Orthogonal optimization of enzymatic hydrolysis technology of Harengula zunasi and molecular weight distribution of the result product

The proximate components of Harengula zunasi are determined in this paper.With the α-amino nitrogen content being the index,four proteases such as neutral protease,trypsin,papain and protamex are used to hydrolysis Harengula zunasi to select the optimum enzyme.Neutral protease is found to be the optimum protease.Single factor design and orthogonal trial are employed to search the optimal reaction condition.The results show that the water content is 76.1%,the crude protein content is 13.9%,the ash content is 3.88%,the crude fat content is 2.81%,and the total sugar content is 0.30% and the non-protein nitrogen 627 mg/100 g.The optimum reaction condition:enzyme dosage of 1000 U/100 g material,temperature at 50 ℃,pH at 7.0,reaction time 4 hours.Under the optimized conditions,the α-amino nitrogen in the hydrolysate is up to 471.82 mg/100 mL and the protein recovery is 74.7%.The fractions under 5000 u take 60% in the total hydrolysate.