UNIVERSITI DARUL IMAN MALAYSIA

KAMPUS KOTA

LAB REPORT

PLANT PHYSIOLOGY

EFFECT OF STORAGE ATMOSPHERES ON THE FRUIT QUALITY

NAME : MOHAMAD IRFANUDIN BIN ROSLI

MATRIC ID : 022427

COURSE : AGRICULTURAL BIOTECHNOLOGY

NO. EXP : EXPERIMENT 14

DEMONSTRATOR : CIK LINDA

LECTURER : ASSOCIATE PROFESSOR DR NASHRIYAH BINTI MAT ASSOCIATE PROFESSOR DR HAFSAH BINTI JA’AFAR

DATE : 9 TH APRIL 2009

Title: Effect of storage atmospheres on the fruit quality

Introduction:

In storing the fruits, we should know how to keep them in good condition in order to maintain the quality and grade level. People have long been aware that overripe and rotting fruit could accelerate ripening of nearby fruit in the closed storage compartment during shipment. Accelerated fruit ripening during storage and shipment is due to the release of ethylene gas hormone by these fruits. As we know, ethylene is been used by the farmer or trader to keep the fruit ripening and quick harvesting period. So, they can pick the green and fresh fruit such as banana and mango before shipping. In the ship, they will apply ethylene gas to ensure ripening before reaching the supermarket counter.

In other case, the degree of fruit ripening is caused by several factors such as low temperature and high ambient CO2 concentration in order to suppress respiration and continuous exchange of air to prevent ethylene gas build up. For example, Heidi mango fruits were harvested at the conventional stage and at an advanced stage of maturation from an orchard in South Africa. Following commercial pack line treatment, fruits were stored at 12.5°C either under controlled atmosphere storage (low or high concentrations of CO2) or under normal atmosphere storage. After 21 days, fruits were allowed to ripen at 20° under normal atmosphere. Quality was assessed on ripening. Fruits harvested at an advanced stage of maturation did not appear to benefit from CA storage. Pulp browning in these fruits was elevated. In fruits harvested at the conventional stage of maturation, CA storage reduced surface scald, pulp browning and internal breakdown, and enhanced shelf life and taste. The semi-commercial adoption of CA storage in Heidi mango is recommended for the coming season.

Objectives;

1. To determine the effect of storage atmosphere on fruit quality2. To determine the weight, colour, hardness and taste of various fruits3. To obtain skills in measuring the sugar content of fruits ( % Brix) by using digital

reflactometer4. To determine aspects of fruit quality affected by potassium carbide treatment5. To explain the roles of KOH and KMnO4 in regulating the storage atmosphere6. Increase the knowledge and understanding

Materials:

o Fruit ( banana, mango, papaya, pineapple, Citrus sp)o Benomyl fungicideo Polyethylene bago Potassium carbide o Potassium permanganate (KMnO4)o Potassium hydroxide (KOH)o Analytical balanceo Digital reflactometer ( PL-3 ATAGO)

Methods;

10 fruits of uniform size, colour and without injury are selected

Each fruit is washed and treated by 500 mg/L benomyl ( 5 minutes)

At the beginning, the fruit is weighed and recorded

Do two replications for each sample PE bag (holed) PE bag (sealed)

PE bag with 10% KOH (Petri dish) PE bag with 10% KOH and 10%(KMnO4) ( 2 separately Petri dish)

PE bag with Potassium carbide (wrapped in moistened paper)

Results:

Replicate 1 Before experiment After experimentPineapple 1353.3 1346.2

Mango 197.2 186.3Citrus 27.8 25.9

Banana 57.1 55.8Papaya 1261.5 1257.3

Replicate 2Pineapple 1297.2 1294.3

Mango 188.9 194.2Citrus 18.0 17.1

Banana 64.4 62.2

Fruit / treatment Color Hardness Taste Sugar content (% Brix)

Replicate 1

Pineapple Green Sweet 13.1Mango Green Sour 10.5Citrus Green Sour 12.5

Banana More green than

yellow with black

spot

24.2

Papaya More yellow

than green

Sweet 12.9

Replicate 2Pineapple Green Sweet 12.9

Mango More yellow

than green

Sour 13.2

Citrus Green Sour 12.8Banana More

green than yellow

with black spot

22.5

Papaya - - - -

Picture’s sample

Pineapple

Treatment Before Ripen After Ripen

Holed PE

(control/air-

cured)

PE (sealed)

-

PE + KOH

PE + KOH +

KMnO4 -

PE Carbide

Mango

Treatment Before Ripen After Ripen

Holed PE

(control/air-

cured)

PE (sealed)

-

PE + KOH

PE + KOH +

KMnO4 -

PE Carbide

-

Citrus

Treatment Before Ripen After Ripen

Holed PE

(control/air-

cured)

PE (sealed)

PE + KOH

PE + KOH +

KMnO4 - -

PE Carbide

-

Banana

Treatment Before Ripen After Ripen

Holed PE

(control/air-

cured)

PE (sealed)

-

PE + KOH

PE + KOH +

KMnO4

PE Carbide

-

Papaya

Treatment Before Ripen After Ripen

Holed PE

(control/air-

cured)

PE (sealed)

-

PE + KOH

PE + KOH +

KMnO4 -

PE Carbide

Discussion:

Fruit ripening is a developmentallo,y controlled process that is regulated by plant hormones. Ripening is a process in fruits that causes them to become more edible. In general, a fruit becomes sweeter, less green, and softer as it ripens. Fruits are considered mature when they have stopped growing and once they have acquired the capacity to ripen. Indicators of maturity can be chronological, physical (e.g., a change in color or a decrease in fruit firmness), or chemical (e.g., a reduction in the amount of starch or acidity, or a gain soluble solids).

Fruits can be categorized as climacteric and non-climacteric. Climacteric fruit is bananas, pears, and tomatoes while non-climacteric such as strawberries and oranges depending on whether or not they have a respiratory peak during their ripening process. The reason for a respiratory climacteric is still poorly understood. One hypothesis is that respiration is required for repair processes to avoid loss of mitochondrial function and uncoupling.

In this experiment, we are using several types of Tropicana fruit such as banana, papaya, mango, and Citrus sp. We pick the green and fresh fruit and put into conditions in order to determine the effect of storage atmosphere on fruit quality. At first, each fruit is weighed to determine initial mass by using analytical balance. Then there are placed in some treatments or ripening agent by using PE bag, KOH, KOH and KMnO4 and Potassium carbide. This treatment will measure the rate of ripening in different condition.

Based on the result, we can see Mango on first replicate shows larger interval between initial weight value and final weight value. It is 10.1 g interval. It is because the ripening process denatures the fruit tissue and contributes to less of fruit weight.Potassium carbide is used for ripening the fruit artificially in some countries. Industrial-grade calcium carbide may contain traces of arsenic and phosphorus and thus use of this chemical for this purpose is illegal in most countries. Potassium carbide once dissolved in water produces acetylene which is the essential gas for ripening process. The moisture in the air reacted with the calcium carbide to release the gas acetylene, which apparently has the same effect as ethylene gas.

PE bag with holes around is less efficient compared to the sealed PE bag. It is because the holes allow ethylene gas release out the bag while sealed PE bag will clump the air and increasing the rate of fruit ripening inside the bag. The effect of potassium permanganate (KMnO4) on the ripening process of papaya fruits and other fruit samples by monitoring the ethylene emission rates is reported. The ethylene emission was monitored by a photoacoustic spectrometer. The use of the ethylene absorber reduces the autocatalytic process of ethylene during papaya fruit ripening. For 20 g of KMnO4 the maximal intensity of the ethylene emission decreases by a factor two. Using the same amount of KMnO4, a reduction of about 2.2% in the concentration of ethylene for a mixture of 1ppmv of ethylene in synthetic air was observed. KOH also plays similar roles like KMnO4. The combination of these both ripening agent will meke rapid ripening to the fruit samples.

Besides that, banana is the most common fruit used in trading materials. When bananas are ripening, they release carbon dioxide which will build up in a ripening room. The CO2 production begins as the fruit ripens enters the “climacteric” phase, or the period when bananas release ethylene and have an elevated rate of respiration (along with a

great deal of other physiological changes). Respiration involves the uptake of oxygen, the release of carbon dioxide, and the breakdown of starches. Carbon dioxide concentrations above 1% (10,000 ppm) will retard ripening, delay the effects of ethylene and cause quality problems. Therefore, it is recommended to vent rooms by opening the doors for 20 minutes every 12 hours, after the first 24 hours of ripening. Other venting methods are by automatic fan (either timed or sensor-based) or "flow-though" (constant) ventilation.

Tomato also has similar method in undergoing ripening process. Tomatoes will respond their best and ripen evenly when external ethylene is applied soon after harvest. On average, fruit ripened at 64° to 70°F to a breaker stage can then be stored for more than two weeks at 55°F (12.5°C) until a full red color is reached. The greatest cause of tomatoes suffering a big loss in flavor and retail quality is cold. When tomato pulp temperatures are allowed to stray out of the proper temperature range, internal damage results in a mushy appearance of flavor decline. Therefore, it is crucial to ensure that pulp temperatures remain above 55°F at all times and at all stages of ripeness.

Finally, when fruits undergo ripening process, they will change in colour and weight. Colour will turn from the light or dark green to the more attractive colour like yellow, orange or reddish. For example, banana will turn to the light yellow when getting ripe. Weight for each sample also become decrease due to denatures of linkage in fruit tissue make in lighter than younger fruit. Then, we use digital reflactometer in order to measure the sugar content of fruits ( % Brix) . Banana shows higher percentage of Brix ( sugar content) compare to the other types of fruits.

Conclusion:

As the conclusion, we are able to know the degree of fruit ripening is caused by several factors such as low temperature and high ambient CO2 concentration in order to suppress respiration and continuous exchange of air to prevent ethylene gas build up

References:

1) http://www.catalyticgenerators.com/tomriptip.html

2) http://chemistry.about.com/od/chemistryexperiments/ss/ethyleneexp_4.htm

3) http://jp4.journaldephysique.org/index.php?option=article&access=standard&Itemid=129&url=/articles/jp4/pdf/2005/03/jp4125201.pdf

4) http://hort.oregonstate.edu/stotzhe/pdf/FRUIT%20RIPENING.pdf