Wash That Knife or Peeler After Cutting Just about Anything
A study suggests you need to wash it in between slicing different kinds of produce
As you’re prepping veggies for that leafy salad, you may think you can go from cutting cucumbers to slicing tomatoes without washing your knife in between. After all, it’s just produce, not raw meat, which we know can carry bacteria and contaminate surfaces. But a new study funded by the Food and Drug Administration suggests you should wash your knife in between cutting different kinds of produce.
Researchers at the University of Georgia wanted to test how kitchen utensils spread bacteria such as salmonella or E. coli from produce item to produce item. The team contaminated fruits and vegetables with pathogens and then cut or grated them to observe how the pathogens spread. They found that knives and food graters can cause cross-contamination in the kitchen if they aren’t washed between uses.
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“A lot of the broken up material and particles from the contaminated produce remained on the graters,” said the team’s leader, Marilyn Erickson, associate professor in the University of Georgia College of Agricultural and Environmental Sciences. “Then if you were to shred another carrot or something else immediately after that, it gets contaminated, too.”
The study was published in the journal Food Microbiology.
Knives and graters aren’t the only utensils you should worry about. Erickson ran a concurrent study that found scrubbing or peeling produce items did not eliminate contamination but instead transferred bacteria to the brush or peeler.
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Some fruits and veggies led to the transfer of more pathogens than others. “After slicing tomatoes, honeydew melons, strawberries, cucumbers and cantaloupes, the average prevalence of knife contamination by the two pathogens was 43 percent, 17 percent, 15 percent, 7 percent and 3 percent, respectively,” Food Safety News reports.
Erickson, whose past work has focused on how bacteria is introduced to produce in fields, said her team doesn’t know why there’s a difference in the levels of contamination. But once a pathogen gets on the food, “it’s difficult to remove,” says Erickson.
Erickson notes it’s unlikely the produce you buy is contaminated with bacteria. But of course it pays to be safe.
“Just knowing that utensils may lead to cross-contamination is important. With that knowledge, consumers are then more likely to make sure they wash them in between uses.”
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