Amino-acid composition and balance of collagen containing raw materials
A prospective source of additional food protein in the meat industry is collagen-containing raw materials: pork skin, connective tissue obtained at meat trimming, collagen-containing by-products, etc., which can be used as part of pro-tein-and-fat emulsions. Collagen emulsions have a wide range of functional properties: moisture and fat retention, foam and gelling abilities, emulsifying activity, active foam, emulsions and dispersions stabilizers, so they can be used as a technological additive in the meat industry. Therefore, the most important task in the process is the complete use of collagen-containing raw materials with the maximum implementation of its properties. The paper presents the results of studies on determining the amino acid composition and balance of collagen-containing raw materials: pork skin, beef tendons, lungs, rumen, beef lips and ears, pork ears, udder, spleen, omasum, skin, head, feet, caruncle, stomach and intestines of poultry. It was determined that collagen-containing raw material contains all the essential amino acids: isoleucine, leucine, lysine, methionine and cysteine, phenylalanine and tyrosine, threonine, valine with the amino acid count in the range of 17.1-185.0 %. At the same time, a more balanced amino acid composition in comparison with other types of collagen-containing raw materials is shown by: pork skin, udder, beef lips and trachea, chitterlings, omasum, rumen, lungs and spleen as evidenced by high values of amino acid score (up to 185 %), essential amino acid index (up to 1.1), utility factor of the amino acid composition (up to 0.84), as well as the approximate values of the comparable redundancy index (0.0007-0.0043). The research results confirm the prospectiveness of combining muscle and connective tissue proteins in recipes of meat products of high nutritional and biological value.