Risky food-safety practices at restaurants, cafeterias, and other food-service providers happen more often than previously thought, according to researchers at North Carolina State University, who conducted a study using video cameras to monitor commercial kitchens to see how well food handlers followed food-safety guidelines.

 

“Meals prepared outside the home have been implicated in up to 70 percent of food poisoning outbreaks, making them a vital focus area for food safety professionals,” says Ben Chapman, assistant professor and food safety specialist in the department of family and consumer sciences at NC State and lead author of the paper published in the Journal of Food Protection. “We set out to see how closely food handlers were complying with food safety guidance, so that we can determine how effective training efforts are.”

Researchers placed small video cameras in spots around eight food-service kitchens that volunteered to participate in the study. There were as many as eight cameras in each kitchen, which recorded directly to computer files and were later reviewed by Chapman and others. The researchers say what they found demonstrates the need for new food safety-focused messages and methods targeting food handlers.

Most previous studies relied on inspection results and self-reporting by food handlers to estimate instances of “cross-contamination” and found that cross-contamination was relatively infrequent. Cross-contamination occurs when pathogens, such as Salmonella, are transferred from a raw or contaminated source to food that is ready to eat. For example, using a knife to cut raw chicken and then using the same knife to slice a sandwich in half. Cross-contamination can also result from direct contact, such as raw meat dripping onto vegetables that are to be used in a salad.

But Chapman's study found approximately one cross-contamination event per food handler per hour – on average eight cross contamination error that could lead to illness in the course of a typical shift per worker.

“Each of these errors would have been deemed a violation under U.S. Food and Drug Administration Food Code inspection guidelines. But more importantly, cross-contamination has the potential to lead to foodborne illnesses and has in recent outbreaks" Chapman says. “And it's important to note that the food-service providers we surveyed in this study reflected the best practices in the industry for training their staff.”

The study also confirmed the long-held supposition that more food-safety mistakes are made when things are busier in the kitchen. “During peak hours,” says Chapman, “we found increases in cross-contamination and decreases in workers complying with hand-washing guidelines.”