Food preservation is a discipline that uses basic theories and knowledge such as microbiology, biochemistry, physics and food engineering to study the causes of food spoilage and put forward reasonable and scientific preventive measures, thus providing theoretical and technical basis for food storage and processing.

Food preservation is the basic theory or theoretical basis for studying food storage and preventing deterioration. Answered the question why food will go bad and under certain conditions, it will not go bad through certain technical control.

The significance of food preservation lies in killing or inactivating microorganisms and enzymes in food during production and storage, preventing external microbial pollution and microbial reproduction in food, and preventing enzymatic and non-enzymatic chemical reactions in food, thus maintaining the quality of food and achieving the purpose of food preservation.

Food preservation can reduce food spoilage. Food spoilage generally refers to that under certain environmental factors, due to the role of microorganisms, food loses its original nutritional value, organizational characteristics, color, fragrance and taste, and becomes food that does not meet the hygiene requirements. Such as fish rancidity, fruit and vegetable rot, oil rancidity, grain mildew and so on.

There are many reasons for food spoilage, which can be summarized as follows: (1) Food spoilage is caused by microbial reproduction; Due to the action of oxygen in the air, food ingredients are oxidized and deteriorated.

Due to the role of oxidase, peroxidase, amylase and protease contained in food, food metabolism is promoted, heat, steam and carbon dioxide are generated, which leads to food deterioration; Food corruption is caused by the erosion and reproduction of insects and the indirect and direct pollution of harmful substances. Among the factors of food corruption, microbial pollution is the most active and common factor, which plays a leading role.