Effect of modified hydrolytic lignin on lipid peroxidation in fish feeds and on fish grown on them

Abstract

Fish feeds are prone to rapid oxidation due to the high concentration of nutrients, including the presence of a large amount of easily oxidizable polyunsaturated fatty acids. There is an active search for antioxidants that can inhibit the development of lipid oxidation in feed and in the body of fish. A significant role among them is played by substances with high sorption properties, which sorb toxic products of lipid peroxidation, thereby slowing down oxidative processes and increasing antioxidant capacity. These include, for example, natural zeolites. The purpose of this work was to investigate the possibility of reducing lipid oxidation in fish feed using a sorbent feed additive that was developed on the basis of hydrolytic lignin to eliminate mycotoxins in animals and birds. To achieve this goal, experiments were carried out on the storage of fishmeal and feed with a sorbent additive and on growing fish on these feeds. When storing fishmeal with 1% and feed with 0.5 and 1.5% additives, a decrease in the activity of oxidative processes in lipids was noted.At the end of the experiments, lipid hydroperoxides in the feed with the additive were lower than in the control feed by 30–39% and acid numbers — by 10–15%. When rearing muksun fingerlings on feed with a sorbent, the survival rate of fish and the total ichthyomass increased by 17%, the content of omega-3 fatty acids in the body of muksun increased and the amount of monounsaturated oleic acid decreased. The results obtained indicate that the test sorbent additive introduced into fishmeal and feed for whitefish slows down the oxidative processes of lipids and increases antioxidant protection. The inclusion of the sorbent in the feed did not affect the intensity of fish growth.