Ngày nhận bài: 28-09-2013 / Ngày duyệt đăng: 22-12-2013
Protein and lipid recovery from yellowfin tuna heads by enzymatic hydrolysis was studied. Hydrolysis of tuna head was carried out using 0.5% Protamex at 45°C without pH control for 120 minutes with a water/material ratio of 1:1 (ml/g). Nitrogen recovery, amino acid composition of protein hydrolysate, lipid recovery and fatty acid composition of fish oil obtained from hydrolysis of tuna heads were determined. Results showed that after 120 minutes of hydrolysis, the nitrogen and lipid recoveries were 70.3% and 65.4% respectively. Protein hydrolysate from yellowfin tuna heads had of 80% protein, 1.3% lipid and 7.9% ash. Protein hydrolysate had high content of essential amino acids (33.67%). The fish oil obtained from hydrolysis of tuna heads was rich in omega-3 fatty acids (18.99%), especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). The content of omega-6 fatty acids was 4.37%. Fatty acids with high contents in tuna head oil were palmitic acid (29.75%), oleic acid (16.76%) and docosahexaenoic acid (14.56%).
