Heterocyclic amines are mutagenic compounds that form when meat and fish are cooked at high temperatures -- especially meats that are grilled, pan-fried, broiled or barbecued -- and are categorized as human carcinogens, the researchers said.
Kansas State University researchers Kanithaporn Puangsombat and J. Scott Smith compared five rosemary extracts with varying concentrations of water and ethanol for their ability to inhibit heterocyclic amines formation in cooked beef patties.
The rosemary extracts were isolated with ethanol concentrations ranging from 10 percent to 40 percent.
The extracts -- containing rosmarinic acid, carnosol and carnosic acid -- were added directly onto the ground beef patties and cooked at two different temperatures: 400 degrees F for 5 minutes each side and 375 degrees F for 6 minutes each side.
When beef patties were cooked at 400 degrees F for 5 minutes per side, the rosemary extracted at the lower ethanol concentrations were most effective in inhibiting heterocyclic amines formation.
The findings are published in the Journal of Food Science.