Development of forage cryo minced fish technology

The technology of grinding the frozen fish raw material using the useful model of a piston-type extrusion plant with cold working bodies for fodder minced fish (cryo minced fish feed) by the method of cryoextrusion has been developed. The possibility of replacing the standard manufacturing operations (defrosting and subsequent grinding of raw materials) to the one (cryoextrusion) has been substantiated. The optimal shape of holes of the die for forcing the raw material has been determined in the form of "hourglass", the hole diameter is 7 mm, the length of the process of pushing is 40 s. It has been established that the finished product (cryo minced fish feed) has a homogeneous grinding, juicy, crumbly texture, the temperature in the thickness of the product is equal to the temperature of the raw material before processing (-18 °C). The technological scheme of producing the minced fish feed by the method of cryoextrusion has been developed. Researching the chemical composition of fish and feed of mince produced by the traditional and developed methods it has been established that protein content in the cryo minced fish feed remains unchanged. The amino acid composition of cryo minced fish feed has been determined, the amount of essential amino acids is 365.6 mg/g of protein. In the proteins of the cryo minced fish feed methionine has been contained in the minimum quantity (10.0 mg/g protein) and in the maximum - serine (155.3 mg/g protein). In the protein of the cryo minced fish feed the only limiting amino acid is methionine. The coefficient of rationality of the cryo minced fish feed whiting is equal to 0.33. The product is not toxic, is not subject to contamination with dangerous microorganisms, has high biological value, contains necessary in animal nutrition mineral elements, the energy value per 100 g of the product is 87 kcal. The combination of the processes of cryoextrusion and lyophilization allows to obtain a new food product with high organoleptic properties. The draft technical specifications for production of the cryo minced fish feed and the technological instructions for production of minced fish for feed purposes have been developed.