BIOTESTING READY-TO-EAT FISH PRODUCTS WITH TETRAHYMENA PYRIFORMIS

Abstract

The article presents the results of biotesting food protein gels and ready-to-eat gel-based fish products. Axenic culture of ciliates Tetrahymena pyriformis was used as an indicator organism, which are known to have similar metabolic processes with cells of higher organisms. The ability of unicells to use intact proteins as a nutrient substrate determines their use in assessing the biological value of food. In the course of research, using a test-organism T. pyriformis , the rational temperature of heat treatment of food protein gel was equal to 85°C. Such temperature provides high rates of the ciliates population in the cultivating environment, the number of cells in which was counted and amounted to 2.3 × 106 cells/ml. In addition, the finished product has a high bioavailability ratio of 160% relative to the non-thermoprocessed product (i.e., raw). Biotesting ready-to-eat fish products enriched with protein from different fish in the Pacific basin made it possible to carry out a comparative characteristic of their biological value. It was determined that ready-to-eat fish products from giant grenadier, in which pollock served as enricher, have the highest index of the relative biological value - 101.4%, which is confirmed by studying the protein content of the products. At the same time, gels from the muscular tissue of giant grenadier without protein enrichers possess high indices of bioavailability and effectiveness of the protein when compared with product samples that contain protein enricher. However, this phenomenon causes the rapid depletion of the nutrient medium after 48 hours and further death of the T. pyriformis population. Thus, biotesting using the simplest allows for a comparative assessment of ready-to-eat fish product quality by simply counting the number of ciliates by experience in culture media. A graphical analysis of the data obtained throughout the life cycle of a T. pyriformis population allows to quickly and accurately assess the viability of ciliates, the degree of assimilation of the nutrient substrate, and draw conclusions about the biological value of the product.