The Washington Post published an interesting article this morning, spotlighting the recent E. coli outbreak associated with pre-cut, bagged lettuce that infected 23 people in four states during March and April of this year. The lettuce was not purchased by consumers, but rather by several food service companies and supermarkets as part of their salad bars and prepared meals. In fact, the majority of infected people were students at colleges in Michigan, Ohio, and New York who consumed the lettuce at their college dining halls. This issue brings up an interesting question, however: Are pre-cut, bagged vegetables more dangerous than whole vegetables?
First, how could E. coli, which is generally associated with animal feces, infect vegetables? According to Caroline Smith De Wall, the food safety director at the Center for Science in the Public Interest, “The process of harvesting lettuce, chopping it or tearing, washing and putting it in a bag is a process similar to mixing ground beef.” As any food handler should know, ground beef is potentially more hazardous than whole beef because bacteria on the outside of the meat is mixed into the center during the grinding process. The same is true for lettuce, and other leafy greens which are grown in fertilized soil. Fertilizer is largely composed of animal feces, and therefore is full of E. coli and other contaminants. So when vegetables are processed for packaging, greens from multiple farmers’ fields (both contaminated and uncontaminated) may be tossed in and cut together–infecting all the produce.
Still, there are strong arguments on both sides of this debate. Those who believe bagged vegetables are more dangerous argue that chlorine spray used to clean the produce before it is packaged does not kill enough of the bacteria. Whereas when consumers purchase whole vegetables, they will commonly remove the outer leaves, thus physically removing the majority of potentially infectious bacteria.
James Gorny, senior advisor for produce safety at the FDA disagrees with the idea the bagged produce is more dangerous. He stated that “bagged greens represent a disproportionate number of recalls, chiefly because they’re easier to identify than whole produce. When you buy a head of lettuce, you have no idea what the brand name is, or who the grower is–so tracing it back is that much harder.” Essentially he is stating that because the source of contaminated bagged vegetables is so much clearer than for whole vegetables, complaints about foodborne illness for those products is much higher. In addition, it is much easier for health department officials to trace the source of the infection for packaged produce, and so it often appears as though pre-cut vegetables are more dangerous, even though they may not be.
Unfortunately there is no clear statistic proving that either whole or pre-cut vegetables are more dangerous. In order to keep your patrons, family, and employees safe at the salad bar–wash your veggies. Even if the bag states “pre-washed” it is always a good idea to rinse your leafy greens and vegetables that will be served as ready-to-eat items. There are also several vegetable washes on the market that may be advisable for households with at-risk individuals. For additional guidance, contact your health department.
