Apple's plastic film bag preservation

The principle of this method is mainly to rely on the respiration of the fruit itself to achieve deoxygenation, increase the concentration of carbon dioxide, and use the permeability of the plastic film to the gas, change the composition of the storage atmosphere, and achieve spontaneous atmosphere. When the apple is stored for 3 to 6 months using this method, the loss rate does not exceed 5%. The material of the bag is a 0.04-0.07 mm thick non-toxic polyvinyl chloride film. When the temperature is high or the amount of fruit stored in each bag is large, a thin plastic film should be used, but thicker. The amount of stored fruit varies depending on the temperature of the storage environment: 17°C or more, 7.5 to 10 kg/bag; 15 to 17°C, 10 to 12.5 kg/bag; 12 to 15°C, 12.5 to 15 kg/bag; 12°C or less ,15 ~ 17.5 kg / bag. When the average size is 12.5 to 15 kg, the size of the bag is 45 cm x 45 cm x 80 cm. When the number of storages is large, the plastic bags can be loaded into the fruit box or baskets for storage.

This kind of plastic bag is made by cutting the plastic bag according to the specification, and the bottom and both sides are heat-sealed with a 300-watt electric iron, a heat pad, and a gasket material (thick, etc.). When heat-sealing, first align the four sides of the pouch to be heat sealed on four sides, and then place the bottom edge and both side edges (about 1 cm) of the pouch on the backing plate, cover the backing with a layer of liner, plastic film and liner Tighten, and then use a hot iron (200-250°C) to press on the pad. The edge of the ironed pouch is white in color. Put the fruit in the bag after the mouth.

Fruits for storage should be carefully selected, and no insects, diseases, broken or injured fruits should be used for storage. After pre-cooling, it is sterilized and sterilized with chemical agents, and the warehouse equipment should be disinfected. During storage, pay attention to the following three aspects:

(1) Temperature control The fruit temperature is about 0°C from late November to early December, and from 0 to -1°C from the end of December to the end of February. The fruit temperature does not exceed 3°C in March and does not exceed 6°C in May.

(2) Gas regulation In the first few days of storage, the gas composition in the bag changes greatly, and the conditional place can measure gas 1 to 2 times per day (it is not necessary to measure every bag and check a few bags). After the gas composition in the bag is stable, it can be measured once in 7 days. It will be measured 15 days after December. After the temperature of the reservoir has rebounded in the second year, the number of gas measurements should be appropriately increased. The composition of gas stabilizing components in the bag varies depending on the species: Guoguang class, oxygen 3%, carbon dioxide 12%; red stars, oxygen 2%, carbon dioxide 14%. When the oxygen content in the bag is lower than the stability index, measures should be taken to reduce the temperature, loose the bag, and even open the bag.

(3) Regularly check the pouches at the front, middle and back of the warehouse, up and down the middle and lower parts of the warehouse, and periodically open the bags to inspect the quality of the fruit after a certain period of time. Under normal circumstances, it does not fall during the storage period.

When the hardness of the fruit of Guoguang and other varieties is reduced to 5.4 kg/cm2, when the hardness of the red star varieties is 4.5 kg/cm2, the bag should be opened and released for sale in time. When the temperature in the general storehouse is higher than 6°C, it will be sold out of the store to avoid rot. The use of clay caverns, cold storage combined with bag storage, Apple fruit can be stored until the following year 5 to June, the general bag storage can only be stored until the Spring Festival.