Evaluation of the nutritional composition and quality ofthree pelagic squid species

In order to investigate the differences in the nutritional composition and quality of muscle and skin of Illex argentines, Dosidicus gigas and Ommastrephes bartrami, fatty acid composition and amino acid composition of their muscle and skin were determined and analyzed using the national standard method, and the texture and moisture distribution of their muscle and skin were analyzed using a mass spectrometer and low-field nuclear magnetic resonance instrument. The results showed that the crude lipid content of I. argentines muscle was 1.23%, which was significantly higher than that of the other two species (P<0.05). In addition to moisture content, the crude protein content, crude lipid content and ash content of the muscle were significantly higher than those of the skin (P<0.05). The unsaturated fatty acid content of both muscle and skin was higher than 61%, and the total unsaturated fatty acid (ΣUFA) of I. argentines muscle was 66.51%, which was significantly higher than those of the other two species (P<0.05). 17 amino acids were detected in different parts of the muscle. The total amount of essential amino acids in the Il. argentines muscle was 5.54, 6.68 and 5.97 g/100 g, which accounted for more than 40% of the total amino acids. The content of non-fluid water in the muscle was significantly higher than that in the skin(P<0.05), and the percentage of immobile water (96.92%) in the I. argentines muscle was the highest. The hardness and springiness of I. argentines were significantly higher than those of the other two species (P<0.05), and the gumminess and adhesiveness of skinned squid muscle were significantly higher than those of unskinned squid muscle (P<0.05). Compared to the other two species of squid, I. argentines muscle had highest unsaturated fatty acid content, best textural properties, and highest water retention capacity. There was no significant difference in hardness, cohesiveness and chewiness between skinned and unskinned squid muscle (P>0.05), and although the nutritional value of squid skin was slightly lower than that of muscle, squid skin still had high processing and utilization prospects.