Edible Coatings May Boost Food Safety

Oregano oil spray kills more than 50 percent of E. Coli O157:H7 bacteria.

By Rick Ansorge
HealthDay Reporter
Monday, November 27, 2006; 12:00 AM

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MONDAY, Nov. 27 (HealthDay News) -- A natural, edible coating could help keep deadly E. coli bacteria and other nasty bugs away from fresh produce, U.S. government scientists report.

Researchers at the U.S. Department of Agriculture say the new compounds reduce the risk of infection from deadly E.coli O157:H7 bacteria and other foodborne microorganisms. They report their findings in the Nov. 29 issue of the Journal of Food and Agricultural Chemistry.

"We hope that these coatings will have wide commercial potential," said Tara McHugh, a food chemist with the U.S. Department of Agriculture's Agricultural Service in Albany, Calif. Her team conducted lab tests on the E. coli-inhibiting ability of apple-puree food coatings containing one of three natural antimicrobial compounds: oregano, lemongrass and cinnamon oil.

The researchers say the oregano oil coating was the most effective, killing more than 50 percent of E. coli O157:H7 bacteria within three minutes.

Because such coatings contain sticky sugars and fats, they may adhere longer to fresh produce and provide a more concentrated, longer-lasting method for killing bacteria than conventional, water-based washes, McHugh said.

That would be welcome news to consumers who have been bombarded with reports this fall about food safety, starting with the E. coli O157:H7 scare in mid-September that killed three Americans and sickened nearly 200 others who ate tainted spinach.

Subsequent scares included a salmonella outbreak that sickened 171 people in 19 states, plus recalls of E. coli-tainted lettuce and ground beef. And on Monday, officials at the USDA announced that a type of salmonella typically found in eggs is turning up with increasing frequency in chicken meat.

But some scientists wonder if edible coatings with antimicrobial compounds will prove practical in improving food safety outside of the laboratory.

"They haven't yet been tested in the real world, which means they need to be tested on fresh fruits and vegetables. So we don't know how efficacious they would really be," said Dr. Pascal James Imperato, chairman of the department of preventive medicine and community health at the State University of New York Downstate Medical Center, and a former New York City health commissioner.