July 12, 2012 at 8:45 AM ET
You’d think a video camera in the kitchen might be one way to ensure food safety, but, boy, you’d be wrong.
Researchers who filmed nearly 200 California residents as they prepared salad and hamburgers at home found disturbing problems with hand-washing, cross-contamination and cooking mistakes, even in the presence of a video crew.
Less than half of the home cooks -- only 43 percent -- washed their hands before beginning food preparation, and nearly a quarter of those who did scrub spent only two seconds, literally, instead of the recommended 20 seconds.
That’s only the beginning of the revealing findings of two studies, conducted by University of California at Davis researchers, which recorded multiple violations of basic kitchen rules that could result in dangerous foodborne illnesses.
“What this tells us is that people aren’t perfect,” said Christine Bruhn, a UC Davis food safety scientist who investigates consumer food handling practices. “Sometimes, even those who know better because of habit or inattention can make an error.”
Bruhn and her colleague, Ho S. Phang, wanted to gather real-world evidence of consumers’ food safety habits instead of simply relying on self-reports. So they recruited volunteers in several Northern California counties, promising $50 and the cost of the groceries used in the experiment. They made sure to exclude people likely to have a high level of food safety skill, including doctors, nurses and microbiologists. But the ranks did include some folks who had previous food safety training, perhaps working in a restaurant or other public setting.
What they found was surprising. First, although 84 percent of people thought they could get sick from eating hamburgers, 18 percent believed they would only become ill if the burgers were prepared outside the home.
Nearly a third of the volunteers who agreed to be videotaped failed to wash their hands directly after handling ground beef and more than three-quarters performed actions that could transfer illness-causing bacteria such as E. coli O157:H7 or salmonella to other surfaces.
On average, each household in the study committed 43 cross-contamination faux pas, including nearly a third who touched lettuce or tomatoes directly after handling raw meat.
About 93 percent of the 6,576 incidents of cross-contamination involved the food preparers’ hands, the researchers found.
When it came to lettuce, less than half of the participants washed each leaf under running water with gentle rubbing, as recommended. Fifteen percent of the volunteers didn’t wash their lettuce at all, while 8 percent failed to wash the celery.
The vast majority of volunteers actually cooked their burgers correctly, with 70 percent reaching the 160 degree Fahrenheit temperature recommended by the U.S. Department of Agriculture. Still, that was largely by chance, as only 4 percent of the participants used a meat thermometer to check doneness, and only 13 percent had any idea about the correct temperature for cooked ground beef.
Four volunteers pronounced their burgers done at internal temperatures of less than 120 degrees Fahrenheit.
The studies were released last year in the Journal of Food Protection, but got little attention outside of food safety circles. Bruhn said they point to the overwhelming need for consumer education and awareness to help prevent the 9.4 million episodes of foodborne illness caused by 31 major pathogens each year, according to the Centers for Disease Control and Prevention.
People need to remember basic hygiene – soap and hot water – and to be careful to keep raw meat and vegetables separate in every way: on cutting boards, when using knives, even when touching the kitchen faucet. Produce should be washed under running water with gentle friction and then dried using a salad spinner or paper towels, not cloth.
Meat should be checked for doneness with a thermometer, not by judging the color of the cooked burger or chicken breast.
“It’s really not hard to wash your hands and do these basic precautions,” said Bruhn.
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