Separation and Purification of antioxidant peptide from fermented whey protein by Lactobacillus rhamnosus B2-1

In this study, a new antioxidant activity peptide was isolated and purified from whey protein fermented by Lactobacillus rhamnosus. The fermentation sample was separated by macroporous resin D101 and Sephadex G-15. The collected fractions were tested for antioxidant and antitumor activities. In order to test the antioxidant activity of fractions, Hydroxyl (·OH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and Oxygen Radical Absorbance Capacity (ORAC) were used. The final purified peptide B11 showed highest ABTS and ·OH radical scavenging rate by 84.36 ± 1.89% and 62.43 ± 2.64%, respectively, and had an ORAC activity of 1726.44 ± 2.76 μM Trolox equivalent/g at 1.0 mg/mL. Further, the effects of B11 on LoVo human colon cancer cells, KB and Cal-27 human oral cancer cells were enhanced with increasing concentrations of B11. B11 contains 51.421% amino acids, with Glu and Asp being the major constituents. This study obtained a new bifunctional peptide B11, which is promising for development.