Refrigerate Lettuce to Reduce Risk of E. coli Contamination
Published:23 May2024 Source:University of Illinois College of Agricultural, Consumer and Environmental Sciences
Leafy green vegetables are important sources of dietary fiber and nutrients, but they can harbor harmful pathogens. In particular, lettuce has often been involved in outbreaks of foodborne illness across the U.S. A new study from the University of Illinois Urbana-Champaign examines factors that affect E. coli contamination on five different leafy greens -- romaine lettuce, green-leaf lettuce, spinach, kale, and collards.
The researchers infected whole leaves from each of the five vegetables with E. coli O157:H7 and observed what happened after storage at 4 °C (39 °F), 20 °C (68 °F), and 37 °C (98.6 °F). The researchers also inoculated cut leaves with E. coli O157:H7 to compare the intact surface of a whole leaf to the damaged surface of a cut leaf. To further explore these findings, they isolated juice (lysate) from kale and collards and applied the liquid to lettuce leaves, finding that it can be used as a natural antimicrobial agent.
We can't completely avoid pathogens in food. Vegetables are grown in soil, not in a sterile environment, and they will be exposed to bacteria. Just follow food safety guidelines, wash your lettuce thoroughly, store it in the refrigerator, and pay attention to any food safety recalls in your area.