Tomato-knife_406x250Poor hygiene and improper food preparation can lead to foodborne illnesses at home. The first step of the government’s safe food handling advice to consumers is to wash hands before and after handling food and clean cutting boards, dishes, utensils and countertops with hot soapy water after preparing each food item. But the U.S. Food and Drug Administration wants to know more about what practices in the kitchen are more likely to lead to contamination. A recent series of studies conducted by researchers at the University of Georgia looked at the extent to which kitchen utensils spread E. coli O157:H7 or Salmonella enterica contamination between produce items. The team — led by Marilyn Erickson, an associate professor in the College of Agricultural and Environmental Sciences — contaminated different fruits and vegetables with pathogens and then cut or grated them and observed how the pathogens transferred. They found that both knives and graters can cause additional cross-contamination in the kitchen and that the pathogens were spread among produce items if the utensils hadn’t been washed. When shredding inoculated carrots, all graters became contaminated and the number of E. coli O157:H7 bacteria present on the utensil was significantly greater than Salmonella. Contamination of knives after slicing inoculated produce could only be detected by enrichment culture. The researchers also found that certain fruits and vegetables spread pathogens to knives to different degrees. 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. “We don’t have a specific answer as to why there are differences between the different produce groups,” Erickson said. “But we do know that once a pathogen gets on the food, it’s difficult to remove.” Erickson’s concurrent studies found that produce brushes and peelers can also transfer dangerous pathogens around the kitchen. “Just knowing that utensils may lead to cross-contamination is important,” Erickson said. “With that knowledge, consumers are then more likely to make sure they wash them in between uses.” (To sign up for a free subscription to Food Safety News, click here.)