In ongoing investigations, U.S. Department of Agriculture (USDA) and university researchers are taking a fresh look at the ability of olive powder and other plant compounds to combat foodborne pathogens and keep food safe to eat.

Some of the studies focus on control of microbes such as Escherichia coli O157:H7 that cause foodborne illness, and have also looked at control of two possibly carcinogenic heterocyclic amines, MelQx and PhIP, that can be formed during cooking of meats.

If used in hamburger patties, olive powder has potential to suppress the foodborne pathogen Escherichia coli O157:H7 and to retard the formation of heterocyclic amines that can form during cooking.Stephen Ausmus  These investigations have been conducted by Agricultural Research Service (ARS) research chemist Mendel Friedman at the agency's Western Regional Research Center in Albany, Calif., in collaboration with university colleagues. The research is highlighted in the May/June 2013 issue of Agricultural Research magazine. ARS is USDA's chief intramural scientific research agency.

Friedman and his colleagues added high levels of E. coli O157:H7 to ground beef patties along with either olive powder or other plant compounds. The patties were cooked to the recommended temperature of 160 degrees Fahrenheit, and then were tested for levels of E. coli and the two amines.

When the E. coli and amine results were evaluated as a whole, olive powder was shown to outperform the other powders (apple, onion, or garlic, for instance) that were tested.

Friedman noted that follow-up studies are needed to pinpoint the compounds in olive powder that are responsible for these effects, and to determine whether the amount added in the ground beef experiments alters the hamburgers' taste.

The ability of olive extracts to kill foodborne pathogens has been reported in earlier studies conducted at Albany and elsewhere. However, this study of E. coli and amines, documented in a 2012 peer-reviewed article in the Journal of Agricultural and Food Chemistry, may be the first to show olive powder's performance in concurrently suppressing three targets of concern: two major amines and a pervasive E. coli.

Friedman collaborated in the work with University of Arizona-Tucson co-investigators Yelena Feinstein, Cody M. Havens, Liliana Rounds and study leader Sadhana Ravishankar.

This research with natural, plant-derived antimicrobials and anti-heterocyclic amines supports the USDA priority of enhancing food safety.