50

60

0 2 4 6 8 10

Tyro

sine

valu

e (m

g/10

0g)

Flavour scores (9-Point hedonic scale)

106

Figure 5.7 Model parameters for tyrosine value versus overall acceptability scores

of Chhana jalebi

Table 5.30 Trend line model parameters for both flavor and overall acceptability

scores of Chhana jalebi

ModelParameters

Flavor scores Overall acceptability scores

‘a’ value ‘b’value R2 value ‘a’ value ‘b’ value R2 value

Exponential 118.8 -0.35 0.953 123.8 -0.36 0.954

Linear -5.382 50.27 0.975 -5.290 49.57 0.978

Logarithmic -30.3 70.31 0.995 -29.9 69.53 0.995

Polynomial 0.548 - 11.92 0.992 0.479 - 11.08 0.993

Power 397.0 -1.93 0.912 431.4 -1.99 0.905

Based on the analysis it was found that, 123, -5.290, - 29.90, 0.479 and 431.4 as

‘a’ values, -0.36, 49.57, 69.53, -11.08 and -1.99 as ‘b’ values and 0.954, 0.978, 0.995,

0.993 and 0.905 as R2 values for exponential, linear, logarithmic, polynomial and power

trend line parameters respectively (Figure 5.7). This analysis reveals that R2 value of

logarithmic model parameter was found to be higher than the other parameters.

y = 123.8e-0.36x

R² = 0.954y = -5.290x + 49.57

R² = 0.978

y = -29.9ln(x) + 69.53R² = 0.995

y = 0.479x2 - 11.08x + 64.99R² = 0.993

y = 431.4x-1.99

R² = 0.905

0

10

20

30

40

50

60

0 2 4 6 8 10

Tyro

sine

valu

e (m

g/10

0g)

Overall acceptability scores (9-Point hedonic scale)

107

Moreover, this analysis discovers that logarithmic model parameter was more

suitable than the other model parameters to address the changes of overall acceptability

of Chhana jalebi during storage period. Hence it was concluded that, tyrosine values of

the product was increased in terms of one log cycle while increasing of storage days.

Similarly positive results were obtained by Peter et al., (2012) [106] in their Research.

Figure 5.8 Chhana jalebi without and with preservative added sample

1. Chhana jalebi samples treated with 800 ppm of potassium sorbate (Preservative) on 14th day

2. Chhana jalebi Control samples (Without Preservative) on 2nd day

1

2

108

PART – III: SHELF LIFE ENHANCEMENT BY USING DIFFERENT

PACKAGING MATERIALS

5.4. EFFECT OF PACKAGING MATERIAL ON CHARACTERISTIC

CHANGES IN CHHANA JALEBI

This part of study deals with the results obtained during investigation on shelf-

life enhancement of Chhana jalebi with different packaging materials and techniques.

The first phase of packaging study was involved with selection of suitable packaging

materials under two major categories like low barrier and high barrier at both ambient

(28±2°C) and refrigeration (4±2°C) temperatures. The second phase of packaging study

was conducted to increase the shelf-life by using Modified Atmospheric Packaging

(MAP) and vacuum packaging in Low Density Poly-Ethylene (LDPE) and Metalized

polyester (MET) packaging material.

The packaging materials were selected based on their properties and suitable

storage conditions. Barrier properties of packaging materials influence the shelf-life of

product when it is packed. Hence, two types of packaging materials were selected under

both low barrier and high barrier categories.

i. Low barrier packaging materials: Polystyrene cups covered with aluminum foil

and Cardboard box lined with butter paper (generally using for packaging of

sweets).

ii. High barrier packaging material: Metalized polyester (MET) and Low density

polyethylene (LDPE) Pouches

These packaging materials were sterilized by exposing to UV light for 45 min

before packaging Chhana jalebi. About 20g Chhana jalebi was packed in each

packaging materials and stored at both ambient (28±2°C) and refrigerated temperatures

(4±2°C). At the interval of every alternate day the packets were cut opened and

evaluated for sensory acceptance.

5.4.1 Basic observation of packaging materials

Four selected packaging materials such as polystyrene cups covered with

aluminum foil, cardboard box lined with butter paper, LDPE and metalized polyester

pouches were selected based on sensory comments of panel members.

109 Table 5.31 Sensory comments on Chhana jalebi packaged in low barrier materials

stored at 28±2°C for various days

Low Barrier Packaging Materials

Sensory comments on different storage period at 28±2°C

Second day Fourth day Sixth day

Polystyrene cups

covered with

aluminum foil

Rich in juiciness,

flavor,

acceptable body

and texture

All sensory parameter

was same except flavor

Lack of freshness

and less juicy and

slightly dry

Cardboard box

lined with butter

paper

Juicy, acceptable

flavor, body and

texture

Less juicy , lack of

freshness and slightly

dry

Sticky and slightly

mold growth

observed

Table 5.32 Sensory comments on Chhana jalebi packaged in high barrier materials and stored at 28±2°C for various days

High barrier packaging materials

Sensory comments on different storage period at 28±2°C

Third day Sixth day Ninth day

LDPE Pouch

with heat sealed

Juicy, Acceptable

flavor, Body and

texture

Lake of freshness and

slightly dry

Mould growth

observed

Metalized

polyester with

heat sealed

Rich in Juiciness,

flavor, acceptable

Body and texture

Juicy, Acceptable

flavor, Body and

texture

Less fresh but

good body and

texture

From Table 5.31 and 5.32, it was observed that Chhana jalebi packaged in low

barrier packaging materials such as polystyrene cups and cardboard box were stayed

well for up to 4 days at 28±2°C, however the product packaged in LDPE and metalized

polyester were remain good more than 5 days.

110

The following analysis were carried out to identify suitable packaging material

i. Physico-chemical characteristics such as pH, water activity, peroxide value and

tyrosine value

ii. Microbiological analysis such as standard plate count and yeast and mold count

iii. Sensory characteristics such as color and appearance, flavor, body and texture

and overall acceptability

5.4.2 Physico-chemical characteristics of Chhana jalebi stored in different

packaging materials

All four packaging materials were considered for analyzing the changes in

various physico-chemical characteristics viz., pH, water activity (aW), peroxide value

and tyrosine value of Chhana jalebi during storage at ambient temperatures 28±2°C.

There were changes in the physico-chemical characteristics of jalebi during storage

period. The initial pH of jalebi was 5.43 which declined during storage (Figure 5.9).

i. Changes in pH

In cardboard box lined with butter paper packed samples, the pH rate was

decreased rapidly. The pH decreased from initial value of 5.43 to 5.14, 5.12, 5.10 and

5.18 for LDPE pouch, metalized polyester, polystyrene cups covered with aluminum

foil and cardboard box lined with butter paper respectively on 30th day of storage at

28±2°C shown in Figure 5.9. Relatively gradual decreasing trend was observed in all

the packaging materials. Kumar et al., (1997) [108] also reported the decrease of pH in

peda during the storage period of 180 days at 20°C. Similar results were also observed

by Londhe et al., (2012) [107] in their brown peda. This may be due to the growth of

yeast and molds and a few water activity tolerant bacteria.

111

Figure 5.9 Effect of packaging materials on pH of Chhana jalebi during storage at

28±2°C

ii. Changes in water activity

The changes in average value of water activity of Chhana jalebi packed in four

different packaged materials with preservative treated samples are illustrated in Figure

5.10. The curves in Figure 5.10 clearly reveal that with progress in storage period, the

water activity of Chhana jalebi decreased from 0.88 to 0.858, 0.851, 0.827 and 0.866 for

LDPE pouch, metalized polyester, polystyrene cups covered with aluminum foil and

cardboard box lined with butter paper respectively on 30th day of storage at 28±2°C.

Hence, it concluded that the growth of microorganism was possible. This could be

attributed to moisture loss through the packaging material or within the packaging

material. This also had a bearing on the body and texture attribute. From graph, it was

clearly understood that all the packaging material samples water activity score were

above 8.0. Similar observations were found in khoa jalebi and khoa samples [39,91].

4.9

5

5.1

5.2

5.3

5.4

5.5

0 10 20 30

pH v

alue

Storage days

LDPE pouches

Polystyrene cups covered with aluminum foil

Cardboard box lined with butter paper

Metalized polyester

112

Figure 5.10 Effect of packaging materials on water activity of Chhana jalebi during storage at 28±2°C

iii. Changes in peroxide value

The Chhana jalebi samples were analysed for peroxide value in terms of free

fatty acids (FFAs) expressed as ml/g of product with a view to monitor lipolytic changes

during storage [109]. Though the milk lipase, which hydrolysed milk fat and produce

lower chain fatty acid, gets inactivated during Chhana jalebi manufacture. Other lipase

is produced by the bacteria and yeast and mold during storage and thus causes increase

in free fatty acid. The excessive production of free fatty acid causes impact on rancid

flavor and defect in dairy based products. There was gradual increase in peroxide

content of Chhana jalebi sample irrespective to packaging materials.

Figure 5.11 Effect of packaging materials on peroxide value of Chhana jalebi during storage at 28±2°C

0.80.810.820.830.840.850.860.870.880.89

0 10 20 30

Wat

er a

ctiv

ity

Storage days

LDPE pouches

Polystyrene cups covered with aluminum foilCardboard box lined with butter paperMetalized polyester

00.5

11.5

22.5

3

0 10 20 30

Pero

xide

val

ue (

ml/g

)

Storage days

LDPE pouches

Polystyrene cups covered with aluminum foilCardboard box lined with butter paper

Metalized polyester

113

The rate of increase of peroxide value was maximum in LDPE pouch and metalized polyester samples. The peroxide value increases from initial value of 0.35 to 2.80 ml/g of product during 30 days of storage shown in Figure 5.11 at 28±2°C. The rate of increase of peroxide value in polyester cup and cardboard box lined with butter paper was less as compared to LDPE pouch and metalized polyester sample. Value of cardboard box lined with butter paper and metalized polyester samples varied from initial value of 0.35 to 1.90 ml/g of product whereas LDPE pouch and polystyrene cups covered with aluminum foil varied from 0.35 to 2.8 ml/g of product during 30 days storage at 28±2°C. Based on the sensory scores, acceptable peroxide values for final product were identified in the range up to 0.73 ml/g of product. Based on observation, it concluded that the LDPE pouch, metalized polyester, cardboard box and polystyrene cup packed samples shelf life were 20 days. During 20 days, all packed samples tyrosine value was 0.73ml /g of product. After 20 days, peroxide value of all the samples were considered as not acceptable limit based on acceptable level of sensory scores which is 6.5. Despite steady increase in FFAs in all samples during storage, none of the samples was found to have rancid flavor indicating that the level of free fatty acid production was not to that level which causes serious defect. Kumar et al., (1997) [108] also observed increasing trend in free fatty acid during storage of peda under different packaging technique however the rate of increase was different. Palit and Dharam Pal (2005) [109] also reported that the rate of increase in free fatty acid was high in control sample of burfi and lowest in vacuum packaged samples. Navajeevan and Rao (2005) [110] reported an increase trend in free fatty acid of retort processed kunda during storage at elevated temperature.

iv. Changes in tyrosine value

Tyrosine value showed a gradual increase during storage. The Chhana jalebi samples were analyzed for the value in terms of mg/100g of product with a view to monitor proteolysis during storage. This increase in tyrosine value may be attributed to the breakdown of proteins by the surviving micro flora or their enzymes [109]. The proteolytic enzymes break the protein down to simpler forms thereby increasing the amount of tyrosine in the product. It may also be attributed to heat stable proteolytic enzymes which survived the heat treatment. Microbial cells of lysis due to heat treated release enzymes from their cell walls, which may act on proteins [111].

114

Figure 5.12 Effect of packaging materials on peroxide value of Chhana jalebi during storage at 28±2°C

There was a gradual increase in tyrosine value in all type of treatment of Chhana

jalebi sample irrespective to packaging materials. The rate of increase of tyrosine value

was higher in LDPE pouch and metalized polyester samples. The tyrosine value

increases from initial value of 3.00 to 21.75 mg/100g of product during 30 days of

storage at 28±2°C (Figure 5.12). The rate of increase of tyrosine value in polyester cup

and cardboard box lined with butter paper was less as compared to LDPE pouch and

metalized polyester sample. Value of polyester cup and cardboard box lined with butter

paper samples varied from initial value of 3.00 to 35.40 mg/100g of product during 30

days of storage at 28±2°C (Figure 5.12). Based on the sensory scores, acceptable

tyrosine values for final product were identified in the range up to 13.30 mg/100g of

product. Based on observation, it concluded that the LDPE pouch, metalized polyester,

cardboard box and polystyrene cup packed samples had the shelf life of 20 days. The

tyrosine values of all packed samples were 13.30 mg/100g of product upto 20 days.

After 20 days, tyrosine value of all the samples were considered as not acceptable limit

based on acceptable level of sensory scores which is 6.5. Similar results were observed

by Goyal et al., (1989a) [112] in khoa samples.

05

10152025303540

0 10 20 30

Tyro

sine

Valu

es

(mg/

100g

)

Storage days

LDPE pouches


Metalized polyester

115 5.4.3 Microbiological characteristics of Chhana jalebi stored in different

packaging materials

Chhana jalebi stored in various packaging materials such as polystyrene cups

covered with aluminum foil, cardboard box lined with butter paper, LDPE and

metalized polyester were considered for analyzing the changes in microbial

characteristics viz., standard plate count (SPC) and yeast and mold count of Chhana

jalebi during storage at ambient temperatures 28±2°C.

i. Changes in standard plate count (SPC)

The observation relating to the standard plate count (in log10 values) of Chhana

jalebi samples packed and stored at 28±2°C is illustrated in Figure 5.13. The total

bacterial count was increased disrespected to the storage period.

The standard plate count of jalebi samples in LDPE pouch without gas flush,

metalized polyester without gas flush, polystyrene cups covered with aluminum foil and

cardboard box lined with butter paper was increased from 3.26 log10 cfu/g on 0th day to

5.28, 4.62, 5.90 and 6.51 respectively on 20th day of storage at 28±2°C. Based on

sensory scores, it concluded that above mentioned SPC values were considered as an

acceptable limit for Chhana jalebi. In the 30 day storage, the SPC count was found

higher in all the samples and spoiled due to contamination from packaging system and

environment. The microorganisms are favorable to grow at the room temperature and

increase their population. Majority of the yeasts and mold and bacteria got destroyed

due to heat treatment. The survivors and contaminants acted on sugars and produced

acids and reduced the pH over the period of storage. The microbial growth was higher

in cardboard box lined with butter paper as compared to metalized polyester without gas

flush treated sample. Earlier Researchers also reported an increasing trend in standard

plate counts of burfi during storage period [113-116].

116

Figure 5.13 Effect of packaging materials on standard plate count (SPC) of Chhana jalebi during storage at 28±2°C

ii. Changes in yeast and mold

Yeast and mold growth tend to be major problem for most of the intermediate

food (e.g. khoa jalebi, peda, burfi, kalakand). Often it is the most single factor limiting

their shelf-life. With a view to improve the shelf-life of Chhana jalebi, the 800 ppm

level of preservative treated sample were packed in LDPE pouch without gas flush,

metalized polyester without gas flush, polystyrene cups covered with aluminum foil and

cardboard box lined with butter paper. The yeast and mold count was increased when

storage days increased. The result showed the increase in log10 counts during storage at

28±2°C (Figure 5.14). The initial count of yeast and mold was 0.41 for all the samples.

The yeast and mold count increases from initial value of 0.41 to 1.21, 0.88, 1.46 and

1.67 log10 cfu/g for LDPE pouch without gas flush, metalized polyester without gas

flush, polystyrene cups covered with aluminum foil and cardboard box lined with butter

paper respectively on 20th day of storage at 28±2°C shown in Figure 5.14.

02468

1012141618

0 10 20 30

Stan

dard

pla

te c

ount

(l og1

0cfu

/g)

Storage days

LDPE pouches


Metalized polyester

117

Figure 5.14 Effect of packaging materials on yeast and mold count of Chhana

jalebi during storage at 28±2°C

Based on results it concluded that above mentioned yeast and mold count were

considered as acceptable limits for Chhana jalebi upto 20 days. After that microbial

count of the samples were found higher in all the samples and spoiled due to

contamination from packaging system and environment. Similar results were obtained

by Garg (1987) [115] and Mishra (1988) [116] in burfi samples.

5.4.4 Sensory characteristics of Chhana jalebi stored in different packaging

materials

Sensory characteristics such as color and appearance, flavor and body and

texture were analyzed for the standardized Chhana jalebi with and without addition of

800 ppm potassium sorbate stored in different packaging materials such as polystyrene

cups covered with aluminum foil, cardboard box lined with butter paper, LDPE and

metalized polyester at both ambient (28±2°C) and refrigerated temperatures (4±2°C).

0

1

2

3

4

5

6

7

8

0 10 20 30

Yeas

t and

mol

d co

unt (

log 1

0cfu

/g)

Storage days

LDPE pouches

Polystyrene cups covered with aluminum foil

Cardboard box lined with butter paper

Metalized polyester

118 i. Changes in color and appearance

The color and appearance scores of the jalebi during storage was influenced by

four different packaging materials are presented in Table 5.33. It is clearly understood

from the Table 5.33 that, as storage days increased, the sensory score of color and

appearance was decreased irrespective to the packaging material used. The packet was

opened and visual appearance was recorded. It observed that the original light brown

colour was retained throughout the storage period, however colour and appearance

scores decreased mainly due to visible mold growth [91]. The scores at the end of 4th

day were 7.21, 7.23, 6.76 and 6.43, respectively for LDPE pouch, metalized polyester,

polystyrene cups covered with aluminum foil, cardboard box lined with butter paper

(Table 5.30). As the storage period increased, the product appeared dry probably

because of moisture evaporation through the packaging material itself in all packaging

materials except metallized polyester and LDPE pouches which are being good barrier

[117].

Table 5.33 Changes in color and appearance score* of Chhana jalebi control

samples packed in various packaging materials stored at ambient temperature

(28±2°C)

Packaging materialsControl samples stored at 28±2°C (days)

0 2 4 6 CD=0.43

LDPE pouch 8.91 8.21 7.21 4.33 7.17b

Metalized polyester 8.95 8.31 7.23 4.54 7.26b

Polystyrene cups 8.94 7.47 6.76 3.33 6.63a

Cardboard box lined with butter paper 8.93 7.45 6.43 3.54 6.59a

CD=0.43 8.93d 7.86c 6.90b 3.93a

*Average three trials; Note: Values with different superscripts are differ significantly at P≤0.05

119

Table 5.34 Changes in color and appearance score* of 800 ppm of potassium

sorbate treated Chhana jalebi samples packed in various packaging materials

stored at ambient temperature (28±2°C)

Packaging materials

Preservative added samples stored at 28±2°C (days)

0 10 20 30 CD=0.77

LDPE pouch 8.91 7.41 6.50 3.13 6.48a

Metalized polyester 8.95 8.62 6.67 5.10 7.33ab



CD=0.77 8.93d 8.11c 6.30b 3.88a


It can also been observed from the Table 5.33, as low barrier and high barrier

packaging material had significant level of color and appearance scores irrespective to

storage period. The mean scores were 7.17, 7.26, 6.63 and 6.59 for LDPE pouch,

metalized polyester, polystyrene cups covered with aluminum foil, cardboard box lined

with butter paper respectively. These scores were statistically significant to low barrier

and high barrier packaging materials. These may be attributed to the effect of packaging

material on mold growth. The ANOVA indicates the significant effect of packaging

material and storage period and their interaction (P≤0.05).

The sensory scores decreased during storage as indicated in Table 5.34. The

initial colour and appearance score of preservative treated samples was 8.91, 8.95, 8.94

and 8.93 which declined to 6.50, 6.67, 6.53 and 5.53 at the end of 20 days for LDPE

pouch, metalized polyester, polystyrene cups covered with aluminum foil, cardboard

box lined with butter paper respectively. Thereafter, all the colour and appearance

scores decreased to below acceptable limits. In general, the jalebi became dry due to

evaporation of moisture either through the packaging material or within packaging

material. However, after 20 days the visible mold growth was observed and the product

appearance dry.

120

Table 5.35 Changes in color and appearance score* of 800 ppm of potassium

sorbate treated Chhana jalebi samples packed in various packaging materials

stored at refrigerated temperature (4±2°C)

Packaging materials

Preservative added samples stored at 4±2°C(days)

0 15 30 45 60 CD=0.33

LDPE pouch 8.91 8.71 8.42 8.16 7.90 8.42a

Metalized polyester 8.91 8.90 8.78 8.77 8.69 8.81b

Polystyrene cups 8.91 8.44 8.29 7.60 7.30 8.11a

Cardboard box lined with butter paper 8.91 8.66 8.38 8.20 7.72 8.37a

CD=0.37 8.91c 8.68bc 8.47ab 8.18a 7.90a


Based on the observation, changes observed in the sensory score of color and

appearance of 800 ppm potassium sorbate treated samples were packed in all four types

of packaging materials and stored at 28°C and 4°C were presented in Table 5.33 and

5.34. At these storage temperatures, the effect of storage period, packaging material and

their interaction found to be significant as was observed at 28°C and 4°C. In that period

within which the color and appearance score remained 6.5 and above for LDPE pouch,

metalized polyester, polystyrene cups covered with aluminum foil packed products until

20 days; whereas cardboard box lined with butter paper samples were minimum of 10

days at 28°C and 60 days at 4°C for all materials. These may be attributed to the effect

of packaging material on mold growth [119]. The ANOVA indicates the significant

effect of packaging material and storage period and their interaction (P≤0.05).

ii. Changes in flavor

The flavor scores of jalebi during storage as influenced by four different

packaging materials are presented in Table 5.33. It is clearly understood from the Table

5.36 that as storage day increased, the sensory score of flavor was decreased

irrespective to the packaging material. The means score decreased from the initial value

of 8.94 to 3.66 at the end of 6 days of storage at room temperature. In case of

121 polystyrene cups covered with aluminum foil and cardboard box lined with butter paper

packed product score of 4th day was 6.74 and 6.41 respectively, which drastically

decreased to 3.62 and 3.46 on 6th day respectively. The LDPE pouch and metalized

polyester scores were 6.63 and 7.21 at the end of 4th day respectively. It is indicating

that the shelf life was 4 days, after this period due to mold growth the flavor turned to

unacceptable condition. This was determined by taking the minimum score of 6.5 as

acceptable limit.

Table 5.36 Changes in flavor score* of Chhana jalebi control samples packed in

stored at ambient temperature (28±2°C)


0 2 4 6 Avg. mean

LDPE pouch 8.91 8.32 6.63 4.32 7.05 NS

Metalized polyester 8.95 8.32 7.21 3.22 6.93NS

Polystyrene cups 8.95 7.43 6.74 3.62 6.69NS

Cardboard box lined with butter paper 8.95 7.41 6.41 3.46 6.56NS

CD=0.59 8.94d 7.87c 6.75b 3.66 a

*Average three trials; Note: Values with different superscripts are differ significantly at P≤0.05; NS-Non significant

Table 5.37 Changes in flavor score* of 800 ppm of potassium sorbate treated

Chhana jalebi samples packed in various packaging materials stored at ambient


Packaging materialsPreservative samples stored at 28±2°C

(days)

0 10 20 30 CD=0.69

LDPE pouch 8.95 7.75 6.51 3.21 6.61a


Polystyrene cups 8.95 8.15 7.55 4.32 7.24b

Cardboard box lined with butter paper 8.95 8.36 7.56 5.25 7.53b

CD=0.69 8.95d 8.23c 7.08b 4.26a


122

All packaging material had significant level of flavor scores irrespective to

storage period. The mean scores were 7.05, 6.93, 6.69 and 6.56 respectively for LDPE

pouch, metalized polyester, polystyrene cups covered with aluminum foil, cardboard

box lined with butter paper. These scores were not statistically significant to all the

packaging materials (Table 5.37).

The ANOVA indicates the significant effect of storage period and their

interaction (P≤0.05) whereas not significant to effect of packaging material. With regard

to the flavor characteristics, the jalebi possessed a pleasant sweet, nutty and flavor. This

was maintained up to 4 days as indicated by acceptable scores (6.41 to 7.21), then

thereafter the product developed off flavor, attributable to microbial growth [91].

Table 5.38 Changes in flavor score* of 800 ppm of potassium sorbate treated

Chhana jalebi samples packed in LDPE pouch, metalized polyester, polystyrene

cups and cardboard box lined with butter paper stored at refrigerated


Packaging materialsPreservative samples stored at 4±2°C (days)

0 15 30 45 60 CD=0.46

LDPE pouch 8.91 8.24 7.93 7.54 7.16 7.96a




CD=0.52 8.91c 8.45bc 8.16ab 7.80a 7.58a


P≤0.05

The flavor was pleasant, however during storage period the flavor score was

declined. Based on the scores which remained above 6.5, it can be observed that the

flavor remained acceptable up to 20 days. Thereafter, off flavor developed which made

the jalebi unacceptable. Based on observation, the changes observed in the sensory

score of flavor for 800 ppm potassium sorbate treated samples were packed in all four

packaging materials and stored at 28°C and 4°C were presented in Table 5.37 and 5.38.

At this storage temperature, also the effect of storage period and effect of packaging

123 material and their interaction found to be significant as was observed at 28°C and 4°C.

In that period within which the flavor score remained 6.5 and above for all packaging

materials were reported upto 20 days at 28°C and 60 days storage period at 4°C.These

may be attributed to the effect of packaging material on mold growth. The ANOVA

indicates the significant effect of packaging material and storage period and their

interaction (P≤0.05).

iii. Changes in body and texture

The body and texture scores of the jalebi during storage as influenced by four

different packaging materials are presented in Table 5.39. It is clearly understood from

the Table 5.39 that as storage day increased the sensory score of body and texture was

decreased irrespective of the packaging material. The means score decreased from the

initial value of 8.90 to 3.80 at the end of 6 days of storage at room temperature. In case

of polystyrene cups covered with aluminum foil and cardboard box lined with butter

paper packed product score of 4th day was 6.58 and 6.43 which marginally decreased to

3.32and 3.45 on 6th day. During storage, the body and texture of jalebi became firm, but

turned slimy later because of mold growth [64]. LDPE pouch and metalized polyester

scores were 6.59 and 7.01 at the end of 4thday respectively. It is indicating that the

LDPE pouch packed samples shelf life was 4 days and metalized polyester packed

samples shelf life was 6 days [120,121]. This was determined by taking the minimum

score of 6.5 as acceptable limit.

Table 5.39 Changes in body and texture score* of Chhana jalebi control samples packed in various packaging materials stored at ambient temperature (28±2°C)

Packaging materialsControl samples stored at 28 ±

2°C (days) Avg. mean

0 2 4 6

LDPE pouch 8.90 8.22 6.59 5.21 7.19NS

Metalized polyester 8.80 8.10 7.01 3.21 6.78NS

Polystyrene cups 8.93 7.50 6.58 3.32 6.58NS

Cardboard box lined with butter paper 8.95 7.46 6.43 3.45 6.57 NS

cd=0.83 8.90d 7.82c 6.61b 3.80a

*Average three trials; Note: Values with different superscripts are differ significantly at P≤0.05; NS-Non significant

124

All packaging material had significant level of body and texture scores

irrespective to storage period. The mean scores were 7.19, 6.78, 6.58 and 6.57

respectively for samples packed in LDPE pouch, Metalized Polyester, Polystyrene cups

covered with aluminum foil, cardboard box lined with butter paper (Table 5.39). These

scores were not statistically significant to all the packaging materials. The ANOVA

indicates the significant effect of storage period and their interaction (P≤0.05) whereas

not significant to effect of packaging material.

Table 5.40 Changes in body and texture* score of 800 ppm of potassium sorbate treated Chhana jalebi samples packed in various packaging materials stored at

ambient temperature (28±2°C)

Packaging materialsPreservative added samples stored at

28±2°C (days)

0 10 20 30 CD=0.73

LDPE pouch 8.90 7.45 6.21 3.15 6.43 a


Polystyrene cups 8.93 8.17 7.51 5.44 7.51b

Cardboard box lined with butter paper 8.95 8.35 7.54 5.34 7.55b

CD=0.73 8.90d 8.02c 6.97b 4.54 a


Table 5.41 Changes in body and texture score of 800 ppm of potassium sorbate treated Chhana jalebi samples packed in various packaging materials stored at

refrigerated temperature (4±2°C)

Packaging materialsPreservative added samples stored at 4±2°C (days)

0 15 30 45 60 CD=0.29

LDPE pouch 8.90 8.66 8.48 8.32 7.87 8.45ab




CD=0.33 8.90c 8.50b 8.42b 8.22ab 7.90a


125

The body and texture score declined from an initial score of 8.8 - 8.95 to 6.21 -

7.54 at the end of 20 days. These decreased scores were due to loss of moisture and

dryness and no mold growth was observed till this period. Based on observation, the

changes observed in the sensory score of body and texture for 800 ppm potassium

sorbate treated samples were packed in all four packaging materials and stored at 28°C

and 4°C are represented in Table 5.40 and 5.41. At this storage temperature and also

the effect of storage period and effect of packaging material and their interaction found

to be significant as was observed at 28°C and 4°C. The body and texture score was

remained 6.5 and above, for all packaging materials upto 20 days at 28°C and 60 days at

4°C [120,121]. These may be attributed to the effect of packaging material on mold

growth. The ANOVA indicates the significant effect of packaging material and storage

period and their interaction (P≤0.05).

iv. Changes in overall acceptability

Up to 4 days of storage, the body and texture score of Chhana jalebi in all

packaging material was remained unchanged and thereafter a decreasing trend with

further advancement of storage period was noticed from the Table 5.42. The overall

acceptability scores of jalebi during storage as influenced by four different packaging

materials are presented in Table 5.42, it clearly understood from observation that as

storage day increased, the sensory score of body and texture was decreased irrespective

to the packaging material. The means score decreased from the initial value of 8.95 to

4.47 at the end of 6 days of storage at room temperature. In case of polystyrene cups

covered with aluminum foil and cardboard box lined with butter paper packed product

score of 4th day was 6.75 and 6.45 which drastically decreased to 3.33 and 3.50 on 6th

day respectively. The scores at the end of 4th day were 7.00, 7.21, 6.75 and 6.45,

respectively for LDPE pouch, metalized polyester, polystyrene cups covered with

aluminum foil, cardboard box lined with butter paper. These scores remained within the

acceptable range up to 4 days of storage. Thus, it can be understood that the jalebi

packaged in LDPE pouch or metalized polyester or polystyrene cups covered with

aluminum foil or cardboard box lined with butter paper remained well up to 4 days,

which is slightly more than the shelf life of the Chhana jalebi left without any

packaging. The spoilage of the product may be attributed mainly due to the growth of

yeasts and molds. There was no change in shelf life of the product packaged in the four

packaging materials, though LDPE pouch and metalized polyester showed higher scores

126 at the end of 4 days. Statistical means of the packaging materials did not show statistical

difference for flavour and body and texture scores, whereas storage period had

significant influence on the change in sensory attributes (P<0.05). LDPE pouch and

metalized polyester scores were 7.00 and 7.21 at the end of 4th day respectively. It is

indicating that the LDPE pouch packed samples shelf life was 4 days and metalized

polyester packed samples shelf life was 6 days. This was determined by taking the

minimum score of 6.5 as acceptable limit. Similarly results were reported by Kumar et

al., (1983) [120] in khoa and Kumar et al., (2008a) [121] in paneer samples.

Table 5.42 Changes in overall acceptability score* of Chhana jalebi control

samples packed in various packaging materials stored at ambient temperature

(28±2°C)


0 2 4 6 CD=0.73

LDPE pouch 8.93 8.31 7.00 5.32 7.39b




CD=0.73 8.95d 7.93c 6.85b 4.47a


The mean scores were 7.39, 7.59, 6.63 and 6.59 respectively for samples packed

in LDPE pouch, metalized polyester, polystyrene cups covered with aluminum foil,

cardboard box lined with butter paper. These scores were statistically significant to all

the packaging materials. The ANOVA indicates the significant effect of packaging

material and storage period and their interaction (P≤0.05). The decreasing score with

advancement of storage period may be mainly attributed to the decline in aroma and

flavor.

127 Table 5.43 Changes in overall acceptability score* of 800 ppm of potassium sorbate

treated Chhana jalebi samples packed in various packaging materials stored at


Packaging materials


0 10 20 30 CD=0.67

LDPE pouch 8.97 7.50 6.50 3.20 6.54a




CD=0.67 8.96d 8.18c 6.55b 4.44a


Overall, the scores remained acceptable up to a storage period of 20 days

(overall acceptance score 6.5 - 6.69). After 20 days the overall acceptance scores fell to

unacceptable limits because of off flavours caused by proteolysis and oxidation.

Rajorhia et al., (1984) [122] reported that by using 0.3% potassium sorbate in khoa

could be preserved up to 23 days at 30oC. Potassium sorbate has been used in a number

of products and is a useful preservative in food industry [21].

Based on observation, the changes observed in the sensory score of overall

acceptability for 800 ppm potassium sorbate treated samples were packed in all four

packaging materials and stored at 28°C and 4°C are represented in Table 5.43 and 5.44.

At this storage temperature, also the effect of storage period and effect of packaging

material and their interaction found to be significant as was observed at 28°C and 4°C.

The overall acceptability score was persisted 6.5 and above for all packaging materials,

were obtained upto 20 days at 28°C and 60 days at 4°C. The decreasing score with

advancement of storage period could be mainly attributed to the decline in aroma and

flavor score of Chhana jalebi. These may be attributed to the effect of packaging

material on mold growth. The ANOVA indicates the significant effect of packaging

material and storage period and their interaction (P≤0.05).

128 Table 5.44 Changes in overall acceptability score* of 800 ppm of potassium sorbate

treated Chhana jalebi samples packed in various packaging materials stored at

refrigerated temperature (4±2°C)

Packaging materials


0 15 30 45 60 CD=0.34

LDPE pouch 8.93 8.67 8.45 8.22 8.00 8.45b

Metalized polyester 8.93 8.93 8.88 8.86 8.86 8.89c


Cardboard box lined with butter paper 8.93 8.33 8.40 8.02 7.75 8.29ab

CD=0.38 8.93c 8.53b 8.43b 8.18ab 8.00a


Based on observation, package material had effect on shelf life of Chhana jalebi.

It was concluded that Chhana jalebi samples packed in all four types of packaging

material without addition of preservative had shown 2 days shelf life at ambient

temperatures (28±2°C) whereas 800 ppm potassium sorbate treated samples had given

20 days. Similarly preservative treated samples stored under refrigeration temperature

(4±2°C) had shown shelf life of 60 days. All four packaging materials along with

Chhana jalebi samples are shown in Figure 5.15.

129

Figure 5.15 Different packaging materials used for shelf life enhancement of

Chhana jalebi

1. Cardboard box lined with butter paper packed samples

2. Polystyrene cups covered with aluminum foil

3. Low density polyethylene (LDPE) packed samples

4. Metalized polyester (MET) packed samples

3 4

21

130 PART – IV: SHELF LIFE ENHANCEMENT OF CHHANA JALEBI BY USING

DIFFERENT PACKAGING TECHNIQUES

5.5 SHELF LIFE ENHANCEMENT OF CHHANA JALEBI BY USING

MODIFIED ATMOSPHERE PACKAGING

Modified Atmosphere Packaging (MAP) technique is based on changing the gas

combination of packaging of the products. MAP has been used to preserve the freshness

of many food products and can improve the food safety under certain conditions

reported by Hotchkiss (1989) [123], Farber et al., (1991) [124]. Compared to traditional

product packaging methods, MAP offers many key benefits the most important one is

extending the shelf life [124]. The MAP has proved to be capable of extending the shelf

life of many foods by altering the relative proportions of the surrounding atmospheric

gases. The MAP can bring about changes in the respiration rate, microbial growth, and

oxidation reactions, hence effective against shelf life of food products [125]. The CO2,

O2 and N2 are normally used in MAP. These gases are tasteless and have peculiar

characteristics such as CO2 inhibits the microbial growth as well as insect infestation in

packaged stored products and N2 is an inert, tasteless gas mostly used as a filler gas.

[126 - 128]. Generally O2 concentration must be below the atmospheric levels (i.e. < 21

% v/v) [124, 129]. The most important gas from a microbiological stand point is CO2,

which effectively inhibits the growth of spoilage bacteria and molds [123].

Two packaging materials such as Low Density Poly-Ethylene (LDPE) and

Metalized polyester (MET) were selected for studying the effect of modified

atmospheric condition. Vacuum packaging technique was also done parallel along with

MAP for both packaging materials. Results were obtained and discussed separately for

both LDPE and MET.

5.6 SHELF LIFE ENHANCEMENT CHHANA JALEBI BY USING

MODIFIED ATMOSPHERE PACKAGING IN LDPE

In this study LDPE pouches were exposed in UV light around 45 min. The 2 to 3

pieces of Chhana jalebi was kept inside the sterile LDPE pouches. Carbon-di-oxide

(CO2) and nitrogen (N2) gases were flushed in three different combinations such as

100% CO2, 100% N2 and combination of 50% CO2 and 50% N2. Gas flushed and sealed

pouches were stored at 28±2°C and 65% RH. Study was conducted based on three

131 characteristics such as physico-chemical (pH, water activity, peroxide value and

tyrosine value), microbiological (standard plate count and yeast and mold count),

textural characteristics (hardness, adhesiveness, springiness, cohesiveness and

chewiness) and sensory characteristics (color and appearance, flavor, body and texture

and overall acceptability). Vacuum packaging was also done in LDPE pouches. Since

the product was compaction and resulting in loss of body and texture though given good

shelf life to the product. Results and discussions of the MAP in LDPE are presented

below.

5.6.1 Physico-chemical characteristics of Chhana jalebi stored in LDPE with

MAP and vacuum technique

Four physico-chemical parameters such as pH, water activity, peroxide value

and tyrosine values were analyzed for Chhana jalebi stored in LDPE with MAP and

Vacuum packaging techniques.

i. Changes in pH

The pH of fresh Chhana jalebi was 5.43 in control as well as in preservative

sample. Data on the pH of Chhana jalebi sample packed in LDPE pouch filled with

100% N2, 100% CO2 and 50% N2 with 50% CO2 and vacuum with preservative treated

samples stored at 28±2°C are given in Figure 5.16.

Figure 5.16 Effect of gas flushed LDPE packaging on pH values of Chhana jalebi

during storage at 28±2°C

4.64.74.84.9

55.15.25.35.45.5

0 10 20 30 40 50

pH v

alue

Storage days

LDPE (Control)

LDPE (100% N2)

LDPE (100% CO2)

LDPE (50% N2+50% CO2)LDPE (Vacuum)

132

In LDPE with gas combination packed samples were reduced the pH rapidly

from initial value of 5.43 to 5.04, 5.05, 5.01 and 5.06 for LDPE pouch filled with 100%

N2, 100% CO2 and 50% N2 with 50% CO2 and vacuum respectively for the period of 40

days at 28±2°C (Figure 5.16). Decreasing trend was observed in all samples during

storage at 28±2°C. Kumar et al., (1997) [108] also reported that pH of peda product

was decreased during storage period of 180 days at 20°C. This was attributed to the

growth of yeast and mold as in present study. Related results were also observed by

other Researchers [32, 64, 91].


Water activity has relationship with moisture content since loss of moisture is

common phenomena during storage; Figure 5.17 shows the trend of Chhana jalebi.

Water activity of Chhana jalebi was decreased from 0.88 to 0.766, 0.725, 0.743 and

0.791 for LDPE pouch filled with 100% N2, 100% CO2 and 50% N2 with 50% CO2 and

vacuum respectively during 40 days of storage at 28±2°C.

Figure 5.17 Effect of gas flushed LDPE packaging on water activity (aW) of

Chhana jalebi during storage at 28±2°C

Several previous studies have been reported an increase in the shelf life of

traditional dairy foods by using hurdle technology, water activity changes, increasing of

sugar content etc. [91, 108, 130-132]. However, not much Scientific literature is

00.10.20.30.40.50.60.70.80.9

1

0 10 20 30 40 50

Wat

er a

ctiv

ity

Storage days

LDPE (Control)

LDPE (100% N2)

LDPE (100% CO2)


133 available on the use of MAP for extending the shelf life of traditional dairy foods except

as reported by Biradar et al., (1985) [130] for peda, Rai et al.,(2008) [133] and

Thippeswamy et al., (2011) [134] for paneer and Londhe et al., (2012) [107] for brown

peda.

iii. Changes in peroxide value

Peroxide shows lipolytic changes during storage in Chhana jalebi samples in

terms of ml /g of product. Lipase enzyme present in milk is responsible for rancidity

gets inactivated during Chhana jalebi manufacturing, but it is produced by the bacteria

and yeast and mold during storage and thus causes increase in free fatty acid. The

excessive production of free fatty acid is responsible for rancidity in dairy products.

There was gradual increase in peroxide value in all Chhana jalebi samples irrespective

to gas combination levels. The rate of increase of peroxide value was higher in LDPE

with gas filled combination of 50% N2 and 50% CO2 sample. The initial value of 0.35

was increased to 0.68, 0.68, 0.65 and 0.73 ml/g of product for LDPE pouch filled with

100% N2, 100% CO2, 50% N2 with 50% CO2 and vacuum respectively during 50 days of

storage at 28±2°C (Figure 5.18).

Figure 5.18 Effect of gas flushed LDPE packaging on peroxide values of Chhana


0

0.5

1

1.5

2

2.5

3

0 10 20 30 40 50 60

Pero

xide

val

ue

(ml/g

)

Storage days

LDPE (Control)

LDPE (100% N2)

LDPE (100% CO2)


134

The rate of increase of peroxide value was minimum in LDPE pouch filled with

100% N2 samples as compared to LDPE with gas combination of 50% N2 with 50%

CO2. During 20 days, all packed samples peroxide value was 0.73ml /g of product

stored at 28±2°C. After 50 days, all samples peroxide value were considered as not

acceptable limit based on acceptable level of sensory scores which is 6.5. None of the

samples was found to have rancid flavor indicating that the level of free fatty acid

production was not to that level that causes serious defect, despite steady increase in

peroxide value in all samples during storage. Kumar et al., (1997) also observed

increasing trend in peroxide value during storage [108]. Jha et al., [59] and Kumar et al.,

(2010) [135] also reported that peroxide value in khoa increased significantly with the

progression of storage period. Oxygen is the causative factor for the occurrence of lipid

oxidation in foods and in this case, elimination of oxygen from the package reduced the

deteriorative changes. Similar findings have been reported by Hong et al., (1995) where

lipid oxidation in cheeses was significantly reduced by the removal of oxygen from the

package environment [136].


The deteriorating agents of the food quality are oxygen contained in the air and

microorganisms such as bacteria and mold. Oxygen promotes several types of

deteriorative reactions in foods including oxidation of fat, browning reactions and

pigment oxidation. Most of the common spoilage bacteria and fungi require oxygen for

growth. Therefore, to increase the shelf life of foods, the package atmosphere should

contain a low concentration of residual oxygen [137]. The increase in tyrosine value

may be attributed to the breakdown of proteins by the surviving micro flora and their

enzymes. The proteolytic enzymes break the proteins down to simpler forms there by

increasing the amount of tyrosine in the product. It may also be attributed to heat stable

proteolytic enzymes which survived the heat treatment [111]. Tyrosine value showed a

gradual increase during storage which depicted in figure 5.19. The Chhana jalebi

samples were analysed for tyrosine value in terms of mg/100g of product with a view to

monitor proteolysis during storage. The rate of increase of tyrosine value was higher in

LDPE with gas filled combination of 50% N2 with 50% CO2 sample.

135

Figure 5.19 Effect of gas flushed LDPE packaging on tyrosine values of Chhana


The initial value of 3.00 increased to 12.5, 12.5, 11.4 and 13.3 and 34.2 mg /

100g of product for LDPE pouch filled with 100% N2, 100% CO2, 50% N2 +50% CO2

and vacuum respectively during 50 days of storage at 28±2°C (Figure 5.19). In 50 days

storage at 28±20C, tyrosine value of all packed samples was 13.3 mg/100g of product.

After 50 days, all samples tyrosine value were considered as not acceptable limit based

on acceptable level of sensory scores which is 6.5. [108, 131]

5.6.2 Microbiological analysis of Chhana jalebi stored in LDPE with MAP and

vacuum technique

There were two microbial analyses such as standard plate count and yeast and

mold count were determined during storage and results are presented below.


The increasing trend in standard plate count (in log10 values) of Chhana jalebi

samples packed and stored at 28±2°C are illustrated in Figure 5.20. The total microbial

count was found to increased when storage period increase. Earlier Researchers also

reported increasing of microbial counts in burfi during their storage studies [113, 115,

116], whereas Kumar et al., (1997) [108] did not observed increase in the microbial

0

5

10

15

20

25

30

35

40

0 10 20 30 40 50 60

Tyro

sine

valu

e (m

g/10

0g)

Storage days

LDPE (Control)

LDPE(100% N2)

LDPE(100% CO2)

LDPE(50% N2+50% CO2)LDPE (Vacuum)

136 growth during storage of the product packed under MAP with oxygen scavengers in his

study on the enhancement of shelf life of peda. Palit and Pal (2005) [109] observed that

the rate of increase of total viable counts in control sample of burfi was higher than that

of vacuum packaged burfi . The initial count of 3.26 was increased to 5.90, 590, 5.55

and 6.51 log10 cfu/g for LDPE pouch filled with 100% N2, 100% CO2, 50% N2 with 50%

CO2 and vacuum respectively during 50 days of storage at 28±2°C (Figure 5.20). Based

on sensory scores, it concluded that above mentioned SPC values were considered as

acceptable limits for Chhana jalebi. During 60th day storage, the SPC count was found

higher in all the samples and spoiled.

Figure 5.20 Effect of gas flushed LDPE packaging on standard plate count (SPC)

of Chhana jalebi during storage at 28±2°C

ii. Changes in yeast and mold

For most of the inter-mediate Indian dairy foods such as peda, burfi and

kalakand etc. are affected by mold growth tends to be a major problem and often most

important single factor limiting their shelf life [107]. Yeast and mold are the most

important factor to limiting the shelf-life of low water activity food. The results shows

the increase in log10 counts during storage at 28±2°C and Figure 5.21 shows the trend in

this respect. Londhe et al., (2012) [107] reported that increase of yeast and mold count

when the progress of storage period for the brown peda. The initial count of 0.41 was

increased to 1.46, 1.46, 1.28 and 1.67 log10 cfu/g for LDPE pouch filled with 100% N2,

100% CO2 and 50% N2 with 50% CO2 and vacuum respectively during 50 days of

0

2

4

6

8

10

12

0 10 20 30 40 50

Stan

dard

pla

te c

ount

(log 1

0cf

u/g)

Storage days

LDPE (Control)

LDPE(100% N2)

LDPE(100% CO2)

LDPE(50% N2+50% CO2)LDPE(Vacuum)

137 storage at 28±2°C (Figure 5.21). The yeast and mold count of samples increased during

storage period due to contamination from packaging system and environment on 60th

day. The yeast and mold count was found to be increased irrespective to the storage

time.

Figure 5.21 Effect of gas flushed LDPE packaging on yeast and mold of Chhana


5.6.3. Textural characteristics of Chhana jalebi stored in LDPE with MAP

technique

A textural characteristic is one of the significant analyses for food products in

order to know consumption comfort ability of the food. The changes in textural quality

of Chhana jalebi in terms of texture profile analysis (TPA) during storage with

packaged under different packaging conditions are given in Table 5.45. The TPA

comprises a two-bite test that gives textural properties of food products in terms of

hardness, adhesiveness, cohesiveness, springiness and gumminess [138]. These textural

characteristics were analyzed for Chhana jalebi during 0th day, 50th day for LDPE

packed samples. Based on sensory scores and other analysis, it was found that shelf life

of Chhana jalebi treated with 800 ppm stored in LDPE packaging materials was 50

days. Hence textural analysis was carried out for the same. The force necessary to attain

a given deformation, called as hardness, is commonly evaluated parameter while

determining the texture of milk products. It is the height of the peak force on the first

compression cycle (first bite) [107].

0

0.5

1

1.5

2

2.5

3

0 10 20 30 40 50

Yeas

t and

mol

d co

unt

(log 1

0cf

u/g)

Storage days

LDPE (Control)

LDPE (100% N2)

LDPE (100% CO2)


138 Table 5.45 Textural characteristics* of Chhana jalebi stored in gas flushed LDPE

packing material during 50th day at ambient temperature (28±2°C)

Textural characteristics 0th Day

50thDay analysis for LDPE packing material

100 % N2 100 % CO2 50% N2 + 50% CO2

Hardness (N) 1.41 1.83 2.23 1.98

Adhesiveness (Ns) -5.65 -4.38 -5.07 -4.65

Springiness (mm) 0.817 0.876 0.945 0.923

Cohesiveness 0.53 0.57 0.614 0.595

Chewiness (Nm) 0.57 1.24 1.68 1.59

*Average three trials

Hardness of the product was increased from 1.41N on 0th day to 1.83N, 2.23N and 1.98N for 100% N2, 100% CO2 and 50% N2 + 50% CO2 gas filled packaging on 50th day respectively. Hardness of the product was increased due to moisture loss,relative permeability of the gases through film and sugar crystallization etc. In another study, a gradual increase in hardness of all brown peda samples irrespective of the packaging techniques was used [107]. Moisture loss occurred due to absorption of moisture by the both the nitrogen and oxygen gases in the packaging materials. Gupta et al., (1990) [139] observed that hardness of khoa (a heat desiccated milk product) was highly correlated with total solids and increasing total solids resulted in higher hardness. Similar findings were reported by Bhatele (1983) [99] and Sachdeva (1982) [140] in burfi samples. They observed that when burfi was packaged in parchment paper, its hardness continuously increased with the progress of storage period due to high amount of moisture loss.

Adhesiveness is the negative force of the first bite representing the work necessary to pull the compressing plunger away from the sample [107]. Adhesiveness also increased from initial value of -5.65Ns on 0th day to -4.38 Ns, -5.07 Ns and -4.65 Ns for 100% N2, 100% CO2 and 50% N2 + 50% CO2 gas filled packaged samples on 50th day respectively (Table 5.45) due to the moisture loss from the product.

The distance that food recovered its height during the time elapsed between end of first bite and start of second bite was defined as springiness [138]. Springiness of the product increased from initial value of 0.817mm on 0th day to 0.876mm, 0.945mm and

139 0.923 mm for 100% N2, 100% CO2 and 50% N2 + 50% CO2 gas filled packaged samples on 50th day respectively. It is believe that, springiness was increased due to increasing the activity of gluten content. In another study on brown peda, all samples showed increasing trend in springiness values irrespective of packaging technique during storage. However the rate of increase differed in each packaging technique [107]. Earlier Researchers [138, 141] reported that springiness was the only textural attribute which had no correlation with any of the compositional parameters of khoa. Palit (1998) [142] reported an increase in springiness value of burfi during storage irrespective to type of packaging.

Cohesiveness is molecular attraction by which the particles of a body are bounded throughout the mass. Cohesiveness may be defined sensorily as the degree to which a substance is compressed between the teeth before it breaks. Instrumentally, it is measured by calculating the ratio of the area of second bite to that of first bite A2/A1) [138]. Cohesiveness of the product increased from initial value of 0.53 on 0th day to 0.57, 0.614 and 0.595 for 100% N2, 100% CO2 and 50% N2 + 50% CO2 gas filled packaged samples on 50th day respectively. Since loss of moisture content from the product, strength of internal bond was increased. Reason for moisture loss was already discussed.

Two other parameters viz., gumminess and chewiness were derived by calculation from the measured parameters. Gumminess was defined as the product of hardness and cohesiveness while chewiness was defined as the product of gumminess and springiness [138]. Gumminess and chewiness are mutually exclusive characteristics since gumminess applicable for semisolid food and chewiness is applicable for solid food. Since Chhana jalebi is considered as solid food, chewiness was analyzed. Chewiness of the product also increased from initial value of 0.57 Nm on 0th day to 1.24 Nm, 1.68 Nm and 1.59 Nm for 100% N2, 100% CO2 and 50% N2 + 50% CO2 packaged material samples respectively on 50th day (Table 5.45). Since loss of moisture content from the product, there may be little increased energy required for converting Chhana jalebi solid food in to semisolid state in order to swallow the product. Reason for moisture loss was already discussed. This increasing trend in chewiness in all Channa jalebi samples during storage could be attributed to increase in gumminess and springiness values. These findings are correlated with Palit et al., (1998) [142] findings and reported that the gumminess and chewiness of burfi increase with the progress of storage period irrespective to type of package used. Bourne (2002) [138] also observed that soft burfi was significantly less gummy than hard burfi.

140 5.6.4 Sensory characteristics of Chhana jalebi stored in LDPE with MAP and

vacuum packaging techniques

Four sensory characteristics such as color and appearance, flavor, body and

texture and overall acceptability analyses were carried out at both ambient (28±2°C) and

refrigerated temperatures (4±2°C) with and without 800 ppm of potassium sorbate

preservative treated Chhana jalebi stored in LDPE with MAP and vacuum packaging.

The results are presented as below.

i. Changes in color and appearance

Under the treatment of gas flushing, the initial color and appearance scores of

Chhana jalebi during storage was influenced by all combination of gas flushing in

LDPE pouches which are presented in Table 5.46. Based on the observation concluded

that as storage days increased or progressed, the sensory score of color and appearance

was decreased irrespective of the gas flushing levels and same results were reported by

other researchers [107, 121]. The mean score decreased from the initial value of 8.92 to

5.35 at the end of 45 days of storage at room temperature, which was due to extensive

mold growth inside the package. LDPE pouch filled with 100% N2, 100% CO2, 50% N2

+ 50% CO2 and vacuum packed products scores were 7.32, 7.23, 7.01, and 7.13 at the

end of 30 days respectively. The sensory scores showed a decreasing trend during

storage in all samples of Chhana jalebi irrespective of packaging techniques. Despite

decreasing trend the samples were found to score well over the minimum acceptable

limit during the storage period of entire storage study but there was fungal growth on

the samples on 45thday. It can be also observed from the Table 5.46 that, LDPE pouch

with gas filled and vacuum packed samples had significant level of color and

appearance scores irrespective of storage period. The mean scores were 7.43, 7.56, 7.43

and 7.51 for samples packed in LDPE pouch filled with 100% N2, 100% CO2, 50% N2 +

50% CO2 and vacuum packed products respectively. These scores were statistically

significant to all combination of gas flushing. Same impact was observed in danedar

khoa [132]. The Table 5.46 indicates the significant effect of gas flushing in LDPE

packing material, storage period and their interaction (P≤0.05). The mean scores of

color and appearance for LDPE pouch filled with 100% CO2 packed sample was 7.56

which is higher score than other gas combinations (Table 5.46). It attributed that CO2 is

having a property of retaining freshness of the product.

141

Table 5.46 Changes in the color and appearance score* of Chhana jalebi control samples packed in gas flushed LDPE packaging materials stored at ambient


LDPE with different MAP Conditions

Control samples stored at 28±2°C (days)

0 15 30 45 CD=0.37

LDPE (100% N2) 8.91 8.25 7.32 5.22 7.43a

LDPE (100% CO2) 8.94 8.54 7.23 5.54 7.56ab

LDPE (50% N2 + 50% CO2) 8.92 8.45 7.1 5.23 7.43a

LDPE (vacuum) 8.93 8.54 7.13 5.44 7.51a

CD=0.33 8.92d 8.44c 7.20b 5.35a


Similarly, studies on color and appearance were carried out for Chhana jalebi

treated with 800 ppm of potassium sorbate as preservative. The changes in the sensory

score of color and appearance of the samples which packed in all combinations of gas

filled and vacuum packed LDPE pouches, stored at 28°C are presented in Table 5.47. At

this storage temperature, the effect of storage period and effect of gas flushing in LDPE

pouches and their interaction found to be significant (Table 5.47).

Table 5.47 Changes in the color and appearance score* of 800 ppm of potassium sorbate treated Chhana jalebi samples packed in gas flushed LDPE packaging

materials stored at ambient temperature (28±2°C)



0 20 40 60 CD=0.54

LDPE (100% N2) 8.95 8.64 6.82 3.21 6.91a

LDPE (100% CO2) 8.95 8.72 7.83 3.21 7.18b

LDPE (50% N2 + 50% CO2) 8.95 8.44 7.21 3.12 6.93a

LDPE (vacuum) 8.93 8.82 7.83 3.11 7.17ab

CD=0.49 8.94d 8.65c 7.42b 3.16a


142

In that period, the color and appearance score was remained 6.5 and above for

all gas filled and vacuum packed samples until 50 days. These may be attributed to the

effect of packaging material on mold growth. The ANOVA indicates the significant

effect of gas flushing in LDPE packaging material, storage period and their interaction

(P≤0.05).


Gas flushing plays key role to retain the aroma and flavor score of Chhana jalebi

at 28±2°C with 65% relative humidity. The flavor scores of Chhana jalebi during

storage was influenced by all combination of gas flushing in LDPE pouches which are

presented in Table 5.48. The mean score decreased from the initial value of 8.93 to 5.00

at the end of 45 days of storage at room temperature due to extensive mold growth. The

mean flavor score of LDPE pouch filled with 100% N2, 100% CO2, 50% N2 + 50% CO2

and vacuum packed products scores were 7.32, 7.20, 7.46, and 7.41 respectively. All

the LDPE packed samples with gas flushing shown retained original flavor

characteristics and no microbial growth for 30 days. There was no deterioration of

flavor until 40th day, however thereafter there was slight mold growth observed,

therefore flavor was unacceptable. It indicated that the packed samples shelf life was 30

days. The findings of the present study are in accordance with the report of Biradar et

al., (1985) [130].

Table 5.48 Changes in the flavor score* of Chhana jalebi control samples packed

in gas flushed LDPE packaging materials stored at ambient temperature (28±2°C)


Control samples stored at 28±2°C(days)

0 15 30 45 Avg. mean

LDPE (100% N2) 8.92 8.01 7.02 5.31 7.32

LDPE (100% CO2) 8.95 8.22 7.09 4.55 7.20

LDPE (50% N2 + 50% CO2) 8.94 8.42 7.03 5.45 7.46

LDPE (vacuum) 8.94 8.23 7.12 5.35 7.41

CD=0.38 8.93d 8.24c 6.98b 5.00a


P≤0.05

143

The changes in the sensory score of flavor of preservative treated samples which

packed in all combinations of gas filled and vacuum packed LDPE pouches, stored at

28°C are represented in Table 5.49. Based on observation, at this storage temperature,

the effect of storage period and effect of gas flushing in LDPE pouches and their

interaction found to be significant. The ANOVA indicates the significant effect of gas

flushing in LDPE packaging material, storage period and their interaction (P≤0.05). It

attributed that CO2 is having a property of retaining freshness of the product. Sharma et

al., (2001) [132], also reported the decrease in mean flavour scores of the control and

MAP packaged malai peda samples in flexible packaging material at room temperature

[132]. The reduction in flavour score for control (without MAP) was much rapid than

for MAP samples. Similar observation was reported by Kumar et al., (1997) [108].

The decrease in flavour scores may be attributed to slight loss of freshness,

which is inherent with any food product. The findings of the present study are in

accordance with the report of Biradar et al., (1985) [130].

Table 5.49 Changes in the flavor score* of 800 ppm of potassium sorbate treated Chhana jalebi samples packed in gas flushed LDPE packaging materials stored at




0 20 40 60 CD=0.52

LDPE (100% N2) 8.94 8.63 6.53 3 6.78 a

LDPE (100% CO2) 8.96 8.73 7.55 3.11 7.09 a

LDPE (50% N2 + 50% CO2) 8.96 8.52 7.32 3.2 7.00 a

LDPE (vacuum) 8.94 8.84 7.86 3.15 7.20 ab

CD=0.46 8.95c 8.68c 7.31b 3.11 a


P≤0.05

Despite decreasing trend the samples were found to score well over the

minimum acceptable limit during the entire storage study. None of the judges reported

the presence of any objectionable off flavour such as oxidized, rancid, acidic etc. during

the entire period of storage.

144 iii. Changes in body and texture

The body and texture score of Chhana-jalebi in LDPE as well as gas flushing

was almost same within 30 days (Table 5.50). Up to 30 days of storage, the mean value

of body and texture scores decreased from 8.89 to 4.21 at 28±2°C. The ANOVA report

indicates that significant effect of gas flushing in LDPE packaging material and storage

period and their interaction (P≤0.05). Due to slight evaporation of moisture Chhana

jalebi surface became slightly hard. The findings of the present study are in accordance

with the report of Biradar et al., (1985) [130] and Londhe et al., (2012) [107]. Another

study also reported the decrease in mean body and texture scores of the control and

MAP packaged malai peda samples in flexible packaging material at room temperature.

The reduction in body and texture score for control (without MAP) was much rapid than

for MAP samples [132]. Similar observation was reported by Kumar et al., (1997)

[108].

The decrease in body and texture scores may be attributed to slight loss of

freshness that is common in food product. The findings of the present study are

correlated with previous Biradar et al., (1985) [130] and Sharma et al., (2001) [132]

also reported the decrease in mean body and texture scores of the control and MAP

packaged malai peda samples in flexible packaging material at room temperature.

Table 5.50 Changes in the body and texture score* of Chhana jalebi control samples packed in gas flushed LDPE packaging materials stored at ambient



Control samples stored at 28±2°C(days) Avg.

mean0 15 30 45

LDPE (100% N2) 8.92 8.02 7.04 4.01 7.00

LDPE (100% CO2) 8.91 8.00 7.03 4.27 7.05

LDPE (50% N2 + 50% CO2) 8.93 8.4 6.92 4.30 7.14

LDPE (vacuum) 8.80 8.21 7.01 4.27 7.07

CD=0.43 8.89d 8.15c 7.00b 4.21 a


145

Table 5.51 Changes in the body and texture scores* of 800 ppm of potassium sorbate treated Chhana jalebi samples packed in gas flushed LDPE packaging




0 20 40 60 CD=0.61

LDPE (100% N2) 8.95 8.59 6.56 3.33 6.86a

LDPE (100% CO2) 8.96 8.76 7.58 3.23 7.13ab

LDPE (50% N2 + 50% CO2) 8.93 8.46 7.1 3.1 6.90a

LDPE (vacuum) 8.8 8.2 7.83 3.11 6.99a

CD=0.54 8.92d 8.50c 7.26b 3.19a


In case of preservative treated samples which packed in all combinations of gas

filled and vacuum packed LDPE pouches samples body and texture score remained 6.5

and above for all gas filled and vacuum packed samples for 40 days (Table 5.51). The

ANOVA indicates the significant effect of gas flushing in LDPE packaging material,



During storage the scores of all the samples decreased at the same rate up to 30

days. The rate of decrease in LDPE gas flushed sample was not significant as storage

days increased the sensory score of overall acceptability was decreased irrespective of

the gas flushing levels. The average overall acceptability score was decreased from the

initial value of 8.93 to 5.32 at the end of 45 days of storage period at room temperature.

Similar observations were reported in brown peda [107].

The LDPE packed samples with gas flushing shown retained their characteristics

and no visible microbial growth for 30 days. The ANOVA Table 5.52 indicates the

significant effect of gas flushing in LDPE packing material and their interaction,

whereas not significant on storage period. The decreasing score with advancement of

storage period may be attributed mainly to the decline in aroma and flavor and product

became dry.

146

Table 5.52 Changes in the overall acceptability score* of Chhana jalebi control

samples packed in gas flushed LDPE packaging materials stored at ambient




0 15 30 45 Avg. mean

LDPE (100% N2) 8.91 8.21 7.01 5.58 7.43

LDPE (100% CO2) 8.91 8.52 7.23 5.74 7.60

LDPE (50% N2 + 50% CO2) 8.95 8.52 7.1 5.48 7.51

LDPE (vacuum) 8.95 8.61 7.2 4.5 7.32

CD=0.38 8.93d 8.46c 7.13b 5.32a


P≤0.05

Similarly, studies on overall acceptability were carried out for Chhana jalebi

treated with 800 ppm of potassium sorbate as preservative. The changes in the sensory

score of overall acceptability of the samples which packed in all combinations of gas

filled and vacuum packed LDPE pouches, stored at 28°C are given in Table 5.53. At

this storage temperature and preservative level, the effect of storage period and effect of

gas flushing in LDPE pouches and their interaction found to be significant (Table 5.53).

The overall acceptability score was remained 6.5 and above for all gas filled and

vacuum packed samples until 40 days. The decreasing score with advancement of

storage period may be mainly attributed to the decline in aroma and flavor. The

ANOVA indicates the significant effect of gas flushing in LDPE packaging material,


Despite decreasing trend the samples were found to score well over the

minimum acceptable limit during the storage period of 40 days of LDPE with various

gas flushing levels and vacuum packaging methods. Same results were observed other

indigenous dairy products such as brown peda, burfi, khoa etc., [107, 113, 114 and 120].

147

Table 5.53 Changes in the overall acceptability score* of 800 ppm of potassium

sorbate treated Chhana jalebi samples packed in gas flushed LDPE packaging




0 20 40 60 CD=0.57

LDPE (100% N2) 8.96 8.65 7.62 3.41 7.16 a

LDPE (100% CO2) 8.96 8.76 7.83 3.32 7.22b

LDPE (50% N2 + 50% CO2) 8.96 8.60 7.23 3.2 7.00 a

LDPE (vacuum) 8.96 8.85 7.85 3.3 7.24 a

CD=0.51 8.96c 8.71c 7.63b 3.30a


P≤0.05

Based on observation, modified atmospheric and vacuum packaging packed

Chhana jalebi samples had effect on their shelf life. It was concluded that Chhana jalebi

samples packed in 100% N2, 100% CO2, 50% N2 with 50% CO2 and vacuum packaging

in LDPE without addition of preservative had shown 30 days shelf life at ambient

temperatures (28±2°C) whereas 800 ppm potassium sorbate treated samples had given

40 days. All four packaging materials along with Chhana jalebi samples are shown in

Figure 5.28-1.

5.7 SHELF LIFE ENHANCEMENT OF CHHANA JALEBI BY USING

MODIFIED ATMOSPHERE AND VACUUM PACKAGING

TECHNIQUE IN METALIZED POLYESTER

Metalized polyester (MET) pouches were selected for study the effect of

modified atmosphere and vacuum packaging instead of LDPE material and same study

was repeated as like above LDPE study. MET pouches were exposed in UV light

around 45 min. The five pieces of Chhana jalebi was kept inside the sterile MET

pouches. Carbondioxide (CO2) and nitrogen (N2) gases were flushed in three different

combinations such as 100% CO2, 100% N2 and combination of 50% CO2 and 50% N2.

Gas flushed and sealed pouches were stored at 28±2°C and 65% relative humidity.

148 Study was conducted based on three characteristics such as physico-chemical (pH,

water activity, peroxide value and tyrosine value), microbiological (standard plate count

and yeast and mould count), textural characteristics (hardness, adhesiveness,

springiness, cohesiveness and chewiness) and sensory characteristics (color and

appearance, flavor, body and texture and overall acceptability). Vacuum packaging was

also done in MET pouches. Similar observations were also found in MET pouches.

Results and discussions of the MAP and vacuum packaging effects in MET are

presented below.

5.7.1 Physico-chemical characteristics of Chhana jalebi stored in MET with MAP

and vacuum packaging techniques

Four physico-chemical parameters such as pH, water activity, peroxide value

and tyrosine value were analyzed for Chhana jalebi which stored in MET with MAP and

vacuum packaging techniques. The results are presented below.

i. Changes in pH Value

Chhana jalebi is slightly acidic in nature as indicated by its pH value of 5.43.

This showed further decreasing trend during storage even in modified atmospheres

(Figure 5.22). In all the metalized polyester with gas flushed and vacuum treated

samples shows decreasing trend in pH. The pH decreased from initial value of 5.43 to

4.84, 4.86, 4.81 and 4.87 for metalized polyester pouch filled with 100% N2, 100% CO2,

50% N2 with 50% CO2 and vacuum respectively on 60th days of storage at 28±2°C. All

the treated samples had shown the pH value between 4.81 and 4.87, thus indicating that

nitrogen, carbon dioxide and vacuum hindered the growth of bacteria and mold. Bharat

and Pagote (2012) [102] also observed decreasing trend of pH during storage period of

khoa jalebi. The changes in pH cannot be directly correlated with change in acidity; still

it was found that with the increase in acidity, the pH exited on decreasing. Kumar et al.,

(1997) [108] also reported a decrease in pH of peda during storage for 180 days at 20°C.

149

Figure 5.22 Effect of gas flushed metalized polyester packaging materials on pH

values of Chhana jalebi during storage at 28±2°C


During storage of Chhana jalebi there was slight evaporation of moisture content

therefore a declining trend was observed in water activity. From the graph 5.23, it was

observed that the initial value of water activity of Chhana jalebi decreased from 0.88 to

0.685, 0.634, 0.657 and 0.721 for metalized polyester pouch filled with 100% N2, 100%

CO2, 50% N2 with 50% CO2 and vacuum respectively on 60th days of storage at 28±2°C.

Hence, it concluded that the samples packed in metalized polyester with 100% CO2 was

shown less water activity and more prone to microbial spoilage as compared to other

gas flushed samples. Earlier, several scientists have been also reported considerable

loss of moisture in peda during storage which made the product dry and hard and thus

sensorily unacceptable. Bhatele et al., (1983) [114] reported that the rate of moisture

evaporation from burfi samples was different from samples packaged in different

packaging materials. A decreasing trend in water activity was observed in brown peda

[117]. Lowest moisture loss was noticed in peda samples packaged in MAP as

compared to control reported by Sharma et al., (2003) [143].

4.54.64.74.84.9

55.15.25.35.45.5

0 10 20 30 40 50 60

pH v

alue

Storage days

Metalized polyester

Metalized polyester (100% N2)Metalized polyester (100% CO2)Metalized polyester (50% N2+50% CO2)Metalized polyester (Vacuum)

150

Figure 5.23 Effect of gas flushed metalized polyester packaging materials on pH

values of Chhana jalebi during storage at 28±2°C

iii. Changes in peroxide content

The free fatty acid production during storage in products produces rancidity

which is unacceptable. Lipase enzyme produced by yeast and mold is responsible for

that because it acts on lipid and released free fatty acid. Therefore a gradual increased in

peroxide value during storage was observed. The Figure 5.24 shown rate of increase of

peroxide value was higher in vacuum as compared to gas filled and packed samples.

Peroxide value increased from initial value of 0.35 to 1.77, 1.29. 0.98 and 2.05 for

metalized polyester with gas filled in the combination of 100% N2, 100% CO2, 50% N2

with 50% CO2 and vacuum respectively during 65 days of storage at 28±2°C (Figure

5.24). During 60 days, all packed samples peroxide value were 0.73 ml /g of product

stored at 28±2°C and 65% relative humidity. After 65 days, all samples peroxide value

were considered as not acceptable limit based on acceptable level of sensory scores

which is 6.5. Navajeevan and Rao (2005) [110] reported the increase trend in free fatty

acid of retort processed kunda during storage at elevated temperature.

00.10.20.30.40.50.60.70.80.9

1

0 10 20 30 40 50 60

Wat

er a

ctiv

ity

Storage days

Metalized polyester (Control)Metalized polyester (100% N2)Metalized polyester (100% CO2)Metalized polyester (50% N2+50% CO2)Metalized polyester (Vacuum)

151

Figure 5.24 Effect of gas flushed metalized polyester packaging on peroxide values

of Chhana jalebi during storage at 28±2°C

Jha et al., (1977) [59] and Kumar et al., (2010) [135] also reported that FFA in

khoa increased significantly with the progression of storage period. The reason for the

delayed lipolysis of the Channa jalebi during storage under MAP could be attributed to

the absence of oxygen in the package during storage. Oxygen is the causative factor for

the occurrence of lipid oxidation in foods and in this case, elimination of oxygen from

the package reduced the deteriorative changes. Similar findings have been reported by

Hong et al., (1995) [136] where lipid oxidation in cheeses was significantly reduced by

the removal of oxygen from the package environment.


Proteolysis during storage of processed food products is a natural phenomenon

due to surviving of microorganisms and their enzymes. Owing to proteolysis, protein

gets broken into simpler form increasing the amount of tyrosine in the product which

shown in Figure 5.25. It may also be attributed to heat stable proteolytic enzymes which

survived the heat treatment. The Chhana jalebi samples were analysed for tyrosine value

in terms of mg/100g of product.

0

0.5

1

1.5

2

2.5

0 10 20 30 40 50 60 65

Pero

xide

val

ue (

ml/g

)

Storage days

Metalized polyester (Control)

Metalized polyester(100% N2)

Metalized polyester(100% CO2)

Metalized polyester(50% N2+50% CO2)

152

Figure 5.25 Effect of gas flushed metalized polyester packaging materials on

tyrosine values of Chhana jalebi during storage at 28±2°C

The rate of increase of tyrosine value was higher in vacuum treated and

packaged in metalized polyester. The tyrosine value increased from initial value of 3.00

to 20.1, 16.3, 14.5 and 24.3 mg/100 g for samples packed in metalized polyester with

gas combination of 100% N2, 100% CO2, 50% N2 with 50% CO2 and vacuum

respectively for 65 days of storage at 28±2°C (Figure 5.25). It concluded that samples

packed in metalized polyester with gas combination of 50% N2 with 50% CO2 showed

less tyrosine value compared to the 100% N2, 100% CO2 and vacuum treated samples.

Since tyrosine value of 13.3 mg/100g was considered as maximum acceptable limit

based on sensory values and all the samples were within the limit or acceptable range.

Hence, it concluded that metalized polyester packaging material is suitable for

packaging the Chhana jalebi with modified atmosphere techniques. A tyrosine value

decreasing trend was reported in brown peda [107]. Goyal and Srinivasan (1989a) [112]

Kumar and Srinivasan (1983) [120] and Sharma et al., (2001) [132] reported in khoa.

Similarly, Palit and Pal (2005) [109] and Sachdeva and Rajorhia (1982) [140] in burfi

whereas, Kumar et al., (2008a) [121] in paneer and Sharma et al., (2003) [143] in peda

and Navajeevan et al., (2005) [110] in retort processed kunda during storage at 37°C.

0

5

10

15

20

25

30

0 10 20 30 40 50 60 65

Tyro

sine

valu

e (m

g/10

0g)

Storage days

Metalized polyester (Control)

Metalized polyester(100% N2)

Metalized polyester(100% CO2)

Metalized polyester(50% N2+50% CO2)

153 5.7.2 Microbiological characteristics of Chhana jalebi stored in MET with MAP

and vacuum packaging techniques

There were two microbial analyses such as standard plate count and yeast and

mold count carried out during storage and results are presented below.


The following Figure 5.26 shows the trend in standard plate count (log10 values)

in Chhana jalebi stored at 28±2°C. The total microbial count was found to be increased

irrespective to storage period.

Figure 5.26 Effect of gas flushed metalized polyester packaging materials on

standard plate count (SPC) of Chhana jalebi during storage at 28±2°C

The initial count of SPC value was 3.26 increased to 16.52, 11.47, 8.59 and

21.33 log10 cfu/g for metalized polyester pouch filled with 100% N2, 100% CO2, 50% N2

with 50% CO2 and vacuum respectively during 65 days of storage at 28±2°C and shown

in Figure 5.26. It was found out that 4.92, 5.28, 4.76 and 6.26 log10 cfu/g for metalized

polyester pouch filled with 100% N2, 100% CO2, 50% N2 with 50% CO2 and vacuum

respectively on 60th days of storage. During 65th day, the SPC count was found higher in

all the samples and spoiled. The control sample supported the growth of microbial flora

as the gaseous atmosphere was same as air containing oxygen. The samples containing

nitrogen showed delayed microbial growth, because nitrogen is an inert gas which does

not support microbial growth. Previous Researchers also reported that increasing

0

5

10

15

20

25

0 10 20 30 40 50 60 65

Stan

dard

pla

te c

ount

(log

10cf

u/g)

Storage days


154 bacterial counts of burfi during their storage studies [113, 115, 116], however Kumar et

al., (1997) [108] did not observe increase in the microbial growth during storage in the

product packed under MAP with oxygen scavengers in study on the enhancement of

shelf life of peda. Palit and Pal (2005) [109] observed that the rate of increase of total

viable counts in control sample of burfi was higher than that of vacuum packaged burfi.

ii. Yeast and mold

In the presence of oxygen, many of oxidation reactions and proceed mold

proliferation occurred. Gas flushing in the present study was able to reduce the oxygen

concentration. [144, 145]. Figure 5.27 shows the increase in log10 counts of mold and

yeast during storage at 28±2°C. Yeast and mold growth tend to be major problem for

high moisture food items. All the sample of Chhana jalebi showed the presence of yeast

and mold count which increased with the progress of storage period.

Figure 5.27 Effect of gas flushed metalized polyester packaging materials on yeast

and mold of Chhana jalebi during storage at 28±2°C

The rate of increase of yeast and mold was higher in vacuum treated samples.

The initial value of 0.41 increased to 7.23, 4.12, 2.43 and 12.41 and 1.67 log10 cfu/g for

metalized pouch filled with 100% N2, 100% CO2 and 50% N2 with 50% CO2 and

vacuum respectively during 65 days of storage at 28±2°C and shown in Figure 5.27.

0

2

4

6

8

10

12

14

0 10 20 30 40 50 60 65

Yeas

t and

mol

d co

unt

(log

10cf

u/g)

Storage days


155

It was found that the yeast and mold counts of Chhana jalebi were 1.05, 1.21,

0.95 and 1.54 log10 cfu/g respectively for metalized polyester pouch filled with 100%

N2, 100% CO2, 50% N2 with 50% CO2 and vacuum respectively on 60th days of storage.

During 65th day, the yeast and mold count was found higher in all the samples and

found spoiled. Due to effect of gas flushing, the growth was slow in gas flushed and

packed in metalized polyester samples compared to vacuum treated samples. The

microorganisms are able to grow at the room temperature and increase their

populations. The yeast and mold count of samples increased during storage due to

contamination from packaging system and environment on 65th day. The yeast and mold

count was found to increase with increase in storage time. Londhe et al., (2012) [107]

reported that increase of yeast and mold count when the progress of storage period for

brown peda.

5.7.3 Textural characteristics of Chhana jalebi stored in MET with MAP and


Based on physic chemical and sensory analysis, it was found that shelf life of

800 ppm potassium sorbate added and packed in metalized polystyrene Chhana jalebi

samples was 60 days. Hence textural analysis was carried out for the same. Hardness of

the product was increased from 1.41N on 0th day to 2.24N, 2.45N and 2.16N for 100%

N2, 100% CO2 and 50% N2 + 50% CO2 gas filled packaging material samples

respectively on 50th day. Hardness of the product was increased due to moisture loss.

Moisture loss occurred due to absorption of moisture by the both the nitrogen and

oxygen gases in the packaging materials. This is in accordance with the earlier findings

of Gupta et al., (1990) [146], Patel et al., (1990) [147] and Suresh et al., (1994) [148]

and reported that the increased hardness of khoa correlated with the increase in the total

solids and the moisture content of peda had a direct relationship with the hardness.

156

Table 5.54 Textural characteristics* of Chhana jalebi stored in gas flushed

metalized polyester packing material during 60th day at ambient temperature

(28±2°C)

Textural characteristics

60th Day analysis for metalized polyester pouches

100 % N2 100 % CO2 50% N2 + 50% CO2

Hardness (N) 2.24 2.45 2.16

Adhesiveness (Ns) -4.27 -4.78 -4.56

Springiness (mm) 0.867 0.924 0.912

Cohesiveness 0.583 0.633 0.624

Chewiness (Nm) 1.28 1.43 1.53

*Average three trials

Adhesiveness also increased from initial value of -5.65 Ns on 0th day to -4.27

Ns, -4.78 Ns and -4.65 Ns for 100% N2, 100% CO2 and 50% N2 + 50% CO2 gas filled

packaging material samples respectively on 50th day.. The decline in the adhesion could

be due to the decrease in free moisture during storage. The adhesiveness of the lal peda

samples were found to be higher than that brown peda reported by Londhe et al., (2012)

[107]. The higher adhesiveness values could be attributed to the higher moisture content

in the lal peda. Springiness refers to a food ability to return to its original form after

compression. The Chhana jalebi samples in all trials showed an increasing trend in

springiness. Springiness of the product increased from initial value of 0.817 mm on 0th

day to 0.867 mm, 0.924 mm and 0.912 mm for 100% N2, 100% CO2 and 50% N2 + 50%

CO2 gas filled packaging material samples respectively on 50th day. It indicates that,

springiness was increased due to increase of activity of gluten content. Current findings

were in accordance with Palit (1998) [142]. Cohesiveness is the ratio of area under the

second bite curve before reversal compression to that under the first bite curve. It is the

measure of the extent to which the Chhana jalebi structure was disrupted during the first

compression.

Cohesiveness of the product increased from initial value of 0.53 on 0th day to

0.583, 0.633 and 0.624 for 100% N2, 100% CO2 and 50% N2 + 50% CO2 gas filled

packaging material samples respectively on 50th day (Table 5.54). However, the

157 cohesiveness of the MAP packed product remained fairly constant throughout the

storage. Londhe et al., (2012) [107] have been reported that cohesiveness of MAP

packed brown peda remained constant upto 20-30 days. Current findings are in

accordance with their observation. Loss in moisture content may be responsible for the

decrement in the cohesiveness with the progression of storage. Similar findings have

been reported by Gupta et al., (1990) [146] where cohesiveness of khoa tended to

decline with increasing the total solids.

Chewiness refers to the energy required to masticate food into a state ready for

swallowing and is a product of gumminess and springiness. Chewiness of the product

also increased from initial value of 0.57 Nm on 0th day to 1.28 Nm, 1.43 Nm and 1.53

Nm for 100% N2, 100% CO2 and 50% N2 + 50% CO2 gas filled packaging material

samples respectively on 50th day (Table 5.54). This increasing trend in chewiness in all

Channa jalebi samples during storage could be attributed to increase in gumminess and

springiness values. These findings are in agreement with the findings of Palit (1998)

[142] who observed that the gumminess and chewiness of burfi increase with the

progress of storage period irrespective to type of packaging. Patil et al., (2002) [138]

observed that soft burfi was significantly less gummy than hard burfi.

Based on textural characteristics ultimately it was revealed that, fresh sample of

final standardized Chhana jalebi was very suitable for consumption. Even after 50 days

or 60 days of storage, there was very small variation in all textural characteristics.

Hence it concluded that, final standardized Chhana jalebi was more suitable and

comfortable for human consumption.

5.7.4 Sensory characteristics of Chhana jalebi stored in MET with MAP and


There were four sensory characteristics such as color and appearance, flavor,

body and texture and overall acceptability analyses carried out and results are presented

as below.

i. Changes in color and appearance

The color and appearance scores of jalebi during storage as influenced by four

different gas flushing are presented in Table 5.55. The sensory scores showed a

decreasing trend during storage in all samples of Chhana jalebi irrespective of

158 packaging techniques. The mean score decreased from the initial value of 8.93 to 4.13

at the end of 60 days of storage at room temperature. All the gas flushed packed

samples scores in range between 7.22 and 7.55 at end of 40th day whereas color and

appearance score of the product was 6.50 until 50th day. After this, due to mold growth

and little dryness of the product, the color and appearance score turned in unacceptable.

This was determined by taking the minimum score of 6.5 as acceptable limit. The mean

scores were 8.93, 8.27, 7.36 and 4.13 respectively for samples packed in metalized

polyester filled with 100% N2, 100% CO2, 50% N2 and 50% CO2 and vacuum. Same

results were observed by other Researchers [107, 121].

Table 5.55 Changes in the color and appearance score* of Chhana jalebi control

samples packed in gas flushed metalized polyester packaging materials stored at


Packaging material


0 20 40 60 Avg. mean

Metalized polyester (100% N2) 8.94 8.25 7.45 4.22 7.22

Metalized polyester (100% CO2) 8.95 8.31 7.23 4.54 7.26

Metalized polyester (50% N2 + 50% CO2)

8.91 8.25 7.55 4.44 7.29

Metalized polyester (vacuum) 8.91 8.25 7.22 3.32 6.93

CD=0.44 8.93d 8.27c 7.36b 4.13a


P≤0.05

Statistical analysis results also showed highly significant effect of all packaging

techniques and storage period on all the sensory attributes of Chhana jalebi during

storage (P<0.05). The colour and appearance of the product was retained well up to 40

days of storage.

159

Table 5.56 Changes in the color and appearance score of 800 ppm potassium

sorbate treated Chhana jalebi samples packed in gas flushed metalized polyester

packaging materials stored at ambient temperature (28±2°C)

Packaging material


0 30 60 65 Avg. mean



Metalized polyester (50% N2 +50%CO2)

8.93 8.42 7.63 7.13 8.02


CD=0.81 8.93c 8.55c 7.11b 5.89a


The acceptability scores became lower because of dry appearance which could

be attributed to moisture evaporation from the product within the package. Also, the

product’s initial moist appearance disappeared during storage imparting slightly cloudy

appearance because of surface moisture evaporation and hydration of proteins. It is

known that protein hydration continues with storage time [149]. These scores were

statistically significant to all the gas filled and packed in metalized polyester packaging

material irrespective of storage period. It can be also observed from the Table 5.56 that

different gas flushing level had not significant. The ANOVA indicates the significant

effect of gas flushing and storage period and their interaction (P≤0.05). Same impacts

were observed in danedar khoa [132].

The changes observed in the sensory score of color and appearance for 800 ppm

potassium sorbate treated samples were packed in all four gas filled metalized polyester

packaging materials and stored at 28°C are represented in Table 5.56. At this storage

temperature and also the effect of storage period found to be significant and effect of

gas flushing and their interaction found to be not significant (P≤0.05). In that period

within which the color and appearance score remained 6.5 and above for all packaging

materials were 60 days. After 60th days, color and appearance turned unacceptable.

160 These may be attributed to the effect of packaging material on mold growth. Despite

decreasing trend the samples were found to score well over the minimum acceptable

limit during the entire storage study.


Like color and appearance, the rate of aroma and flavor deterioration was not

rapid in the sample of Chhana jalebi packed in metalized polyester with different gas

flushed. There was no significant (P>0.05) difference between all the combination of

gas filled and packed in metalized polyester packaging material whereas statistically

significant difference were observed on storage period. The mean scores of flavor were

8.94, 8.22, 7.28 and 4.38 for respectively for samples packed in metalized polyester

filled with 100% N2, 100% CO2, 50% N2 and 50% CO2 and vacuum. It indicated that the

all gas flushing packed samples shelf life was 40 days (Table 5.57).

Similarly, preservative treated samples which packed in all combinations of gas

filled and vacuum packed metalized polyester packed samples flavor score remained 6.5

and above for 60 days whereas the flavor score was turned unacceptable after 60 days.

The decrease in flavour scores may be attributed to slight loss of freshness, which is

inherent with any food product.

Table 5.57 Changes in the flavor score* of Chhana jalebi control samples packed

in gas flushed metalized polyester packaging materials stored at ambient


Packaging materialControl samples stored at 28±2°C (days)

0 20 40 60 Avg. mean



Metalized polyester (50% N2 + 50% CO2) 8.92 8.00 7.24 4.02 7.05


CD=0.20 8.94d 8.22c 7.28b 4.38a


161

Table 5.58 Changes in the flavor score* of 800 ppm potassium sorbate treated

Chhana jalebi samples packed in gas flushed metalized polyester packaging


Packaging material


Avg. mean

0 30 60 65

Metalized Polyester (100% N2) 8.95 8.42 7.69 5.45 7.63

Metalized Polyester (100% CO2) 8.97 8.87 7.75 4.58 7.54

Metalized Polyester (50% N2 + 50% CO2) 8.95 8.41 7.90 5.86 7.78

Metalized Polyester (vacuum) 8.94 8.65 7.39 4.25 7.31

CD=1.48 8.95c 8.59c 7.68b 5.04a


The findings of the present study are in accordance with the report of Biradar et

al., (1983) [130] and Sharma et al., (2001) [132] also reported the decrease in mean

flavour and body and texture scores of the control and MAP packaged malai peda

samples in flexible packaging material at room temperature. The reduction in flavour

and body and texture score for control (without MAP) was much rapid than MAP

samples. Similar observation was reported by Kumar (1997) [108]. The ANOVA

indicates the not significant effect of gas flushing in metalized polyester packaging

material, but significant effect on storage period and their interaction (P≤0.05) (Table

5.58).

iii. Changes in body and texture

Up to 45 days of storage the body and texture score of Chhana jalebi in all gas

filled metalized polyester packed samples remained unchanged and thereafter a

decreasing trend with further advancement of storage period was noticed in Table 5.59.

The mean value of body and texture scores decreased drastically from 8.89 to 4.28 up to

60 days of storage at 28±2°C. There was no significant (P>0.05) difference between gas

flushing in metalized polyester packaging material but significant difference on storage

period and their interaction.

162

Table 5.59 Changes in the body and texture score* of Chhana jalebi control



Packaging material


Avg. mean

0 20 40 60



Metalized polyester (50% N2and 50% CO2) 8.93 8.10 7.64 4.92 7.40


CD=0.36 8.89d 8.11c 7.26 b 4.28a


The changes in sensory score of body and texture of the preservative treated

samples which packed in all combinations of gas filled and vacuum filled metalized

polyester packing material, stored at 28°C are presented in Table 5.60. The mean score

of body and texture samples were 8.91 to 4.97 at the end of 65 days stored at 28°C. In

that period, within which the body and texture score remained 6.5 and above for all gas

filled and vacuum packed samples until 60 days of storage at 28±2°C. The product’s

initial moist appearance disappeared during storage imparting slightly cloudy

appearance due to surface moisture evaporation and hydration of proteins. It is known

that protein hydration continues with storage time [149]. This affected the body and

texture scores and became firm during storage attributable not only to loss of moisture,

however also to continued conformational changes of proteins [110]. The findings of

the present study are in accordance with the report of Londhe et al., (2012) [107] and

Biradar et al., (1985) [130]. Another study also reported the decrease in mean body and

texture scores of the control and MAP packaged malai peda samples in flexible

packaging material at room temperature. The reduction in body and texture score for

control (without MAP) was much rapid than MAP samples [132]. Similar observation

was reported by Kumar et al., (2008a) [121]. The ANOVA indicates that there was no

significant (P>0.05) difference between gas flushing in metalized polyester packaging

material but significant difference on storage period and their interaction.

163 Table 5.60 Changes in the body and texture score* of 800 ppm potassium sorbate

treated Chhana jalebi samples packed in gas flushed metalized polyester


Packaging material


Avg.

mean0 30 60 65



Metalized polyester (50% N2 + 50% CO2) 8.93 8.40 7.93 5.51 7.69


CD=1.16 8.91c 8.42c 7.17b 4.97a



The average overall acceptability scores for all gas filled and vacuum filled and

packed samples control and preservative treated sample are given in Table 5.61. A

decreasing trend with further advancement of storage period was noticed in Table 5.61.

The mean score of overall acceptability samples were 8.95 to 7.22 at the end of 40 days.

Later on, the mean scores of overall acceptability decreased drastically from 7.22 to

4.08 on 60 days of storage at 28±2°C. From Table 5.61, it indicates that the shelf life of

all gas flushed and packed in metalized polyester samples had 40 days. The effect of the

gas flushing and the interval of storage on overall acceptability of Chhana jalebi were

found significant (P>0.05).

The overall changes are reflected in changes in overall acceptance scores. These

gradually decreased and remained acceptable up to 40 days of storage at 28oC. The

scores were 7.21, 7.18, 7.34 and 7.14 respectively for 100% N2, 100% CO2, 50% N2 and

50% CO2 and vacuum packaging at the end of 40 days. After 40 days, the scores knock

down to unacceptable limit because of visible mold growth, dry appearance and rancid

flavor which could be attributed to chemical reactions.

164

Table 5.61 Changes in the overall acceptability score* of Chhana jalebi control



Packaging material

Control samples stored at 28±2°C(days)

Avg. mean0 20 40 60




8.95 8.56 7.34 4.18 7.26


CD=0.56 8.95d 8.37c 7.22b 4.08a


P≤0.05

Thus, the shelf life of the product could be ascertained as 40 days irrespective of

the type of gas used. The effect of the gas flushing and the interval of storage on overall

acceptability of Chhana jalebi were found significant (P<0.05). Despite decreasing trend

the samples were found to score well over the minimum acceptable limit (65% score of

the total score) during the 40 days of storage study in metalized polyester with various

gas flushing levels and vacuum packaging methods.

The changes in sensory score of overall acceptability of the preservative treated

samples which packed in all combinations of gas filled and vacuum filled metalized

polyester packing material, stored at 28°C are presented in Table 5.62. The mean score

of overall acceptability scores were 8.95 to 5.31 at the end of 65 days stored at 28°C. In

that period, within which the overall acceptabilty score remained 6.5 and above for all

gas filled and vacuum packed samples until 60 days of storage at 28±2°C. Same results

were observed other indigenous dairy products such as brown peda, burfi, khoa etc.,

[107, 113, 114, 120]. The MAP was found to enhance the sugar containing products.

Kumar et al., (1997) reported that peda packed under 80% N2 and 20% CO2 stayed well

up to 15 days at 37oC and 30 days at 20oC [108]. Malai peda shelf life was enhanced to

31 days at 11oC when packed under vacuum-nitrogen [143].

165

Table 5.62 Changes in the overall acceptability scores* of 800 ppm potassium

sorbate treated Chhana jalebi samples packed in gas flushed metalized polyester


Packaging material

Preservative added samples stored at 28±2°C Average

mean0 30 60 65




8.95 8.50 7.34 6.04 7.71


CD=1.31 8.95c 8.62c 7.07b 5.31a


Based on the study, it was concluded that Chhana jalebi samples packed in

100% N2, 100% CO2, 50% N2 with 50% CO2 and vacuum packaging in MET without

addition of preservative had shown 40 days shelf life at ambient temperatures (28±2°C)

whereas 800 ppm potassium sorbate treated samples had given 65 days. All four

packaging materials along with Chhana jalebi samples are shown in Figure 5.28-2.

5.8. EFFECT OF VACUUM PACKAGING ON SHELF LIFE OF CHHANA

JALEBI PACKED IN LOW AND HIGH BARRIER MATERIAL

Chhana jalebi samples were packed in low density polyethylene and metalized

polyester with different vacuum levels viz. 608 mm of Hg (80%), 646 mm of Hg (85%),

684 mm of Hg (90%), 723 mm of Hg (95%) and 750 mm of Hg (100%). Settings of

heating time were 1.5 and 2 sec for metalized polyester and LDPE respectively and

cooling time for both samples were 9 sec. Chhana jalebi samples were observed that

compressed appearance, ruptured the coils, oozed out the sugar syrup at all the level of

treatment after opened whereas, very slow microbial growth, less increase of acidity and

peroxide values were observed for the same samples (Figure 5.28-3). Same results were

observed for other dairy products such as brown peda [107], lal peda [150] etc., in

microbial growth, acidity and peroxide value. Several earlier Researchers also reported

166 the similar trends for different dairy products during their storage studies. Goyal and

Srinivasan (1989a) [112], Kumar and Srinivasan (1983) [120] and Sharma et al., (2001)

[132] reported in khoa. Similarly, Palit and Pal (2014) [105], Sachdeva and rajorhia

(1982) [140] in burfi, whereas Kumar et al., (1997) [108], and Sharma et al., (2001)

[132], in peda and Navajeevan and Rao (2005) [110] in retort processed kunda.

Interesting fact is that, all these Researchers have found vacuum packaging was one of

the best suited packaging techniques for their products since those products nature was

dried and solid, whereas, nature of jalebi was different from other mentioned dairy

products since it was fried in oil and soaked in sugar syrup. Hence, it was experiential

that, vacuum packaging was not suitable for commercialization due to loss of desirable

appearance, body and texture and oozing out of sugar syrup though product retaining

good internal characteristics such as slow microbial growth, less increase of acidity and

peroxide value.

167

Figure 5.28 Different packaging techniques for Chhana jalebi storage

1. Modified atmospheric packaging in low density polyethylene 2. Modified atmospheric packaging in metalized polyester 3. Vacuum packaging technique

1

2

3

168 5.9 CONSOLIDATED SHELF LIFE OF CHANNA JALEBI IN VARIOUS

PACKAGING MATERIALS AND TECHNIQUES

Based on the study, it was reported that 800 ppm of potassium sorbate

preservative treated and packed in metalized polyester packaging material with all the

gas flushed samples was acceptable for storage at both ambient and refrigerated

temperatures. Table 5.63 represented shelf life of all packaging materials with different

conditions.

Table 5.63 Shelf life of all packaging materials for control and 800 ppm potassium sorbate treated Chhana jalebi stored at both ambient (28 ±2°C) and refrigerated

temperatures (4 ±2°C)

Packaging materials

Ambient temperature(28 ±2°C)

Refrigerated temperature (4±2°C)

Control(days)

800 ppm Potassium sorbate(days)

Control(days)

800 ppm Potassium sorbate(days)

LDPE pouch 4 20 15 60

Metalized polyester 4 20 15 60

Polystyrene cups 4 20 15 60

Cardboard box lined with butter paper 4 20 15 60

LDPE (100% N2) 30 40 - -

LDPE (100% CO2) 30 40 - -

LDPE (50% N2 + 50% CO2) 30 40 - -

LDPE (vacuum) 30 40 - -

Metalized polyester (100% N2) 40 60 - -

Metalized polyester (100% CO2) 40 60 - -

Metalized polyester (50% N2 + 50% CO2) 40 60 - -

Metalized polyester (vacuum) 40 60 - -

Based on the chemical and microbial analyses, metalized polyester with 50% N2

and 50% CO2 was found as more suitable for packing Chhana jalebi samples to store at

ambient temperature.

169 5.10 COST ANALYSIS OF STANDARDIZED CHHANA JALEBI

Cost of Chhana jalebi was calculated based on the cost of all the ingredients used

for making and the processing cost which is 30% of ingredient cost. Along with that

packaging material cost was also included. After preparing Chhana jalebi it was packed

in polystyrene cups, cardboard box, metalized polyester pouch and LDPE pouches. In

polystyrene cups/cardboard box/metalized polyester/LDPE pouches 3-4 pieces of

Chhana jalebi of 20g weight was considered for packaging (Table 5.64).

Table 5.64 Cost analysis for standardized product packed in gas flushed metalized

polyester packaging material

Ingredients Quantity Cost per unit (Rs.)

Total cost (Rs.)

Milk (3% fat) for 3 kg Chhana yield 18 liters 26.00 468.00Maida 3 kg 40.00 120.00

Corn flour 0.5 kg 90.00 45.00Sugar 15 kg 35.00 525.00

Water 20 liters 0.30 6.00Refined oil 4 liters 88.00 176.00*

Cardamom 0.009 kg 750.00 6.75Preservative 0.1384 kg 1728 239.16

Citric acid 0.02 kg 360 7.20Total raw material cost 1593.11

Processing (30% of ingredient cost) 477.93

Packaging cost in cardboard box / polystyrene cup / LDPE pouch / metalized polyester for 1000 pieces (1000 × 0.60) 600.00

Total cost of production for 1000 pieces including packaging cost 2671.04

*same oil can be used for frying, partial oil price (50%) was considered

Cost of production per piece of Chhana jalebi (2671.04/1000) = Rs. 2. 67 (approx.)

Weight per piece of Chhana jalebi = 5 g

Total number of Chhana jalebi in 1 kg (1000 / 5) = 200 Nos.

Cost of production of Chhana jalebi per kg (200 x 2.67) = Rs. 534 /-

chapter 5 results and discussion -...

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