Preparation And Application Of Antioxidant Peptides From Mung Bean By Complex Enzyme Method

Plant peptides are easily absorbed and utilized in the human body and have the advantages of high oxidation resistance,high safety,low production cost,etc,have a good market prospect.The preparation of mung bean polypeptide by mung bean protein is one of the good methods to increase the market value of mung bean,and provides new thinking for the efficient use of mung bean resources.The research content of this dissertation has the following points:1.The protein content was determined by Kjeldahl test to be 85.41%.Mung bean protein was used as a raw material by single enzymatic hydrolysis.The process conditions for preparing mung bean polypeptide by alkaline protease hydrolyzed mung bean protein were p H 8.5,temperature 60 ?,substrate concentration 9%,enzyme dosage 5% and degree of hydrolysis was 31.55% and polypeptide yield was12.5%;the process conditions for preparing mung bean polypeptide by neutral protease hydrolyzed mung bean protein were p H 7.0,temperature 50 ?,substrate concentration 9%,enzyme dosage 6% and degree of hydrolysis was 30.49% and polypeptide yield was 12.1%.2.The alkaline protease and neutral protease were combined to study the effect of the complex enzyme addition method on the hydrolysis.The best way to add enzymes was to add alkaline protease first,without the need of high temperature enzyme digestion,and then added neutral protease digestion.The process conditions for preparing mung bean polypeptide by the complex enzyme synergistic hydrolysis method were p H 8.5,temperature 56?,substrate concentration 8%,enzyme dosage4%,ratio of complex enzyme 1:1,hydrolysis time 180 min and degree of hydrolysis was 33.95% and polypeptide yield was 13.17%.3.Using mung bean protein and Vc as control,the antioxidant activity of mung bean polypeptide was studied by measuring the ability to scavenge DPPH free radicals,scavenging the ability of OH· radicals and scavenging O2-· free radicals.It was found that the mung bean antioxidant polypeptide had good scavenging ability to DPPH free radicals,superoxide anion radicals and hydroxyl radicals,and the DPPH free radicals,superoxide anion radicals and hydroxyl radical scavenging rates were82.8%,76.82% and 56.85%,respectively.4.The mung bean peptide was applied to beverages to develop a new antioxidant beverage product with added mung bean antioxidant polypeptide.The optimum technological conditions for the study of antioxidant beverages were mung bean polypeptide 0.7%,tea sugar 4%,and citric acid 0.04%.The scavenging rates of DPPH free radicals,superoxide anion radicals and hydroxyl radicals were 81.48%,73.18%and 54.9%,respectively,and had good antioxidant activity.5.The enzymatic hydrolysate of mung bean protein was formulated to develop mung bean antioxidant peptide glutinous rice wine with good flavor and quality.Theoptimum fermentation conditions for studying mung bean peptide glutinous rice wine were fermentation temperature 30 ?,fermentation time 5d,feed water ratio 1:0.6(g/m L),volume added 0.5%(g/100g),and the amount of peptide added was 0.1%.The rice wine obtained at this time had the best taste and was suitable for traditional fermentation.At this time,the clearance rate of hydroxyl radicals of mung bean peptide glutinous rice wine was 79.85%,the superoxide radical scavenging rate was69.6%,and the DPPH free radical scavenging rate was 82.53% and had good antioxidant activity.