Evaluation of the nutritional value of freeze-dried hydrolysates obtained from fish skin

Protein hydrolysates have a wide range of applications in the food industry. The additives obtained by enzymolysis of collagen-containing secondary fish waste (fish skin) have been freeze-dried. The following protein content is established in freeze-dried protein additives: 95.4/100 g (in pollock skin hydrolysates); 94.8 (cod skin); 92.5 g/100 g (pike-perch skin). The amino acid composition of the additives includes glycine, proline, valine, lysine, and arginine. Comparison of the amino acid composition with the reference protein demonstrates a high degree of satisfaction of the daily requirement for amino acids. The utility coefficient of the amino acid composition indicates a balance of amino acids, which determines the biological value of additives from pollock skin (88.67 %), cod (86.65 %), and pike-perch (79.68 %). Protein additives contain low-molecular peptides with biologically active properties. The assessment of the harmlessness index has been carried out using the simplest organisms: growth, reproduction and absence of death of the cells of the Tetrachymena pyriformis ciliate indicate the harmlessness and high biological value of the protein of protein supplements. The obtained food supplements are proposed to be used in the production of sports nutrition products.