A Study on the Properties of Alosa (Alosa caspia) By-Products Protein Hydrolysates Using Commercial Enzymes

In current study, protein hydrolysates were produced using microbial proteases of Alcalase, Protamex and Flavourzyme from by-products (head, skin and viscera) of Alosa (Alosa caspia), a major Clupeonella species in the Caspian Sea. The results indicated that the protein hydrolysate from Alcalase, had the highest protein content (78.91%), protein recovery (80.42%) and degree of hydrolysis (21.06%). No significant differences in lipid were observed among the enzymes (P>0.05). The results of amino acids composition showed that all hydrolysates were almost similar in amino acids composition. In addition, the protein efficiency ratio showed that all hydrolysates had high nutritional value. The chemical score results indicated that all hydrolysates could fulfill human amino acid requirements. While, in comparison with common carp requirements, the amino acids of methionine, lysine, phenyl alanine and threonine were the limiting amino acids in hydrolysates. According to the results of this study, Alcalase is the most affective enzyme. The by-products of the Alosa hydrolysate has high nutritional value, which can be used as a protein source in fish feed.