Adding a sprinkle of fresh basil or parsley takes your meals from good to gourmet, but you may be adding more than you bargained for. Your fresh herbs may be carrying E. coli, which indicates fecal contamination, according to research published in the Journal of the Science of Food and Agriculture.
The researchers collected more than 130 samples of cilantro, basil, and parsley at 13 farmer's markets in Los Angeles and Orange counties in California and in the Seattle area in Washington. They found that nearly a quarter of the herbs tested positive for E. coli and one batch of parsley tested positive for Salmonella.
"There hasn't been a lot of studies on food safety at farmer's markets, so it's just good to get a general idea of what the microbial levels are of the foods being sold at farmer's markets," says Rosalee Hellberg, PhD, assistant professor of food science at the Schmid College of Science and Technology at Chapman University and coauthor of the study. "We don't want to scare people away from going to farmer's markets because they definitely fill a need; it's just something to be aware of."
In fact, Hellberg points out that this issue isn't just at farmer's markets. "Previous studies have found E. coli in herbs at supermarkets as well, so it's not unique to farmer's markets."
Points of contamination may be at the farm, if animals are allowed to roam near the produce, or upon improper handling, either at the farm or at the farmer's market. "I think it would be good to look more into how the produce is handled when it's brought to the farmer's market and how it's maintained," suggests Hellberg.
The best precaution against bacteria, Hellberg says, is to cook your food. "Anytime you're eating fresh produce, there's going to be some level of risk associated with that because you're eating an uncooked product," she says.
Drying fresh-bought herbs may help reduce bacteria levels, but Hellberg says that it doesn't always kill off all of the bacteria. Similarly, studies have shown that washing fresh produce with water alone isn't always effective at eliminating the germs. So you may want to consider making your own veggie wash.