海蜇低分子肽制备及体外抗氧化活性

Preparation and in vitro antioxidant activity of low molecular weight peptides from Rhopilema esculentum Kishinouye

中文关键词:  海蜇  低分子肽  双酶酶解  抗氧化活性  超滤  氨基酸分析

英文关键词:Rhopilema esculentum Kishinouye  low molecular weight peptide  double enzyme hydrolysis  antioxidant activity  ultrafiltration  amino acid analysis

中文摘要:

      目的 优化海蜇低分子肽(low molecular weight peptide from Rhopilema esculentum Kishinouye, RKLP)制备工艺, 评价其抗氧化活性及分析氨基酸组成。方法 海蜇利用碱性和中性蛋白酶双酶分步酶解制备海蜇肽, 以1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl, DPPH)自由基清除率为指标, 响应面实验优化酶解工艺条件。采用超滤技术, 获得分子量≤3.5 kDa RKLP。通过测定DPPH自由基、2,2’-联氮-双-3-乙基苯并噻唑啉-6-磺酸[2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), ABTS]自由基及超氧阴离子(O2?)自由基的清除率, 评价RKLP抗氧化活性。氨基酸分析仪分析RKLP氨基酸组成。结果 酶解制备海蜇抗氧化肽的最佳工艺条件为: 酶解温度50℃、3%碱性蛋白酶pH 7.5酶解2 h、1%中性蛋白酶pH 7.0酶解2 h, 所得的DPPH自由基清除率为71.52%±0.59%, 接近与预测值70.57%。RKLP水解度为62.10%±0.57%, 具有较强的DPPH自由基、ABTS自由基及O2?自由基的清除能力, 表明RKLP具有较好的抗氧化活性。RKLP氨基酸种类丰富, 必需氨基酸含量达29.87%, 蛋白质营养价值较高, 且含有较多的与抗氧化活性密切相关的疏水氨基酸、酸性氨基酸、碱性氨基酸和芳香族氨基酸。结论 优化海蜇酶解工艺条件, 超滤制备的RKLP具有较强的抗氧化活性及较高的水解度, 初步阐释其抗氧化活性机制, 为海蜇高值化应用提供一定的理论依据。

英文摘要:

      Objective To optimize the preparation of low molecular weight peptide from Rhopilema esculentum Kishinouye (RKLP) and investigate the antioxidant activity and amino acid composition of RKLP. Methods Rhopilema esculentum Kishinouye peptides were prepared by double enzymatic hydrolysis with alkaline and neutral protease. The enzymatic hydrolysis process conditions were determined based on the clearance rates of 1,1-diphenyl-2-trinitrophenylzyl (DPPH) radical, and response surface methodology was applied to optimize the enzymatic hydrolysis process conditions. RKLP with molecular weight less than 3.5 kDa were obtained by ultrafiltration technique. The antioxidant activity was investigated by measuring the clearance rates of DPPH radical, 2,2’-biazo-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical and superoxide anion free radical. Amino acid composition of RKLP was analyzed by amino acid analyzer. Results The optimum process conditions for the preparation of Rhopilema esculentum Kishinouye peptides by enzymatic hydrolysis were enzymatic hydrolysis temperature 50℃, 3% alkaline protease pH 7.5 enzymatic hydrolysis for 2 hours, 1% neutral protease pH 7.0 enzymatic hydrolysis for 2 hours. Under these conditions, the DPPH radical scavenging rate was 71.52%±0.59% (close to the predicted value 70.57%). The degree of hydrolysis of RKLP was 62.10%±0.57%, and it also had strong scavenging ability of DPPH free radical, ABTS free radical and superoxide anion free radical. DPPH free radical scavenging rate. The results indicated that RKLP displayed good antioxidant activity. RKLP was rich in amino acids and contained 29.87% of essential amino acids. It not only had high nutritional value but also contained hydrophobic amino acids, acidic amino acid, basic amino acid and aromatic amino acid which were closely related to antioxidant activity. Conclusion RKLP is prepared by optimizing enzymatic hydrolysis process conditions and the ultrafiltration technique. RKLP has strong antioxidant activity and high degree of hydrolysis. The mechanism of its antioxidant activity is preliminarily explained. It provides some theoretical basis for application of high value of Rhopilema esculentum Kishinouye.