CHICAGO - Adding rosemary extract to ground beef reduces cancer-causing agents that can develop during the cooking process, according to a recent study in the Journal of Food Science, published by the Institute of Food Technologists.

Heterocyclic amines (H.C.A.s) are mutagenic compounds that form when meat and fish are cooked at high temperatures — especially grilled, pan-fried, broiled, or barbecued meats. The National Toxicology Program of the U.S. Department of Health and Human Services categorizes H.C.A.s as human carcinogens that can increase the risk of certain types of cancers.

Kansas State University researchers Kanithaporn Puangsombat and J. Scott Smith investigated the theory that reducing the amount of H.C.A.s in meat cooked at high temperatures would reduce the associated health risks. Five rosemary extracts with varying concentrations of water and ethanol and their ability to inhibit HCA formation in cooked beef patties were compared.

Rosemary extracts were isolated with ethanol concentrations ranging from 10% to 40 %. The extracts were added directly onto the ground-beef patties and cooked at two different temperatures: 400°F for five minutes each side and 375°F for six minutes each side.

All of the concentrations significantly decreased the levels of H.C.A.s at both cooking temperatures, researchers discovered.

When beef patties were cooked at 400°F for five minutes per side, the rosemary extracted at the lower ethanol concentrations were most effective in inhibiting H.C.A. formation.

Rosemary extracts prepared at these lower ethanol concentrations contain a mixture of rosmarinic acid, carnosol and carnosic acid, and these compounds may work together in inhibiting H.C.A. formation. Thus, rosemary extracts may not be the same depending on what solvents are used.