Nutritional value of tuna: Tuna is tender, rich in protein, fat, vitamins A and D and trace elements, especially polyunsaturated fatty acids such as DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), and rich in methionine, taurine, minerals and vitamins. Tuna is high in protein, low in fat and low in calories. Eating tuna regularly can balance nutrition and lose weight. It is helpful for liver function. EPA and DHA mainly inhibit platelet aggregation and enhance autoimmunity. Enhance nervous system function. Processing technology of tuna 1, canning Processing can not only prolong the shelf life of tuna, but also increase its commodity value. Canned tuna is an important variety of canned aquatic products, and has formed a series of canned products. Canned tuna are mainly albacore tuna and yellowfin tuna. 2. Ultra-high pressure processing in a closed container, with water or other liquids as the medium, exerts certain pressure on food or other substances to achieve the purpose of sterilization, modification, processing and preservation. The sale of tuna in the whole international market is mainly canned tuna, but with the increasing demand for fresh tuna slices, how to ensure the fresh quality and edible safety of tuna in the process of processing and preservation is an urgent problem to be solved.