复合酶制备鱼蒸煮液水解肽及其抗氧化活性研究

目的:研究鳀鱼蒸煮液的最佳酶解工艺条件,并分析所制备水解肽的分子量分布和抗氧化特性。方法:以三氯乙酸氮溶解指数(Trichloroacetic acid-nitrogen soluble index,TCA-NSI)为酶解效率的评价指标,在单因素实验基础上,运用中心组合设计法优化水解肽的制备工艺,并对酶解产物的分子量分布及抗氧化活性进行分析。结果:鳀鱼蒸煮液的最佳酶解条件为酶解时间45 min、酶解温度54.5 ℃、酶解pH8.2、碱性蛋白酶与中性蛋白酶比例1:1,在此条件下TCA-NSI可达76.51%。所制备的水解肽中分子量低于1500 Da的多肽含量可达81.941%。水解肽对DPPH自由基、羟自由基和超氧阴离子自由基清除率的IC₅₀分别为2.45、1.37和3.45 mg/mL,表明其具有较强的抗氧化活性。结论:采用复合酶法可高效酶解鳀鱼蒸煮液,并获得具有较强抗氧化活性的水解肽,可为鳀鱼蒸煮液高值化利用及活性肽产品开发提供理论依据。

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.