The appearance of the freezer allows us to eat off-season fruits and vegetables in different seasons, which is so beautiful for us. Then why use a freezer to keep fresh fruits and vegetables? Because fruits and vegetables in our country are essential non-staple foods for human society, their nutritional education value varies greatly due to different developments in variety, growth, maturity, and storage environmental conditions, mainly due to the large amount of water, sugar, and organic Acids, enzymes, cellulose, pigments, vitamins, etc. After fruits and vegetables are picked, there is still active metabolism in the fruit tissues, which is to a large extent the continuation of the maternal process, immature fruits can continue to mature, and mature fruits can develop to the final stage of aging and decay. Most fruits and vegetables change from a living body to an inanimate body through a normal metabolic process, and will lose their lives after being frozen and stored. The fruits and vegetables in the freezer have a variety of transportation management methods ranging from bulk bulk to small packaging for retail. Special attention should be paid to the special requirements of the goods to avoid damage. The general rule is that the lower the temperature in the freezer, the better the preservation of the goods.
Secondly, fruits and vegetables are still alive after being picked, and the fruit tissue is still undergoing an active metabolism process, which has the ability to resist the invasion of microorganisms. Therefore, it is necessary to use a freezer to keep it fresh. This can block the metabolism and even stop. The fruit composition and tissue have undergone irreversible changes, causing it to lose its nutritional value and unique flavor, and begin to rot under the action of microorganisms. The respiratory system of fruits and vegetables is essentially the slow oxidation of organic matter in the fruits. Under aerobic conditions, the sugars, organic acids and complex carbohydrates in the fruit are used as substrates and are completely oxidized into carbon dioxide, water and heat to maintain normal life activities. Under hypoxic conditions, the substrates in the fruit cannot be completely oxidized and decomposed, only compounds with relatively simple structures, such as ethanol and acetaldehyde. And can generate a small amount of heat. In order to obtain the same amount of energy as the aerobic respiratory system, the hypoxic respiration fruit must be oxidized with more respiration matrix, that is, it consumes more storage materials of the enterprise, so that the quality of the fruit product continues to deteriorate, and the storage period is shortened. Respiration of fruits and vegetables also produces a certain amount of water, ethylene and some other trace gases. Ethylene induces an increase in the respiration intensity of fruits from maturity to maturity.