Antioxidant activities of Se-MPS: A selenopeptide identified from selenized brown rice protein hydrolysates

Se-enriched brown rice (Se-BR) protein hydrolysates are a good source of antioxidant peptides. SeMet-Pro-Ser (Se-MPS) is one the antioxidative selenopeptides identified to date. In this study, the antioxidant activity and the related antioxidative mechanisms of Se-MPS and Met-Pro-Ser (MPS) were evaluated by measuring free radical and reactive oxygen species (ROS) scavenging activities, chromium reduction, myoglobin protection and inhibition ability of lipid peroxidation. Se-MPS showed higher oxygen radical absorbance capacity (ORAC) values, ABTS•+ scavenging activity, and chromium VI-reducing activity than MPS. Se-MPS and MPS exerted similar influence on hydroxyl radical scavenging activity. In biological components of myoglobin, Se-MPS effectively inhibited the myoglobin structure modified by its oxidizing reaction with hypochlorite ion, peroxyl radical and hydroxyl radical. Se-MPS also exhibited strong inhibition activity of linoleic acid emulsion peroxidation. Overall, selenium (Se) showed synergistic effects on the antioxidant activity of peptides.