Study On Anti-oxidant Soybean Peptide

Many chronic diseases and senile phenomenon of human being are all relevant to radical level unbalance in the body. Excessive radicals may cause oxidation damage in the body. It would lead to some diseases if the damage could not be repaired timely and be accumulated to some degree. Bio-antioxidant can help people hold radical balance in the body. It is possible to develop potent antioxidant drugs and functional foods through studying and modifying some natural foods having anti-oxidative. Due to high output and low cost of soy, it has been one of the important foods. Hence, there is important social significance and economic value to study and develop soy peptides with antioxidative activity. In this research, many important parameters of enzyme hydrolysis of soy protein and anti-oxidative activity of soy peptides were analyzed. The aim of the subject is to find important factors which affect anti-oxidative activity of soy peptides and to offer theoretical guidance and technological parameters for the production of anti-oxidative activity of soy peptides.Papain was selected to produce antioxidative activity of soy peptides by hydrolysis. Soy protein was pre-treated by hot, the effect of pre-treating temperature and time on degree of hydrolysis were researched. The optimum condition of pre-treatment is 50℃, 20min. The relation between hydrolytic time and hydrolytic degree and anti-oxidant capacity were analyzed, the better condition was obtained which is T50℃, pH 7.0, W(S)5%, Φ(E) 4%,4hours. By analyzed the relation between hydrolytic degree and anti-oxidant capacity, the result that it is not deeper hydrolysis, higher anti-oxidant capacity was got, so a new advice was given. The reasons of bitterness about soybean peptides and the relation between bitterness and anti-oxidative were learned on, the conclusion is that some bitterness peptides are the part of anti-oxidative peptides. The value of K_m about hydrolysis soy protein with papain was calculated.Finally the general principles were given to produce anti-oxidative peptides. The conclusion is that to increase the concentration of small peptides and to use the proteases whose cleavage sites are hydrophobic amino residues thereby enhance relative hydrophobic degree of amino acid side chain.