The main process of canning is: raw material selection → pretreatment → canning → exhaust, sealing → sterilization, cooling → heat preservation and inspection → packaging

Raw material selection: fruit and vegetable raw materials should have good nutritional value, organoleptic qualities, freshness, free of pests and diseases, no mechanical injuries, but also have a long period of supply, a high proportion of edible portions, which are the general requirements for processing of general food using fruit and vegetable raw materials. These are the general requirements for the processing of general food using fruit and vegetable raw materials. For canned food processing, different varieties of raw materials should have their good adaptability to canning. For livestock and poultry raw materials used for canning, the chemical composition of different raw materials is different, and the adaptability of processing is also different. Different products on the same type of raw materials requirements are different, but all livestock and poultry raw materials must be from non-infected areas, good health, slaughtered before and after the slaughter of veterinary inspection of qualified raw materials.

Pre-treatment: fruit and vegetable raw materials canned before the pre-treatment process includes raw material sorting, washing, peeling, trimming, hot blanching and rinsing. Livestock and poultry raw materials pretreatment mainly includes thawing, meat splitting, boning and finishing, pre-cooking, deep-frying. The pretreatment of aquatic raw materials, on the other hand, is mainly thawing, washing, scaling, finning, head, tail, offal, shelling, etc., pickling of raw materials, dehydration.

Canning: canning method is divided into manual canning and mechanical canning two kinds. Artificial canning is mostly used for meat and poultry, aquatic products, fruits and vegetables and other lumpy materials. Because of the large differences in raw materials, canning needs to be selected, reasonable matching, and according to the requirements of the arrangement of canning. Mechanical canning is generally used for granular, minced, fluid or semi-fluid products canning, such as luncheon meat, various jams, juices and so on. This method is characterized by fast, uniform and hygienic canning.

Exhaust: exhaust helps to prevent the growth and reproduction of aerobic bacteria and yeast, and is conducive to the preservation of food color, aroma, taste and nutrients, exhaust methods are mainly thermal exhaust, vacuum exhaust and spray steam exhaust.

Sealing: different containers, to use different methods of sealing. Sealing of metal cans refers to the flip side of the can body and the rounded edge of the can cover to go sealing machine for the roll sealing, so that the can body and the can cover each other rolled to form a close overlap of the twofold rolled edge of the process.

Roll sealing glass bottles sealed by the roll sealing method, it relies on the sealing machine's pressure head, bottom plate, the role of the rollers to complete the operation. There are three to six threads on the rotary glass bottles, and there are a corresponding number of cap claws on the cap, which can be sealed by aligning and tightening the cap claws with the beginning of the threads.

Sterilization: there are many ways to sterilize canned food, such as heat sterilization, flame sterilization, radiation sterilization and high pressure sterilization, etc., the most widely used is still heat sterilization. Commonly used sterilization methods are intermittent static high-pressure sterilization, intermittent static atmospheric pressure sterilization, continuous atmospheric pressure sterilization.

Cooling: small cans with pasteurization, can be directly cooled with atmospheric pressure. However, cans with a diameter of 102mm or more are sterilized at a temperature of 116 degrees Celsius or more, and cans with a diameter of <102mm are sterilized at a temperature of 121 degrees Celsius or more, they need to be cooled by counterpressure cooling.