WASHINGTON — Pick a tomato in the blazing sun and plunge it straight into cold water. If that happened on the way to market, it might be contaminated.
Too big a temperature difference can make a tomato literally suck water inside the fruit through the scar where its stem used to be. If salmonella happens to be lurking on the skin, that's one way it can penetrate, and if the tomato isn't eaten right away, have time to multiply.
That doesn't mean people shouldn't wash their tomatoes. They should, just probably not in cold water.
But as the Food and Drug Administration investigates the nation's outbreak of salmonella from tomatoes, the example shows that the farm isn't the only place contamination can occur — and checking water quality and temperature control in packing houses and other supply stops is one key to safety.
Raw fruits and vegetables are crucial to a healthy diet. But they're also the culprits in a growing list of nasty outbreaks: E. coli in spinach and lettuce. Hepatitis A in green onions. Cyclospora in raspberries. Salmonella in cantaloupe. Shigella in parsley.
This newest salmonella outbreak is the 14th blamed on tomatoes since 1990.
Preventing future illnesses depends on learning how salmonella sneaks onto and inside tomatoes, which might seem to be pretty well protected by their smooth, waxy skin. Yet scientists have few answers, prompting the FDA last year to begin a Tomato Safety Initiative that is studying industry practices in Virginia and Florida, the origin of several previous outbreaks.
On July 1, Florida's agriculture department begins enforcing so-called ”tomato best practices,“ farming and handling guidelines that leading growers pushed the state to adopt, and that many farms voluntarily began following in the past year.
The FDA likewise wants the authority to set mandatory safe-handling rules, what it calls ”preventive controls,“ for growers and suppliers of foods linked to repeated outbreaks of serious illness, such as tomatoes and leafy greens. Congress hasn't yet acted on that request.
”We need them, we've asked for them, and we don't yet have them,“ says Dr. David Acheson, the agency's food-safety chief, who is directing the CSI-like hunt for the tainted tomatoes.
Further complicating the picture, budget woes mean the FDA's inspections of food-producing facilities have plummeted by 56 percent between 2003 and last year. Acheson says the drop has continued this year, and the FDA plans to hire more inspectors with a pending budget boost from Congress.
But inspections aren't the solution to food poisoning, insists Acheson, who also hopes to double or triple the 10 percent of FDA's budget historically devoted to prevention. FDA ”is not arguing that you can inspect your way out of these problems,“ he says. ”The critical point is to build safety up front, not load up inspection at the end.“
Washing fresh produce under running water is a commonsense consumer defense.