What is the difference between cold processing and hot processing of food?

Cold working is done at low temperatures, and hot working is done at high temperatures.

Food cold processing

It includes four processes of cooling, freezing, refrigeration and thawing. Generally, the temperature of food cooling is ±4℃-0℃. Freezing refers to freezing the moisture contained in the food into ice, usually at -8℃. Then it is frozen Preservation under certain conditions.

Food thermal processing

It uses heating during the production process, such as cooking, frying, baking and other processing techniques.

Refrigeration of food at low temperatures can inhibit the growth of microorganisms and preserve the flavor, nutrients, and original properties and freshness of the food. Low-temperature refrigeration is also called food cold processing, which includes four processes: cooling, freezing, refrigeration and thawing. The general food cooling temperature is ±4℃-0℃. Freezing refers to freezing the moisture contained in the food into ice, usually at -8℃. Then store it while frozen.

Freeze drying is a drying method in which the moisture of raw materials is removed by direct sublimation of frozen ice crystals into water vapor under vacuum conditions. It can effectively prevent oxidative deterioration of heat-sensitive substances, prevent product surface hardening, enhance rehydration, and maintain the original quality of food to the maximum extent. This technology is now widely used in the production of quick-frozen foods.

Without any preservation treatment, it is almost impossible to store food for a long time without deterioration. If unpreserved food is left at room temperature for a period of time, it will undergo changes such as deterioration, fermentation, and corruption and become inedible. The reason for food spoilage is that the microorganisms that make up the food multiply under high temperature conditions and cause decomposition. Freezing and refrigeration can reduce temperature, moisture content and water activity, prevent microbial reproduction and reduce the occurrence of biochemical reactions. Therefore, frozen and refrigerated food can be stored for a long time. With the improvement of people's living standards, the demand for cold-processed food is also increasing, and food cold-processing projects will develop rapidly.

References:

Baidu Encyclopedia - Cold Processing ?Baidu Encyclopedia - Food Thermal Processing