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How Canned Foods Are Processed
- Aug 29, 2018 -

The main process of canning processing is: raw material selection → pretreatment → canning → exhaust, sealing → sterilization, cooling → insulation inspection → packaging

◆Raw material selection: Fruit and vegetable raw materials should have good nutritional value, sensory quality, freshness, no pests and diseases, no mechanical injury, but also have a long supply period and a high proportion of edible parts. These are the general requirements for processing general foods from fruits and vegetables. . For processed canned foods, different varieties of raw materials should have good can processing adaptability. For raw materials for canning, the chemical composition of different raw materials is different, and the processing adaptability is also different. Different products have different requirements for the same kind of raw materials, but all livestock and poultry raw materials must be raw materials from non-epidemic areas, which are in good health and have passed veterinary inspection after slaughter.

◆Pretreatment: The pretreatment process before loading and unloading raw materials for fruits and vegetables includes sorting, washing, peeling, trimming, blanching and rinsing of raw materials. Raw material pretreatment of livestock and poultry mainly includes thawing, meat segmentation, deboning and finishing, pre-cooking and frying. The pretreatment of aquatic raw materials is mainly thawing, washing, descaling, fins, head, tail, viscera, shelling, etc., pickling and dehydration of raw materials.

◆Canning: The filling method is divided into manual canning and mechanical canning. Manual cans are mostly 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 and properly match the cans, and arrange the cans according to the requirements. Mechanical cans are generally used for the filling of products such as granules, enamel, fluids or semi-fluids, such as luncheon meat, various jams, juices, and the like. The method has the characteristics of fast, uniform and hygienic filling.

◆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. The exhaust gas extraction methods mainly include thermal exhaust, vacuum exhaust and steam exhaust. .

◆Sealing: Different containers should be sealed in different ways. The sealing of the metal can refers to the process of winding the flange of the can body and the round side of the can lid to seal, so that the can body and the can lid are rolled together to form a tightly overlapping double bead.

The roll-sealed glass bottle is sealed by a crimp sealing method, which relies on the action of the indenter, the bottom plate and the roller of the sealing machine. There are three to six threaded threads on the rotating glass bottle. There are a corresponding number of caps on the cap. When sealing, align and tighten the cap and the beginning of the thread.

◆Sterilization: There are many methods for sterilization of cans, such as heat sterilization, flame sterilization, radiation sterilization and high pressure sterilization. The most widely used is heat sterilization. Common sterilization methods include intermittent static high pressure sterilization, intermittent static atmospheric sterilization, continuous atmospheric sterilization and the like.

◆Cooling: When small cans are pasteurized, they can be directly cooled by normal pressure. However, when a can with a diameter of 102 mm or more is sterilized at a temperature of 116 ° C or higher and a can having a diameter of < 102 mm is sterilized at a temperature of 121 ° C or higher, it is required to be cooled by back pressure cooling.