Study On The Separation Of Soybean Antioxidative Peptides And Their Antioxidant Activity

Previous data showed that many chronic diseases and senile phenomenon were all relevant to radical level unbalance in the body. If the damage could not be repaired timely and be collected to some degree, it would result in some diseases. Bio-antioxidant can help hold radical balance in the body. It is possible to develop potent antioxidant drugs and functional foods through studying and separating some natural foods which have antioxidative activity. Due to high output and low cost of soy, it has been one of the important foods. Hence, there is important social signigicance and economic value to study and develop soybean peptides with antioxidative activiry. In this research the separating of soybean protein hydrolysis, the composition and antioxidative activity of soybean peptides were analyzed. The aim was to offer theoretical guidance for the production of antioxidative soybean peptides. This study consists of three parts as follows:1. The separation of soybean antioxidative peptides and its consitutionVarious peptides existed in the hydrolysates from soybean protein were fractionated by Sephadex G-25 gel filtration. The antioxidative activity of soybean separated peptides were studied using linoleic acid-Fe (SCN)³⁺. The amino acids composition and the RP-HPLC of the strongest antioxidative peptides were analyzed. The results indicated that six fractional peptides were fractionated by Sephadex G-25 gel filtration from the hydrolysates of soybean protein. In these peptides the fraction SP4 has strong antioxidant activity, which APCL is 4. For further research, the peptide SP4 was separated into 3 chromatogram peaks by RP-HPLC. Amino acids composition of peptide SP4 was showed to be rich on Leu and Val. Molar content of Leu and Val were 21.72% and 11.24% respectively.2. Effects of soybean peptides on antioxidative activity in vitroThe quenching effects of soybean peptides on free radicals, and the influences of soybean antioxidant peptides on auto-hemolysis of mice RBC, the malonaldehyde (MDA) content in mice liver juice and liver mitochondria, and the swelling of mitochondria were studied. The results showed that all different fractionated peptides had scavenging effects...