Document Type : Original Article
Department of Fisheries,Gorgan Agricultural Sciences and Natural Resources University, Gorgan, Iran
Department of Food Technology, Faculty of Agro-industry, Prince of Songkla University, Hat Yai, Songkhla, Thailand
Iranian Fisheries Research Organization, Caspian Sea Ecology Research Center, Sari, Iran
Department of Food Science, Sari Agricultural Sciences and Natural Resources University, Sari, Iran
Protein hydrolysates were prepared from ground yellowfin tuna head, a by-product from tuna canning industry, using 1.5% Alcalase (PHA) and Protamex (PHP) at a natural pH for 4 and 24 h with a water/material ratio of 1:1 (w/v). The higher degree of hydrolysis (DH), nitrogen recovery and protein content of both hydrolysates increased when the longer hydrolysis time was used (P < 0.05). In addition, DH and protein content of PHA were higher than those of PHP (P < 0.05). The amino acids composition of both PHA and PHP could fulfill human amino acid requirements. With respect to common carp requirements, lysine, methionine and phenylalanine were the limiting amino acids in both protein hydrolysates. However,both hydrolysates had high content of flavoring and essential amino acids. Protein efficiency ratio (PER) results revealed that both hydrolysates had the similar PER.Therefore, protein hydrolysates from yellowfin tuna were found to have high nutritional value and can be used in human and animal diets.