Preparation Of Ruditapes Philippinarum Oxidation Active Peptide And The Activity Research

Ruditapes philippinarum is one of the most important economic aquatic product in China.The manufacturing process of the Ruditapes philippinarum in our country is still dominated by the traditional way,have less high value-added productions of Ruditapes philippinarum.This problem severely restricts the development of the Ruditapes philippinarum product market.Therefor,this paper took the Ruditapes philippinarum as raw material,prepared the Ruditapes philippinarum enzymatic hydrolysate by enzymolysis method,separating and purifying the enzymatic hydrolysate to get the antioxidant peptide.Study on the antioxidative activity to provide some theoretical basis and data support for the development of high value-added manufacturing process and the adjustment of industrial structure.The main research contents and conclusions are as follows:1.The basic components of the Ruditapes philippinarum was analyzed and the results showed that:the protein content in the Ruditapes philippinarum was 15.05%,moisture,fat and ash content were 78.87%,1.30%,1.98%.It suggested that the Ruditapes philippinarum was a kind of high protein but low fat content aquatic product.2.Through the comparison of the yield of polypeptide of 5 enzymes(trypsin,flavourzyme,neutral protease,alkaline protease,papain)to screening experimental enzyme.The results showed trypsin enzymolysis preparation had the highest yield of polypeptide,therefor,choose the trypsin enzyme as the experimental enzyme.3.Research on process of Ruditapes philippinarum enzymolysis:the effect of concentration of trypsin,enzymolysis time and enzymolysis temperature on the yield of polypeptide was studied.Based on single factor experiment,the response surface methodology were designed.The mathematical regression model for yield of polypeptide(Y),concentration of trypsin(X1),enzymolysis time(X2)and enzymolysis temperature(X3)was established.The resulted regression equation was listed as follows:Y=67.63+2.01X1+0.49X2+0.21X3-1.13X1X2+0.14X1X3+0.055X2X3-4.03X12-3.43 X22-3.89X32The optimal parameters were:the concentration of trypsin 6147.59U/g,enzymolysis time 3.52h,enzymolysis temperature 50.16?,the yield of polypeptide was 67.88mg/g.Considering the actual operation,change the optimal technological condition of enzymolysis as concentration of trypsin 6120U/g,enzymolysis time 3.5h,enzymolysis temperature 50?.Under this experiment condition,the actual yield of polypeptide was 67.83(�0.23)mg/g,the results were consistent with the theoretical value.4.The RPTE was fractionated by chromatographic methods using Sephadex G-25 gel filtration and gained six main components named RPTE1,RPTE2,RPTE3,RPTE4,RPTE5,RPTE6.The antioxidation of these six component was evaluated by scavenging capability of DPPH,hydroxyl and superoxide anion radical.The results showed that the RPTE2 component had the highest antioxidant activity.When the RPTE2 component concentration was 3.2mg/mL,the scavenging rates of DPPH,hydroxyl and superoxide anion radicals were 72.10%,69.74%,62.28%.5.The RPTE2 was fractionated by chromatographic methods using Sephadex G-15 gel filtration and gained four main components named RPTE2-1,RPTE2-2,RPTE2-3,RPTE2-4.The anti oxidation of these four component was evaluated by scavenging capability of DPPH,hydroxyl and superoxide anion radical.The results showed that the RPTE2-2 component had the highest antioxidant activity.When the RPTE2-2 component concentration was 3.2mg/mL,the scavenging rates of DPPH,hydroxyl and superoxide anion radicals were 69.54%,91.67%,78.89%.Therefor,choose the RPTE2-2 component as the Ruditapes philippinarum antioxidant peptide.6.The stability of antioxidation activity from Ruditapes philippinarum antioxidant peptide obtained the following conclusions:(1)The antioxidant peptide in the lower temperature range of 20?100? and light,activity retention rate was relatively high.(2)The activity retention rate of antioxidant peptide was affected by acid and alkali environment,at 6,7,8 of the pH value,activity retention rate was higher.(3)The antioxidant activity reduced rapidly when the addition of K+,Ca2+,Mg2+,Cu2+,Zn2+.When the Ca2+concentration was 5mmol/L,the superoxide anion radical scavenging capacity retention rate is only 25%.There was lowest effect on the antioxidant activity when addition of K+.(4)The effects of NaCl solution,sorbic acid sodium,sodium benzoate on antioxidant peptide are not obvious,glucose solution with mass fraction 7.0%made the activity dramaticly increase.7.Research on the effect of simulated gastrointestinal digestion on antioxidant activity of antioxidant peptide.The results showed that:during gastric digestion process the antioxidant activity reduced largely,but during intestinal digestion process the antioxidant activity remained unchanged basically.