Modified atmosphere storage fresh-keeping method

At present, there are two main ways widely used in China:

1.CA modified atmosphere storage is studied by domestic high-tech enterprises. It uses mechanical equipment to manually control the gas in the storage environment of modified atmosphere storage to realize fruit preservation. Controlled atmosphere refrigeration needs to accurately control the concentration of gas components required by different fruits and strictly control the temperature and humidity. The temperature can be the same as that of the cold storage, or slightly higher than that of the cold storage to prevent low temperature injury. Combined with low temperature controlled atmosphere, the fresh-keeping effect (color, hardness, etc. ) is superior to ordinary refrigeration, and the preservation period is obviously prolonged.

2. Modified atmosphere storage (plastic film bag modified atmosphere storage, also known as modified atmosphere storage packaging) According to the physiological characteristics of food and the needs of preservation, food is stored in a proper proportion of packaging to extend its preservation period. Widely used in the preservation of fresh fruits and vegetables, with an annual growth rate of 20%. The effect of the combination of fresh-keeping packaging and refrigeration is basically close to that of modified atmosphere refrigeration. There are two kinds of MA modified atmosphere packaging: one is passive modified atmosphere packaging, that is, the fruit wrapped with plastic wrap reduces the oxygen content through respiration, and the ratio of oxygen to carbon dioxide is adjusted through gas exchange in packaging; The other is active modified atmosphere, that is, mixed gas is filled according to the breathing speed of different fruits, and films with different breathability are used. However, due to the complex process and high requirements on the variety and performance of packaging materials, it has not been widely used in China.

Characteristics of modified atmosphere preservation listening to sound

1) Wide application range: it is suitable for the storage and preservation of various fruits, vegetables, flowers and seedlings in the north and south of China. (2) Long storage period and high economic benefit. For example, grapes are kept fresh for 7 months, apples for 6 months and garlic moss for 7 months. The quality is as fresh as ever, and the total loss is less than 5%. Generally, the origin price of grapes is only 1.5 yuan/kg, but the price can reach 6 yuan/kg around the Spring Festival. Once put into cold storage, the service life can reach 30 years, and the economic benefit is very remarkable. The investment was effective that year. (3) The operation process is simple and the maintenance is convenient. The temperature of refrigeration equipment is controlled by microcomputer, which can start and stop automatically without special supervision, and the supporting technology is economical and practical.

The effects of modified atmosphere storage: (1) inhibit respiration, reduce the consumption of organic matter, and maintain the excellent flavor and aroma of fruits and vegetables. (2) Restrain water evaporation and keep the freshness of fruits and vegetables. (3) Inhibit the propagation of pathogenic bacteria, control the occurrence of some physiological diseases, and reduce the rate of fruit decay. (4) inhibiting the activity of some after-ripening enzymes, inhibiting the production of ethylene, delaying the aging process of after-ripening, keeping the fruit hardness for a long time and prolonging the shelf life. 、