Some of the ways that can be applied, among others, the cooling, wrapping with polyethylene and the addition of chemicals. Storage of agricultural commodities usually also be combined with the efforts of preservation / damage prevention measures such as waxing, use of KMnO4, Samper fresh, CaCl2.
1. Cooling
Storage of fruits and vegetables require the optimum temperature to maintain the quality and freshness. Storage by means of cooling is one way to keep the product in a low-temperature room. Low temperatures are expected to reduce the aging activities and microbial activity destroyer. The conditions to be considered in the low-temperature storage is temperature, humidity, air composition, and pressure.
All of these factors varies according to each commodity as listed in Table 5. Storage temperatures below 15 0C and above the freezing point of the material known as cold storage (storage chilling). Although the cooling can increase the shelf life of agricultural commodities, but cooling can also lead to damage to the so-called chilling injury. Damage to the cooling of bananas in the critical temperature (13 0 C) is a dull color, change in taste and can not cook.
According to Santoso (2006), the optimum conditions of storage of bananas is 11-20 0 C and 85-95 percent RH. In this condition oxidative metabolism such as respiration goes more perfect. Cooling does not affect the quality of taste, except when the fruit is cooled excessively so that the ripening process stops.
2. Packaging in plastic / polyethylene (PE)
Storage with plastic can be used to slow ripening fruit vegetables. Wisnuwati (2011) states that the storage is done by inserting a plastic fruit vegetables in plastic bags with a thickness of about 0.02 mm (plastic bags used), and tied tightly and perforated plastic surfaces with a pin or pin as much as 4-5 hole. The vegetables can be stored at room temperature and maturation process can be delayed at least 3 days of normal conditions.
Water loss can be reduced by giving the wrapper on the material to be cooled. One type of wrapper is a pretty good use of plastic wrapping. Based on research Scott and Robert (1987) storage is still green bananas in polyethylene bags can slow the ripening of bananas for 6 days at a temperature of 20 o C.
Slowing the process of fruit ripening vegetables can be explained as follows. Sealed plastic change (modify) the air so it is not the same as the conditions of the air outside the plastic bag. Ethylene gas from vegetables remain volatile and accumulate in it so that the holes were made not too big to be enough to throw a pile of ethylene gas in the bag.
3. Fruit with Emulsion Coating Wax
Storage with wax coating technique is one way to maintain the freshness of the vegetables though placed at room temperature. Wax coating to prevent evaporation is too high, preventing breathing too quickly and to beautify the appearance. Wax coating can be done by using beeswax, carnauba wax, and paraffin wax plus emulsifier such as oleic acid and tretanolamin. Some vegetables can be a layer of wax is potatoes, carrots, peppers, cucumbers, and tomatoes. How to wax coating is by dipping the vegetables into the wax emulsion for 30 seconds and drained with aerated.
More fully, Santoso (2006) describes the process of waxing fruits and vegetables. For example, commodities are to be coated llilin mangoes, apples, star fruit, banana, guava, tomato, red pepper, green beans, cucumber, wax. Materials used for waxing process is triethanolamine, oleic acid, some of the necessary equipment include plastic buckets, enamel pot, wire basket, a thermometer, a stirrer, a stop watch. Ways of making wax and waxing process is as follows.
Ways of making wax emulsions can be done by heating the wax with a temperature of 90-95 ° C) until the wax melts. The solution was added with oleic acid little by little and slowly while stirring. Furthermore plus trietanolamine stirring constantly with temperature is kept constant, then added water (hardness), which already bring to a boil (90-95 0 C) by slowly, stirring constantly.
The solution was cooled rapidly using running water to get a wax emulsion with the desired concentration can be done dilution with water (hardness). To use should be used wax emulsions are still fresh. Fruits and vegetables that have been drained, put in a wire basket and then dip it in wax emulsion (concentrations of 6 and 12%) until everything is submerged for 30-60 seconds and then removed and drained on a draining rack with dry air blown so that the coating felt on the entire surface skin and not sticky. Materials that have been coated with wax can be stored at room temperature or in the refrigerator.