Released: May 2, 2000
MANHATTAN, Kan. – A message for meat lovers: pour on the garlic. The more you like, the better.
In June, Kansas State University microbiologist Daniel Y.C. Fung will release details of a study showing that a couple teaspoons of garlic powder in ground meat provide protection against the food borne pathogen E. coli O157:H7 in undercooked hamburgers.
"We worked with ground beef patties, but garlic powder can have this same effect in any ground meat product," said Erdogan Ceylan, the K-State doctoral candidate who conducted the tests.
Undercooked hamburgers often are blamed for sickness caused by E. coli O157:H7, a strain that causes vomiting, diarrhea and even death in severe cases. Children, the elderly and people with compromised immune systems are especially vulnerable to this pathogen.
E. coli O157:H7 is normally killed by cooking meat to an internal temperature of 160 degrees F (71 C). When meat is undercooked, bacteria that may be present can survive and cause sickness.
The K-State study’s main conclusion is that "garlic or other natural spices can give an additive protection to heating and other treatments," according to Fung, whose work with rapid detection of microorganisms in food has earned him international acclaim.
Two years ago, K-State researchers discovered that five common kitchen spices – among them, garlic – can kill E. coli O157:H7. At the time, however, they were using large, seemingly-unpalatable amounts of spices for experimental purposes. Now, the same research group is coming forward with their recommendations on amounts that are more palatable to consumers.
They used approximately 2.2 pounds of ground beef, then added 1 million cells of the E. coli bacteria per gram. (By comparison, if E. coli is present in consumer foods, there is normally no more than 10 cells per gram, Fung said). Then the researchers mixed in garlic powder: 0.5 percent (about 1 2/3 teaspoons), 1 percent (3 1/3 teaspoons) and 1.5 percent (5 teaspoons).
The burgers were cooked at eight temperatures between 123 F and 161 F.
"The results showed that ground beef patties with garlic had an E. coli count that was approximately 90 percent lower than the control sample, which did not have garlic added," Ceylan said. "And the extent of the effect increased with the amount of garlic added."
Consumers’ safest approach, Ceylan said, is to add 3-5 teaspoons of garlic powder to 2.2 poundsof ground beef. In fact, when hamburgers were undercooked by 10 degrees F (or to approximately 150 F), the researchers found that adding 5 teaspoons of garlic powder decreased the presence of E. coli O157:H7 by 97 percent over the control sample.
None of the findings, however, disputes the fact that consumers still should cook ground beef to an internal temperature of 160 F. According to Fung, cooking meat thoroughly is the only way to kill all E. coli cells and other food borne pathogens such as salmonella. This study only confirms that garlic is another safety measure.
"What we are saying is that if somebody undercooks a hamburger, but they have added garlic, there will be some protection," Ceylan said.
Ceylan and Fung will present the findings June 10-14 in Dallas during the annual meeting of the Institute of Food Technologists. Last year at the same meeting, the researchers reported that cinnamon kills E. coli O157:H7 in unpasteurized apple juice.
K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus in Manhattan.