The first is the clever use of quick-freezing procedures. 0℃-3℃ is the temperature zone where water in food cells freezes into the largest ice crystals. The shorter the time for food to drop from 0℃ to-3℃, the better the preservation effect of food. Quick freezing can make food complete this freezing process at the fastest speed. In the process of quick freezing of food, the smallest ice crystals will be formed, which will not puncture the cell membrane of food, so that the cell tissue fluid can be completely preserved during thawing, reducing nutrient loss and achieving the purpose of food preservation.

The temperature of the cold room is low on the top and high on the bottom, so fruits, vegetables, etc. are placed below. In addition, the food in the refrigerator should be packaged (including plastic wrap), which can prevent food from freeze-drying, cross-flavor, and mutual pollution, and also reduce the number of defrosting.