Isolation and Evaluation of Bioactive Properties of Peptides Derived from Enzymatic Hydrolysis of Soy whey

Today, special attention is paid to the use of bioactive peptides in the production of functional foods and drugs. In the present study, isolation and evaluation of bioactive properties of peptides derived from enzymatic hydrolysis of soy whey were investigated. For enzymatic hydrolysis of soy whey protein, two types of enzymes, ficin and trypsin, were used at temperatures of 37 °C and 45 °C and at times of 2 and 4 hours. Then, the obtained protein hydrolysates were separated by reverse phase- high performance liquid chromatography and the obtained fractions were collected for biological activity. Statistical analysis of hydrolysis degree results was conducted by factorial method. One-way analysis of variance was used to analyze the results of the bioactive properties of peptides. The means were compared by Duncan's multiple range test at 5% probability level. Based on the results, peptide fractions had good antioxidant activity and also showed antimicrobial effect against Escherichia coli and Staphylococcus aureus. The T4F7 fraction (the seventh fraction obtained from trypsin-prepared protein hydrolyzate at 45 °C for 4 hours) had the highest antioxidant and antimicrobial properties. Therefore, this fraction was considered as the superior fraction. Electrophoregram of separation of peptide components in the selected bioactive peptide fraction (T4F7) showd that the presence of peptides with a molecular mass often of about 5 to 10 kDa and Less than 50 kDa is the main cause of desirable antioxidant properties in this treatment. Therefore, soy whey peptide can be used as a functional ingredient and natural preservative in food products.