Characterization of mutagenic activity in cooked-grain-food products.

Wheat gluten or flour from several plant sources heated at 210 degrees C for 1 hr produced 0-1800 revertant colonies/g in the Ames/Salmonella test using strain TA98 with metabolic activation. Baked or toasted foods and a heated grain beverage showed a mutagenic response in all cases from 2 to 320 revertants/g, with higher values seen when overcooked. Fried meat-substitute patties showed 0-23 revertants/g when fried at 210 degrees C. A greater mutagenic response in bacterial strain TA98 than in strain TA100 and a requirement for metabolic activation suggests that one or more aromatic amine mutagens are formed at normal cooking temperatures, but the mutagenic activity measured cannot be accounted for by the known heterocyclic amines commonly found in cooked meats. We conclude that grain products from aromatic amine chemicals during heating that are mutagenic in bacterial mutation tests.