Studies on Browning Reaction Products from Reducing Sugars and Amino Acids

Fractionation of browning reaction products prepared from a mixture of glycine and D-xylose on Sephadex G-15 gave two peaks; high molecular melanoidin and low molecular reductone fraction.This melanoidin fraction also exhibited reducing power for potassium ferricyanide. Antioxidative activity of each fraction against autoxidation of linoleic acid was examined in aqueous system. Strong antioxidative activity among fractions tested was found in the fraction which contained high molecular melanoidin, but not in low molecular reductone. On the other hand, antioxidative activities of the fractionated materials decreased by dialysis with exception of fraction 12 (high molecular melanoidin).Fractionation of browning reaction products on Sephadex G-25 gave two peaks consisting of melanoidin and reductone respectively and low molecular reductone fraction contained brown pigment to a large extent. The result of this experiment indicated that the most brown fraction had the strongest antioxidative activity for autoxidation of linoleic acid.