Antioxidative properties of products from amino acids or peptides in the reaction with glucose.

The livers of rats fed with a brownish "soybean paste" (Miso) or peptides-glucose reaction mixture showed lower TBA and chemiluminescence values than those of the control. From these results, it was clear that Miso and peptide-glucose reaction products also exhibited antioxidative effect in vivo. In order to explain this mechanism, the scavenging activity against reactive oxygen species (ROS) of various Maillard reaction products (MRPs) were studied. It was confirmed that peptide-glucose reaction products. Amadori rearrangement products, melanoidins, modified protein and its hydrolysate, brown pigments isolated from Miso and other foodstuffs showed strong scavenging activity against hydroxyl radical and superoxide anion. Consequently, it was estimated that scavenging activity of MRPs against ROS played an important role in the antioxidative effect of MRPs in vivo.