Research Of Soybean Mini-peptides’ Preparation And Clinical Application

Soybean peptide is a kind of active peptides derived from soy protein controlled hydrolysis and refinement.In this study,compound proteases were adopted for soybean proteolysis.Process flow concerning parameters of reaction temperature,substrate concentration,reaction time,pH,amount of enzyme,and the biological characteristics were investigated systematically.It came to the conclusion that the optimal digestion temperature is 45~48 ℃,the optimum pH value 8.0,the optimal substrate concentration 8%,enzyme dosage 2%(W / V),and reaction time 4h.Hydrolysis degree is up to 80%,and oligo-peptides(molecular weight ≤ 500Da)content over 80%.Six kind of peptide fragments were obtained from soybean hydrolysates with SephadexG-25 separation.The majority of the molecular weight is below 1000 D,the average measured peptide molecular chain length(PCL)2.59 amino acid residues,Under these conditions,The production technology has the advantages of low cost,simple process,high levels of small peptides,and good quality.In vitro single bacterial culture was used to determine the effects of soybean peptide on six strains of animal intestinal bacteria proliferation.The results showed that the SBP can significantly promote the proliferation of bacteria.In vitro tests showed that soy peptides have anti-oxidation function,can remove O2.-generated from pyrogallol auto-oxidation reaction,inhibit H2O2-induced lipid peroxidation significantly,and reduce the incidence of hemolysis to maintain normal physiological function.Clearance rate and inhibition rate reached 47.77% and 52.23%,and showed a certain dose-effect relationship with the increase of small peptide concentration.Soybean small peptides significantly stimulate lymphocyte proliferation in the concentration range1.25~5mg/mL.This study aimed to verify peptide growth role,feed conversion,death rates,and economic impact with broiler diets supplementing some small peptides in replace of partial soybean meal.400 AA broilers were used for single-factor randomized trial design,and divided into four treatments,The control group,treatment group Ⅰ,was fed the basal diet;6% of soybean meal basal diet was replaced by 0.2%,0.3%,0.4% of soybean small peptides for treatment group Ⅱ,Ⅲ,Ⅳ respectively.The results indicated that,l)the addition concentration increases of soybean small peptides accelerate the broiler daily gain.Treatment group Ⅱ,Ⅲ,Ⅳ daily gain more 7.45 g,8.52 g,8.84 g weight than the control group.Feed conversion of treatment groupⅡis 0.13 lower than the control groupⅠ;2)soybean peptide can increase metabolic rate,protein metabolic rate of experiment group Ⅱ,Ⅲ,Ⅳ,increasing 8.82%,8.9% and 10.72% respectively compared with group Ⅰ.3)For economic benefits,the treatment group Ⅱ,Ⅲ,Ⅳ,profited more 29.37%,15.37%,2% per bird than the control group.The study showed that,soy peptides can be effectively used in broiler production,and the optimum amount 0.2% substitutes 6% of soybean meal through a comprehensive comparison including economic benefits.The addition may significantly promote the growth of broiler chickens,improve the intestinal environment,and provide a theoretical basis for the soybean peptides application in broiler production.