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THESIS

EFFECT OF DIFFERENT RICE BRAN CONCENTRATIONS

AND BAKING TIME ON THE CONSUMER PREFERENCES

AND PHYSICO-CHEMICAL CHARACTERISTICS OF

GLUTEN FREE – RICE BRAN BROWNIES

Written as partial fulfillment of the academic requirementsto obtain the degree of Sarjana Teknologi Pertanian Strata Satu

By :NAME : MERRYO SETYAWAN NPM : 03420080102

FOOD TECHNOLOGY DEPARTMENTFACULTY OF INDUSTRIAL TECHNOLOGY

UNIVERSITAS PELITA HARAPANKARAWACI

2012

STATEMENT OF THESIS AUTHENTICITY

I, a student of Food Technology Department, Faculty of Industrial Technology, Universitas Pelita Harapan,

Name : Merryo SetyawanStudent Id. Number : 03420080102Department : Food Technology

Hereby declare that my thesis, entitled “EFFECT OF DIFFERENT

RICE BRAN CONCENTRATIONS AND BAKING TIME ON THE

CONSUMER PREFERENCES AND PHYSICO-CHEMICAL

CHARACTERISTICS OF GLUTEN FREE – RICE BRAN BROWNIES” is:

1) An original piece of work, written and completed on my own, based on

lecture notes, data observation, reference books, journals, and other

sources as listed on the work cited section.

2) Not a duplication of other writing that has been published or used for

obtaining the degree of Sarjana in other Universities, except for passages

that include information on respective references.

3) Not a translation of other works from books or journals, which are listed

on the work cited section.

I understand that if my statement above is proven untrue, this Thesis will be

canceled.

Karawaci, June 15th, 2012

(Merryo Setyawan)

Materai Rp

UNIVERSITAS PELITA HARAPANFACULTY OF INDUSTRIAL TECHNOLOGY

APPROVAL BY THESIS SUPERVISORS

EFFECT OF DIFFERENT RICE BRAN CONCENTRATIONS AND BAKING TIME ON THE CONSUMER PREFERENCES AND PHYSICO-

CHEMICAL CHARACTERISTICS OF GLUTEN FREE – RICE BRAN BROWNIES

Written By :Name : Merryo SetyawanStudent Id. Number : 03420080102Department : Food Technology

has been approved to be examined for obtaining the degree of Sarjana Teknologi Pertanian Strata Satu in the Food Technology Department, Faculty of Industrial Technology, Universitas Pelita Harapan Karawaci – Tangerang, Banten.

Karawaci, June 15th, 2012

Approved by:

Supervisor Co-Supervisor

(Dr. Ir. Raffi Paramawati, M.Si) (Natania, M. Eng )

Acknowledged by,

Head of Food Technology Department

(Nuri Arum Anugrahati, MP)

UNIVERSITAS PELITA HARAPAN FACULTY OF INDUSTRIAL TECHNOLOGY

APPROVAL BY THESIS EXAMINATION COMMITTEE

We the undersigned, certify that a thesis defense has been held on February 10th, 2012, as partial fulfillment of the academic requirement to obtain the degree of Sarjana Teknologi Pertanian Strata Satu in the Food Technology Department, Faculty of Industrial Technology, Universitas Pelita Harapan, for the student:

Name : Merryo Setyawan

Student Id. Number : 03420080102

Department : Food Technology

Faculty : Industrial Technology

With the following title “EFFECT OF DIFFERENT RICE BRAN

CONCENTRATIONS AND BAKING TIME ON THE CONSUMER

PREFERENCES AND PHYSICO-CHEMICAL CHARACTERISTICS OF

GLUTEN FREE – RICE BRAN BROWNIES”, and that the thesis has been approved by the examination committee.

Examiners Signature1. Head of Examiners2. Member 3. Member

ABSTRACT

Merryo Setyawan (03420080102)

EFFECT OF DIFFERENT RICE BRAN CONCENTRATIONS AND BAKING TIME ON THE CONSUMER PREFERENCES AND PHYSICO-CHEMICAL CHARACTERISTICS OF GLUTEN FREE – RICE BRAN BROWNIES

Rice bran is by product of rice milling categorized as a food source which contains good source of dietary fiber and other nutritions components. However, the utilization of rice bran in Indonesia is very limited, on the other hand, Indonesian people lack of dietary fiber consumption in their daily diets. Food product which is made from wheat flour contains gluten that is restricted in the diet of patient with celiac disease. Hence, replacing the use of wheat flour in the production of brownies with gluten free food sources such as cassava flour, rice flour and potato flour with rice bran substitution is expected to overcome the problem above. The general objective of this research is to study the utilization of rice bran in the making of gluten free rice bran brownies. The preliminary research was conducted with by incorporating different types of flour (cassava flour, rice flour, potato flour). From the preliminary research the rice bran brownies made from cassava flour was not significant different with rice bran brownies made from wheat flour in term of overall acceptance. The main research was conducted with two factors, which is rice bran concentration (0,10,20,30 and 40%), and baking time (35,45, and 55 minutes). The analysis that was done was the sensory analysis and phsyico – chemical analysis regarding hardness, moisture content and water activity. From the main research, the rice bran brownies which obtained the highest value of overall acceptance was the rice bran brownies made using 30% rice bran and 55 minutes baking time. Therefore, it was selected as the best formulation. The dietary fiber content of the best rice bran brownies formulation was 7.99%, and it was categorized as high fiber food because it fulfilled more than 20% RDA of dietary fiber.

Keywords: Rice Bran, Gluten Free, BrowniesReferences: 45(1991 – 2012)

ACKNOWLEDGMENT

This thesis was written as one of requirements to obtain the degree in Sarjana

Strata Satu Teknologi Pangan. The title of this thesis is “EFFECT OF

DIFFERENT RICE BRAN CONCENTRATIONS AND BAKING TIME ON

THE CONSUMER PREFERENCES AND PHYSICO-CHEMICAL

CHARACTERISTICS OF GLUTEN FREE – RICE BRAN BROWNIES”.

The writer should express his greatest gratitude to God, because of His

blessing this thesis could be finished on time. This thesis would not be completed

on time without the help and support from many people. The writer wants to

express his gratitude to :

1) Dr. Ir. Raffi Paramawati, M.Si as the thesis supervisor who gave her time,

efforts and patience to guide, help, and support the writer during the

completion of this thesis.

2) Mrs. Natania, M. Eng as the thesis co-supervisor who has given her greatest

help, support, and guidance for the writer for the completion of this thesis.

3) Mrs. Nuri Arum Anugrahati, MP as the Head of Food Technology

Department, Universitas Pelita Harapan who has given the chance for this

research to be done.

4) Mr. Jeremia Manuel Halim, Ms. Ratna Handayani, and Mrs. Sisi Patricia who

have given the opportunity for the writer to conduct the research in the

laboratories.

i

5) My father (Johnny), mother (Liliany) and sister (Merrvina) for the support

and prayer during the research and during the writing of this thesis until the

completion.

6) Mr. Rudi, Mr. Hendra and Donny who have given their best helps and

supports for the writer during the work in the laboratories.

7) All of my friends in Food Technology Department of Universitas Pelita

Harapan.

8) People who cannot be mentioned one by one.

The writer realizes that this thesis is far from perfect, so the writer

welcomes to every comments and suggestions that can help the writer to improve

report writing in the future. The writer hopes this paper would give useful

information to the people who read it.

Karawaci, 15 June 2012

Writer

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TABLE OF CONTENTS

PageCOVER

APPROVAL BY THESIS SUPERVISOR

APPROVAL BY THESIS EXAMINATION COMMITTEE

ABSTRAC

T

ACKNOWLEDGMENT........................................................................................i

TABLE OF CONTENTS.....................................................................................iii

LIST OF TABLES...............................................................................................vii

LIST OF FIGURES............................................................................................viii

LIST OF APPENDICES......................................................................................ix

CHAPTER I INTRODUCTION

1.1 Background........................................................................................................1

1.2 Research Problem..............................................................................................3

1.3 Objectives...........................................................................................................3

1.3.1 General Objectives................................................................................3

1.3.2 Specific Objectives................................................................................3

CHAPTER II LITERATURE REVIEW

2.1 Rice Bran............................................................................................................4

2.1.1 Qualities of Rice Bran...........................................................................4

2.1.2 Deterioration of Rice Bran Qualities.....................................................5

2.1.3 Utilization of Rice Bran.........................................................................7

iii

2.1.4 Rice Bran Nutritional Value..................................................................8

2.2 Dietary Fiber....................................................................................................10

2.3 Brownies..........................................................................................................12

2.3.1 Eggs.....................................................................................................12

2.3.2 Wheat Flour.........................................................................................13

2.3.3 Sugar....................................................................................................14

2.3.4 Fat........................................................................................................14

2.4 Brownies Processing........................................................................................15

2.5 Potato Flour......................................................................................................16

2.6 Rice Flour.........................................................................................................16

2.7 Cassava Flour...................................................................................................17

CHAPTER III RESEARCH METHODOLOGY

3.1 Materials and Equipments................................................................................18

3.1.1 Materials..............................................................................................18

3.1.2 Equipments..........................................................................................18

3.2 Research Procedure..........................................................................................19

3.2.1 Preliminary Research...........................................................................19

3.2.2 Main Research.....................................................................................19

3.3 Experimental Design........................................................................................22

3.3.1 Preliminary Research...........................................................................22

3.3.2 Main Research.....................................................................................23

3.4 Analysis Procedure..........................................................................................25

3.4.1 Sensory Qualities.................................................................................26

3.4.2 Physical Characteristic........................................................................26

3.4.3 Chemical Characteristic.......................................................................26

iv

3.4.4 Proximate Analyses for the best gluten free - high dietary fiber

brownies formulation....................................................................................26

CHAPTER IV RESULTS AND DISCCUSIONS

4.1 Result of Preliminary Research........................................................................28

4.1.1 Sensory Analysis................................................................................28

4.1.1.1 Aroma................................................................................................29

4.1.1.2 Taste..................................................................................................31

4.1.1.3 Texture...............................................................................................33

4.1.1.4 Overall Acceptance...........................................................................34

4.1.2 Physical and Chemical Analysis..........................................................36

4.1.2.1 Texture...............................................................................................36

4.1.2.2 Moisture Content...............................................................................38

4.1.2.3 Water Activity...................................................................................40

4.1.3 Determination of the Best Gluten Free Flour in the Making of Rice

Bran Brownies..............................................................................................42

4.2 Main Research..................................................................................................42

4.2.1 Sensory Analysis.................................................................................43

4.2.1.1 Aroma................................................................................................44

4.2.1.2 Taste..................................................................................................47

4.2.1.3 Texture...............................................................................................50

4.2.1.4 Overall...............................................................................................53

4.2.2 Physical Analysis.................................................................................57

4.2.2.1 Texture...............................................................................................57

4.2.2.2 Moisture Content...............................................................................59

4.2.2.3 Water Activity...................................................................................62

4.3 Proximate Analysis of Rice Bran Flour...........................................................65

4.4 Determination of the Best Gluten Free Rice Bran Brownies Formulation......66

CHAPTER V CONCLUSIONS AND SUGGESTIONS

v

5.1 Conclusion.......................................................................................................68

5.2 Suggestion........................................................................................................69

BIBLIOGRAPHY................................................................................................70

vi

LIST OF TABLES

Table 2.1 Chemical Composition of Rice Bran................................................10

Table 2.2 Rice Bran Fatty Acid Composition..................................................11

Table 3.1 Rice Bran Brownies Formulation.....................................................20

Table 3.2 Formula Modification.......................................................................21

Table 3.3 Combination of Factors....................................................................25

Table 4.1 Interaction of Rice Bran Concentration and Baking Time towards Aroma Parameter .............................................................................................48

Table 4.2 Interaction of Rice Bran Concentration and Baking Time towards Texture Parameter ............................................................................................54

Table 4.3 Interaction of Rice Bran Concentration and Baking Time towards Texture Parameter ............................................................................................57

Table 4.4 Proximate Composition of Rice Bran Flour.....................................66

Table 4.5 Proximate Composition of The Best Formulation............................67

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LIST OF FIGURES

Figures 3.1 Flowchart of main research.........................................................22

Figure 4.1 Preference of Aroma by Panelists.................................................30

Figure 4.2 Preference of Taste by Panelists...................................................32

Figure 4.3 Preference of Texture by Panelists...............................................34

Figure 4.4 Preference of Overall Acceptance by Panelists............................36

Figure 4.5 Hardness Parameter of Rice Bran Brownies.................................37

Figure 4.6 Moisture Content of Rice Bran Brownies ....................................39

Figure 4.7 Water Activity of Rice Bran Brownies.........................................41

Figure 4.8 Effect of Rice Bran Concentration Towards Aroma Parameter. . .45

Figure 4.9 Effect of Baking Time Towards Aroma Parameter......................46

Figure 4.10 Effect of Rice Bran Concentrations Towards Taste Parameter. .49

Figure 4.11 Effect of Baking Time Towards Taste Parameter.......................50

Figure 4.12 Effect of Rice Bran Concentration Towards Texture Parameter

........................................................................................................................51

Figure 4.13 Effect of Baking Time Towards Texture Parameter ..................53

Figure 4.14 Effect of Rice Bran Concentration Towards Overall Parameter

........................................................................................................................55

Figure 4.15 Effect of Baking Time Towards Overall Parameter...................56

Figure 4.16 Effect of Rice Bran Concentration Towards Hardness Parameter

........................................................................................................................58

Figure 4.17 Effect of Baking Time Towards Hardness Parameter ...............59

Figure 4.18 Effect of Rice Bran Concentration Towards Moisture Content

........................................................................................................................61

Figure 4.19 Effect of Baking Time Towards Moisture Content....................62

viii

Figure 4.20 Effect of Rice Bran Concentration Towards Water Activity

........................................................................................................................64

Figure 4.21 Effect of Baking Time Towards Water Activity.........................65

ix

LIST OF APPENDICES

x

CHAPTER 1

INTRODUCTION

1.1 Background

Agriculture is the biggest business in Indonesia, especially the

production of rice which is also staple food for Indonesian people. The

production, processing and distribution of rice become one of the most important

agricultural business in Indonesia which support the national food security. In

2011 the production of rice in Indonesia reaching the amount of 65.39 millions

tons (Badan Pusat Statistik, 2011).

The production of rice bran is proportional with the production of rice,

because rice bran is by product from the milling process of paddy into rice. In the

production process of rice, about 8 – 12 % of rice bran is produced from the

paddy milling process (Widowati,2001). Indonesia produce a large amount of

rice, hence Indonesia also produce a large amount of rice bran. However, rice bran

usually only used as a feed for poultry or cow, although actually rice bran has a

potential value to be processed in food for human and has many benefits towards

human health (Alvita et al,2007).

Rice bran contains very rich in valuable nutrition. Rice bran rich in B

complex vitamins which includes B1,B2,B3,B5,B6 and B12 vitamins. It also rich

in vitamin E, essential fatty acid, dietary fibers and proteins. In the stabilized rice

bran about 20 - 27 % of dietary fibers can be found (Yu et al, 2012). The other

benefits from rice bran is that rice bran is free from gluten, easy to digest and rich 1

in complex carbohydrate. These benefits from rice bran can be utilized in the food

processing. Because of the nutritious value in rice bran, nowadays rice bran has

been applied in the food processing for some food products. Rice bran can be used

as the substitute of wheat flour in the processing of food product like bread as

studied by Hu et al (2009) or cookies as studied by Fauziyah (2011). The

substitution of rice bran can increase the dietary fiber content in a food product

such as frozen pizza whose the research was conducted by Delahaye (2005).

Based on study done by Huang et al (2005), rice bran can be added to pork

meatballs with concentration up to 10% that will produce meatballs which is still

accepted by the panelist.

Coeliac diseases is a life long intolerance to gluten proteins. A decade

ago, coeliac disease has a rate of 1 in 1000 or lower population and only

considered as an uncommon disorder, however nowadays the rates of coeliac

disease increase and study shown that it may affect 1 in 100 population, To avoid

the symptomps of coeliac disease, the only effective method is strict adherence to

the diet free of the allergence, which is gluten based product that are toxic to the

small intestine (Korus, 2008).

Therefore in this research, we want to substitute the use of wheat flour

in brownies with several substitutes for wheat flour, such as cassava flour, potato

starch, or rice flour, in order to accomodate a gluten sensitive people. The best

formulation will be later enriched with rice bran flour. Substitution of rice bran

flour is expected to increase the amount of dietary fibers in the brownies.

2

1.2 Research Problem

Rice bran that contains good source of dietary fiber and othe nutritions

components has very limited usage in Indonesia. People like to produce bread or

cookies that made from wheat flour, although wheat contain gluten that prohibited

in the diet of coeliac diseases patient. On the other hand, Indonesian people lack

of dietary fiber in their daily diets. Hence, replacing the use of wheat flour in

brownies making with other sources such as cassava flour, rice flour and potato

flour with rice bran substitution is expected to overcome the problem above.

1.3 Objectives

1.3.1 General Objectives

The general objectives of this research is to study the utilization of rice

bran in the making of gluten free rice bran brownies.

1.3.2 Specific Objectives

The specific objectives of this research is to :

1. Determine the best wheat flour substitute in the making of gluten free rice bran

brownies based on the consumer acceptance using the sensory evaluation test.

2. Evaluate the effect of rice bran concentration and different baking time on the

physical and chemical characteristics of gluten free rice bran brownies.

3. Observe the consumer preferences by utilizing sensory evaluation method.

4. Determine the dietary fiber and nutritional composition in the best gluten free

rice bran brownies formula.3

CHAPTER 2

LITERATURE REVIEW4

2.1 Rice Bran

The source of rice bran is from the rice milling process, which are the

conversion of brown rice to white rice. After paddy is harvested, then the paddy

undergo drying process. After the paddy has been dried, then the hull of the paddy

need to be removed by the milling process. After the hull is being removed by the

milling process, the resulted product is called brown rice. The brown rice has the

outer layer that need to be removed. The removal process is done by the process

called abrasive milling. The resulted product is called white rice which most

people commonly know as rice. The rice bran, is the side product which produced

from the separation of the brown layer in the brown rice. (Choo et al, 1999).

According to Hu et al (2009), Rice bran is a by product which is

produced from the outer layer of rice. Rice bran is considered as a good source of

nutrients such as protein, mineral and fatty acids. Rica bran is also rich in dietary

fiber content. Although rich in nutrients, the utilization of rice bran is very

minimal. Rice bran is mostly burnt off at the rice milling facilities and also used

as animal feeds.

2.1.1 Qualities of Rice Bran

During the application of rice bran in the food products, rice bran may

produce a mild sweet and bitter taste. Rice bran may produce the bitter taste

because rice bran contain saponin compound which can produce the bitter taste.

The sweet taste in rice bran is produces by the sugar content in the rice bran

including glucose, sucrose and fructose. Besides flavor, color is one of the most 5

important consideration when applying rice bran to the food products. Rice bran

has important functional properties in terms of color which are the change in color

during the processing. The rice bran color can be changed during the processing

because of the heat treatment and increase of the moisture content in the food

product. This will affect the end result of the food product. Rice bran also has the

ability to absorp water and oil, and can be used as emulsifier. Rice bran also has

low foaming ability (Luh, 1980).

2.1.2 Deterioration of Rice Bran Qualities

According to Choo et al (1999), the bran containing lipid and lipase,

which make rice bran is prone to rapid degradation of lipid because of the lipase

activity toward the lipid. The contact between the lipid and lipase in the bran is

occur during the milling process of the brown rice. This lipid degradation will

cause the rice bran become unpalatable and so the rice bran cannot be utilized for

human and only utilized for animal feed.

According to the Shahidi (2005), Most lipids in rice bran consists as

lysophospholipids, triacylglycerols and free fatty acids. The nonstarch lipids in the

aleurone, sub aleurone, and germ layers were 86 – 91 % neutral lipids, 2 – 5 %

glycolipids, and 7 – 9 % phospholipids. These percentage amounts of lipids are

different and affected by the milling degrees. The instability of rice bran is

affected by the lipase enzymatic activity. When the kernel of the rice bran is

intact, lipase is physically isolated from the lipids. However, when dehulling

process is done, it will disturb the surface structure and the lipase and oil will be

6

mixed together. As the result, the oil in rice bran will be hydrolyzed by lipase

enzyme into glycerol and free fatty acid.

Rice bran stabilization is essentially needed to inactivate lipase and

lipoxygenase activity, sterilize the bran and reduce color development.

Lipoxygenase activity will increases with the presence of FFA resulting in

oxidative rancidity which is responsible for the flavor and odor rancid of the rice

bran. There are many methods of rice bran stabilization. These methods include

dry heating method, wet heating method, and extrusion methods (Shahadi, 2005).

According to Choo et al. (1999) the activity of lipase in the rice bran

can be destroyed by applying short term high temperature treatment to the rice

bran, and the thermal process will produce stabilized rice bran. The application of

heat will destruct peroxidases as well, as stated by Silva (2006). In dry heating

methods, the rice bran is dried using hot air and this drying process will reduce the

moisture content of the rice bran to 3 – 4 %. The rice bran must be kept in dry

condition, moisture proof containers could be used to maintain the dryness of the

rice bran, because rehydration of the rice bran bran will cause it regains its lipase

activity (Shahidi, 2005). Silva (2006) also mentioned several other methods for

rice bran stabilization such as chemical stabilization and stabilization by

microwave.

2.1.3 Utilization of Rice Bran

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As an agricultural crop by products, rice bran utilization are now

widely increase, research has done to utilize their pharmaceutical or nutraceutical

potencial. Rice bran contains good source of antioxidants including vitamin and

oryzanol, high quality oil and protein, and cholesterol lowering waxes and anti

tumor compounds like rice bran saccharide. In a study on tumor prevention and

suppresion of tumor growth in rats, riced bran saccharides was found to suppress

carcinogenesis and to prolong survival rate (Rebecca et al, 2007).

Study also show that when rice bran is added to the prudent diets of

moderately hyperlipidemic individuals, will produces significant reduction in

trygliceride levels and improvement in the HDL ratio. The study shown that rice

bran has some insoluble fiber including cellulose and hemicellulose which can

bind to bile acids (Takakori et al, 2005). Rice bran also utilzed to produce food

which is rich in dietary fiber, because rice bran has large amount of dietary fiber

content (Chotimarkorn and Silalai, 2008). Rice bran has been processed into

several products. There is rice bran beverage which is produced by using rice bran

extract and added strawberry and cocoa flavor (Faccin et al,2009). There is also

pizza which is enriched by using rice bran as studied by Delahaye et al (2005),

Bunde et al (2010) also studied the supplementation of biscuit using rice bran

powder. Chortimarkorm et al (2007) also study the utilization of rice bran powder

to prevent the oxidative reaction of fried dough from riced flour during storage.

The other food products that has been utilizing rice bran are rice bran sponge cake

which was studied by Aftasari (2003) and utilization of rice bran oil in the

processing of red bean paste which was studied by Metta (2003). The rice bran

8

also utilized to produce a low fat frankfurter, which has reduced fat content,

reduced cholesterol and trans fat value (Choi et al, 2010).

2.1.4 Rice Bran Nutritional Value

Rice bran is rich in nutritional value, it contains 12 – 25 % fat, 10 –

16% protein, 10 – 20% starch, 3 – 8% reducing sugars, 8 – 11% hemicelluloses,

10 – 12% celluloses, 6 – 15% crude fiber and 6.5 – 10% ash content. Rice bran is

abundant in vitamins of the B group and tocopherols, although it is poor in

vitamins A and C (Sharma, 2004).

Rice bran is also source of antioxidant, one of the natural antioxidant

found in the rice bran is gamma oryzanol. Gamma oryzanol is a group of ferulic

acid esters of phytosterols and triterpene alcohols which has been reported to

exhibit antioxidant activity and has other health beneficial properties. Gamma

oryzanol exists mainly in bran layers and therefore it is also found in extracted

rice bran oil.Gamma oryzanol has potential in lowering blood cholesterol (Cicero

and Gaddi, 2001).

The component in rice bran which has the highest antioxidant activity

is 24-methylenecycloartanyl ferulate. It had activities higher than any of the

components in vitamin E. The quantity of oryzanol is up to 10 times higher

compared to the quantity of vitamin E in the rice bran. The oryzanol is the most

important bioactive compound of rice bran and has the ability to reduce

cholesterol oxidation. Because of the antioxidant activity of these components in

rice bran, rice bran has potential hypocholesterolemic property (Xu et al, 2001).

9

Rice bran also contains carbohydrate, mostly in the form of cellulose,

hemicelullose and starch. The endosperm of rice bran is rich in starch. Naturally,

the starch is not present in the outer layer of the bran. But during the milling

process, the outer layer (pericarp) will be released. The endosperm will be broken

down during the abrasion process and causing the starch to be released and

developed in the bran. The starch content in the bran is affected by the degree of

milling which determine the amount of breakage (Hargrove, 1994). The chemical

composition of rice bran could be seen in Table 2.1.

Table 2.1 Chemical Composition of Rice BranComponent AmountProtein (%) 12 – 15.6Fat (%) 15 – 19.7Crude Fiber (%) 7 – 11.4Carbohydrate (%) 34.1 – 52.3Ash (%) 6.6 – 9.9Calcium (mg/g) 0.3 – 1.2Magnesium (mg/g) 5.0 – 13.0Phosphor (mg/g) 11.0 – 25.0 Silica (mg/g) 5.0 – 11.0Zinc (mg/g) 43.0 – 258.0Thiamin (µg/g) 12.0 – 24.0Riboflavin (µg/g) 1.8 – 4.0Tocopherol (µg/g) 149 – 154Source : Luh et al, 1991

The protein in the rice bran is rich in nutrient compared to the milled

rice, the majority of protein in rice bran is lysine. Most protein in rice bran exists

in the form of albumin and globulin with the ratio of albumin-globulin-prolamin-

glutelin is 37 : 36 : 5 : 33 (Champagne, 2008). Rice bran is also rich in fatty acid,

especially unsaturated fatty acid which is about 80 %. The palmitic acid, oleic

acid and linoleic acid is the main fatty acid component which contained in the rice

bran oil (Gibson, 2009).

10

Table 2.2 Rice Bran Fatty Acid compositionType of Fatty Acid %Myristic Acid 0.2Palmitic Acid 15.0Stearic Acid 1.9Oleic Acid 42.5Linoleic Acid 39.1Linolenic Acid 1.1Arachidonic Acid 0.5Behenic Acid 0.2Source : McCaskill and Zhang, 1999

Rice bran also has an antinutrient compound, which is phytic acid,

anti – trypsin and hemaglutinin or lectin (Luh, 1991). These anti nutrient

compounds exist in a low amount in the rice bran and can be inactivated by heat

treatment as stated by Hargrove (1994). There are several enzymes which are

contained in rice bran such as α amylase, β amylase, catalase, peroxidase,

esterase, lipase, α glucosidase, β glucosidase, maltase, pectinase, phytase,

poliphenoloxidase, and so on. The enzymatic activity in the germs and the outer

layer of the paddy is higher compared to the other part of the paddy. This higher

activity of the enzyme in the outer layer causing rice bran also have high activity

of the enzyme (Luh, 1991).

2.2 Dietary Fiber

Dietary fiber is a class of compounds which includes a mixture of

plant carbohydrate polymers, both oligosaccharides and polysaccharides, such as

cellulose, hemicelluloses, pectic substances, gums, resistant starch, inulin, it could

be associated with lignin and other non-carbohydrate components such as

polyphenols, waxes, saponins, cutin, phytates, and resistant protein. Resistant

starch and resistant protein withstand digestion in the small intestine. Resistant

starch is composed of four groups, which are RS1 as the physical inaccessible

11

starch, RS2 as the ungelatinised starch granules, RS3 as the retrograded starch and

RS4 as the chemically modified starch as stated by FuentesZaragozaet al (2010).

As stated by Turowski (2007), dietary fiber could be divided into two categories

which are soluble dietary fiber and insoluble dietary fiber. These two categories

are distinguished by their solubility in water.

There are many health benefits which associated with an increased

intake of dietary fiber. The health benefits including the reduced risk of coronary

heart disease, diabetes, obesity, and some forms of cancer. Some food commodity

which are rich in dietary fiber such as oat bran, barley bran, and psyllium,mostly

soluble fibre, have earned a healthy reputation for their ability to lower blood lipid

levels. Wheat bran and other more insoluble fibres are typically linked to laxative

properties (American Dietetic Association, 2008). Dietary fiber supplementation

can result in fitness-promoting foods, low in calories, cholesterol and fat. Food

and Nutrition Board, Institute of Medicine (2001) recommend the average daily

requirement of dietary fiber is 25 g per day for women younger than 50, 21 g per

day for women older than 50; 38 g per day for men younger than 50, and 30 g per

day for men older than 50. Most nutritionists and diet experts suggest that 20–

30% of human daily dietary fiber intake should come from soluble fiber.

Dietary fiber also have effects toward functional properties of foods

such as increase water holding capacity, oil holding capacity, emulsification

and/or gel formation. When dietary fiber incorporated into food products (bakery

products, dairy, jams, meats, soups) it can modify the textural properties, avoid

synaeresis (the separation of liquid from a gel caused by contraction), stabilise

high fat food and emulsions, and improve shelf-life (Elleuch et al, 2011).12

2.3 Brownies

Brownies is a type of cookies which is usually has dark brown colour.

Brownies is classified as bar cookies. Bar cookies is the simplest type of cookies

to made, the process is spreading the batter in a pan and bake it. Basically, cookies

are made from a batter or dough that may be similar to some types of cake batter

(Suas, 2008).

There are two types of brownies which are steamed brownies and

baked brownies. Similar with cake, brownies has specific structure which are

slightly porous and has soft texture. But different with cake, brownies structure is

more compact compared to cake and does not leaven as in the processing of cake.

The main ingredients of brownies is eggs, fat, sugar, and wheat flour (Sulistyo,

2006). Brownies also can be categorized as fudgy brownies or cakey brownies, for

fudgy brownies, less flour is used during the processing, for cakey brownies, more

flour is used during the processing (Corriher, 2008). Because brownies is a type of

cookies, it can be produced using wheat flour that have relativele weak gluten

strength. In general cookies processing, the gluten development is very low.

Minimum gluten formation is contribute in the crispness and softness of the

cookies product, such as brownies (Hui,2006).

2.3.1 Eggs

Eggs have five major components which is the yolk, albumen, shell

membranes, air cell and shell. Eggs, and especially the egg white are composed of

dozens of different proteins. Each of these proteins has its own characteristics and

functions (Brown, 2008).

13

In the brownies processing, the function of eggs is as the substitute of water, to

form the brownies structure, contribute to the softness of the brownies structure,

aeration and to distribute the dough. The eggs also contribute to the color, aroma

and the flavour of the brownies.

2.3.2 Wheat Flour

Wheat is the seed of a grass like plant which is cultivated widely in

temperate climates. The grains or seeds consist of about 85% endosperm, 2%

embryo or germ and 13% husk (bran). The seeds are ground to produce a variety

of flours where most wheat being used in this form. The endosperm and hence

flour consist mainly of starch and also contains from 7 to 15% protein. The

proteins can be divided into four groups, the water soluble albumins (15%),

globulins (7.5%), prolamins which consist of gliadin (32.5%) and glutelins which

consist of glutenin (45%). These last two groups, making up the majority of wheat

protein, interact in the presence of water to form a viscous, colloidal complex,

known as gluten. The elastic, network forming gluten plays a major role in the

structure and texture of the food product (Street, 1991). In the brownies

processing the function of the wheat flour is to form the brownies structure and

texture and also to bind the other ingredients evenly (Matz, 1991).

Gluten, or the gluten matrix, is noted for its strong, three dimensional

viscoelastic structure that is created by specific proteins. Specifically, it is the

hydrophobic, inslouble gliadin proteins that contribute sticky, fluid properties to

the dough and the insoluble glutenins that contribute elastic properties to the

dough. Not all flours and therefore not all dough, forms gluten. Nongluten flours

14

contain starch that provides some structure; however, it is gluten protein that

provides the major framework for many batters and dough (Vaclavik, 2007).

2.3.3 Sugar

Sugar in high concentration can act as a preservative by inhibiting the

growth of microorganisms. The concentration of sugar dehydrates the bacteria or

yeast cells to the point of inactivation or death. The hygroscopic nature of sugars

is responsible to their influence on a food’s moistness and texture. The main

ability of sugar in the food is act as sweetener (Brown, 2008). In the brownies

making, the function of sugar is to act as sweetener and also bind the water in

brownies.

2.3.4 Fat

All baked products contain lipids. Fat has versatile function in baked

products, the major function of fat are affecting the richness and tenderness in

bakery product, improving the flavor and eating characteristics, enhancing

aeration for leavening and volume, promoting desirable grain and texture

qualities, providing flakiness in pastry product, provide lubrication for wheat

gluten, affecting the moisture retention of the bakery product and also providing

structure for cakes. Product like cake is highly dependent on fat to gain proper

aeration that will affect the quality of the final product. Fat will contribute to the

texture, mouthfeel and lubricity of the cake. In cookies making, fat acts as

lubricant, it keeps the dough from sticking to the feeding and forming equipment.

It also facilitates mixing by lubricating with other ingredients (Hui et al, 2008).

2.4 Brownies Processing15

The making process of brownies is almost like the making process of

cake. There are several steps in the making of brownies which are mixing,

depositing, baking, cooling and packaging. There are several methods of mixing,

such as sugar batter method, flour batter method and single stage mixing method.

In the flour batter method, the mixing process is done by mixing the flour and

shortening together, but the egg and sugar is mixed together with medium speed

mixer in a separated container. Then after all of the ingredients have been mixed

together, all of the ingredients is mixed together. In the sugar batter method, the

shortening, sugar, and the dry ingredients is mixed in low speed until the

ingredients are mixed properly, after that the addition of eggs, milk and flour is

done. In the single stage mixing, all of the ingredients is mixed together in a

container, and mixed together until the mixture is properly homogenized (Suas,

2008). After the mixing process is done, the next step in the making of brownies

is to pour the mixed dough into the baking pan. After that the pan is put into the

oven. The baking is the main factor that determine the quality of the cake. The

improper baking time can result in the lower quality of the end product. The

improper temperature during baking can affect the color, the texture, and the

volume of the brownies product.

2.5 Potato Flour

Potato Flour is the oldest commercial potato product and it can be

used in several processed food products, such as bakery product. Potato flour has

long been used in baking, and it could be used to impart the potato flavor and also

improve retention of freshness in bread. Potato has the ability to increase the

growth of yeast cells and also increase the activity of sugar fermentation. Potato 16

flour also has a distinctive flavor while incorporated in bakery product, and also

could reduce product firming and staling and also helps in the leavening of the

product (Preedy et al, 2011). Misra et al (2003) stated that potato is not an rich

source of protein, but contain good quality protein, dietary fiber, several minerals

and trace elements. It also contains essential vitamins and little or no fat.

2.6 Rice Flour

Rice flour is a flour made from rice which has soft taste, colourless,

hypoallergenic properties, low levels of sodium and easy digestible carbohydrate.

Because of this properties, rice flour is the most suitable cereal to make gluten

free product. But, when utilizing rice flour, it cannot be used to produce fermented

food products because their proteins cannot develop viscoelastic network like

gluten. According to Hui et al (2006), The source of rice flour is from rice grain, it

could be from long rice grain, medium rice grain, short rice grain, or waxy rice.

The chemical composition of rice flour is affected by different types of grain, and

furthermore it will also affect the starch content. The chemical composition of rice

flour is consist of glucose polymer made of amylose and amylopectin, the

amylose and amylopection has different ratio which depends on the variety of

rice. The starch content in the rice flour is about 80% from carbohydrate content.

2.7 Cassava Flour

Cassava flour is the product prepared from dried cassava chips or

paste by a pounding, grinding or milling process and then followed by sifting to

separate the fiber from the flour. The production of cassava flour is done by

milling of the dried raw root, whereas the starch is obtained by washing and wet

17

milling of the root, followed by multi-stage purification of the slurry. Cassava

flour has been utilized for making gluten free product such as bread. Flours are

fine, powdery materials which is obtained by grinding and by sifting the starch-

containing plant organelles such as grain, seed, root, tuber, fruit and so on.

Basically flours contain almost the same components as the components present

in the raw materials, except the moisture content. Some components that are often

found in flours include starch, non-starch polysaccharide, sugar, protein, lipid, and

inorganic materials (Shittu et al, 2009).

CHAPTER 3

18

RESEARCH METHODOLOGY

3.1 Materials and Equipments

3.1.1 Materials

The materials used in the making of rice bran brownies are stabilized

rice bran which are obtained from rice milling unit at Semarang, cassava flour

which obtained from PD Sumberwangi Semarang, rice flour “Rose Brand”, potato

flour which obtained from PD Sumberwangi Semarang, sugar “Gulaku”, cocoa

powder”Bensdorp”, vanilla powder, egg, margarine “Blueband”. The chemical

materials used in the proximate analysis are aquadest, concentrated H2SO4,

NaOH – Na2SO3, selenium, H2O2, H3BO3, methyl red indicator, HCl, petroleum

benzene, asbestos, K2SO4, ethanol 95 %, sodium phosphate, termamyl, pepsin

enzyme, pancreatin enzyme, dry celite.

3.1.2 Equipments

The main equipments used to produce rice bran brownies in this

research are analytical balance, oven,mixer, wok, frying spatula, dry blender,

sifter, aluminum pan, brush, bowl, spoon, graduated cylinder, and glassware. The

equipment used in the analysis are oven, desicator, texture analyzer, aw meter,

furnace, reflux, watch glass, burette, heating bath, crucible, kjehdahl tube,

buchner, fat extractor, stirrer, thermometer, volumetric pippete, spatula, filter

paper, and funnel.

3.2 Research Procedure

19

3.2.1 Preliminary Research

The preliminary research was done to determine the best gluten free

flour that would be used as the wheat flour replacer in the making of rice bran

brownies. The rice bran brownies would be made by using three different types of

flour, i.e cassava flour, potato flour and rice flour. In this preliminary research the

addition of 10 % of rice bran concentration was done as the substitute of each

flour used in the formulation. The treatment formulas could be seen in the Table

3.1. The best gluten free flour that would be used in the making of Rice bran

brownies was determined by sensory evaluation. The sensory evaluation method

used was the hedonic test, the method could be seen in appendix 1. The physical

and chemical parameter of the rice bran brownies was also analysed, the

parameter analysed was texture, in term of hardness, moisture content, and water

activity.

Table 3.1 Rice bran brownies formulationIngredients AmountFlour (g) 90 g flourRice bran flour (g) 10Margarine (g) 225Sugar (g) 225 (See Table 3.2)Eggs 3 (270 g)Vanilla Powder (g) 1.25Cocoa Powder (g) 50Source : Wulandari (2011), with modification

3.2.2 Main Research

The procedure of the main research was divided into several steps.

The first step was making the gluten free rice bran brownies utilizing the best

wheat flour replacer obtained from the preliminary research. The next step was

evaluating the brownies produced by observed the physical and chemical

20

parameter, including texture, moisture content and water activity. The next step

was sensory evaluation test of gluten free rice bran brownies using the hedonic

test. After sensory qualities of the brownies were evaluated, then the best gluten

free rice bran brownies formulation could be determined. Proximate analysis was

done for the best gluten free rice bran brownies formulation including moisture

content, protein content, ash content, fat content, and dietary fiber content.

Proximate analysis for the rice bran flour was also conducted.

The formula which was used in the making of the gluten free rice bran

brownies was modified from formula stated by Wulandari (2011). The

modification done was the substitution of wheat flour with potato starch, rice flour

or cassava flour and the use of palm sugar. The formula of brownies could be

seen in Table 3.1, while the modification according to the treatment could be seen

in Table 3.2.

Table 3.2 Formula modification

Flour and rice bran flour ratio100 % selected90 % selected flour + 10 % rice bran flour80 % selected flour + 20 % rice bran flour70 % selected flour + 30 % rice bran flour60% selected flour + 40% rice bran flour

The flowchart of the main research activities can be seen in Figures 3.1.

21Selected flour and rice bran flour (See Table 3.2)

Cocoa powder, margarine, eggs, sugar and vanilla powder

Figures 3.1 Flowchart of main research Source : Szafranski et al (2005)

The selected flour and rice bran flour (see Table 3.2), sugar, cocoa

powder, margarine, eggs, and vanilla powder were mixed using mixer with

medium speed for 5 minutes. After that the dough was deposited in the aluminium

pan and spread evenly. The dough was put to the oven in 200o C temperature and

baked according to treatment (35, 45 and 55 minutes). After the baking process

was done, the gluten free rice bran brownies was produced and ready to be further

analysed.

3.3 Experimental Design

22

Mixing of all of the ingredients using mixer with medium speed for 5 minutes

Depositing the dough into aluminium pan and the dough is spread evenly in the pan

The dough is put to the oven in 200o C temperature and baked according to the treatment (35, 45 and 55 minutes)

Gluten Free Rice Bran Brownies

3.3.1 Preliminary Research

The treatment that was done in the preliminary research is the

replacement of wheat flour (A1) with cassava flour (A2), rice flour (A3), and

potato flour (A4). Based on the treatment, the experimental design in the

preliminary research was complete random design with one factorial. Factors

observed were the different types of flour used for making the rice bran brownies,

which consists of A1, A2, A3 and A4. The preliminary research was done in six

replications. The randomized factorial design is :

Yij = µ + Ri + Ɛ1 (ij)

Where :

Yij = Random variable denoting the (ij)th variable

µ = real mean value

Ri = effect of different types of flour on level i

Ɛ1 (ijk) = Galat factor

Hypothesis of the preliminary research :

Ho : There is no effect of different types of flour towards the sensory acceptance

of rice bran brownies

H1: There is effect of different types of flour towards the sensory acceptance of

rice bran brownies.

3.3.2 Main Research

23

The treatment that was done is the main research consists of two treatments which

are :

1. Ratio of substituted flour : rice bran flour (R), which consists of five levels

:

- 100 % substituted flour : 0 % rice bran flour (R0)




- 60% substituted flour : 40% rice bran flour (R4)

2. Baking time (B), which consists of three levels :

- 35 minutes baking time (B1)



Based on the treatment, the experimental design used in this research is complete

random design with two factorials, R x B (5x3). The main research was conducted

in three replications. Factor which observed were :

1. The concentration of rice bran which was added to the formulation, which

consist of R0, R1, R2, R3 and R4.

2. The different baking time, which were B1, B2 and B3.

The combination of the factors can be seen in Table 3.3.

Table 3.3 Combination of FactorsBaking Time Rice Bran Concentration

24

R0 R1 R2 R3 R4B1 R0B11

R0B12

R0B13

R1B11

R1B12

R1B13

R2B11

R2B12

R2B13

R3B11

R3B12

R3B13

R4B11

R4B12

R4B13

B2 R0B21

R0B22

R0B23

R1B21

R1B22

R1B23

R3B21

R3B22

R3B23

R3B21

R3B22

R3B23

R4B21

R4B22

R4B23

B3 R0B31

R0B32

R0B33

R1B31

R1B32

R1B33

R2B31

R2B32

R2B33

R3B31

R3B32

R3B33

R4B31

R4B32

R4B33

The randomized factorial design is :

Yijk = µ + Ri + Sj + Rsij + Ɛ1 (ijk)

Where :

Yijk = value of observation at level one, with factor of concentration of rice bran

flour on level i and different type of sugar on level j

µ = real mean value

Ri = effect of concentration of rice bran flour on level i

Sj = effect of different type of sugar used on level j

Rsij = effect of interaction between factor of concentration of rice bran flour on

level i and factor of different type of sugar used on level j

Ɛ1 (ijk) = Galat factor

Hipotesis of this research :

Ho :

25

1. There is no effect on concentration of rice bran flour towards the quality

and sensory acceptance of gluten free – high dietary fiber brownies

2. There is no effect on concentration of different types of sugar used

towards the quality and sensory acceptance of gluten free – high dietary

fiber brownies

3. There is no interaction on concentration of rice bran flour and different

types of sugar used towards the quality and sensory acceptance of gluten

free – high dietary fiber brownies

H1 :

1. There is effect on concentration of rice bran flour towards the quality and

sensory acceptance of gluten free – high dietary fiber brownies

2. There is effect on concentration of different types of sugar used towards

the quality and sensory acceptance of gluten free – high dietary fiber

brownies

3. There is interaction on concentration of rice bran flour and different types

of sugar used towards the quality and sensory acceptance of gluten free –

high dietary fiber brownies

3.4 Analysis Procedure

The parameters which were observed in this research were the sensory qualities,

physical, and chemical characteristic of the gluten free rice bran brownies. The

proximate analysis and the dietary fiber analysis was done for the best gluten free

rice bran brownies formulation.

3.4.1 Sensory Qualities26

The sensory qualities of the gluten free rice bran brownies was determined by

using sensory evaluation test which was the hedonic test (Meilgaard, 2007). The

hedonic test was conducted to determine the gluten free rice bran brownies

formula which was most preferred by the panelist. The panelist in this sensory

evaluation procedure was untrained panelist. The method for the hedonic test

could be seen in Appendix 1.

3.4.2 Physical Characteristic

The physical characteristic of the gluten free rice bran brownies was determined

by using texture analyzer towards the hardness parameter. The method of

determining the texture of the gluten free high rice bran brownies could be seen in

Appendix 2.

3.4.3 Chemical Characteristic

The chemical characteristic of the gluten free rice bran brownies which was

evaluated consists of moisture content and water activity. The water activity was

measured using Aw meter while the method of determining moisture content could

be seen in appendix 3.

3.4.4 Proximate Analyses for the best gluten free - high dietary fiber

brownies formulation

The proximate analyses of the gluten free rice bran brownies included the oven

method to determine the moisture content of the rice bran (AOAC, 2005), ash

content using the dry ashing method (AOAC, 2005), protein content using the

27

micro Kjehdahl method (AOAC, 2005),fat content using the soxhlet extraction

(AOAC, 2005) and carbohydrate content using by difference method. The

proximate analyses methods could be seen in Appendix 3. The dietary fiber

content of the gluten free - high dietary fiber brownies was also analyzed by using

enzyme analysis (AOAC,2005). The method for dietary fiber analysis could be

seen in the Appendix 4.

CHAPTER IV

RESULTS AND DISCUSSIONS

4.1 Result of Preliminary Research

28

The preliminary research was conducted to determine the best gluten

free flour that would be used as the wheat flour replacer in the making of rice bran

brownies. There were four types of flour which were used in the preliminary

research which were cassava flour, rice flour, potato flour and wheat flour. The

subjective and objective test were conducted to analyze the rice bran brownies

which were made using different types of flour. The subjective test that was

conducted was sensory evaluation using hedonic test. The hedonic test was

conducted in order to determine the best wheat flour replacer. There were four

quality parameters of the hedonic test which was observed, which was aroma,

taste, texture and overall acceptance of the rice bran brownies. The objective

analysis was conducted to observe several physical and chemical parameters

which consist of moisture content, water activity and the texture of rice bran

brownies.

4.1.1 Sensory Analysis

The determination of the best gluten free flour was conducted based

on sensory evaluation procedure. The hedonic test was conducted as the sensory

evaluation procedure. According to Moskowitzt et al (2006), The number of

panelists required for conducting the consumer sensory acceptance tests was 50 –

100 panelists, therefore in this research, the hedonic test were conducted using 70

panelists. The panelists were untrained panelists and the panelists were asked to

evaluate each of the rice bran brownies samples using a 7 points hedonic scale.

The scale was ranged from 1 to 7, 1 stands for extremely dislike and 7 stands for

extremely like. The evaluation of each samples were done based on the preference

29

of the panelists toward each samples. All of data obtained from the hedonic test

were analyzed using the IBM SPSS 19 utilizing the one way ANOVA.

4.1.1.1 Aroma

Aroma was chosen as one of the parameter in the hedonic test to

observe the consumer preference towards the different types of flour used to make

the rice bran brownies.

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05The range of hedonic scaling : 1=extremely dislike, 2=dislike, 3=slightly dislike, 4=neutral, 5=slightly like, 6=like, 7=extremely like

Figure 4.1 Preference of Aroma by PanelistsThe result of the hedonic test towards the aroma parameter can be

seen in the Figure 4.1. From the statistical analysis using one way ANOVA, from

the ANOVA table, it could be seen that there was a significant different between

the types of flour used toward the consumer acceptance of rice bran brownies

aroma. The most preferable rice bran brownies based on aroma parameter was the

30

Types of Flour4.2

4.4

4.6

4.8

5

5.2

5.4

5.0857a

5.2a

4.7571ab

4.5857b

Wheat FlourCassava FlourRice FlourPotato Flour

rice bran brownies made from cassava flour as shown in the Figure 4.1. Although

the rice bran brownies made from cassava flour has the highest score in terms of

aroma parameter, from the statistical analysis done using one way ANOVA, it

was not significantly different with the consumer acceptance of aroma parameter

toward the rice bran brownies made from rice flour and wheat flour. There was a

research conducted by Katama et al (2002) about the substitution of wheat flour

with cassava flour in chapatti, in that research, substitution 50 % of wheat flour

with cassava flour still produced chapatti with acceptable aroma. The result of that

research was coherent with the result of this research. It could be concluded that

the replacement of wheat flour with cassava flour still could produce baked

product, in this case was rice bran brownies, which was still acceptable to

consumers, in terms of aroma parameter. The aroma of rice bran brownies

produced from rice flour was also still acceptable for consumers.

The rice bran brownies made from potato flour gave the lowest score

of the consumer acceptance toward aroma parameter, it was not significantly

different with the rice bran brownies made from rice flour, but it was significant

different with the rice bran brownies made from cassava flour and wheat flour.

Basically the aroma of the rice bran brownies was produced from the rice bran

and the cocoa powder which were used in the formulation. A research was

conducted by Thybo et al (2006) regarding several aromatic compounds which

were found in potatoes from several different cultivars. According to Berger

(2007) approximately 50 compounds contributed to the aroma of raw potato.

Because of the existence of such aromatic compounds, it could be inferred that

potato flour would have a distinctive aroma. These aroma compounds could give

31

changes towards the aroma properties of the rice bran brownies and affect the

consumer preference towards the rice bran brownies aroma.

4.1.1.2 Taste

Taste was chosen as one of the parameter in the hedonic test to

observe the consumer preference towards the different types of flour used to make

the rice bran brownies.


Figure 4.2 Preference of Taste by Panelists

The result of the hedonic test towards the taste parameter can be seen

in the Figure 4.2. From the result of statistical analysis by one way ANOVA, from



taste. As shown in Figure 4.2, the rice bran brownies which gave the highest score

32

Types of Flour0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

4.4a4.2143a 4.1a

3.5857b


towards the taste parameter was the rice bran brownies made from wheat flour,

but from the statistical analysis, there was no significant difference between wheat

flour, cassava flour and rice flour toward the sensory acceptance of rice bran

brownies regarding taste parameter. There was a research conducted by Gan et al

(2007) about the optimization of cassava cake formulation which produce cassava

cake with high consumer acceptance, the research was stated that the baked

cassava cake had a strong cassava flavour. The cassava flavour produced from the

cassava flour during baking could possibly affect the consumer acceptance toward

the taste parameter, although the cassava flavour itself had not beed studied

extensively yet. According to Dziedzoave (2006), high quality cassava flour

should have bland taste without indication of acidity or off flavour, and also

should have the flavour of freshly peeled cassava.

The rice bran brownies made from potato flour was slightly

unacceptable because as shown in the Figure 4.2 the mean score for taste

parameter was 3.5857, while based on the hedonic scaling range, the score 3

already categorized as “slightly dislike”. The low acceptance towards the taste of

rice bran brownies made from potato flour could be affected by the potato flavour

produced from the potato flour. Thybo et al (2006) stated that the potato flavour is

correlated with the aromatic compounds contained in the potato, furthermore, it

also stated that potato could possible have an off flavour which was correlated

with the non volatiles compounds in the potato.

4.1.1.3 Texture

33

Texture was chosen as one of the parameter in the hedonic test to observe the

consumer preference towards the different types of flour used to make the rice

bran brownies.

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05The range of hedonic scaling : 1=extremely dislike, 2=dislike, 3=slightly dislike, 4=neutral, 5=slightly like, 6=like, 7=extremely likeFigure 4.3 Preference of Texture by Panelists

The result of the hedonic test towards the taste parameter can be seen

in the Figure 4.3. From the result of statistical analysis by one way ANOVA, from



texture. As shown in Figure 4.3, the rice bran brownies which gave the highest

score towards the texture parameter was the rice bran brownies made from wheat

flour, but it was not significantly different with rice bran brownies made from

cassava flour. From the Figure 4.3 it could be seen that the mean score given by

the panelist is slightly lower for the rice bran brownies produced from cassava

flour. There was a research conducted by Gan et al (2007) about the optimization 34

Types of Flour0

1

2

3

4

5

6

5.0857a 4.9143a

4.4571b

3.3143c Wheat FlourCassava FlourRice FlourPotato Flour

of cassava cake formulation, in that research the texture parameter of the product

which was firmness was not quite acceptable by the panelists. It could be assumed

that the cassava flour could affect the texture of the baked product which would

affect the consumer preference of the baked product in terms of texture.

The lowest acceptance in term of texture was given by the rice bran

brownies produced from potato flour. From the result in could be concluded that

potato flour utilization in the making of rice bran brownies might cause a textural

change towards the product which could reduce the textural acceptability of the

rice bran brownies from the consumer.

4.1.1.4 Overall Acceptance

The overall acceptance parameter was chosen as one of the parameter

to be evaluated in the hedonic test as its importance to determine the preference of

the consumer towards the rice bran brownies product in terms of combined

evaluation regarding the aroma, taste and texture of the rice bran brownies.

35

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05The range of hedonic scaling : 1=extremely dislike, 2=dislike, 3=slightly dislike, 4=neutral, 5=slightly like, 6=like, 7=extremely likeFigure 4.4 Preference of Overall Acceptance by Panelists

The result of the hedonic test towards the overall parameter can be

seen in the Figure 4.4. From the result of statistical analysis by one way ANOVA,

from the ANOVA table, it could be seen that there was a significant different

between the types of flour used toward the consumer acceptance of rice bran

brownies regarding the overall acceptance. As shown in Figure 4.4, the rice bran

brownies which gave the highest score towards the overall acceptance parameter

was the rice bran brownies made from wheat flour, but it was not significantly

different with rice bran brownies made from cassava flour.

From Figure 4.4, the flour which gave the lowest overall acceptance

towards the rice bran brownies was the potato flour, although it was not

significantly different with rice bran brownies made from rice flour. Based on the

sensory evaluation result utilizing hedonic test, the best gluten free flour which

could be used in the making of rice bran brownies was the cassava flour, because

36

Types of Flour0

1

2

3

4

5

6

5.1286a4.9143a

4.2143b3.9429b


it still gave product which was acceptable by the consumer and was not

significantly different with rice bran brownies made from wheat flour.

4.1.2 Physical and Chemical Analysis

4.1.2.1 Texture

The texture of rice bran brownies made from different types of flour

was analyzed using texture analyzer. The textural parameter which was observed

was hardness parameter. As stated by Sczcneiak (2002), hardness could be

defined physically as force give to attain a given deformation and from sensory

perspective hardness was defined as force require to compress between molar

teeth and palate. The hardness parameter of rice bran brownies made with

different types of flour could be seen in the Figure 4.5.

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05Figure 4.5 Hardness Parameter of Rice Bran Brownies

37

Types of Flour0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

5676.04a6158.58a

4156.073b

8982.1587c


The hardness parameter from rice bran brownies made from different

types of flour was statistically analyzed using one way ANOVA, and from the

ANOVA table it was resulted that there was a significant difference between rice

bran brownies made from different types of flour towards the hardness parameter.

From Figure 4.5 it could be seen that the highest level of hardness was given by

rice bran brownies made using potato flour, and the lowest one was the rice bran

brownies made using rice flour. This result could be correlated with the result

obtained from sensory analysis, in the sensory analysis, the rice bran brownies

made from potato flour had the lowest score in terms of acceptance towards

texture parameter, this could be caused because the rice bran brownies produced

from potato flour had harder texture compared to the others. According to Preedy

(2011), potato flour had been utilized to produce flat bread, which was an

unleavened product. The utilization of potato flour in the making of flat bread

could possibly be correlated with its effect toward the hardness of bakery

products. Singh et al (2005) also stated that potato flour had different size of

starch granules which varied according to its cultivars. Potato flour which has

smaller starch granules would produce harder and more cohesive product, this

could be an explanation why the rice bran brownies made from potato flour had

higher level of hardness compared to the others.

The low hardness level of rice flour could be caused by the protein

content of rice flour. As stated by Muksprasirt (2001), rice flour has lower level of

protein compared to wheat flour, therefore the hardness of the rice bran brownies

made from rice flour was lower and significantly different compared to rice bran

brownies made from wheat flour. This was also supported by the theory stated by

38

Hui et al (2008) that in the making of cake, flour which has low level of protein

would produce softer texture.

The hardness parameter of rice bran brownies made using wheat flour

and cassava flour was not significantly different and this could be correlated with

the result of the sensory analysis in term of texture parameter. In the sensory

analysis, the acceptance toward texture parameter of rice bran brownies made

from cassava flour and wheat flour was not significantly different and it could be

assumed that it was not significant different because basically the texture profile

of those two products was not significantly different as resulted from the objective

measurement using texture analyzer.

4.1.2.2 Moisture Content

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05Figure 4.6 Moisture Content of Rice Bran Brownies

The moisture content of rice bran brownies made using different types

of flour was analyzed in this preliminary research. Moisture content is an 39

Types of Flour0.00%

5.00%

10.00%

15.00%

20.00%

25.00%

14.99%a

17.86%b

19.87%c

13.13%dWheat FlourCassava FlourRice FlourPotato Flour

important parameter to determine the quality of bakery products, such as

brownies.

Moisture content of the bakery product would affect the eating quality

of the finished products, as stated by Hui et al (2008). The moisture content of

rice bran brownies made using different types of flour could be seen in the Figure

4.6.

The moisture content of rice bran brownies made from different types

of flour was statistically analyzed using one way ANOVA, and from the ANOVA

table it was resulted that there was a significant difference between rice bran

brownies made from different types of flour towards the moisture content. From

Figure 4.6 it could be seen that the highest level of moisture content was given by

rice bran brownies made using rice flour, and the lowest one was the rice bran

brownies made using potato flour.

As shown in Figure 4.6, all of the rice bran brownies made with

different types of flour were significantly different towards each other, prior to

this it could be inferred that each of the rice bran brownies possessed different

characteristics because Hui et al (2008) stated that the amount of water could

affect the texture and mouth feel of bakery products. The low level of moisture

content given by the rice bran brownies made using potato flour could be

correlated with the result of texture analysis, whereas the hardness of the rice bran

brownies made using potato flour was the least among the others. This assumption

was supported by theory stated by Kilcast (2004) about the relation between

moisture content and the hardness of food products whereas loss of moisture

could increase the hardness of bakery products. The presence of water is also very 40

important in baking because it is essentially needed in order to gelatinize the

starch during heating, besides it also plays an important role by interact with

proteins in order to give desirable features for bakery products (Hui et al, 2008).

The moisture content of rice bran brownies made using rice flour was higher and

significantly different with rice bran brownies made using rice flour, according to

the research conducted by Park et al (2002) and Nura (2011), the ability of rice

flour to absorb water is higher compared to that in wheat flour.

4.1.2.3 Water Activity

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05Figure 4.7 Water Activity of Rice Bran Brownies

Water activity was one of the observed parameter in this preliminary,

because water activity was considered as an important parameter to the quality of

rice bran brownies. As stated by Hui et al (2008), water activity has a relationship

with moisture content, and furthermore, in bakery products water provides

lubrication when the bakery product is being eaten and affects its texture. This

41

Types of Flour0.61

0.62

0.63

0.64

0.65

0.66

0.67

0.68

0.69

0.663a0.667a

0.681b

0.634c


theory also supported by another theory stated by Barbaso-Canovas (2007) which

stated that water activity affects the textural properties of foods, foods with high

Aw have moist and juicy texture, while foods with lower Aw have harder and

tougher texture.

The water activity of rice bran brownies made using different types of

flour could be seen in Figure 4.7. The water activity of rice bran brownies made

from different types of flour was statistically analyzed using one way ANOVA,

and from the ANOVA table it was resulted that there was a significant difference

between rice bran brownies made from different types of flour towards its water

activity. From Figure 4.7 it could be seen that the highest level of water activity

was given by rice bran brownies made using rice flour, and the lowest one was the

rice bran brownies made using potato flour. As show in Figure 4.7, all of the rice

bran brownies product had water activity value ranged from 0.634 – 0.681,

according to Barbosa-Canovas (2007), foods which have water activity values

from 0.6 – 0.9 are categorized as intermediate moisture foods. It could be

concluded that all of the rice bran brownies product, either made from rice flour,

wheat flour, potato flour or cassava flour were categorized as intermediate

moisture foods. The highest water activity was given by the rice bran brownies

made using rice flour, and it could be related with the moisture content of the rice

bran brownies made using rice flour which was also the highest compared to the

others as shown in Figure 4.6. On the other hand, the least water activity was

given by rice bran brownies made from potato flour, and it also could be related

with its moisture content which was also the least among the others as shown in

42

Figure 4.6. Therefore, the result was quite coherent with the theory stated above

about the relation between water activity and moisture content.

4.1.3 Determination of the Best Gluten Free Flour in the Making of Rice

Bran Brownies

The best gluten free flour in the making of rice bran brownies was

determined by means of sensory analysis. From the result of sensory analysis, for

the overall parameter, the rice bran brownies which had the highest sensory

acceptance was the rice bran brownies made using wheat flour, and the second

one was the rice bran brownies made using cassava flour. From the statistical

analysis, the consumer acceptance of rice bran brownies made from wheat flour

and rice bran brownies made from cassava flour was not significantly different, so

it could be concluded cassava flour could be used as the wheat flour replacer in

the making of rice bran brownies. This also supported by the result of objective

analysis, whereas the hardness of rice bran brownies made from cassava flour and

wheat flour was not significantly different. From the preliminary research, it could

be concluded that among rice flour, potato flour, and cassava flour, cassava flour

incorporation in rice bran brownies as wheat flour replacer would give the best

characteristic and consumer acceptance, therefore, cassava flour was determined

as the best gluten free flour in the making of rice bran brownies. Prior to the result

of the preliminary research, cassava flour would be used in the making of rice

bran brownies in the main research.

4.2 Main Research

43

The main research was conducted to determine the best rice bran

concentration and the best baking time in the making of rice bran brownies. The

rice bran brownies was made using cassava flour, which was selected from the

result of the preliminary result. The rice bran concentration which was

incorporated as the substitute for cassava flour consists of five different

concentrations which were 0%, 10%, 20%, 30%, and 40%, while the baking time

was 35, 45 and 55 minutes. The subjective and objective test were conducted to

analyze the rice bran brownies which were made using different rice bran

concentrations and different baking time. The subjective test that was conducted

was sensory evaluation using hedonic test. The hedonic test was conducted in

order to determine the best rice bran brownies formulation. There were four

quality parameters of the hedonic test which was observed, which was aroma,

taste, texture and overall acceptance of the rice bran brownies. The objective

analysis was conducted to observe several physical and chemical parameters

which consist of moisture content, water activity and the texture of rice bran

brownies.

4.2.1 Sensory Analysis

The determination of the best rice bran concentration and the best

baking time in the making of rice bran brownies was conducted based on sensory

evaluation procedure. The hedonic test was conducted using 70 panelists. The

panelists were untrained panelists and the panelists were asked to evaluate each of

the rice bran brownies samples using a 7 points hedonic scale. The scale was

ranged from 1 to 7, 1 stands for extremely dislike and 7 stands for extremely like.

The evaluation of each samples were done based on the preference of the panelists 44

toward each samples. All of data obtained from the hedonic test were analyzed

using the IBM SPSS 19 utilizing the one way ANOVA.

4.2.1.1 Aroma

Aroma was chosen as one of the parameter in the hedonic test to observe the

consumer preference towards the different concentration of rice bran and different

baking time incorporated during the making of rice bran brownies.

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05The range of hedonic scaling : 1=extremely dislike, 2=dislike, 3=slightly dislike, 4=neutral, 5=slightly like, 6=like, 7=extremely likeFigure 4.8 Effect of Rice Bran Concentration Towards Aroma Parameter

The result of the effect of rice bran concentration toward the consumer

acceptance of aroma could be seen in Figure 4.8. From the statistical analysis

using two factor ANOVA, there was an effect of rice bran concentration towards

the consumer acceptance of rice bran brownies in terms of aroma, and as shown in

Figure 4.8, there was a significant different of the rice bran brownies made using

different concentration of rice bran towards the consumer acceptance in term of

45

Rice Bran Concentration4

4.2

4.4

4.6

4.8

5

5.2

5.4

5.1667a

4.9714ab 4.9381ab

4.8b

4.4762c

0%10%20%30%40%

aroma parameter. The highest acceptance was given by rice bran brownies made

with 0% rice bran concentration and the lowest acceptance was given by rice bran

brownies made with 40% rice bran concentration. From Figure 4.8, it also could

be seen that there was not a significant different between rice bran brownies made

using 0,10, and 20% rice bran concentration. Rice bran brownies made using 40%

of rice bran concentration was significantly different with rice bran brownies

made using 0,10,20 and 30% rice bran concentration.

There was a research conducted by Caesario (2011) which was

incorporation of rice bran in the meat ball. In that research, increasing the rice

bran concentration resulted in the decreasing of the consumer acceptance toward

aroma parameter, therefore it was coherent with the result of this research.

Kusumasari (2011) also incorporated rice bran in the making of ready to eat

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05The range of hedonic scaling : 1=extremely dislike, 2=dislike, 3=slightly dislike, 4=neutral, 5=slightly like, 6=like, 7=extremely likeFigure 4.9 Effect of Baking Time Towards Aroma Parameter

46

Baking Time4.7

4.75

4.8

4.85

4.9

4.95

5

4.3a

2.4a

2a

35 Minutes45 Minutes55 Minutes

breakfast cereal, and at certain point of rice bran addition, decreasing of consumer

acceptance towards aroma parameter was occurred. The decreasing of the

consumer acceptance in term of aroma parameter as the rice bran concentration

increased could be attributed to the unpleasant odor which was possessed by rice

bran as stated by Kaewka (2009), it also supported by another theory by

Sukonthara (2009) which stated that rice bran had several volatiles compound

contributed to its unpleasant aroma.

The result of the effect of baking time toward the consumer

acceptance of aroma could be seen in Figure 4.8. According to Hui et al (2008),

the production of aromatic compounds in bakery products is related to the baking

process, therefore baking time is one of the important consideration which will

determine the quality of bakery products. However, from the statistical analysis

using two factor ANOVA, there was no effect of baking time towards the

consumer acceptance of rice bran brownies in terms of aroma, and as shown in

Figure 4.8, there was no significant different of the rice bran brownies made using

different baking time towards the consumer acceptance in term of aroma

parameter.

The result of the interaction of rice bran concentration and baking

time toward the consumer acceptance of aroma could be seen in Table 4.1. From

the statistical analysis using two factor ANOVA, there was interaction between

rice bran concentrations and baking time towards the consumer acceptance of rice

bran brownies in terms of aroma, and as shown in Table 4.1, there was significant

different of the rice bran brownies made using different rice bran concentrations

and different baking time towards the consumer acceptance in term of aroma

47

parameter. The rice bran brownies made using 30% rice bran concentration and

baked for 35 minutes gave lower and significantly different value compared to

that which baked for 45 minutes, and so rice bran brownies made using 10 % rice

bran concentration which baked for 35 minutes gave lower and significantly

different value compared to that which baked for 45 minutes.

Table 4.1 Interaction of Rice Bran Concentration and Baking Time towards Aroma Parameter

Baking TimeRice Bran Concentration

0% 10% 20% 30% 40%

35 minutes 5.5429e 4.9714bcd 4.8857bcd 4.4857ab 4.2429a

45 minutes 5.2286e 5.1000cde 4.9429bcd 4.9714bcd 4.6000ab

55 minutes 4.7286bc 4.8429bcd 4.9857bcd 4.9429bcd 4.5857ab


From those results, it might be assumed that increasing the baking

time would affect the volatile compounds of rice bran which was attributed to the

aroma of the rice bran brownies as stated in theory above by Sukonthara (2009).

4.2.1.2 Taste

Taste was chosen as one of the parameter in the hedonic test to observe the

consumer preference towards the different concentration of rice bran and different

baking time incorporated during the making of rice bran brownies. The result of

the effect of rice bran concentration toward the consumer acceptance of taste

could be seen in Figure 4.9. From the statistical analysis using two factor

ANOVA, there was an effect of rice bran concentration towards the consumer

acceptance of rice bran brownies in terms of taste.

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05

48

The range of hedonic scaling : 1=extremely dislike, 2=dislike, 3=slightly dislike, 4=neutral, 5=slightly like, 6=like, 7=extremely likeFigure 4.10 Effect of Rice Bran Concentrations Towards Taste Parameter

As shown in Figure 4.10, there was a significant different of the rice

bran brownies made using different concentration of rice bran towards the

consumer acceptance in term of taste parameter. The highest acceptance was

given by rice bran brownies made with 0% rice bran concentration and the lowest

acceptance was given by rice bran brownies made with 40% rice bran

concentration. From Figure 4.10, it also could be seen that there was no

significant different between rice bran brownies made using 20 and 30% rice bran

concentration. Rice bran brownies made using 40% of rice bran concentration was

significantly different with rice bran brownies made using 0,10,20 and 30% rice

bran concentration. From the result, it could be assumed that increasing the rice

bran concentration would reduce the consumer acceptance of rice bran brownies

regarding its taste parameter, this also coherent with the research conducted by

Huang et al (2005) about the incorporation of rice bran in the pork meatballs. In

that research, the increasing of rice bran concentration lowered the consumer

49


1

2

3

4

5

6

5.2429a

4.7b4.3952c

4.1857c

3.7238d0%10%20%30%40%

acceptance towards taste parameter. The taste of rice bran brownies product might

be affected by several aromatic compounds contained in rice bran, which has been

studied and characterized by Jarunrattanasri (2004). Hui et al (2008) also stated

that there is correlation between aromatic compounds toward sensory perception

of taste. Luh (1991) stated that the dominant flavor characteristics of rice bran are

sweet taste which is attributed to high sugar content in bran and bitter taste which

is attributed to saponins content in rice bran. The decreasing of consumer

acceptance in term of taste parameter as the rice bran concentration increasing

could be affected by the unpleasant flavor given by rice bran prior to the flavor

profile described above.

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05The range of hedonic scaling : 1=extremely dislike, 2=dislike, 3=slightly dislike, 4=neutral, 5=slightly like, 6=like, 7=extremely likeFigure 4.11 Effect of Baking Time Towards Taste Parameter


acceptance of taste could be seen in Figure 4.11. From the statistical analysis

50

Baking Time4.25

4.3

4.35

4.4

4.45

4.5

4.55

4.6

4.4429a

4.5429a

4.3629a

35 minutes45 minutes55 minutes

using two factor ANOVA, there was no effect of baking time towards the

consumer acceptance of rice bran brownies in terms of taste

As shown in Figure 4.11, there was no significant different of the rice

bran brownies made using different baking time towards the consumer acceptance

in term of taste parameter. There was no interaction between rice bran

concentrations and baking time towards the consumer acceptance of rice bran

brownies in term of taste parameter.

4.2.1.3 Texture

Texture was chosen as one of the parameter in the hedonic test to

observe the consumer preference towards the different concentration of rice bran

and different baking time incorporated during the making of rice bran brownies.

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05The range of hedonic scaling : 1=extremely dislike, 2=dislike, 3=slightly dislike, 4=neutral, 5=slightly like, 6=like, 7=extremely likeFigure 4.12 Effect of Rice Bran Concentration Towards Texture Parameter

51

Rice Bran Concentration3.6

3.8

4

4.2

4.4

4.6

4.8

54.8952a

4.5667b 4.5762b

4.4238b

4.119c

0%10%20%30%40%

The result of the effect of rice bran concentration toward the consumer

acceptance of texture could be seen in Figure 4.12. From the statistical analysis

using two factor ANOVA, there was effect of rice bran concentration towards the

consumer acceptance of rice bran brownies in terms of texture.

As shown in Figure 4.12, there was significant different of the rice


consumer acceptance in term of texture parameter. The highest acceptance was



concentration. From Figure 4.8, it also could be seen that there was no significant

different between rice bran brownies made using 10, 20 and 30% rice bran

concentration. This result was coherent with the research conducted by Huang et

al (2005), in that research the increased rice bran concentration lowered the

consumer acceptance of the pork meatball products in term of texture parameter.

This result was also supported by another research conducted by Delahaye et al

(2005) which was the study of rice bran utilization in frozen pizza. Sensory

analysis was conducted to determine the consumer acceptance of frozen pizza,

and textural acceptance was one of the parameter observed in the sensory analysis,

which specifically was hardness. The research resulted with lowered sensory

acceptance toward the hardness parameter as the rice bran concentration

increased.


acceptance of texture could be seen in Figure 4.11. From the statistical analysis

52

using two factor ANOVA, there was effect of baking time towards the consumer

acceptance of rice bran brownies in terms of texture.

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05The range of hedonic scaling : 1=extremely dislike, 2=dislike, 3=slightly dislike, 4=neutral, 5=slightly like, 6=like, 7=extremely likeFigure 4.13 Effect of Baking Time Towards Texture Parameter

As shown in Figure 4.13, there was significant different of the rice bran brownies

made using different baking time towards the consumer acceptance in term of

texture parameter. The highest acceptance was given by rice bran brownies baked

in 45 minutes and the lowest acceptance was given by rice bran brownies baked in

55 minutes, however there was no significant different between rice bran

brownies baked in 55 minutes and 35 minutes towards the consumer acceptance

regarding texture parameter. According to Hui et al (2008), there are many

features which are occurred during baking such as Maillard reaction, starch

gelatinization, and moisture loss. These occurrences could possibly affect the

texture of the final product which could affect the consumer preference toward the

texture of the rice bran brownies.

Table 4.2 Interaction of Rice Bran Concentration and Baking Time towards Texture Parameter

53

Baking Time4.25

4.3

4.35

4.4

4.45

4.5

4.55

4.6

4.65

4.7

4.4657a

4.6771b

4.4057a



0% 10% 20% 30% 40%

35 minutes 5.3143d 4.4143abc 4.3714abc 4.2429ab 3.9857a

45 minutes 4.8714cd 4.6571bc 4.6857bc 4.8000c 4.3714abc

55 minutes 4.5000abc 4.6286bc 4.6714bc 4.2286ab 4.0000a


From the statistical analysis using two factor ANOVA, there was

interaction between rice bran concentrations and baking time towards the

consumer acceptance of rice bran brownies in term of texture, and as shown in

Table 4.2, there was significant different of the rice bran brownies made using

different rice bran concentrations and different baking time towards the consumer

acceptance in term of texture parameter.

4.2.1.4 Overall

The overall acceptance parameter was chosen as one of the parameter

to be evaluated in the hedonic test as its importance to determine the preference of

the consumer towards the rice bran brownies product in terms of combined

evaluation regarding the aroma, taste and texture of the rice bran brownies. The

result of the effect of rice bran concentration toward the consumer acceptance of

overall parameter could be seen in Figure 4.14. From the statistical analysis using

two factor ANOVA, there was effect of rice bran concentration towards the

consumer acceptance of rice bran brownies in terms of overall parameter.


54

Figure 4.14 Effect of Rice Bran Concentration Towards Overall Parameter

As shown in Figure 4.14, there was significant different of the rice


consumer acceptance in term of overall parameter. The highest acceptance was



concentration. From Figure 4.14, it also could be seen that there was no

significant different between rice bran brownies made using 10, 20 and 30% rice

bran concentration. This result was similar with the research conducted by Huang

et al (2005) about the utilization of rice bran in the making of pork meatballs. In

that research, increasing the concentration of rice bran would reduce the overall

acceptance of the pork meatballs.


55


1

2

3

4

5

6

5.1571a4.8b

4.5619b 4.5524b

3.919c

0%10%20%30%40%

The range of hedonic scaling : 1=extremely dislike, 2=dislike, 3=slightly dislike, 4=neutral, 5=slightly like, 6=like, 7=extremely likeFigure 4.15 Effect of Baking Time Towards Overall Parameter

The result of the effect of baking time toward the consumer overall

acceptance could be seen in Figure 4.15. From the statistical analysis using two

factor ANOVA, there was no effect of baking time towards the consumer

acceptance of rice bran brownies in term of overall parameter.

The result of the interaction of rice bran concentration and baking

time toward the consumer acceptance of overall parameter could be seen in Table

4.3. From the statistical analysis using two factor ANOVA, there was interaction

between rice bran concentrations and baking time towards the consumer

acceptance of rice bran brownies in terms of overall parameter, and as shown in

Table 4.3, there was significant different of the rice bran brownies made using

different rice bran concentrations and different baking time towards the consumer

acceptance in term of overall parameter parameter.

56

Baking Time4.48

4.5

4.52

4.54

4.56

4.58

4.6

4.62

4.64

4.66

4.6a

4.6514a

4.5429a


Table 4.3 Interaction of Rice Bran Concentration and Baking Time towards Texture Parameter


0% 10% 20% 30% 40%

35 minutes 5.5143e 4.8000cd 4.5714bc 4.2286ab 3.8857a

45 minutes 5.2286de 4.8000cd 4.5429bc 4.6286bc 4.0571a

55 minutes 4.7286c 4.8000cd 4.5714bc 4.8000cd 3.8143a



interaction between rice bran concentrations and baking time towards the overall

acceptance of rice bran brownies, and as shown in Table 4.3, there was significant

different of the rice bran brownies made using different rice bran concentrations

and different baking time towards the consumer acceptance in term of overall

parameter. From the Table 4.3, the rice bran brownies which gave the highest

acceptance was the rice bran brownies made with 0% rice bran and 35 minutes

baking time, which was not significantly different with rice bran brownies made

with 0% rice bran and 45 minutes baking time. Rice bran brownies made with

10% rice bran and 35 minutes baking time, 10% rice bran and 45 minutes baking

time, 10% rice bran and 55 minutes baking time, 30% rice bran and 55 minutes

baking time and 0% rice bran and 45 minutes baking time were not significantly

different as can be seen in the Table 4.3. Therefore it could be assumed, that

increasing the rice bran concentration in the making of rice bran brownies up to

30% concentration would produce rice bran brownies which was still acceptable

for the consumer.

57

4.2.2 Physical Analysis

4.2.2.1 Texture

The texture of rice bran brownies made using different rice bran

concentration and different baking time analyzed using texture analyzer. The

textural parameter which was observed was hardness parameter. The result of the

effect of rice bran concentration toward the hardness parameter could be seen in

Figure 4.16.

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05Figure 4.16 Effect of Rice Bran Concentration Towards Hardness Parameter


effect of rice bran concentration towards the hardness parameter of rice bran

brownies. As shown in Figure 4.16, there was significant different of the rice bran

brownies made using different concentration of rice bran towards the hardness

parameter. The highest value of hardness was given by rice bran brownies made

with 40% rice bran concentration and the lowest one was given by rice bran

58


1000

2000

3000

4000

5000

6000

7000

8000

6050.522a6363.705ab

7073.377bc 6910.001bc

7535.644c

0%10%20%30%40%

brownies made with 0% rice bran concentration. From Figure 4.16, It could be

seen that as the rice bran concentration increased the value of hardness also

increased. The hardness value of rice bran brownies made with 40% rice bran

concentration was higher and significantly different compared to the rice bran

brownies made with 0 and 10% rice bran concentration, however it was not

significantly different with rice bran brownies made with 20 and 30% rice bran

concentration. This result is similar with several result which was already

conduced, regarding the incorporation of rice bran in the food products. Huang et

al (2005) studied the effect of rice bran concentration towards the hardness of

pork meatballs, and it resulted in the increasing of hardness value as the rice bran

concentration increased. Another research was conducted by Sairam et al (2011),

and showed similar result, in that research the rice bran was incorporated in the

bread making, and as the rice bran concentration increased, the value of hardness

also increased. Therefore it could be assumed that the rice bran concentration had

positive correlation toward the increasing of the hardness value in a food product.

59

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05Figure 4.17 Effect of Baking Time Towards Hardness Parameter


effect of baking time towards the hardness parameter of rice bran brownies. As

shown in Figure 4.17, there was significant different of the rice bran brownies

made using different baking time towards the hardness parameter. The highest

value of hardness was given by rice bran brownies made with 55 minutes baking

time and the lowest value was given by rice bran brownies made with 35 minutes

baking time. From Figure 4.17, It could be seen that as the baking time increased

the value of hardness also increased. The hardness value of rice bran brownies

made with 55 minutes baking time was higher and significantly different

compared to the rice bran brownies made with 35 and 45 minutes baking time.

Hui et al (2008) stated that the duration of baking is related to the characteristic of

the finished product. During baking process, moisture loss is occurred gradually,

and this could be the cause why the hardness of the rice bran brownies increased

as the baking time increased. It could be assumed that as the baking time

increased, the moisture content decreased and therefore affected the textural

60

Baking Time5800

6000

6200

6400

6600

6800

7000

7200

7400

6366.126a

6778.847a

7214.977b


properties of the rice bran brownies, in term of hardness. From the statistical

analysis using two factor ANOVA, there was no interaction between rice bran

concentrations and baking time towards the hardness parameter of rice bran

brownies.

4.2.2.2 Moisture Content

The moisture content of rice bran brownies made using different rice

bran concentration and different baking time was analyzed. Moisture content was

considered as an important parameter in determining the quality of baking, as

stated by Hui et al (2008), water plays a major role during baking process because

water reacts with baking ingredients and evaporates when heated. The result of the

effect of rice bran concentration toward the hardness parameter could be seen in

Figure 4.18. From the statistical analysis using two factor ANOVA, there was

effect of rice bran concentration towards the moisture content of rice bran

brownies. It could be seen in Figure 4.18 that there was significant different of the

rice bran brownies made using different concentration of rice bran towards its

moisture content.


61

Figure 4.18 Effect of Rice Bran Concentration Towards Moisture Content

The highest moisture content was given by rice bran brownies made

with 40% rice bran concentration and the lowest one was given by rice bran

brownies made with 0% rice bran concentration. From Figure 4.18, It could be

seen that as the rice bran concentration increased the moisture content also

increased. The moisture content of rice bran brownies made with 40% rice bran

concentration was higher and significantly different compared to the rice bran

brownies made with 0, 10, 20, and 30% rice bran concentration. The moisture

content of rice bran brownies made using 30% rice bran concentration was not

significant different with the one made using 20% rice bran concentration,

however it was significant different with rice bran brownies made using 0 and

10% rice bran concentration. This result was coherent with the result which was

conducted by Saputra (2008), in that result rice bran was incorporated in cookies,

and by substituting wheat flour with 25 % rice bran in the cookies the moisture

content of the product was increased. Similar result was obtained from research

conducted by Delahaye (2005), whereas as the rice bran concentration increased

62


0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

12.96%a14.03%ab 14.48%bc

15.67%c

17.09%d

0%10%20%30%40%

the moisture content of the product was also increased. From this information, it

could be assumed that increasing the rice bran concentration might be contributed

in the increasing of moisture content in a bakery product.

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05Figure 4.19 Effect of Baking Time Towards Moisture Content

The result of the effect of baking time toward the moisture content

could be seen in Figure 4.19. From the statistical analysis using two factor

ANOVA, there was effect of baking time towards the moisture content of rice

bran brownies. It could be seen in Figure 4.19 that there was significant different

of the rice bran brownies made using different baking time towards its moisture

content. As shown in Figure 4.19, Rice bran brownies made with 35 minutes

baking time gave the highest moisture content while the rice bran brownies made

with 55 minutes baking time gave the lowest moisture content. From Figure 4.19,

It could be seen that as the baking time increased the moisture content was

decreased. It could be correlated with the theory stated by Sakin et al (2007),

during baking moisture transfer is occurred, which consists of internal and surface

63

Baking Time0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2 18.77%a

14.31%b

11.46%c


evaporation. So it could be assumed that the prolonged baking time would reduce

the amount of moisture in bakery products. From the statistical analysis using two

factor ANOVA, there was no interaction between rice bran concentrations and

baking time towards the moisture content of rice bran brownies.

4.2.2.3 Water Activity

Water activity was one of the observed parameter in the making of

rice bran brownies, because water activity was considered as an important

parameter to the quality of rice bran brownies. As stated by Hui et al (2008),

water activity is a vital parameter for food monitoring, and the value of water

activity is related to the moisture content of the food product.

The result of the effect of rice bran concentration toward the water

activity could be seen in Figure 4.20. From the statistical analysis using two factor

ANOVA, there was effect of rice bran concentration towards the water activity of

rice bran brownies. It could be seen in Figure 4.20 that there was significant

different of the rice bran brownies made using different concentration of rice bran

towards its water activity. The highest water activity was given by rice bran

brownies made with 40% rice bran concentration and the lowest one was given by

rice bran brownies made with 10% rice bran concentration. From Figure 4.20, It

could be seen that as the rice bran concentration increased the water activity was

also increased.

Notes : Means followed by the same letter are not significantly different in Duncan Test at α=0.05Figure 4.20 Effect of Rice Bran Concentration Towards Water Activity

Although the rice bran brownies made using 10% rice bran

concentration gave the lowest water activity among the others, from the statistical 64

analysis it was not significantly different with the rice bran brownies made using

10 and 20% rice bran concentration, however it was significant different with rice

bran brownies made using 30 and 40% rice bran concentration. This result could

be correlated with the moisture content of the rice bran brownies, as the rice bran

concentration increased, the moisture content was increased, therefore it could be

assumed that the increasing moisture content affect the water activity in rice bran

brownies, as stated in the theory above regarding the relation of moisture content

and water activity.

The result of the effect of baking time toward the water activity could

be seen in Figure 4.21. From the statistical analysis using two factor ANOVA,

there was effect of baking time towards the water activity of rice bran brownies.


65

Rice Bran Concentration0.660

0.670

0.680

0.690

0.700

0.710

0.720

0.682a0.678a

0.690a

0.709b

0.713b

0%10%20%30%40%

Figure 4.21 Effect of Baking Time Towards Water Activity

The result of the effect of baking time toward the water activity could

be seen in Figure 4.21. From the statistical analysis using two factor ANOVA,

there was effect of baking time towards the water activity of rice bran brownies.

As shown in Figure 4.21, there was significant different of the rice bran brownies

made using different baking time towards its water activity. Rice bran brownies

made with 35 minutes baking time gave the highest water activity while the rice

bran brownies made with 55 minutes baking time gave the lowest water activity

value. From Figure 4.21, It could be seen that as the baking time increased the

water activity was decreased. This phenomenon could be correlated with the result

of the moisture content analysis, whereas it showed similar result. As the baking

time increased, the moisture content decreased. Since water activity had a

relationship with moisture content, it could be inferred that the decreasing of

water activity as the baking time increased was affected by the moisture content of

the food product. From the statistical analysis using two factor ANOVA, there

66

Baking Time0.650

0.660

0.670

0.680

0.690

0.700

0.710

0.7200.714a

0.692b

0.677c


was no interaction between rice bran concentrations and baking time towards the

water activity of rice bran brownies.

4.3 Proximate Analysis of Rice Bran Flour

The proximate analysis of rice bran flour was conducted to determine

the nutritional value of rice bran. The result of the proximate analysis could be

seen in the Table 4.4.

Table 4.4 Proximate Composition of Rice Bran FlourAnalysis Amount (Research Data) Amount (Huang et al, 2005)Moisture Content 5.59% 11.23%Ash Content 18.69% 8.20%Protein Content 17.18% 15.00%Fat Content 15.51% 20.79%Carbohydrate Content 43.09% 35.78%Total Dietary Fiber Content 22.67% 26.98%

From Table 4.4, it could be seen that rice bran flour which was used in

this research had different amount of proximate composition. This difference

could be attributed to the variety of the rice from which the rice bran was derived.

Huang et al (2005) studied the composition of rice bran flour obtained from

different rice cultivator, and rice bran which derived from different rice varieties

would have different proximate composition. The total dietary fiber in rice bran

flour used in this research was 22.67% as shown in Table 4.4, and according to

Delahaye et al (2005) rice bran was considered as a good source of dietary fiber.

4.4 Determination of the Best Gluten Free Rice Bran Brownies Formulation

The best gluten free rice bran brownies formulation was determined

by sensory analysis. From the result of sensory analysis, the gluten free rice bran

brownies which was selected as the best gluten free rice bran brownies 67

formulation was the rice bran brownies made using 30% rice bran concentration

and 55 minutes baking time. Regarding the statistical analysis, the rice bran

brownies made using 30% concentration and 55 minutes baking time was not

significantly different with rice bran brownies made with 10% rice bran and 35

minutes baking time, 10% rice bran and 45 minutes baking time, and 10% rice

bran and 55 minutes baking time as could be seen in Table 4.3. Rice bran

brownies made using 30% rice bran and 55 minutes baking time, although had

lower acceptance compared to rice bran brownies made using 0% rice bran

concentration with 35 and 45 minutes baking time, was still acceptable for the

consumer in term of overall acceptance. The nutritional composition of rice bran

brownies made using 30% rice bran and 55 minutes baking time could be seen in

Table 4.5.

Table 4.5 Proximate Composition of The Best FormulationAnalysis AmountMoisture Content 11.06%Ash Content 2.68%Protein Content 6.74%Fat Content 30.91%Carbohydrate Content 48.61%Total Dietary Fiber 7.79%

According to Handori (2006), the serving size of brownies is 125

gram. Because the total dietary fiber content was 7.79%, so the total dietary fiber

in the rice bran brownies per serving size was 9.74 grams. As stated by Choo and

Dreher (2001), food containing 20% or more RDA of dietary fiber could be

categorized as “high in” or “rich in” fiber, Therefore the best gluten free rice bran

brownies formulation obtained from this research could be categorized as food

which was high in fiber.

68

CHAPTER V

CONCLUSIONS AND SUGGESTIONS

5.1 Conclusion

The preliminary research was conducted to determine the best wheat

flour replacer in the making of gluten free rice bran brownies. The gluten free

flour which was incorporated as the wheat flour replacer was cassava flour, potato

flour, and rice flour. Sensory analysis was conducted in order to evaluate the

consumer preference towards the rice bran brownies product made from different

types of flour. From the result of the sensory analysis, among the cassava flour,

rice flour and potato flour, rice bran brownies made using cassava flour gave the

highest value of overall acceptance compared to the others. Therefore it could be

concluded that cassava flour was the best wheat flour in the making of gluten free

rice bran brownies. From the result of the preliminary research, cassava flour

would be used in the making of rice bran brownies in the main research.

The main research was conducted to determine the best rice bran

concentration and the best baking time in the making of gluten free rice bran

brownies. The subjective analysis was done using sensory analysis and the

objective analysis was done towards the hardness, moisture content, and water

activity of the rice bran brownies product. From the result of the sensory analysis,

the best rice bran concentration to produce the gluten free rice bran brownies was

30% rice bran concentration, while the best baking time was 55 minutes. From the

result of sensory analysis it could be concluded that rice bran might contribute to

70

the consumer perception of taste, aroma and texture because as the rice bran

concentration increased the consumer acceptance was decreased. From the result

of objective analysis, the increasing of rice bran concentration as well as baking

time would increase the hardness of the rice bran brownies. The increase of rice

bran concentration also attributed to the increasing of the moisture content and

water activity, and as the baking time increased the moisture content and water

activity was decreased. The proximate composition of the best gluten free rice

bran brownies formulation was 11.06 % moisture content, 2.68 % ash content,

6.74 % protein content, 30.91 % fat content, 48.61 % carbohydrate content, and

7.79% dietary fiber content. The best gluten free rice bran brownies formulation

was considered as high fiber food because it contained more than 20% of dietary

fiber RDA per serving size.

5.2 Suggestion

Rice bran has already been incorporated in several food product, such

as brownies as done in this research. Further study on the shelf life of the product

made using addition of rice bran needs to be done. Furthermore, study towards

method to increase the shelf life stability of a food product with rice bran addition

also needs to be done, it might be possible that pre – treatment of the rice bran

before processing could affect the shelf life stability of the food product

incorporated with rice bran although it has not yet studied extensively.

Furthermore, a research about the optimization of the gluten free rice bran

brownies formulation could be conducted to increase the consumer acceptance

towards the gluten free rice bran brownies product.

71

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APPENDICES

76

Appendix A. Hedonic Test Questionnaire

QUESTIONNAIRE UJI HEDONIK

NAMA : TANGGAL :

SAMPEL : BROWNIES

Intruksi: Cicipilah sampel dari kiri ke kana sesuai kode sampel yang tertera pada kuesioner, lalu berikan penilaian berdasarkan aroma, rasa, warna, tekstur, dan penerimaan keseluruhan (berdasarkan tingkat kesukaan anda) dengan spontan tanpa membandingkan antar sampel. Bilaslah mulut dengan air mineral setiap selesai mencoba sampel. Pencicipan sampel dilakukan satu kali saja tanpa pengulangan. Terima kasih.

Kode SampelAromaRasaWarnaTeksturOverall

Keterangan :

1=sangat tidak suka 5=agak suka

2=tidak suka 6=suka

3=agak tidak suka 7=sangat suka

4=netral

77

Appendix B. Sensory Analysis Procedure

1. Hedonic Test (Meilgaard et al, 2007)

The hedonic test is a sensory evaluation method to determine the

consumer acceptance of the product based on the overall sensory qualities of the

food product. The hedonic test is done using scale from 1 to 7 (1 = extremely

dislike, 2 = dislike, 3 = slightly dislike, 4 = neutral, 5 = slightly like, 6 = like, 7 =

extremely like). This test is performed by 70 untrained panelist. The panelists are

required to taste and evaluate the sample. The panelists are informed not to

compare the sample with the other samples.

78

Appendix C. Physical Analysis Procedure

1. Texture Profile Analysis

The physical characteristic of the rice bran brownies was done by measuring the

hardness parameter of the brownies. The equipment which was used to measure

the texture of the brownies is Stable Micro System texture analyzer. The texture

was measured by using cylindrical probe TA 25/1000 with 50 mm diameter. The

measure the texture of the brownies, the brownies sample should be put in the

texture analyzer table, and then the proper probe should be used based on the

texture characteristic of the food product. The test speed for the texture

measurement was 1.0 mm/s and the measurement result in terms of number and

graph are shown by Texture Exponent software.

79

Appendix D. Chemical Analysis Procedure

A. Moisture content analysis using Oven method (AOAC, 2005).

1. Moisture content analysis is done by weighing five grams of sample

and put the sample into the evaporating dish which has constant

weight.

2. The sample is then dried in the oven for 6 hours at 105C. Before

weighed in analytical balance, the sample should be cooled down first

in the desicators, and then the sample should be dried again until the

constant weight is obtained. The moisture content calculated is wet

basis moisture content.

Moisture content (%) = x− y

x × 100%

Where:

x = initial weight of the sample before drying in gram

y = final weight of the sample after drying in gram

B. Ash content determination, using Dry ashing method (AOAC, 2005).

1. Ash content determination is done by weighing five grams of sample

using analytical balance, the sample is put into crucible. The crucible

should have constant weight before used for weighing.

2. After the sample is put in the crucible, the sample is burnt on the burner

until the white smoke disappears.

80

3. The next step is ashing the sample in the furnace at 450C for 1 hour and

then after 1 hour the temperature should be raised up to 550C. The ashing

process is finished when the color changed from grey to white.

4. The resulted ash is then weighed using analytical balance and the ash

content is calculated using the formula below.

Ash content (%) = x− y

z × 100%

Where:

x = weight of evaporating dish and the sample after ashing in gram

y = weight of evaporating dish in gram

z = weight of the sample in gram

C. Protein content determination using Micro Kjeldahl method (AOAC,

2005).

1. The protein analysis is conducted by weighing two grams of sample and

then the sample is put into Kjeldahl tube and the addition of 7 grams of

K2SO4, 5 mg of selenium, 15 ml of 96% H2SO4, and 10 ml of 35% H2O2

are done.

2. And then, the next step is the destruction of the sample at 420 C, the

sample is destructed until the solution became clear and then sample is

cooled down.

3. The next step is placing the tube the Kjeldahl distillation equipment.

After that, the addition of 25 ml of 4% saturated boric acid and 3 drops of

mixed indicator are done. The mixed indicator is mixture of methyl red

and methylene blue and should be put into erlenmeyer flask. The flask is

81

placed below the condenser and the tip of condenser pipeline should be

soaked in boric acid solution.

4. The next step is the distillation process. The distillation process is done

by the addition of NaOH 35% for 5 minutes.

5. 0.2 N HCl is used to titrate the result of distillation until slightly pink

color appeared. The protein content is calculated as percent of nitrogen as

showed by the equation below.

% N = (ml HCl−ml blank ) × N HCl ×14.007

weight of sample (mg) × 100%

The percentage of nitrogen is multiplied by specific conversion factor

based on type of sample used to obtain the percentage of protein content.

D. Fat content, using Soxhlet method (AOAC, 2005).

1. In the fat content analysis using soxhlet method, the sample used is five

grams of water-free sample, the sample is wrapped using filter paper

(thimble) and then it is put into Soxhlet equipment.

2. After that, the condenser should be put above Soxhlet equipment. The

round bottom flask is filled with petroleum benzene (solvent) and boiling

chips. The round bottom flask is put under Soxhlet equipment. The

extraction process of fat from sample is required for about 6 hours.

3. The extraction result is heated in oven at 105C. Then the sample should

be cooled down in desiccators and weighed until reaching the constant

weight. The fat content can be calculated using the equation below.

Fat content = weight of fat extracted (g)

weight of sample (g) × 100%

82

E. Carbohydrate content, using By difference method (AOAC, 2005)

Carbohydrate content (%) = 100% - (% moisture + % ash + % protein + % fat)

F. Total Dietary Fiber Analyses (AOAC, 2005)

1. The fat contained in the samples need to be extracted with petroleum

eter for 15 minutes.

2. One gram of dry fat-free samples and 25 ml of 0.1 M buffer sodium

phosphate is added to the erlenmeyer.

3. Termamyl enzyme with amount of 0.1 ml is added to the mixture and

then covered with aluminium foil. The mixture is then incubated in the

water bath at temperature 100 oC for 15 minutes.

4. The mixture in the erlenmeyer is cooled down, after cooling, 20 ml

aquadest and HCl 1 M is added to the mixture. The pH of the mixture

should reach 1.5

5. After the pH of the mixture reach 1.5, 100 mg of pepsin enzyme added

the the erlenmeyer covered again with alumunium foil and then incubated

inside the water bath at temperature 40 oC and agitated for 60 minutes.

After that, the addition of 20 ml of aquadest and NaOH was done, to adjust

the pH of the mixture to reach 6.8

6. Then, 100 mg of pancreatin is added to the mixture. The erlenmeyer is

closed again, and incubated in the waterbath at temperature 40 oC and

83

agitated for 60 minutes. Addition of HCl is done to adjust the pH to reach

4.5.

7. It was filtered with dry crucible (pores 2) which has been weighed, and

contains 0.5 gram dry celite.

8. The mixture is then washed with 10 ml aquadest twice.

9. The filtrate and the precipitate are used to differentiate insoluble fiber

and soluble fiber. The filtrate is used to determine the soluble fiber, while

the precipitate is used to determine the insoluble fiber.

10. The precipitate need to be washed with 10 ml ethanol 95 % and 10 ml

acetone twice in order to get the insoluble fiber. After that, the precipitate

is dried in 105 oC until it reaches constant weight (12 hours). (A)

11. Then, the precipitate ia ashed in furnace 550 oC for 5 hours. It was

cooled in dessicators and weighed until the weight is constant. (B)

% Insoluble fiber = (A – B – C )/W x 100%

A = weight after being dried (gram)

B = weight after being ashed (gram)

C = weight of fat free blank (gram)

W = sample weight

84

12. The soluble fiber can be determined by adding water to the filtrate until

reaching volume 100 ml. The 400 ml of 95 % ethanol is added and the

mixtures is cooled down for 1 hour.

13. It then filtered with dry crucible (pores 2) which has been weighed and

contains 0.5 gram dry celite.

14. The filtrate then washed with 10 ml ethanol 78 %, 10 ml ethanol 95 %

and 10 ml acetone, each was done twice. Then it was dried in temperature

105 oC until the weight is constant (12 hours ) (A)

15. The filtrate is then ashed in furnace at 550 oC for 5 hours, and cooled

down in desicator to be weighed after reaching constant weight. (B)

% Soluble fiber = (A – B – C )/W x 100%

A = weight after being dried (gram)

B = weight after being ashed (gram)

C = weight of fat free blank (gram)

W = sample weight

Total Dietary Fiber (%) = Insoluble fiber (%) + Soluble Fiber (%)

85

Appendix E. Hedonic Test for Aroma Parameter Result of The Preliminary

Research

Panelist Cassava Flour Rice Flour Potato Flour Wheat Flour

1 5 6 6 62 5 5 6 53 6 5 4 64 6 5 2 55 7 6 5 76 3 4 2 47 5 6 6 58 6 6 2 69 6 4 4 510 6 5 4 611 4 5 5 312 4 4 4 413 7 2 5 414 6 3 6 715 6 4 6 616 5 6 6 517 6 6 6 618 5 4 2 619 5 7 5 620 2 2 2 321 6 3 5 622 4 2 5 223 2 5 6 524 4 4 6 425 4 4 5 526 5 5 6 527 2 2 3 228 5 3 3 329 4 4 5 430 4 6 2 531 6 6 6 632 6 6 6 733 5 6 6 534 5 5 6 535 6 3 5 436 4 4 3 537 5 6 5 638 6 4 5 539 6 3 2 6

86

40 6 5 6 641 4 7 7 542 6 4 5 643 4 4 4 544 5 6 4 545 2 6 3 346 6 6 6 647 3 3 3 248 7 5 5 749 5 5 6 350 6 4 1 651 6 6 3 652 6 6 6 553 6 4 6 454 6 6 5 655 6 6 5 756 5 5 3 557 7 7 7 758 6 5 4 259 6 6 7 560 6 3 1 561 6 3 6 762 6 7 7 763 6 6 4 664 5 4 4 665 6 5 3 466 5 5 4 567 6 4 4 468 6 4 5 569 6 5 4 470 4 5 5 7Note:1 = extremely dislike2 = dislike3 = slightly dislike4 = neutral5 = slightly like6 = like7 = extremely like

87

ANOVAAroma

Sum of Squares df Mean Square F Sig.

Between Groups 17.043 3 5.681 3.120 .026Within Groups 502.543 276 1.821Total 519.586 279

AromaDuncana

Flour NSubset for alpha = 0.051 2

Potato 70 4.5857Rice 70 4.7571 4.7571Wheat 70 5.0857Cassava 70 5.2000Sig. .453 .067Means for groups in homogeneous subsets are displayed.a. Uses Harmonic Mean Sample Size = 70.000.

88

Appendix F. Hedonic Test for Taste Parameter Result of The Preliminary

Research

Panelist Cassava Flour

Rice Flour Potato Flour Wheat Flour

1 3 4 6 42 5 5 5 53 3 4 3 44 6 3 4 65 6 5 4 76 5 4 2 57 1 5 6 38 2 6 2 39 2 5 3 310 4 5 3 411 1 2 4 212 2 3 2 213 6 3 3 414 4 4 5 415 5 3 2 416 5 5 6 617 3 3 3 218 6 3 2 519 6 7 5 520 2 4 4 521 3 5 2 422 6 3 2 623 4 5 3 524 2 5 6 525 3 5 5 426 2 3 6 227 2 3 3 328 4 5 5 429 5 5 2 530 6 4 5 731 3 5 4 332 6 6 6 533 4 4 3 634 2 3 1 335 6 3 3 636 2 3 3 337 3 2 3 438 3 3 4 339 7 1 2 6

89


90

ANOVA

TasteSum of Squares df Mean Square F Sig.


TasteDuncana


Potato 70 3.5857Rice 70 4.1000Cassava 70 4.2143Wheat 70 4.4000Sig. 1.000 .234Means for groups in homogeneous subsets are displayed.a. Uses Harmonic Mean Sample Size = 70.000.

91

Appendix G. Hedonic Test for Texture Parameter Result of The Preliminary

Research



1 5 5 2 62 4 4 4 43 3 4 4 44 4 3 4 45 6 5 6 66 3 5 2 37 2 6 6 78 6 6 1 59 4 6 2 610 3 5 3 311 4 5 3 512 4 4 2 513 6 4 2 414 5 3 3 515 6 4 2 616 6 5 6 517 6 5 4 618 5 4 4 619 6 7 3 720 4 5 5 321 4 5 2 422 5 2 3 523 3 5 3 324 3 5 5 425 6 5 3 626 4 5 4 727 4 4 4 428 6 4 3 729 6 6 4 630 7 3 2 631 5 4 2 432 6 7 3 633 6 3 3 534 2 3 1 335 6 4 4 736 4 5 2 637 4 5 2 538 5 4 4 439 4 5 1 5

92


93

ANOVATexture



TextureDuncana

Flour NSubset for alpha = 0.051 2 3

Potato 70 3.3143Rice 70 4.4571Cassava 70 4.9143wheat 70 5.0857Sig. 1.000 1.000 .441Means for groups in homogeneous subsets are displayed.a. Uses Harmonic Mean Sample Size = 70.000.

94

Appendix H. Hedonic Test for Overall Parameter Result of The Preliminary

Research



1 3 4 6 62 5 5 5 53 5 5 4 54 6 4 3 55 6 5 5 66 5 6 2 47 2 6 6 58 3 6 2 59 3 6 3 610 5 5 4 511 3 5 5 312 3 3 2 313 6 3 3 514 4 3 4 615 6 5 3 616 5 5 6 717 4 5 5 318 6 4 3 719 6 7 4 720 3 3 4 421 4 5 3 622 6 2 4 623 4 5 4 524 3 5 6 425 5 5 5 426 3 5 6 627 3 4 4 328 4 5 6 629 6 6 4 730 6 4 3 731 3 4 4 532 6 7 4 733 5 4 3 634 3 5 2 435 6 3 5 636 3 4 3 537 3 2 3 538 5 4 4 539 5 2 2 6

95

40 5 5 5 641 3 3 4 542 5 4 6 343 6 2 2 444 6 6 5 545 4 4 4 446 5 4 4 747 3 5 2 348 6 5 5 649 3 2 4 350 6 2 4 651 2 3 1 252 6 3 3 553 7 3 6 454 6 6 5 655 4 5 6 656 7 5 3 557 3 3 5 458 6 5 3 359 5 6 7 460 7 3 1 661 7 3 3 662 7 4 5 663 6 6 4 564 6 6 4 665 7 3 4 666 6 3 3 567 7 3 3 668 7 2 3 569 7 3 4 470 7 2 4 7

Note:1 = extremely dislike2 = dislike3 = slightly dislike4 = neutral5 = slightly like6 = like7 = extremely like

96

ANOVAOverall



OverallDuncana


Potato 70 3.9429Rice 70 4.2143Cassava 70 4.9143Wheat 70 5.1286Sig. .235 .348Means for groups in homogeneous subsets are displayed.a. Uses Harmonic Mean Sample Size = 70.000.

APPENDIX I. Texture Analysis of The Preliminary Research97

Hardness (g. Force)

Cassava Flour


Replication 1 5248.609 3715.686 6009.317 4822.847

4766.138 3938.524 6183.232 4443.458

Average 5007.374 3827.105 6096.275 4633.152

Replication 2 7707.611 4536.134 6522.175 6751.903

6331.653 4563.834 6972.743 5810.251

Average 7019.632 4549.984 6747.459 6281.077

Replication 3 6091.520 4324.873 10801.501 6567.101

5434.169 4534.274 10162.479 7302.796

Average 5762.845 4429.573 10481.99 6934.948

Replication 4 7346.344 5267.213 8998.610 7791.055

7846.385 4907.875 11325.384 5779.864

Average 7596.365 5087.544 10162 6785.460

Replication 5 5663.967 3416.502 10206.234 4556.668

5353.758 3117.869 8963.468 4528.831

Average 5508.862 3267.185 9584.851 4542.749

Replication 6 5997.534 3733.601 10069.733 5121.480

6115.361 3816.494 11571.029 4636.322

Average 6056.448 3775.048 10820.38 4878.901

98

ANOVAHardness


Between Groups

73120881.610 3 24373627.203 14.440 .000

Within Groups 33759360.174 20 1687968.009Total 1.069E8 23

HardnessDuncana

Flour NSubset for alpha = 0.05

1 2 3Rice 6 4156.0733Wheat 6 5676.0478 5676.0478Cassava 6 6158.5877Potato 6 8982.1587Sig. .056 .527 1.000Means for groups in homogeneous subsets are displayed.a. Uses Harmonic Mean Sample Size = 6.000.

APPENDIX J. Moisture Content of The Preliminary Research

99

Cassava Flour

Evaporation Dish

Wet Sample Evp. Dish + Dry Sample

Moisture Content

Average

Replication 1 41.0126 5.0185 45.1452 17.65% 17.74%20.3799 5.0218 24.5065 17.83%

Replication 2 22.6522 5.0697 26.7833 18.51% 18.82%20.1297 5.0167 24.1874 19.12%

Replication 3 34.1157 5.1211 38.4049 16.24% 16.24%38.1409 5.0178 42.3436 16.24%

Replication 4 27.2551 5.0891 31.406 18.44% 19.00%27.4057 5.0456 31.4643 19.56%

Replication 5 41.8255 5.1255 45.9812 18.92% 19.17%40.1991 5.0453 44.2644 19.42%

Replication 6 30.8814 5.0678 35.1254 16.26% 16.18%20.7188 5.0681 24.9703 16.11%

Rice Flour Evaporation Dish


Moisture Content

Average

Replication 1 42.7812 5.1975 46.9481 19.83% 19.30%43.6979 5.0471 47.7978 18.77%

Replication 2 35.4775 5.0446 39.6328 17.63% 19.31%38.6775 5.0134 42.6386 20.99%

Replication 3 20.3656 5.1215 24.4716 19.83% 20.00%22.3453 5.0786 26.3994 20.17%

Replication 4 18.7256 5.0445 22.7749 19.73% 19.25%18.7767 5.0312 22.8637 18.77%

Replication 5 38.6576 5.0256 42.8147 17.28% 19.72%41.2352 5.0987 45.2044 22.15%

Replication 6 34.1213 5.0345 38.0967 21.04% 21.68%43.2878 5.2278 47.3491 22.31%

Potato Flour Evaporation Dish


Moisture Content

Average

100

Replication 1 22.0776 5.0754 26.4715 13.43% 13.78%18.7285 5.0801 23.0911 14.12%

Replication 2 18.792 5.1014 23.2755 12.11% 12.67%41.0252 5.1211 45.4686 13.23%

Replication 3 34.5775 5.0871 39.0363 12.35% 11.78%41.7283 5.1271 46.2805 11.21%

Replication 4 40.2551 5.0665 44.6851 12.56% 13.54%22.6552 5.0453 26.9676 14.53%

Replication 5 22.6213 5.0298 27.0367 12.22% 12.38%18.9263 5.1342 23.4169 12.54%

Replication 6 18.5671 5.1217 22.9448 14.53% 14.63%34.6143 5.0981 38.9615 14.73%

Wheat Flour Evaporation Dish


Moisture Content

Average

Replication 1 42.7812 5.0404 47.173 12.87% 13.32%41.2527 5.1593 45.7014 13.77%

Replication 2 34.1613 5.0751 38.575 13.03% 14.65%42.7187 5.0667 46.9609 16.27%

Replication 3 34.5356 5.0781 38.8201 15.63% 15.07%34.2278 5.2341 38.7023 14.51%

Replication 4 22.0717 5.1435 26.5233 13.45% 15.09%22.1898 5.0716 26.413 16.73%

Replication 5 20.3756 5.0312 24.5106 17.81% 16.72%41.0126 5.1211 45.3334 15.63%

Replication 6 18.6785 5.1672 23.0951 14.53% 15.13%18.7291 5.0139 22.9545 15.73%

Example of Calculation

Moisture content (%) = Initial weight of sample – Weight of dried sample x 100%Initial weight of sample

= ((5.0185) g – (45.1452-41.0126) g) x 100% 5.0185 g

= 17.74 %

101

ANOVAMoisture


Between Groups .016 3 .005 42.874 .000Within Groups .003 20 .000Total .019 23

MoistureDuncana

flour NSubset for alpha = 0.051 2 3 4

potato 6 .131297wheat 6 .149967cassava 6 .178590rice 6 .198746Sig. 1.000 1.000 1.000 1.000Means for groups in homogeneous subsets are displayed.a. Uses Harmonic Mean Sample Size = 6.000.

102

APPENDIX J. Moisture Content of The Preliminary Research

Types of FlourAw

Average1 2

Cassava Flour

Replication 1 0.673 0.671 0.672Replication 2 0.663 0.668 0.666Replication 3 0.667 0.669 0.668Replication 4 0.671 0.672 0.672Replication 5 0.664 0.661 0.663Replication 6 0.659 0.663 0.661

Rice Flour


Potato Flour


Wheat Flour


103

ANOVAAw


Between Groups .007 3 .002 59.220 .000Within Groups .001 20 .000Total .008 23

Aw

Duncana

flour NSubset for alpha = 0.051 2 3

potato 6 .63433wheat 6 .66317cassava 6 .66700rice 6 .68167Sig. 1.000 .305 1.000Means for groups in homogeneous subsets are displayed.a. Uses Harmonic Mean Sample Size = 6.000.

104

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