When cinnamon is in, Escherichia coli O157:H7 is out. That's what researchers at Kansas State University discovered in laboratory tests with cinnamon and apple juice heavily tainted with the bacteria. Presented at the Institute of Food Technologists' 1999 Annual Meeting in Chicago on July 27, the study findings revealed that cinnamon is a lethal weapon against E. coli O157:H7 and may be able to help control it in unpasteurized juices.
Lead researcher Erdogan Ceylan, M.S., reported that in apple juice samples inoculated with about one million E. coli O157:H7 bacteria, about one teaspoon (0.3 percent) of cinnamon killed 99.5 percent of the bacteria in three days at room temperature (25 C). When the same amount of cinnamon was combined with either 0.1 percent sodium benzoate or potassium sorbate, preservatives approved by the Food and Drug Administration, the E. coli were knocked out to an undetectable level. The number of bacteria added to the test samples was 100 times the number typically found in contaminated food.
"This research indicates that the use of cinnamon alone and in combination with preservatives in apple juice, besides its flavoring effect, might reduce and control the number of E. coli O157:H7," concluded Ceylan, a Ph.D. graduate assistant at K-State. "Cinna-mon may help protect consumers against foodborne bacteria that may be in unpasteurized juices and may partially or completely replace preservatives in foods to maintain their safety," he said.
"If cinnamon can knock out E. coli O157:H7, one of the most virulent foodborne microorganisms that exists today, it will certainly have antimicrobial effects on other common foodborne bacteria, such as Salmonella and Campylobacter," noted Daniel Y.C. Fung, Ph.D., professor of Food Science in the Department of Animal Sciences and Industry at K-State, who oversaw the research.
Last year, Fung and Ceylan researched the antimicrobial effects of various spices on E. coli O157:H7 in raw ground beef and sausage and found that cinnamon, clove, and garlic were the most powerful. This research led to their recent studies on cinnamon in apple juice, which proved to be a more effective medium than meat for the spice to kill the bacteria.
"In liquid, the E. coli have nowhere to hide," Fung noted, "whereas in a solid structure, such as ground meat, the bacteria can get trapped in the fat or other cells and avoid contact with the cinnamon. But this cannot happen in a free-moving environment."
Regardless of the K-State findings, people who are at greater than normal risk for foodborne diseases-- namely the elderly, young children, or immune-compromised-- would be urged to avoid drinking unpasteurized juices or unthoroughly cooked hamburgers, which may contain harmful microorganisms.
For a copy of the study presented at IFT's Annual Meeting, contact Angela Dansby at 312-82-8424 x127 or via e-mail at aldansby@ift.org .
Founded in 1939, IFT is a non-profit scientific society with 28,000 members working in food science, technology and related professions in industry, academia and government. As the society for food science and technology, IFT brings sound science to the public discussion of food issues.