The controlled atmosphere storage can be done with the following ways:
1. Hypobaric or Sub-atmospheric System:
In hypobaric system at the low pressure the produce is placed in a vacuum-tight an refrigerated container by removing air. The process of ripening and senescence are greatly retarded by decreasing respiration and evacuation of ethylene given out by the produce. This process is very expensive.
2. Waxing:
The outer surfaces have a natural waxy layer which is removed during handling and washing. Application of waxy layer artificially provides protection against decay organism. Reduction in evaporation and respiration takes place after waxing. It is reported that were refrigerated facilities are not available waxing is alternate to increase storage- life of fruits.
3. Polymeric Film:
In controlled atmosphere the semi-perishable film and packaging material must be come in use while establishing “Controlled atmosphere” produce package. In this process respiration and permeation occurs simultaneously. Uptake of O2 and evolution of CO2, C2H4 and H2O by the produce at the same times specific restricted permeation can brought by packaging film. It folds that polythene bags retarded respiration and transpiration also increase shelf-life and retention of fresh fruits.
Ex. The shelf-life of mango can be increased by plastic film.
4. Chemicals:
The use of growth regulators delay ripening and senescence. GA markedly retards ripening of banana. Alkaline potassium permanganate on a silicate carrier proved effective in the complete absorption of ethylene from banana held in sealed polythene bags.
Maleic hydrazide is used in ripening fruits. 1000 -2000 ppm MH delayed ripening in mango. Ripening of Sapota very early done by MH foliar spravs of IPC reduced the rate respiration, ripening and spoilage of Sapota during storage. Storage life of citrus was prolonged by application of 2-4D, and the 2,4,5-T. In orange , physiological losses in weightless Vit-C content occurs by the application of 2,4,5-T. spray of calcium chloride and calcium nitrate resulted in enhancement of shelf-life of mango and guava.
5. Irradiation:
The potential use of ionizing rotation to extend the shelf-life of perishable varieties. The microorganism are destructed by Gamma rays and alters the physiology of fruits.
Same studies shows that ripening of the mango can be retarded by application of ionizing radiation.
Use of Radiation:
Ionizing radiation generally caused delayed ripening. Minimum insect infestation and retarded microbial spoilage of fruits. These effect many result in shelf-life extension, destruction of a contaminating organism. In the past 10 year the quarantine problems has been successfully demonstrated.
He fruit on which disinfection by radiation has been successful are: fruit by control on citrus, mango, weevil control, papaya fruit fly control for some fruits, like mango, banana, and papaya, an additional bonus obtained in the use of irradiation for disinfestations purposes is retardation of ripening.
The major interest in the application of ionizing radiation to vegetables is thorough sprout inhibition. A dose of 5 to 15 krad given shortly after the harvest was effectively shown to inhibit sprouting of onions. Chemically it is shown that low-dose. Gamma- radiation affected the nucleic acid metabolism is the meristematic tissue of onion the synthesis of soluble RNA at the start of growth was particularly suppressed in irrigated inner bunds. Thus, subsequent growth was inhibited.
In the case of mango ionizing radiation cause extending of shelf-life at ambient as well as at refrigeration temperature. Three possible reasons were given concerning the effect of gamma radiation on shelf-life extension:
a) Interference with basic metabolic process resulting in delay of ripening and senescence.
b) Destruction of spoilage micro-organisms and
c) Fruit fly and or weevil disinfestations.
Source: agriinfo
