Introduction to the processing flow of cans

What are the canning processes?

According to the information provided by the China Canning Industry Association, the main process flow of canning is: raw material selection → pretreatment → canning → exhaust, sealing → sterilization, cooling → heat preservation inspection → packaging.

Raw material selection: Fruit and vegetable raw materials should have good nutritional value, sensory quality, freshness, no pests, no mechanical damage, long supply period, high proportion of edible parts, these are general requirements for the use of fruit and vegetable raw materials to process general food . For processed canned food, different varieties of raw materials should have good canned processing adaptability. For the livestock and poultry raw materials used in canned food processing, the chemical composition of different raw materials is different, and the processing adaptability is also different. Different products have different requirements for the same type of raw materials, but all raw materials for livestock and poultry must be raw materials that come from non-epidemic areas, are in good health, and have passed veterinary inspection before and after slaughter.

Pretreatment: The pretreatment process of fruit and vegetable raw materials before canning includes raw material sorting, washing, peeling, trimming, blanching and rinsing. The pretreatment of livestock and poultry raw materials mainly includes thawing, meat segmentation, deboning and finishing, pre-cooking and frying. The pretreatment of aquatic raw materials mainly includes thawing, washing, removing scales, fins, head, tail, viscera, shelling, etc., pickling and dehydrating the raw materials.

Canning: Canning methods are divided into manual canning and mechanical canning. Manual canning is manyly used for bulk materials such as meat and poultry, aquatic products, fruits and vegetables. Due to the large difference in raw materials, it is necessary to select them when filling cans, match them reasonably, and arrange the cans according to the requirements. Mechanical canning is generally used for canning granular, minced, fluid or semi-fluid products, such as luncheon meat, various jams, juices, etc. This method has the characteristics of fast filling speed, uniformity and hygiene.

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

Sealing: Different containers must be sealed in different ways. The sealing of metal cans refers to the process in which the flanging of the can body and the round edge of the can cover are rolled in a sealing machine, so that the can body and the can cover are rolled together to form a closely overlapping double curling process.

The roll-sealed glass bottle is sealed by the crimping sealing method, which relies on the pressure head of the sealing machine, the supporting plate and the roller to complete the operation. There are three to six thread lines on the rotating glass bottle, and the cap has a corresponding number of claws. When sealing, align the claws with the beginning of the screw line and tighten them.

Sterilization: There are many ways to sterilize cans, such as heat sterilization, flame sterilization, radiation sterilization, and high-pressure sterilization. The many widely used is still heat sterilization. Commonly used sterilization methods include intermittent static high pressure sterilization, intermittent static normal pressure sterilization, continuous normal pressure sterilization, etc.

Cooling: When small cans are pasteurized, they can be directly cooled under normal pressure. However, when cans with a diameter of 102mm or more are sterilized at a temperature above 116 degrees Celsius, and cans with a diameter of less than 102mm are sterilized at a temperature above 121 degrees Celsius, they need to be cooled by back pressure cooling.