Improving the technology of chilled semi-finished products from Japanese mackerel with an extended shelf life

Abstract

One of the actual areas of processing the aquatic biological resources is the production of chilled fish semi-finished products, the most prepared for heat treatment. Such products have a very limited shelf life, because fish raw materials have high enzymatic activity. This research work aimed to improve the technology of chilled fish semi-finished products from Japanese mackerel with an extended shelf life. To achieve this goal, Japanese mackerel was injected with multicomponent salting media, containing food additives that slow down microbial contamination, have a bacteriostatic effect and assist in improving the organoleptic characteristics of the finished product. New receptions of salting multicomponent compositions provide faster salting and ripening of raw materials compared to the control sample. Salt concentration in fish, amine nitrogen and peroxide value were determined by titration methods. The total number of mesophilic aerobic and facultative anaerobic microorganisms (КMAFAnM) in fish semi-finished products was determined by identifying the number of grown colonies of microorganisms on nutrient media from agar. The treatment of Japanese mackerel with developed salting media, including moisture-retaining components, organic acids and flavoring additives with anti-bactericidal properties, improves the organoleptic characteristics of the finished product, promotes more salting and maturation of fish, as well as reducing the number of microorganisms (KMAFAnM). The increase in amine nitrogen content ranged from 1.4 g/kg (at the beginning of the salting) to 1.55 g/kg in the control and up to 3.05 g/kg in the test samples by the end of the salting. Salt concentration in Japanese mackerel treated with control salting media amounted to 1.19%, new developed salting media - from 2.84% to 3.17%. The total abundance of microorganisms in Japanese mackerel was 2.0 x 102 CFU/g, after salting it decreased to 0.1 to 3.0 x 101 CFU/g depending on the formulation of media for salting. According to the research results, the rational duration of the salting of Japanese mackerel, with new media for salting was 4 to 5 h at a temperature of 6 °С to 8 °С. Along with the salting media developed by us, the use of modern packaging materials in the technology provided chilled culinary semi – finished products from Japanese mackerel with longer shelf life of up to 20 days at a temperature of 0 °С to 5 °C, and humidity 95% to 98%.