Technology Optimization Of The Peptides Preparation For Euphausia Superba And Study On The Antioxidant Activity

In this study, the ability of remove superoxide anion,hydroxyl free radical and DPPH was taked as an index to study the antioxidant activities of three kinds of peptides in vitro which are obtained by hydrolysis of Euphausia superba using three different kinds of protease(papain, alkaline protease, trypsin), respectively. As can be seen from the experimental data, the antioxidant activity of peptides prepared by papain hydrolysis the Euphausia superba is best, followed by alkaline protease.So the papain was chosen as enzyme reagent for the preparation of peptides.It show that the optimum process conditions of preparation of peptides is that p H of 6.0,solid-liquid ratio of 1:2 mg/m L, enzyme amount of 1.0%, the temperature of55 ℃ and time of 2.9hours,under the condition of the Euphausia superba protein hydrolysis degree was 12.88%,with the response surface method optimize the peptides preparation technology of Euphausia superba using papain.Then the molecular weight of the peptides was determined by gel electrophoresis.The results show that the peptides has three distinct bands, the molecular weight of which is located at 3ku~7ku.Peptides solution defluorinated through the ultrafiltration system for molecular interception of 10000 and5000,respectively.According to molecular weight(molecular weight, MW) size into MW≥10ku, 5k~10ku, MW≤5ku three peptides, then compare the strength of its antioxidant activity.In the experimental system, three different molecular weight peptides have different ability to remove superoxide anion, hydroxyl free radical and DPPH.With the increase of the concentration of peptides, the scavenging ability increased, which was obviously dose-dependent.According to the results,the clearance rate of potein peptides that the molecular weight less than 5ku,on superoxide anion, hydroxyl free radical,DPPH was highest,reached 19.62%, 68.23% and 68.23%, respectively.It indicates that the antioxidant activity is best of peptides with this molecular weight, in vitro.Mice experimental model was established to determinate the content of MDA and the activity of SOD, CATand GSH-Px in blood, liver and brain tissue of mice.Then the strength of the antioxidant activity in vivo of Euphausia superbal peptides of different molecular weight was measured.