Research on the determination of concentration of bioactive peptides derived from milk protein

In this study, we investigated the method to determine peptides concentration. Based on traditional Folin-phenol method, we established concentration standard curves using BSA, Tryptone and Peptone as standard samples, respectively. Then the gel chromatography Superdex 30 was used to analyze the component ratio of the peptides in Tryptone and Peptone. In conclusion, we selected Peptone as the best standard sample, and the correlation coefficient (R) of the standard curve is 0.99936. With developed Peptone-folin-phenol method, we tested the peptides concentration in fermented milk with different strains and conditions. The result showed that peptides could be produced with the highest concentration from milk protein using Lactobacillus delbrueckii ssp. bulgaricus LB340