The study found that 39% of the 208 bagged lettuce samples tested had higher-than-acceptable levels of bacteria. While Dr. Michael Hansen, senior scientist with the Consumer's Union and the author of the study, stressed that none of the samples contained deadly pathogens, like E. coli or salmonella, they did contain bacteria that are common indicators of poor sanitation and fecal contamination.
This is not the first time bagged lettuce has come under fire. As you probably recall, in September of 2006, there was an outbreak of E.coli from contaminated bagged spinach that left 205 people ill and three dead.
Practical Tips for Using Bagged Salads
So what's a concerned parent to do? The common wisdom has been to ignore the triple-washed claims on the salad bags, and wash the lettuce at home. But that probably won't do much. Neither will expensive vegetable washes.
According to Dr. O. Peter Snyder, a food scientist with the Hospitality Institute of Technology & Management in St. Paul, MN, "There is no way to wash food, vegetable or meat and poultry, and make it really safe."
Hansen said it's a mistake to assume that bunched lettuces are any less contaminated than bagged lettuces. The USDA has sampled both bagged and unbagged lettuces extensively and has found no evidence that bagged salads are any better or worse than unbagged.
Interestingly, spinach could be a factor. "We did find that the more spinach there was in the bagged salad mix, the more contamination," Hansen said. He said it may have something to do with the shape of spinach leaves that make them more hospitable for bacteria.
Of course, no one recommends you steer clear of spinach or greens, altogether. And truthfully, all food has some bacteria on it; it's just a question of how much and how harmful that bacteria is. A few steps you can take to ensure your family's safety:
- Shop at farmer's markets or small stores that sell local produce. Large scale processing can mean more likelihood of serious contamination. Of course, if your local farmer has pickers who aren't washing their hands, you can run into problems there, too.
- If you buy bagged lettuces, especially bagged spinach, look at the sell by dates. The bags with the most contamination in Hansen's study were ones within four days of their sell by dates.
- Cook your greens. The exact temperature to which you need to cook your greens will depend on the type of bacteria that's on the greens and how long you're cooking it, but Snyder recommends stir-frying or blanching vegetables in boiling water for 15 seconds. "It gives you a perfect surface pasteurization while not destroying the nutrition," he said.
Baking also works. Recipes like spinach quiche, chicken pasta casserole or baked macaroni and cheese with spinach are good choices.
Kevin Week's, our Cooking for Two Guide, has an excellent article on how bacteria contaminates food, with good guidelines for cooking times and temperatures. Check it out: Tips for Safe Food Handling.