Preparation of Hydrolyzed Peptides from Anchovy Cooking Liquid by Complex Enzyme and Its Antioxidant Activity

Objective:This paper intended to study the optimal enzymatic hydrolysis conditions of anchovy cooking liquid,and analyze the molecular weight distribution and antioxidant activities of hydrolyzed peptides. Methods:Taking trichloroacetic acid-nitrogen soluble index(TCA-NSI)as the evaluation index of enzymatic hydrolysis efficiency,central composite design based on single factor experiment was used to optimize the hydrolysis process of protein peptides,and molecular weight distribution and antioxidant activities of the hydrolyzed peptides were characterized. Results:The optimal conditions for enzymatic hydrolysis of anchovy cooking liquid were as follows:hydrolysis time 45 min,hydrolysis temperature 54.5 ℃,pH8.2,and the ratio of alkaline protease to neutral protease 1∶1.Under these conditions,the hydrolysate exhibited the best TCA-NSI of 76.51%. The polypeptide with molecular weight below 1500 Da reached 81.941%. The IC₅₀ of scavenging rates of DPPH radical,hydroxyl radical and superoxide anion radical were 2.45,1.37,and 3.45 mg/mL,respectively,indicating that the hydrolyzed peptides had strong antioxidant activity. Conclusion:The complex enzyme method can be used for efficient enzymatic hydrolysis of anchovy cooking liquid,and the obtained hydrolyzed peptides are found to have strong antioxidant activities. Thus,it can provide theoretical basis for high value utilization of anchovies cooking liquid and development of active peptide products.