Spice-Rack Favorites Battle E. coli and OtherFoodborne Pathogens

Herbs and spices like oregano, thyme,cinnamon and clove do more than add pleasing flavors and aromas to familiarfoods. The oils from these plants, or compounds extracted from those oils, packa powerful, antimicrobial punch—strong enough to help quell such foodbornepathogens as Escherichia coli O157:H7.

That's according to Agricultural ResearchService (ARS) chemistMendelFriedman, who several years ago evaluated the bacteria-bashing power ofthese and dozens of other plant compounds.

Now, some of the compounds that Friedman and co-investigators determinedwere the strongest combatants of E. coli, Salmonella enterica,Campylobacter jejuni, or Listeria monocytogenes in the2002 study are being tapped for new research focused on food safety.

For example, Friedman, research leaderTara H.McHugh, and other scientists at theARSWestern Regional Research Center in Albany, Calif., are evaluating thehighest-ranking botanical bactericides as potential ingredients in what areknown as edible films.

A thin, pliable, edible film for the future might be made of puréedspinach spiked with carvacrol, the compound responsible for oregano's rankingas a top fighter of E. coli in the Friedman study.

The scientists want to find out whether adding small squares ofcarvacrol-enhanced spinach purée film to bags of chilled, ready-to-eatspinach leaves would help protect this salad green against E. coli.

Friedman is also exploring other new uses of the top-rated botanicals fromthe earlier study. That investigation, which he conducted with technicianPhilipR. Henika and research leaderRobertE. Mandrell at Albany, was the most extensive of its kind at the time itwas published. Also notable was the common basis of comparison, which the teamestablished by inventing new methods to prepare and test all of the samples.For even more consistency, the scientists used the same bacterialstrains—from the same suppliers—throughout the investigation.

Readmore about the research in the July 2008 issue of AgriculturalResearch magazine.

ARS is a scientific research agency of the U.S. Department of Agriculture.