Enzymatic Hydrolysis of Soy Proteins to Prepare Potentially Immunomodulating Active Peptides

摘要

It was suggested by several reports that some positively charged small peptides had immunomodulating activity. In this study, four commercial enzyme, Alcalase, Flavourzyme, Protease A and Peptidase R, were used individually or paired each other as protease, with soy protein isolate (SPI), soluble soy protein (SSP) or insoluble soy protein (InSP) as substrate, to hydrolyze soy protein under varying enzyme-substrate ratio, substrate concentration, pH and temperature. The degree of hydrolysis (DH), molecular weight distribution and relative content of the positively charged peptides for soy protein hydrolysates were determined. Results showed that higher DH and average molecular weight were achieved by using Alcalase while the highest relative content of positively charged peptides was obtained when InSP was used as substrate. Hydrolyzing conditions affected DH markedly but had only weak influence on average molecular weight and positively charged peptide content.