Beef patties were prepared by mixing minced meat with water and either glucose (1, 2 or 4%), lactose (1, 2 or 4%) or powdered milk (2, 4 or 8%) before frying. In another experiment, minced meat was mixed with starch from golden bread crumbs (3%) or potatoes (4%), with and without glucose (1, 2 or 4%). The patties (100 g) were fried for 3 min at 150 or 180 degrees C in a double-sided fryer. The mutagenic activity in the crust was determined using the Ames test. With the addition of glucose or lactose (1-4%), the mutagenic activity was inhibited by 34-76%. A similar inhibition of the mutagenic activity was obtained with powdered milk. However, starch from golden bread crumbs or potatoes caused only a slight (not significant) decrease in mutagenic activity whereas adding both starch and glucose to the beef patties inhibited mutagenic activity by up to 54%.