Shelf life of grass carp, bighead carp, Siberian sturgeon, and wels catfish stored under refrigerated conditions

Abstract Microbiological, pH, color and texture changes in the muscles of grass carp, bighead carp, Siberian sturgeon , and wels catfish during 14 days of refrigeration storage were investigated. The level of aerobic bacteria that is unacceptable for fresh fish (7.0 log cfu/g) was reached only in wels catfish muscles during this period. The pH values in the muscle tissues that were of unacceptable quality, from the investigated fish species, ranged between 6.32 and 6.75. The herbivorous fish species displayed a change in the muscle tissue color. The L * parameter value for the fish of unacceptable quality was higher by 9.7% (grass carp) and up to 22.7% (bighead carp) than for fresh fish. The fish species gradually lost hardness and toughness during the storage period. The hardness of the fish of unacceptable quality was lower by 25.8–64% and the toughness by 25.2–60.8% as against fresh fish. The earliest unacceptable organoleptic quality occurred in wels catfish (6 days of storage), followed by grass carp, bighead carp, and S. sturgeon (12 days of storage). Practical applications Grass carp, bighead carp, Siberian sturgeon , and wels catfish are food fish of commercial significance in many countries. Fresh fish are highly perishable foods. One of the methods of preservation fresh fish is storage in refrigeration conditions. This method is widely used in the fish industry and distribution. The results of this study can be used by manufacturers, distributors, traders, and in scientific studies on the shelf life of fish stored in refrigeration conditions.