银鲳酶解物抗氧化活性研究

Antioxidant activity of Silver pomfret protein hydrolysates

选用胃蛋白酶、胰蛋白酶、碱性蛋白酶和中性蛋白酶对银鲳蛋白进行酶解以制备蛋白酶解物,以羟基自由基清除活性为指标确定银鲳最佳水解酶。结果显示,碱性蛋白酶的水解物抗氧化活性最强。实验对碱性蛋白酶水解银鲳的酶解条件(时间、温度、pH、酶添加量和固液比)进行正交实验设计,并对最佳水解条件下所获得的酶解物进行抗氧化活性测试。结果表明,银鲳蛋白碱性蛋白酶水解物对DPPH自由基和羟基自由基具有清除作用,其自由基清除效果呈现剂量依赖性,而且银鲳蛋白水解物还具有明显还原能力。所有这些体外抗氧化数据说明,银鲳蛋白水解物有明显的抗氧化效力。

Silver pomfret protein hydrolysates were prepared using commercial enzymes,namely pepsin,trypsin Alcalase,and neutral protease.The hydrolysates so prepared were effective as antioxidants in model systems,mainly by scavenging of hydroxyl free radicals.The hydrolysate prepared using Alcalase showed the highest antioxidant activity among all samples.Hydrolysis conditions（temperature,pH,enzyme to substrate level and solid/liquid ratio） for preparing protein hydrolysates with Alcalase from the Silver pomfret proteins were optimized by orthogonal design.the hydrolysates were assessed using methods of DPPH radical scavenging ability.In the best hydrolysis conditions,The antioxidant and free radical-scavenging activities of Silver pomfret protein hydrolysates prepared with alcalase were investigated by employing several in vitro assay systems,including the 1,1-diphenyl-2-picrylhydrazyl（DPPH）,hydroxyl radical-scavenging,and reducing power.Silver pomfret protein hydrolysates showed scavenging activity against free radicals such as DPPH· and hydroxyl radicals.The radical-scavenging effect was in a dose-dependent manner.Moreover,Silver pomfret protein hydrolysates also exhibited notable reducing power.The data obtained by the in vitro systems obviously established the antioxidant potency of Silver pomfret protein hydrolysates.