Antimutagenic effect of Maillard browning products obtained from amino acids and sugars

The antimutagenic effects of Maillard reaction products (MRPs) prepared by heating three sugars (fructose, glucose and xylose) and four amino acids (arginine, glycine, lysine and tryptophan) at 100 degrees C for 10 hr was evaluated in the Salmonella/microsome assay. The highest extent of browning was found in the MRPs of sugars-lysine and xylose-amino acids. The MRPs of xylose-amino acids showed stronger antioxidative activity and reducing power than did the other combinations. No mutagenicity or toxicity in Salmonella typhimurium TA98 was observed with any of the MRPs in the presence of S-9. Most MRPs, especially those of sugars-tryptophan and xylose-amino acids, strongly inhibited the mutagenicity of 2-amino-3-methylimidazo(4,5-f)quinoline (IQ), 3-amino-1,4-dimethyl-5H-pyridol-(4,3-b)indole (Trp-P-1) and 2-amino-6-methyldipyrido(1,2-a:3',2'-d)imidazole (Glu-P-1) in the presence of S-9. However, the MRPs of fructose-glycine and fructose-arginine increased the mutagenicity of Trp-P-1. The antimutagenic effect of the MRPs was well correlated with their antioxidative activity and reducing power. The mutagenicity of benzo[a]pyrene was moderately inhibited by most MRPs, but was increased by the MRP of glucose-arginine. Aflatoxin B1 mutagenicity was increased greatly by all the MRPs except that of xylose-tryptophan. The findings suggested that MRPs might have a bifunctional property of co-mutagenicity and antimutagenicity in certain cases.