Enzymatic Preparation And Application Of Functional Peptides From High Temperature Peanut Meal

In this study,the high temperature peanut meal was taken as the research object,we mainly studied the influence of protease types on the enzymatic hydrolysis process of high temperature peanut meal and hydrolysate properties,screened out the good product properties of hydrolysate protease.Then the enzymatic hydrolysis process of the optimal protease was optimized and the enzymatic hydrolysis kinetic model was established.Finally,two kinds of functional polypeptide compound juice drinks were developed from peanut polypeptide with good functional properties and antioxidant activity.Single factor test and orthogonal optimization test were used to determine the optimal formula and determine the physical and chemical indexes of compound drinks prepared under the optimal technological conditions.The results are as follows:(1)Screening of the optimal protease.After hydrolysis by different proteases,the protein recovery of alkaline protease,papain and compound protease hydrolysate was above 60%.The DH of alkaline protease hydrolysate was the highest(24.87%),which contained more peptides with less than 3 k Da.The DH of papain hydrolysate had the highest efficiency,which reach the maximum hydrolysis degree in a short time.In addition,the foaming ability and stability of papain hydrolysate were 216.24%and 67.19%,respectively.The DPPH free radical scavenging rate of papaya hydrolysate was the highest(IC₅₀ was 0.72 mg/m L),and the ABTS free radical scavenging rate was 1.52 mg/m L.Then,the protease hydrolysis process was optimized to explore the influence of protease addition amount and hydrolysis time on protein recovery.Finally,the optimal addition amount of protease was 5%and the optimal hydrolysis time was180 min.(2)Construction of kinetic model of enzymatic hydrolysis.In view of the classic Miley's equation,the kinetic model of papain hydrolysis with high temperature peanut meal was established by mathematical derivation combined with experimental study,and the kinetic parameters were determined.According to the deduced formula model,the relationship between hydrolysis degree and hydrolysis time under different enzyme concentration and substrate concentration to obtain the kinetic model:DH=0.839ln[1+(1826.859E₀/S₀-78.772)t],and explore the relationship between a value and E₀/S₀,a=1532.6(E₀/S₀)-66.084.Finally,the model was verified by comparing the theoretical value of degree of hydrolysis with the actual value,with an average error of 7.6%.It proved that the kinetic model could better simulate the enzymatic hydrolysis process and had certain practical application value.(3)Determination of functional peptide compound juice beverage formula.Two functional peptide complex juice drinks were developed.The best formula was determined by using diluted hawthorn juice concentrate and papaya pulp as the main raw materials and adding bioactive peptides prepared by enzymolysis.Through single factor test and orthogonal optimization test,the optimal formula of hawthorn juice and functional peptide compound juice beverage was determined as followed:peanut polypeptide was 1%(w/w),honey was 5%(w/w),citric acid was 0.6%(w/w),carrageenan was 0.3%(w/w).The optimal formula of the compound juice beverage was determined as followed:peanut polypeptide was 1.0%(w/w),lemon juice was 2.0%(w/w),carrageenan was 0.3%(w/w)and honey was 4.0%(w/w).(4)Determination of physical and chemical indexes of functional peptide compound juice beverage.The p H,soluble solids,centrifugal precipitation rate,total acid and reducing sugar contents of hawthorn juice were 3.96,12.7%,5.69%,3.73 g/L and 6.85%,respectively.The p H,soluble solids,centrifugal precipitation rate,total acid content and reducing sugar content of papaya juice were 4.61,10.2%,17.87%,1.80 g/L and 10.96%,respectively.