low temperature storage is a common method to store cooked food. Its main principle is to effectively inhibit the growth and reproduction of microorganisms through low temperature, reduce the activity of enzymes, weaken the chemical reaction in food, and better maintain the original flavor and nutritional value of food.

High-temperature storage is a common method for food storage in catering industry, because microorganisms have weak tolerance to high temperature. When the temperature increases, they can effectively kill microorganisms and destroy the activity of enzymes, thus preventing the influence of microorganisms on food and achieving the purpose of food storage. The method is to boil or steam the food thoroughly (reaching a high temperature above 111 degrees), take it out or soak it in the original soup. Put it in a cool and ventilated place without stirring to prevent the food from being polluted again. This method can keep food from spoiling for a long time. This method is suitable for the preservation of finished and semi-finished products of animal foods, as well as dried foods such as water.

salting, pickling, dipping and soaking storage. This method generally uses salt, sugar, vinegar, sauce and five spices to be added into food according to a certain proportion, so that the food can absorb a certain concentration. To inhibit the growth of microorganisms and achieve the purpose of long-term preservation of food. For example, pickled products include salted radish strips, salted beans, sweet and sour garlic and so on. Pickle products include spiced kohlrabi, pickled cucumber and pickled cabbage. Pickle products include pickled cabbage, pickled pepper and pickled eggplant. Generally, the nutritional value of foods treated by salting, pickling, dipping, dipping, etc. will be reduced, because some vitamins and inorganic salts in foods are destroyed and lost, especially the fibrous muscles of animal foods will become hard and difficult to be absorbed and digested by the human body.

The foods that are refrigerated mainly include vegetables, fresh meat, fresh fish, fruits, dairy products, cooked products and semi-finished products. Freezing method is to freeze food in an environment below freezing point, which is suitable for storing animal food. Freezing can keep food for a long time without spoilage. However, after long-term storage, although the quality of food has not changed much, the moisture content is reduced, its back-nourishing value is reduced, and it tastes bad. In addition, when more than two kinds of food are stored in the same freezer, they should be sealed and isolated with non-toxic food bags. Prevent odor from polluting each other. At the same time, it can also reduce the loss of water in food.