ANTIOXIDATIVE EFFECT OF MAILLARD REACTION-PRODUCTS USING GLUCOSE-GLYCINE MODEL SYSTEM

Using a glucose-glycine system as a Maillard reaction model, the rate of inhibition toward active oxygen by Maillard reaction products (MRP) was investigated by electron spin resonance (ESR). MRP obtained throu gh heating a glucose-glycine mixture for 1 h inhibited more than ca. 9 0% of active oxygen species existing in the form of hydroxyl radicals (. OH) in the sample and decreased its inhibition power as heating tim e increased. Studies have revealed the direct scavenging activity of M RP along with the depression of the Fenton reaction, which is brought about by the strong chelating ability of MRP with Fe2+ due to the inhi bition of . OH. Moreover, the decrease in the inhibition activity towa rd . OH during the prolonged heating period can be explained by the in crease in reducing power of MRP promoting the reduction of Fe3+ to Fe2 +, and thus, activating the Fenton reaction. The high molecular weight fraction obtained from MRP, because of its stronger metal-chelating c apability, inhibited . OH more efficiently than the low molecular weig ht fraction. In addition, MRP obtained after 1 h of heat treatment exh ibited ca. 14% inhibition of superoxide anion (O-2(-)), indicating a l ower rate of inhibition compared to that of . OH, which can be explain ed by the contribution of trace amounts of O-2(-) formation during the early stage of glucose-glycine reaction.