EFFECTS OF MODIFIED ATMOSPHERE PACKAGING USING ACTIVE BAGS ON

THE SHELF LIFE AND QUALITY OF MANGO FRUITS

DANIEL MUTAHI KARUGAA85/3487/2010

SUPERVISOR: DR. JANE AMBUKO

INTRODUCTION Horticulture contributes significantly to the Kenya's

economy.

It is ranked the third most important foreign

exchange earner in Kenya after tourism and tea

respectively contributing 60% of the total export

earnings .

Mango is ranked 2nd after avocado in the fruit

industry.

Currently, there is an increasing demand for mango

locally, regionally & internationally leading to

increased production

Problem statement and justification Mango fruits being climacteric have a short shelf life(6-10

days) and are highly perishable.

This attributes are the main causes of post harvest losses in

the fruit.

There is need to use the applicable technologies to prolong

the shelf life of mango and maintain quality.

Packaging fruits under modified atmosphere is one of the

techniques employed to prolong fruit shelf life .

Active bag® packaging is a form of modified atmosphere

packaging that controls and prevents excessive water loss

from the packaged fruits enhancing fruit shelf life and

prevent shriveling

It also slows down metabolic processes such as respiration

through a modified in-pack gas composition.

Objective and hypothesis

OBJECTIVE

To evaluate the efficacy of modified atmosphere packaging using Activebag® to extend the postharvest shelf life of Ngowe and Apple mango fruit varieties.

HYPOTHESIS

The effect of Activebag® packaging on postharvest shelf life of mango fruit variet‘Apple’ and ‘Ngowe’ will not be different from that of ordinary bags .

Materials and method

Ngowe and Apple mango fruits (75% ripe) were harvested from commercial farms in Embu.

NGOWE MANGO

APPLE MANGO

Sampling ProcedureThe fruits were divided into 3 batches of 42 fruits for each

variety and labeled.

The 1st batch was packaged into commercially used polythene bags. The 2nd batch was packaged into Activebag®. The 3rd

batch was left unpackaged to serve as the control. ( Each treatment was replicated three times)

The packaged fruits, a self-sealing septum was inserted into the bags and tied from outside using rubber bands to facilitate measurement of changes in head-space gases (CO2 and Ethylene) every 2 days.

From the other packaged bags and control batch , 3 fruits were randomly sampled every 4 days for determination of other ripening related changes

The experimental design was completely randomized design (CRD) with 3 treatments and 3 replications

Analysed parameters

Cumulative weight – Digital weighing balance

Ethylene Evolution – Gas chromatograph

Respiration rate – Gas chromatograph

Peel and flesh Color – Color meter

0Brix(Total soluble solids) – Digital refractometer

Total titratable acidity – Titration with 0.1NaOH

Peel and flesh firmness- Penetrometer

Data is presented as means of replicates (6

or 3) with standard deviation

RESULTS

RESPIRATION AND ETHYLENE EVOLUTIONAPPLE NGOWE

Respiration and Ethylene levels increased in all the treatments upto a peak then reduced

Active bags are a form of MAP thus the trends for low CO₂ and ethylene levels in the

active bags compared to Control and Ordinary bags.

Also, active bags are fitted with ethylene absorbers which removed C2H4 from the

internal environment.

0

10

20

30

40

50

60

70

80

90

0 2 4 6 8 10 12 15

CO

2(m

L/K

G/H

R)

DAP

CONTROL

OB

AB

0

10

20

30

40

50

60

70

80

90

0 2 4 6 8 10 12 15

RES

PIR

ATI

ON

(mL/

KG

/HR

)

DAP

CONTROL

AB

OB

0

5

10

15

20

25

30

35

0 2 4 6 8 10 12 15

C2

H2

(uL/

KG

/HR

DAP

control

OB

AB

0

5

10

15

20

25

30

35

0 2 4 6 8 10 12 15

C2

H2

(uL/

KG

/HR

DAP

control

OB

AB

PEEL COLOR

APPLE NGOWE

0

20

40

60

80

100

120

140

0 4 8 12 15

HU

E A

NG

LE

DAP

APPLE

CONTROL PEEL

OB PEEL

AB PEEL

0

20

40

60

80

100

120

0 4 8 12 15 18

HU

E A

NG

LE

DAP

NGOWE

CONTROL PEEL

OB PEEL

AB PEEL

As the fruits ripened, peel hue angle reduced due change in color from green to yellow.

Packaged fruits retained a higher hue angle throughout the storage period with active

bag being the highest.

FLESH COLORAPPLE NGOWE

0

20

40

60

80

100

120

0 4 8 12 15

HU

E A

NG

LE

DAP

CONTROL FLESH

OB FLESH

AB FLESH

0

20

40

60

80

100

120

0 4 8 12 15 18H

UE

AN

GLE

DAP

CONTROL FLESH

OB FLESH

AB FLESH

As the fruits ripened, flesh hue angle reduced due change in

color from yellow towards orange.

Packaged fruits retained a higher hue angle throughout the

storage period with active bag being the highest in Ngowe mango.

FLESH FIRMNESS

APPLE NGOWE

0

5

10

15

20

25

30

35

40

45

50

0 4 8 12 15

FOR

CE(

N)

DAP

APPLE

CONTROL FLESH

OBFLESH

ABFLESH

0

5

10

15

20

25

30

35

1 2 3 4 5 6 7

FOR

CE(

N)

DAP

NGOWE

control flesh

Ob flesh

AB flesh

Firmness reduced with storageFruits packaged in active bag retained a higher flesh

firmness for both varietiesApple fruits retained a higher firmness compared to

ngowe fruits. in the package

PEEL FIRMNESS

APPLE NGOWE

0

10

20

30

40

50

60

70

0 4 8 12 15

FOR

CE(

N)

DAP

APPLE

CONTROL PEEL

OB PEEL

ABPEEL

0

5

10

15

20

25

30

35

40

0 4 8 12 13 15 18FO

RC

E(N

)DAP

NGOWE

control PEEL

OB peel

AB peel

%TTAAPPLE

NGOWE

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

1 2 3 4 5

%TT

A

DAP

control

OB

AB

0

0.05

0.1

0.15

0.2

0.25

0.3

1 2 3 4 5 6

%TT

A

DAP

CONTROL

OB

AB

TTA levels reduced with storage in both varieties.

Apple fruits had a higher %TTA levels than Ngowe fruits for all the

treatments.

Fruits packaged in Active bag maintained the highest %TTA levels

followed by Ordinary bag through out storage.

TOTAL SOLUBLE SOLIDSAPPLE

NGOWE

0

2

4

6

8

10

12

14

16

0 4 7 12 15 18

OB

RIX

DAP

APPLE

CONTROL

OB

AB

0

2

4

6

8

10

12

14

16

18

0 4 8 11 13 15 18

ob

rix

DAP

ngowe

CONTROL

AB

OB

In all the treatments and both varieties, °BRIX levels increased with

ripening

Fruits packaged in active bag retained the lowest °BRIX levels

compared to Ordinary bag and control for both varieties.

DISCUSSION AND CONCLUSIONActivebag® produced the longest shelf life compared to ordinary

bag and control because of their reduced rate of respiration and inhibition of ethylene production

Water loss was reduced in Active bag hence the slow loss in weight.

Consequently quality was preserved longer in Activebag followed by Ordinary bag ®.

Control fruits had the shortest shelf life and faster deterioration of quality.

Active bag packaging prolonged shelf life of both apple and ngowe mango fruits due to reduction in respiration and ethylene evolution consequently slowing down deterioration.

Apple mango fruits responded well to Packaging compared to Ngowe mango fruits

Active bag packaging could be used to prolong mango fruit shelf life and to maintain post harvest quality.

APPLE Apple mango

INSECONTROL ENDSTAGE HERE

INSERT AB ENDSTAGE HERE

APPLE