Effect of body weight on the nutrient composition of the muscle and skin tissues of Oncorhynchus mykiss

Abstract

To provide basic research data for the processing and comprehensive utilization of triploid rainbow trout, we studied the nutritional quality of muscle and skin tissue of different sizes of fish (1250.10 ± 1.22 g, 2555.31 ± 1.32 g, and 3823.10 ± 1.44 g). The results showed that the proportion of skin and muscle was the highest when fish body size was 2555.31 ± 1.32 g. In muscle, lysine content was the highest and methionine content was the lowest among the essential amino acids (EAAs). Glutamic acid content was the highest and glycine content was the lowest among all umami-related amino acids. With increasing size, EAA, D-aspartic acid (DAA), and total amino acid (TAA) levels first increased and then decreased. The Met + Cys group contained the most restricted amino acids in the skin and muscle, and 2555.31 ± 1.32 g triploid rainbow trout had better amino acid balance and the best nutritional value. Of the essential minerals, Na, Mg, and K were the most abundant. According to Dietary Reference Intakes (DRI), Mg, Fe, and Zn can provide higher nutritional quality. Finally, the results showed that nutritional quality was highest in the muscle of the intermediate-sized triploid rainbow trout.