The main function of vacuum packaging is to deoxidize, in order to prevent food from deteriorating, TThe principle of vacuum packaging machine is also simple， because food decay is mainly caused by microbial activity, and most microorganisms (such as mould and yeast) need oxygen for survival, and vacuum packing is used in packing bags and food. The removal of oxygen from the cells causes microorganisms to lose their living environment. The experiment shows that when the oxygen concentration in the bag is less than 1%, the growth and propagation speed of microorganism drops sharply. When the oxygen concentration is less than 0.5%, most microbes will be inhibited and stop breeding. (Note: vacuum packaging can not inhibit the degradation and discoloration of food caused by anaerobes and enzyme reactions, so it is necessary to combine other auxiliary methods, such as refrigeration, quick freezing, dehydration, high temperature sterilization, irradiation sterilization, microwave sterilization, salt pickling, etc.).
In addition to restraining the growth and reproduction of microbes, the other important function is to prevent food oxidation. The oxidation of fatty acids in the oils and fats is oxidized to make food flavour and metamorphic. In addition, oxidation also causes the loss of vitamin A and C, and the oxygen of the unstable substances in the food pigments. Use it to darken the color. Therefore, deoxidization can effectively prevent food deterioration.
In addition to the function of deoxidization and quality of vacuum packing, vacuum packing is the main function of compression, gas resistance and preservation. It can make food keep the original color, aroma, taste, shape and nutritional value for a long time.