UC HEALTH LINE: 'Prewashed' Salad Still Needs Cleaning
CINCINNATI—For people trying to get in their recommended daily servings of fruits and vegetables, prepackaged green salads are an easy way to start a meal. But there’s growing concern that these convenient items aren’t as ready to eat as advertised.
In an article in this month’s Consumer Reports, investigators at Consumers Union, publishers of the magazine, report finding high levels of certain bacteria in common brands of prepackaged salads.
Investigators had an outside lab test more than 200 containers from 16 brands of prepackaged salad greens sold in New York, New Jersey and Connecticut last summer.
They assessed for several types of "indicator bacteria” that can serve as indicators of fecal contamination and inadequate sanitation.
The test found no evidence of three pathogenic bacteria, including E. coli and salmonella, which have resulted in foodborne illness. But they did find that 39 percent of samples exceeded an "unacceptable level” for total coliforms and 23 percent for enterococcus, bacteria often found in the digestive tract of humans and other animals.
Among other findings, the report found that produce labeled "organic” was just as likely to have high levels of bacteria as other samples. Consumers Union scientists report that the indicator bacteria generally do not make healthy people sick, but are advocating for stricter produce safety standards from the Food and Drug Administration.
According to University of Cincinnati (UC) associate clinical professor of nutritional sciences Rebecca Smith, MEd, RD, it’s not unusual to have bacteria on all kinds of produce, which is why it’s so important to wash all produce before you eat it.
"I think most consumers get a false sense of security when they buy packaged, prewashed salad greens and other vegetables because they believe prewashing removes all contaminants,” she says.
Smith says the bacteria found in the Consumers Union test can come from several sources, including farm workers who don’t have access to adequate bathroom facilities or runoff from streams and other water sources on the fields.
Though greens and other produce grown close to the ground would be more susceptible to water runoff contamination, Smith says any fruit or vegetable can be contaminated during the packaging process, either from human contact or improperly cleaned equipment.
Transportation of the produce can also result in increased bacterial growth.
"Although bagged salad greens are kept refrigerated during transportation, storage and display in the supermarket, the bags provide a moist environment where bacteria can multiply. If the bagged salad is not held at below 40 degrees F, the bacteria will multiply even in a refrigerated environment,” she says.
"Most of the emphasis on food safety, until recently, has been placed on meat, poultry and dairy products,” says Smith. "However, the majority of the recent national outbreaks of foodborne illness have been caused by fruits and vegetables, because they aren’t as carefully regulated.”
But that doesn’t mean you should eliminate salads and greens from your diet. Smith said washing fruits and vegetables before use can not only reduce pesticide contamination from conventional produce, but also contamination from microorganisms that cause foodborne illness.
She says there are several rules for everyone to keep in mind to reduce exposure to bacteria:
• Wash all fresh fruits and vegetables before using them, even prepackaged items and produce with skins that are not eaten. This includes produce from supermarkets and from local farmers’ markets.
• Buy packages far from their use-by date and keep greens refrigerated.
• Prevent cross-contamination by keeping all produce away from raw meat and poultry. Use different cutting boards and utensils when preparing produced and raw meat.