Abstract

In order to investigate the hypocholesteremic effect of soybean perptides, soybean protein(ISP), casein(CNP), their peptic hydrolyzates fractionated by acid precipitation at different pH's(SHT, SH8, SH6, SH4, CHT, CH5, CH4) and amino acid mixtures of the same composition as the proteins(SAA, CAA) were fed to rats and the concentration of serum cholesterol was measured. Then in vitro digestibility and molecular weight distribution of the peptides by pepticpancreatic hydrolysis was measured by FPLC. The lower the in vitro digestibility of peptides is, the lower the concentration of serum cholesterol becomes(r=0.986) and the higher the ratio of macropeptides is, the lower the concentration of serum cholesterol becomes(r=-0.932) in rats. These results suggest that the in vitro digestibility of peptides has close relationship to the concentration of serum cholesterol in rats and non-digestible meacropeptides or polypeptides especially more than 1 kDa, formed through digestion in gut, may lower the serum cholesterol in rats.

Keywords

• soybean peptides;
• in vitro digestibility;
• scrum cholesterol