Gases produced in the process of liquid nitrogen quick freezing are inert nitrogen, gas and nitrogen, which isolate air in the production process and play a role in protecting food. At the same time, due to the extremely fast freezing speed, the temperature of food quickly drops below the normal growth temperature of microorganisms, which is beneficial to inhibit the growth of microorganisms and their biochemical reactions. Quick-frozen food is of high quality: due to the quick freezing speed of liquid nitrogen and short freezing time, it takes less than 5 minutes to pass through the ice crystal generation zone, and ordinary freezing takes more than 190 minutes. Because quick freezing does not destroy the cellular structure of food, it can make the water in cells and intercellular spaces freeze into countless tiny and uniform ice crystals at the same time, so that the cellular tissue is not destroyed, so that the thawed food can recover its original fresh state and original nutritional components to a great extent, and maintain its original taste and flavor, thus achieving the effect of "original flavor". Long shelf life: the shelf life of liquid nitrogen quick-frozen food is more than 3 times that of traditional freezer.