Food Poisoning Bacteria Found in Packaged Greens

We've all seen the "prewashed" and "triple-washed" salad in a bag in the produce section of the supermarket, and they're a welcome convenience. Available since the early 1990s, annual sales of the easier than ever side dish has reached almost $ 3 billion a year. The trouble is that despite what it says on the package, the contents may not be as clean as you'd like, with some containing food poisoning bacteria.

A new investigation from the Consumers Union, publishers of Consumer Reports, found high levels of bacteria usually linked to poor sanitation and fecal contamination in many of the packaged salads they sampled.

The organisms investigators found do not pose a health risk to the public, but because bacteria were there, this makes it more likely there's contamination by rare (and potentially deadly) pathogens such as E. coli and salmonella.

The last E. coli outbreak, coming in the fall of 2006, was traced to packaged spinach and killed three, hospitalizing more than 100. The cause of the contamination was never confirmed, but E. coli was widely believed to have reached the spinach via groundwater that had cattle and pig feces in it.

The sample for the testing included 208 packaged salads that were bought last summer in Connecticut, New Jersey and New York. Sixteen brands were represented, and the salads were sold in either bags or plastic clamshell containers.

Bacteria levels varied quite a bit, with some samples having undetectable levels while others were literally teeming with organisms, more than 1 million colony forming units (CFUs) per gram.

The investigators found that 39% of the samples had more than 10,000 CFUs per gram – a measure of total coliforms, bacteria associated with fecal contamination. What's more, 23% had more than 10,000 CFUs per gram of the bacterium enterococcus. Experts contacted by Consumer Reports as part of the research found that these levels were unacceptable.

The investigation also found the following:

– Salad mixes that had spinach tended to have higher bacteria levels.

– Packaging, either bagged or clamshell container, did not effect contamination levels.

– National distributed brands and smaller, regional brands showed little difference in bacteria levels. All brands with more than four samples had at least one package with relatively high levels of total coliforms or enterococcus.

– Products labeled "organic" were just as likely to have bacteria as those not labeled this way.

– Packaged produce tested within 5 days of the use-by date had higher levels of bacteria than those tested at the 6-day mark.

The produce industry has responded to the piece in Consumer Reports by reminding everyone that the bacteria found by the investigators did not pose a health risk to people.

The trade groups are also calling on Congress to pass food safety reform and adequately fund the FDA to allow the agency to fulfill its mission to protect the public.

Consumers Union senior scientist Michael Hansen, Ph.D. suggests that consumers should look for products that are at least 6 days from their use-date when shopping for packaged salads.

To protect yourself against food poisoning bacteria, you need to wash the contents again, no matter what it says on the package, to make sure the good-for-you greens really do your body good.