Fresh and locally grown produce available at farmers’ markets comes with some health risks, according to a study that found Salmonella and E. coli in samples of basil, cilantro, and parsley purchased at 13 such markets in the Los Angeles, Orange County, Calif., and greater Seattle areas. The finding is a reminder that federal food safety regulations such as the Food Safety Modernization Act that govern large-scale farm practices do not apply to produce sold by smaller farms that sell their harvest at local farmers’ markets.
Researchers at Chapman University and University of Washington collected 133 samples of the fresh herbs from 49 different vendors at 13 farmers’ markets. Among the samples, 24.1 percent tested positive for generic E. coli and 84.2 percent were positive for total coliforms. Sixteen samples (12 percent) had average E. coli counts that are considered unsatisfactory by Public Health Laboratory Service guidelines for microbiological quality of ready-to-eat foods. Basil yielded the highest percentage of samples with generic E. coli (26.9 percent), followed by cilantro (24.4 percent), and parsley (20.0 percent). Fifteen fresh herb samples had suspicious growth of Salmonella, and one sample, in parsley, tested positive, according to the research published in the November 2014 issue of the Journal of the Science of Food and Agriculture.
Several factors may lead to contamination of the herbs, Rosalee S. Hellberg, PhD, assistant professor in the Food Science Program at Chapman University, and colleagues point out. “Storing herbs at ambient temperatures in the open environment during warm summer days could impact the microbiological safety and quality of these items.” Also, fecal contamination of fresh produce is a significant problem because the herbs are consumed raw with no intervening steps that could inactivate potential pathogens.
Foodborne illness outbreaks involving Salmonella in parsley, basil, and cilantro have been widely reported over the past 20 years. Concerns about foodborne illness led to testing for E. coli as an indicator of fecal contamination and potential pathogen presence. A CDC report issued in 2013 said that most foodborne illnesses between 2001 and 2008 could be attributed to plant commodities, with 22 percent attributed to leafy vegetables.
According to the FDA Center for Food Safety and Applied Nutrition, many farmers’ markets have established food safety guidelines that vendors must follow, as well as local, state, or county regulations. The FDA advises, however, that consumers follow basic measures to ensure that their food is safe, such as careful handwashing before and after preparing fresh produce and use of appropriate refrigeration of vegetables within two hours of purchase.
Holliman is a veteran journalist with extensive experience covering a variety of industries. Reach her at [email protected].