The Eco Friendly Earthen Pot Cool Chamber

Published Date: 02 Nov 2017

1Department of Botany and Microbiology, College of Science, King Saud University,

Riyadh, Kingdom of Saudi Arabia.

2Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK.

3Department of Botany and Microbiology, A.V.V. M Sripushpam College, Thanjavur, India.

4PG and Research Department of Microbiology, Srimad Andavan Arts & Science College,

Thiruvanaikoil, Tiruchirappalli - 620 005, India.

(Received: 09 March 2012; accepted: 11 April 2012)

Present investigation was performed to assess the effect of storage of fruits and

vegetables in eco-friendly earthen pot cool chamber (EPCC-2) for the purpose of house

hold storages. Fruits and vegetables were stored in (EPCC-2) to find out the physiological

loss in weight (PLW), heterotrophic microbial population, biochemical characteristics,

organoleptic changes and shelf –life period. The results were compared with ambient and

refrigerator storages. It was observed that the vegetables stored in earthen pot cool

chamber remained fresh with a minimum changes in physiological weight loss, microbial

load, organoleptic values and biochemical characteristics. EPCC-2 showed a higher degree

of consumer preferences when compared with other two storage systems.

Key words: Post harvest, Earthen Pot Cool Chamber, Organoleptic Values,

Physiological Weight Loss, Fruits and Vegetables Storage, Nutritive Value.

and handling1. The excellent quality of fruits and

vegetables are generally available only for few days

and it cannot be stored for long period under the

ambient condition, because most of the agricultural

products are perishable and harvested in summer

time. In harsh dry climates, food preservation plays

a vital role in maximizing both economic and

nutritional yield from the rare opportunity of a good

harvest. The dry heat significantly reduces the life

of produce and the fruits and vegetables are spoiled

in enormous amount2. Also, Fruit and vegetables

are highly susceptible to microbial contamination

during growth, harvest and postharvest

operations3. There is more than 15% of

postharvest decay of fruits and vegetables are due

The world wide agricultural practices

have been improved due to the results of high

yielding varieties, irrigation facilities and modern

technologies, but the worldwide post-harvest fruit

and vegetables losses are as high as 30 to 40%

and even much higher in some developing

countries due to improper post harvest processing

86 MURUGAN et al., Biosci., Biotech. Res. Asia, Vol. 9(1), 85-96 (2012)

to the action of bacteria, fungal and mold, which in

turn affects the quality of fruits and vegetables

during storage4. Despite high market demand after

production, 20 to 50% of commodities are lost

before reaching consumers due to a shortage of

cooling facilities5. These reports indicated that the

producers have to suffer huge economic losses

due to lack of proper preservation methods. Hence,

the reduction of post harvest losses could

enhance trade and distribution, and increase the

farmer’s income.

Fresh produces can play an important

role in satisfying the demand of the customers, by

providing high nutrition, good flavor and attractive

color. There are several factors influencing the

storage of fruits and vegetables including physical,

physiological, mechanical, hygienic conditions,

pathological and environmental factors such as

temperature, relative humidity and oxygen balance.

This is due to inadequate storage facilities. At

present many chemical and mechanical

refrigeration methods are widely used to reduce

the post harvest losses. But most of these devices

are not eco-friendly, high cost, and needs

electricity. More over these kinds of storage will

cause pollution. Hence, ground-breaking and low

cost technology must be needed.

Traditional processing technologies are

generally effective in storing fruits and vegetables

by providing high nutrition, good flavor, and

attractive color6. There are more work have been

done in the field of zero energy cool

chambers7,8,9,10,11,12,13,14,15.The main aim of our study

is to create and maintaining low temperature, high

relative humidity storage facilities by natural

means, because most tropical produces should be

stored at 20-250 C and 85 - 95% of relative humidity.

Currently only few house hold cooling storage

chambers have been designed and used15,16. These

chambers were made by traditional pottery making

procedure and used for storing the harvested fruits

and vegetables fresh for a reasonable time.

However the cool chambers used by earlier workers

have some demerits like needs two vessels (inner

and outer), plenty of water and sand for cooling

purposes, leakage of water into the inner vessel,

(it leads to enhance more fungal growth) and very

difficult to transfer from one place to another.

Beside, all storage cool chambers do not have the

routinely free air circulation facilities i.e. cool chain

management. Uneven cooling will cause

inconsistent product quality within the storage

chamber. The cool chain management is essential

for removing respiratory heat produced by the

stored fruits and vegetables. The removal of

respiratory heat is necessary, because it increases

the product temperature and surrounding air

temperature, which in turn is responsible for

increasing respiration and causes acceleration of

substrate utilization, predominantly sugars17,18. So

cool chain management ensuring retains the quality,

safety and extends shelf life of fruits and

vegetables. Chain Cool method is usually 75-90%

faster than room cooling. Due to high cost and

high consumption of power supplies, make it

impossible maintaining the cold chain management

in poor countries. To overcome above mentioned

problems, in the present investigation two feet

height and 25 cm width EPCC-2 was designed and

analyzed for house hold storage purposes.

The outcome of the present study was

aimed to help the rural population by providing

them with low cost, easily handling storage

facilities to store the fruits and vegetables fresh

up to 9 days. This cooling device can store 7-8 kg

of vegetables and the total cost of this cooling

system is less than Rs 400 only, which is affordable

to the poors.

MATERIALSAND METHODS

Experimental Design

The EPCC-2 consist of two water jackets

(5 and 3.5 cm diameter each) one behind another at

1 feet interval for water storage (Figs.1- 2). Three

numbers of holes (2cm diameter each) present at

bottom and lid of the pot for free air circulation

inside the pot. The pot system was standing on 2

feet height earthen pot stand. After the whole

system was immersed in the water for 30 minutes,

1 lit of water was poured into the jackets and

allowed the system for 2 to 3 hrs for cooling the

water by evaporative principle method. After that

87- 92% of relative humidity and 4-5o C less than

room temperature was calculated inside EPCC-2.

Working principle of EPCC-2

Generally, pot is made of a porous clay

material. When pot is fed with water; by evaporative

principle method the water evaporates into the air

raising its humidity and at the same time reducing

MURUGAN et al., Biosci., Biotech. Res. Asia, Vol. 9(1), 85-96 (2012) 87

Table 2. Changes in the total weight of different products after storage in

different storage system for nine days

S. Nature Samples Weight changes (gms) during Final

No. of the storage intervals (Days) Weight

Storage loss(Percentage)

1stday 3rdDay 5thDay 7thDay 9thDay

1. Room Carrot 123±2 122.5±2 119.3±2 115.5±1 103±2 15.57

Temperature Ladies finger 49.36±2 45.79±2 41.94±2.5 37.30±2 35.58±3 27.91

Banana 78.08±3 73.47±2 67.19±1 61.04±2 56.02±1 28.24

2. Refrigerator Carrot 130±2 130±2 125±3 120±2 118±1 9.23

storage Ladies finger 46.59±1 46.39±2 45.52±2 44.74±2 42.84±1 8.04

Banana 85.13±2 84.38±2 82.07±2 78.91±3 75.59±2 11.19

3. EPCC2 Carrot 137±3 135.6±1 132.9±2 130.5±2 128±0.8 6.50

Ladies finger 41.3±2 41±2 40.9±1 40±2 39.6±2 4.11

Banana 79±1 78±1 77.7±1 76±1 74±1 7.59

Table 3. Total heterotrophic bacterial load in the stored products

during different storage periods

S. Nature of Sample Total heterotrophic bacterial population

No. storage after different storage duration

( x105 cfu/ g )

1st day 3rd day 5th day 7th day 9th day

1. Room Carrot 30 61 210 TNTC TNTC

Temperature Ladies finger 32 56 196 TNTC TNTC

Banana 16 53 103 190 TNTC

2 Refrigerator Carrot 4 22 50 63 137

storage Ladies finger 2.0 12 20 65 185

Banana 13 20 39 50 70

3 Carrot 13 24 73 90 120

EPCC2 Ladies finger 20 35 70 85 97

Banana 8 24 43 51 80

TNTC – Too Numerable Too Count

Table 1. Table showing evaluation scale for organoleptic qualities.

Scale Skin color Flavour Texture Taste & Overall quality

Appearance Odour expected

10 Very Excellent Very hard Excellent Excellent

Attractive

08 Attractive Very acceptable Hard Quiet acceptable Quiet acceptable

06 Good Good Soft Good Good

04 Fair in Poor Very soft Fair Fair

Appearance

02 Poor Poor Too Soft Poor Poor

88 MURUGAN et al., Biosci., Biotech. Res. Asia, Vol. 9(1), 85-96 (2012)

Table 4. Total fungal colonies in the stored products during different storage periods

S. Nature of Sample Total heterotrophic fungal population

No. storage in different periods

days( x105 cfu/ g )

1st day 3rd day 5th day 7th day 9th day

1. Room Carrot 12 48 187 TNTC TNTC

Temperature Ladies finger 16 42 234 TNTC TNTC

Banana 9 27 80 272 TNTC

2 Refrigerator Carrot 16 30 47 74 98

storage Ladies finger 2 22 50 67 82

Banana - 7 22 33 60

3 Carrot 4 9 12 18 38

EPCC2 Ladies finger 8 13 23 42 46

Banana 2 7 10 14 23

TNTC – Too Numerable Too Count

Table 5. Changes in the carbohydrate content in the stored products during the different

storage periods (percentage loss is given in parenthesis)

S. Nature Sample Carbohydrate content (mg/1g)

No. of storage

1st day 3rd day 5th day 7th day 9th day

1. Room Carrot 99±4 97±3 93±3 86±4

Temperature 102±4 (2.94) (4.90) (8.82) (15.68)

Ladies finger 76.1±3 65.3±2 64.2±3 60.2±3

79.0±3 (3.67) (17.34) (18.73) (23.79)

Banana 390±0.4 379±.6 368±0.8 359±0.5

402±0.6 (2.98) (5.72) (8.45) (10.69)

2 Refrigerator Carrot 99±4 95±2 91±3 88±3

storage 102±4 (2.94) (6.86) (10.78) (13.72)

Ladies finger 78.3±2 76.8±3 75.3±2 73.1±2

79.0±3 (0.88) (2.78) (4..68) (7.46)

Banana 390±0.8 378±0.5 370±0.8 363±0.7

402±0.6 (2.98) (5.97) (7.96) (9.70)

Carrot 100±3 98±4 96±4 94±4

3 EPCC2 102±4 (1.96) (3.92) (5.88) (7.84)

Ladies finger 77.9±3 77.0±3 76.4±2 75.0±3

79.0±3 (1.39) (2.53) (3.29) (5.06)

Banana 394±0.3 388±0.4 379±0.4 371±0.3

402±0.6 (1.99) (3.48) (5.72) (7.71)

the temperature of the air inside the pot where kept

the food samples for storing purposes.

Sample collection

For the present study freshly harvested

Carrot, Ladies finger and banana were obtained

from farmer’s field, Alwarkurichi, Tamilnadu, India.

The samples were collected in sterile polythene

bags to avoid the possible contamination and

dehydration19.The collected samples were washed

with sterile water and packed with sterile polythene

pack with some respiratory holes and were stored

in room temperature, refrigerator and in EPCC-2.

The initial weight of the samples was noted and

stored in all three types of storages. All stored

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Table 6. Changes in the protein content in the stored products during the different storage

periods (percentage of loss is given in parenthesis)

S. Nature of Sample Protein content (mg/g)

No. storage

1st day 3rd day 5th day 7th day 9th day

1. Room carrot 9.0±3 8.6±2 8.1±2 7.3±1 6.8±2

Temperature (4.44) (10.00) (18.88) (24.44)

Ladies finger 18.4±2 17.5±1 17±1 16±2 14.2±1

(4.89) (7.60) (13.04) (22.82)

Banana 11.0±0.8 10.2±0.6 10.0±0.6 9.5±0.6 9.0±0.7

(7.27) (9.09) (13.63) (18.18)

2 Refrigerator Carrot 9.0±3 8.7±1 8.3±3 7.5±4 7.1±4

storage (3.33) (7.77) (16.66) (21.11)

Ladies finger 18.4±2 17.5±1 17±2 16.2±1 15±1

(4.89) (7.60) (11.95) (18.47)

Banana 11.0±0.8 10.8±0.6 10.2±0.6 9.8±0.7 9.0±0.6

(1.81) (7.27) (10.90) (18.18)

3 EPPC2 carrot 9.0±3 8.5±4 8.1±2 7.9±3 7.6±2

(5.55) (10.00) (12.22) (15.55)

Ladies finger 18.4±2 18.00±2 17.4±2 17.00±1 16.5±0.9

(2.17) (5.43) (7.60) (8.15)

Banana 11.0±0.8 10.9±0.5 10.7±0.3 10.6±0.4 10.3±0.7

(0.90) (2.72) (3.63) (6.36)

Fig. 1. Earthen Pot Cool Chamber -2 (EPCC-2)

vegetables were subjected to study on percentage

of physiological loss in weight (PLW), total

heterotrophic bacterial and fungal load, Changes

in the carbohydrate and protein content and

percentage changes in organoleptic values and

results were recorded for every 48 hrs up to nine

days.

Physiological Loss of Weight (PLW) (%)

The PLW of stored samples was

calculated by considering the differences between

initial weight and final weight of the stored samples

divided by their initial weight by using the following

formula15, 20.

PLW= Initial weight- Final weight x 100/ Initial

weight.

Total heterotrophic bacterial count

The initial and final microbial profiles were

studied. Each vegetables stored at 1st 3rd, 5th, 7th

and 9th days was taken out and it was not put into

the storage again. One gram of sample was cut,

homogenized and serially diluted with saline.

Serially diluted samples (0.5 ml) were plated on

plate count agar and potato dextrose agar to

determine bacterial and fungal load respectively.

All plates were incubated for 48 hrs at 37oC and 18-

220 C for counting bacterial and fungal colonies

respectively. Observations were recorded and the

results were expressed as colony forming units

(cfu) per gram21.

Bio-chemical analysis

The Bio-chemical content of

90 MURUGAN et al., Biosci., Biotech. Res. Asia, Vol. 9(1), 85-96 (2012)

Table 7a. Organoleptic qualities of Carrot sample stored in different storage system

S.No Nature Characters of Storage of Carrot in days Overall Percentage

of storage sample acceptability change

9 days of

Day0 Day1 Day3 Day5 Day7 Storage

1 Room Skin colour 9±0.6 7±0.2 6±0.4 4±0.5 6.00±0.4

Temperature appearance 10 57.50(F)

Flavour 8±0.2 6±0.4 5±0.3 4±0. 6 5.75±0.3

Texture 8±0.4 5±0.2 4±0.2 3±0.1 5.00±0.2

Taste 9±0.3 5±0.2 5±0.3 2±0.4 5.25±0.3

2 Refrigerator Skin colour 8±0. 2 7±0.5 4±0.6 3±0.3 5.50±0.4

storage appearance 10 50.60(F)

Flavour 8±0.5 7±0.4 3±0.1 3±0.2 5.25±0.3

Texture 7±0.4 6±0.4 4±0.2 3±0.5 5.00±0.3

Taste 8±0.2 5±0.4 3±0.2 2±0.5 4.50±0.3

3 EPCC2 Skin colour

appearance 10 10 9±0.2 9±0.6 9.50±0.2

10

Flavour 8±0.6 9±0.7 10 8±0.5 8.75±0.4 91.80(QA)

Texture 10 10 9±0.4 9±0.3 9.50±0.1

Taste 8±0.5 10 9±0.5 9±0.3 9.00±0.3

Note : P – Poor; F-Fair ; A- Acceptable; Q.A-Quite Acceptable .

Fig. 2. Auto card of Earthen Pot Cool Chamber -2 (EPCC-2)

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Table 7b. Organoleptic qualities of Ladies finger sample stored in different storage system.

S.No Nature Characters of Storage of Ladies finger in days Overall Percentage

of storage sample acceptability change

9 days of

Day0 Day1 Day3 Day5 Day7 Storage

1 Room Skin colour 8±0.2 4±0.3 3±0.2 1±0.5 4.00±0.3

Temperature appearance 10 57.50(F)

Flavour 8±0.6 8±0.7 8±0.5 6±0.3 7.50±0.5

Texture 7±0.5 6±0.1 4±0.2 2±0.4 4.70±0.3

Taste 8±0.4 8±0.3 7±0.5 6±0.4 6.70±0.4

2 Refrigerator Skin colour 9±0.5 7±0.6 6±0.4 5±0.3 6.70±0.4

storage appearance 10 62.50(F)

Flavour 9±0.2 8±0.3 8±0.2 6±0.3 7.80±0.2

Texture 8±0.3 7±0.4 7±0.5 7±0.2 5.50±0.3

Taste 7±0.3 6±0.4 6±0.4 5±0.5 5.00±0.4

3 EPCC2 Skin colour

appearance 10 10 8±0.5 6±0.3 8.50±0.2

10

Flavour 10 10 8±0.3 8±0.4 9.00±0.1 90.00(A)

Texture 9±0.3 9±0.7 9±0.5 8±0.6 8.80±0.4

Taste 10 10 10 9±0.5 9.75±0.1

Note : P – Poor; F-Fair ; A- Acceptable; Q.A-Quite Acceptable .

carbohydrate and protein in all the stored

vegetables were determined by Anthrone and

Lower’s method respectively22.

Organoleptic quality analysis

Organoleptic quality includes the typical

sensory properties of the vegetables: its skin color

appearance, flavor, texture, taste and odor were

also assessed by using evaluation scale (Table 1).

Samples stored in the three storage systems were

presented to a laboratory panel of five judges for

sensory evaluation by using suitable method23.

The panel was asked to rate the samples for skin

color appearance, flavor texture, taste and odor on

a 10 points hedonic scale using a numerical scale

ranging from 2 to 10, where 2,4,6,8 and 10,

represented as Poor, fair, good, attractive and very

attractive respectively (Table 1). All the scales were

converted into percentage wise. Vegetables

scoring lower than 4 out of 10 were considered

unacceptable. There were five samples assessed

for each storage in order to get average results.

The same vegetable was examined only once.

RESULTS AND DISCUSSION

In the present investigation the efficiency

of an EPCC-2 system to store vegetables was

studied in relation to the storage efficiency.

Vegetables stored in the EPCC-2 had good

acceptance at the end of nine days of storage period

than room temperature and refrigerator storages.

During this study period, changes in physiological

loss in weight (PLW), total heterotrophic bacterial

and fungal load, Changes in the carbohydrate and

protein content and organoleptic changes have

been analyzed and it was compared with room

92 MURUGAN et al., Biosci., Biotech. Res. Asia, Vol. 9(1), 85-96 (2012)

Table 7C. Organoleptic qualities of Banana sample stored in different storage system.

S.No Nature Characters of Storage of Ladies finger in days Overall Percentage

of storage sample acceptability change

9 days of

Day0 Day1 Day3 Day5 Day7 Storage

1 Room Skin colour 7±0.3 6±0.3 6±0. 4 4±0.3 5.75±0.3

Temperature appearance 10 55.60(F)

Flavour 8±0.2 6±0. 5 5±0.3 4±0.1 5.75±0.2

Texture 8±0.3 7±0.4 4±0.2 3±0.1 5.50±0.2

Taste 8±0.6 6±0.2 5±0.3 2±0.4 5.25±0.3

2 Refrigerator Skin colour 8±0.5 6±0.3 4±0.1 2±0.1 5.00±0.

storage appearance 10 51.80(F)

Flavour 8±0.4 7±0.3 3±0.1 3±0. 5 5.25±0.3

Texture 7±0.4 6±0.3 6±0.2 3±0.2 5.50±0.2

Taste 8±0.5 6±0.3 3±0.2 3±0.4 5.00±0.3

3 EPCC2 Skin colour

appearance 9±0.3 8±0.4 10 9±0.4 9.00±0.2

10

Flavour 9±0.4 8±0.5 9±0.5 8±0.4 8.50±0.4 85.70(A)

Texture 9±0.3 9±0.6 9±0.5 8±0.2 8.75±0.4

Taste 9±0.4 9±0.5 7±0.4 7±0.3 8.0±0.4

Note : P – Poor; F-Fair ; A- Acceptable; Q.A-Quite Acceptable .

temperature and refrigerator storages. Physical

parameters like temperature and relative humidity

was noted in all storage systems. It was observed

that the relative humidity was higher (87- 92%) in

EPCC-2 than room temperature (58- 60%) and

refrigerator (58 -61%). In terms of temperature, the

EPCC-2 has maintained 25-260 C i.e. less than 4-5oC

than room temperature (29-30oC). Where as in

refrigerator it was measured as 4-5o C

The loss of PLW of all stored products is

given in the Table 2. The weight of all three

products was recorded before keeping them in all

three storage units. After storage, weight changes

due to physiological stress were noted on 3rd, 5th,

7th and 9th days respectively and highly significant

differences were recorded. At the end of 9 days of

storage the total weight loss in EPCC-2 was noted

as 6.50 % in carrot, 4.11 % in tomato, 7.59 % in

banana respectively (Table 2). Whereas the total

weight loss in room temperature 15.57 %, 27.91 %

and 28.24 % and in refrigerator 9.23 %, 8.04 % and

11.09 % were noted respectively in different

produces. These results indicated that EPCC-2

showed low increase in PLW when compared to

other two storages. This might be due to minimum

mechanical stress, high relative humidity, reduced

temperature and minimum evaporation process

prevailing inside the cool chamber as compared to

room temperature and refrigerator. High

mechanical stress leads loss of quality during the

post harvest period19stated that stress leads to

loss of membrane integrality, leakage, loss of

permutation changes in the enzyme activity.

Temperature is the major environmental factor that

considerably affects the postharvest physiological

weight loss of stored vegetables24. In most of the

MURUGAN et al., Biosci., Biotech. Res. Asia, Vol. 9(1), 85-96 (2012) 93

cases moisture content of fresh fruits and

vegetables are very high (usually greater than 70%).

Therefore, the air inside the flesh is nearly saturated

that is, close to 100% relative humidity. The lower

humidity ratio causes desiccation and marked

softening of carrots together with some increase

in decay. High relative humidity is therefore

desirable for reducing physiological weight loss

during storage of fruits and

vegetables25.Temperature is the other major

environmental factor that considerably affects the

postharvest physiological weight loss of stored

vegetables24and the lower temperature and high

relative humidity must have reduced the respiration

and transpiration losses thereby lower mean weight

loss in stored products stored in Zero energy cool

chamber (ZECC). Fruit weight loss during storage

is attributed to loss of moisture and reserve food

materials by evapotraspiration and respiration

respectively 26. The high increase in PLW in room

and refrigerator, due to high mechanical stress,

water stress, freezing and chilling injury and

freezing injury reduced the physiological weight

loss of produces; it was reported15, 27that vegetables

stored in modified earthen pot cool chamber

showed low level of PLW than room and refrigerator

storages.

The total heterotrophic bacterial load in

the products stored at room temperature,

refrigerator and EPCC-2 at the end of nine days of

storage indicated significant variation (Table 3).In

the product stored at room temperature the

bacterial load was too numerable too count (TVC)

while in refrigerator storage the bacterial and fungal

colonization was less at the end of 9 days of

storages respectively and where as in the EPCC-2

preserved products the bacterial and fungal

colonization was minimum (Table 4). The main

reason for highest bacterial and fungal count in

the vegetable kept at room temperature was

because of the fact that room environment is a

good medium for the dispersion of microorganisms

whereas in refrigerator was due to mechanical

stress, chilling injury, ethylene stress, which leads

to the ooze out of nutrients, which provide a better

growth medium for the organisms. But in the EPCC-

1 the low temperature did not support the growth

of mesosphillic as well as psyhcrophillic bacteria.

Also, EPCC-1 has more fungal load it might be

caused more antibiosis effect on bacterial cells and

inhibiting the growth of bacterial cell15.Even though

EPCC-2 could maintain high level of humidity a

very low number of fungal colonies were noted

(Table 4). The reason might be the effect of calcium

carbonate adheres in the wall of EPCC-2. The Use

of calcium carbonate nanoparticles as an antimicrobial

agent is recommended in different fields

of medicine, food industry and agriculture and can

be of importance considering health and economic

issues28.

The carbohydrate and protein content of

three stored products were recorded before and

after storage (Table 5). It was found that after nine

days of storage period the carbohydrate and

protein content was reduced much in room

temperature than in refrigerator and EPCC-2 in all

stored samples. At the end of nine days of storage

the percentage of carbohydrate content decreased

in room temperature was noted as 15.68%, 23.79%

and 10.69% in carrot, ladies finger and banana

respectively where in refrigerator was 13.72%,

7.40% and 9.70% respectively. However there was

slight decrease in carbohydrate content of EPCC-

2 noted as 7.84%, 5.06% and 7.71% in all three

stored samples. It was found that the loss of

carbohydrate in the products stored in earthenware

storage system was less. Like carbohydrate

content, the protein content of the stored products

kept at earthenware storage system showed less

change compared to refrigerator and room

temperature storages (Table 6). The reason for the

low level of nutrient loss in EPCC-2 due to less

physiological changes in the samples, low

mechanical stress, less microbial activity especially

fungal growth by the inhibition of calcium

carbonate present in the pot and reducing more

respiration of fruits and vegetables by continuous

air supply through air holes of the pot. In general,

the storage life of commodities varies inversely

with the rate of respiration. During storage period,

organic materials (carbohydrates, proteins, and

fats) are broken down into simple end products

with a release of energy by respiration process5.

Respiration which increases in free sugars in some

fruit and vegetables are due to the breakdown of

polysaccharide and reduce the carbohydrate

content29. Temperature also regulates the rate at

which the Biochemical changes occur during

storage5.But in refrigerator storage, due to

wounding stress, as a result of chilling or

94 MURUGAN et al., Biosci., Biotech. Res. Asia, Vol. 9(1), 85-96 (2012)

mechanical injuries, microbial activity, and the

respiration rate and overall metabolic activities

usually increase. so it leads to decrease the

carbohydrate and protein content while in the

room temperature due to the higher temperatures

increase ethylene production and result in

advanced physiological and biochemical changes

in vegetables30.

The products stored in EPCC-2 were

noted the highest overall acceptability i.e. more

than 90% for the period of nine days with the

retention of fresh appearance, color, texture, taste

and flavor and was rated (Tables7A, 7B, 7C). So all

the products stored in EPCC-2 were mostly

acceptable or quit acceptable. But the overall

acceptability of the products stored under room

and refrigerator storage systems were noted as inbetween

50-60% only and all produces were

retained fair quality. From the result it is quite

evident that earthenware storage system is an

efficient device to preserve raw vegetables like

Carrot, Tomato, and banana for more than 9 days

in a good condition. The reason for high

organoleptic value in EPCC-2 were mainly because

the rise in relative humidity, low PLW, and

maintenance of other quality characteristics like

minimum loss of nutrient composition, staying

microbial activity and fall in temperature from

ambient condition . But in room temperature

storage low humidity was maintained hence the

water loss was higher whereas in refrigerator

dehydration process was taken placed. This might

be reason for maintained low level organoleptic

quality both in room and refrigerator storages

respectively. The higher relative humidity which

retains the water content of post-harvested sample

and higher temperature during storage, as a result,

fruits and vegetables loose firmness faster at higher

temperature due to high enzymatic activity31.Water

is an important factor in maintaining post harvest

quality; it helps to maintain pH inside the storage

area. Any change in pH results in water loss and

affect the appearance, texture and in some case

flavors. Water loss also affects the crispness and

trimness32. Maintaining of cool chain management

might be reduced worm temperature around the

vegetables and reduce the respiration rate and

maintained high level of organoleptic qualities. In

general, the storage life of commodities varies

inversely with the rate of respiration. This is

because respiration supplies compounds that

determine the rate of metabolic processes directly

related to quality parameters, eg. firmness, sugar

content, aroma, flavor, etc. Commodities and

cultivars with higher rates of respiration tend to

have shorter storage-life than those with low rates

of respiration and the loss of freshness of

perishable commodities depends on the rate of

respiration33.The main physiological manifestation

of metabolic activities include increased respiration

rate and in some cases, ethylene production and

the calcium chloride treatment which extent storage

life and reduce the incidence of physiological

disorder and storage rots34, 35.

CONCLUSION

Fresh produce has become one of the

most desirable foods because todays’s consumer

perceives it as being healthy, tasty, convenient

and fresh. All of these characteristic are strong

selling point to a busy and healthy conscious

consumer. Once harvested or purchased fruits and

vegetables must be stored under proper conditions,

the most important of which are temperature and

humidity. Very high and very low temperature

which affect rate of chemical reactions and the shelf

life of the produces. Hence, ambient temperature

and refrigerator like electrical instrumental storages

not suitable for fruits and vegetables storage

because both are maintain high and very low

temperature respectively. In order to overcome

these problems zero energy cool chambers was

developed and stored the produces11, 12, 14, 36, 37.But

it could be used to store fruits and vegetables for

mass scales storage in open space not for house

hold. So in order to house hold utility in the

present study, EPCC-2 was designed and studied.

At the end of nine days storage all stored produces

in the EPCC-2 had minimized the physiological loss

of weight and preserved organoleptic qualities,

biochemical chaecterisitics and extended the shelflife

compared to room temperature and refrigerator.

The reason might be EPCC-2 remove respiratory

heat produced by produces by cool chain

management by natural means, maintain high

relative humidity, low temperature and presence of

natural preservatives calcium hydroxide on wall of

the chamber. It is concluded that this house hold

storage chamber EPCC-2 is affordable for everyone

MURUGAN