The risk-based control of the safety and quality of freshwater fish for sale in the agri-food market

Abstract

Scientifically substantiated and experimentally proven the feasibility of conducting proper risk-based control of the safety and quality of freshwater fish in the Kyiv region's agro-food markets following the regulatory document's requirements, developed by express, improved methods for determining freshness and microstructural examination of muscle tissue. At organoleptic assessment Ukrainian scaly carp, crucian carp, and pike perch were fresh, and rotan was of dubious freshness. Regarding pH value, Nesler number, and qualitative reaction to the content of ammonia and ammonia salts with ’Nesler’s reagent, the meat of Ukrainian scaly carp, crucian carp, and pike perch corresponded to fish of a fresh degree. For rotan meat, its dubious freshness was established. In the photometric determination of the studied fish's freshness, the optical density of the supernatant correlated with the quality indicators for the content of ammonia and ammonia salts. An improved benzidine test with a filtrate from the gills of the mouth confirms the doubtfulness of the freshness of the fish. The studied fish samples corresponded to the standard indicators according to microscopic indicators and the number of mesophilic aerobic and facultative anaerobic microorganisms. By determining the chemical parameters of the studied fish, it was found that the mass fraction of water in meat was the highest in rotan (78.30±0.13%) and was accompanied by the smallest mass fraction of dry matter (21.70±0.09), the proportion of proteins (16.96±0.06), indicators of fat in meat (3.01±0.06%) and formed the lowest indicator of its relative biological value – 92.5%. In benign fish with organoleptic indicators, a microstructural study of muscle tissue revealed significant changes in its structure with atrophy of individual muscle fibers and growth in these areas of connective, mainly fatty tissue.