FORMATION OF MUTAGENIC ACTIVITY FROM AMINO-ACIDS HEATED AT COOKING TEMPERATURES

To investigate the formation of aromatic amine-like mutagenic activity in cooked grain foods, amino acids were heated alone or in binary com binations at either 150 or 210 degrees C. About half of the binary mix tures of arginine heated with other amino acids produced potent mutage nic responses in the Ames/Salmonella assay, but only cysteine produced mutagenic products when heated alone. One-to-one molar ratios of argi nine heated with threonine, valine, cystine, cysteine or tryptophan pr oduced reaction products that gave 1200-3200 revertants/mmol in Salmon ella strain TA98 with metabolic activation. 1-Methylguanidine, a fragm ent of arginine, produced a mutagenic response when heated alone or in binary mixtures with all amino acids tested. Analysis of reaction pro duct extracts by solid-phase extraction and HPLC failed to find the kn own heterocyclic amines commonly found in cooked meats that would expl ain the measured mutagenic activity. As judged by biological and chemi cal characterization, several new aromatic amine mutagens are formed b y heating some simple amino acids-combined with arginine, and these re actants may be the source of the mutagenic products detected in the ex tracts of some cooked grain-based foods.