Antioxidant peptides derived from hydrolyzed milk proteins by Lactobacillus strains: A BIOPEP-UWM database-based...

Milk-derived peptides have been identified as the essential ingredients in the food industry for the health-promoting properties. Some bioactive peptides in the milk product can be released by the specific protease system of lactic acid bacteria (LAB) during the fermentation processing. In this research, the bioactive peptides released from the casein and whey protein are investigated by the hydrolyzing ability of the Lactobacillus brevis CGMCC15954, Lactobacillus reuteri WQ-Y1 and Lactobacillus plantarum A3. Results found that the hydrolysates of casein/whey protein generated by L. reuteri WQ-Y1 have the potential antioxidant activity. Furthermore, milk-derived peptides identified by the liquid chromatography-mass spectrometry (LC-MS/MS) with the BIOPEP-UWM database showed the YLGYLEQLLR (α_S1-casein), VKEAMAPK (β-casein), YIPIQYVLSR (κ-casein) fragment had the promising antioxidant activity, especially VKEAMAPK, which exhibited IC₅₀ of 0.63 and 0.86 mg/mL in DPPH and ABTS free radical scavenging activity. The finding of this study sheds some light of obtaining milk-derived peptides by using the Lactobacillus strains and proves the potential bioactive function of the LAB fermented milk products.