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Bagged lettuce or bulk? Experts offer food safety advice

Benjamin Sklar / AP

Prewashed, packaged salad may be more convenient for consumers, but some worry that bagged lettuce is more likely to be contaminated.

A recall this week of 8,000 cases of Fresh Express Hearts of Romaine salad marks the sixth time since April that the nation’s top producers of bagged lettuce have pulled products because of worries about food safety.

Listeria was the problem that forced Fresh Express officials to recall certain 10-ounce bags of the greens, the same potentially dangerous bug that led Dole Fresh Vegetables to withdraw bagged salads four times since spring, most recently on Aug. 22.

No illnesses have been tied to the voluntary withdrawals and company press releases describe each one as an “isolated incident” unlikely to harm human health.

But for consumers roaming the produce aisles at the grocery store, each new recall raises the question: How safe is my salad?

Food safety experts say they hear all the time from shoppers wondering which is better, bagged lettuce or the loose variety.

“We call it faith-based food safety,” says Doug Powell, a professor of food safety of Kansas State University. “And most of it is faith-based.”

Powell and Christina Bruhn, a researcher in food science and technology at UC Davis, say that while figuring out what fraction of the lettuce may make you sick is a gamble, they still place their bets on the bagged stuff.

“I do know some professionals who do not buy bagged lettuce,” says Bruhn. “I buy it. I like the convenience. I think they do the best job of anyone of cleaning the product, better than I do. They use chlorinated water. They wash it really thoroughly.”

She figures the big manufacturers, including Dole and Fresh Express, have a huge stake in safety and an incentive to get it right.

“They have the size of staff and the resources to use the most up-to-date processes,” she said.

Powell, too, says he usually opts for bagged lettuce.

“I go to the biggest grocery store I can find,” he said. “They have requirements for what they put on the shelf.”

Some consumers, haunted by the 2006 outbreak of E. coli O157 in spinach that sickened 205 people and killed three, have sworn off bagged greens.

Others, worried about contamination from fields and shipping, cringe at the thought of gritty bulk lettuce and take comfort in the “triple-washed” claims on the shiny bags. Still others swear by farmer’s market produce -- or eat only the greens they grow themselves.

About 9 billion pounds of lettuce is produced in the U.S. each year, according to the U.S. Department of Agriculture, and, to be sure, the vast proportion of it is safe.

Story: Garden Fresh recalling 7 tons of packaged salads

Indeed, Marty Ordman, a spokesman for Dole, said the company has hired two third-party listeria experts in the wake of the recent recalls, which were prompted in part by Food and Drug Administration inspections. The experts hope to help identify any potential improvements to the processes and procedures used in Dole's bagged salad plants. 

Additionally, Dole scientists have been working "very closely" with the FDA to find alternative methods of sanitizing products to control contamination while still providing fresh, high quality products, Ordman added.

But Seattle food safety lawyer Bill Marler, who regularly represents clients hurt or killed by tainted produce, isn't convinced. Asked what kind of lettuce he prefers, he said: "Not bagged."

Even the crisp heads of lettuce in a farmer's market stall can be suspect, said Powell. They may be fresh and local, but that’s no guarantee of safety.

“The lettuce was sitting swamped in water for days,” he said. “If I go to a farmer’s market, I don’t want to know that it’s lovingly grown. I want to know you’ve taken steps for microbiological safety. If you can't answer those questions, I don't want to buy your lettuce."

Both Bruhn and Powell acknowledge that the big growers can have problems, as evidenced by the recent recalls. And both are big proponents of companies posting their food testing results publicly and marketing the safety of their products as a selling point.

Bruhn is also a staunch advocate of irradiation, which she says can ensure food safety.

She encourages consumers to take steps to avoid compromising bagged lettuce. Buy only bags kept very cold in the grocery store and pay attention to sell-by dates. Once you’ve got it home, open the bag and dump it directly into a clean bowl.

“Don’t stick your own hands in there,” she said.

She also urges home cooks not to re-wash bagged greens because of the possibility of cross-contamination with other bacteria already in the kitchen.

If you want to use bulk lettuce, make sure to clean it correctly, Bruhn said. First, wash your hands and also the sink with hot soapy water.

Then, break off each lettuce leaf individually, rinse it under cold running water while rubbing gently. Dry in a salad spinner or with paper towels, not with cloth towels, which may transmit bacteria.

“Keep in mind, you only get about 90 percent (of the pathogens) off,” she said. “Ninety percent sounds like a lot to a lay person, but to a microbiologist, it’s hardly anything. You can’t get it all off.”

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