Friday, October 10, 2008

Packinghouse, supplier practices are checked for problems by FDA

By LAURAN NEERGAARD
THE ASSOCIATED PRESS

last updated: June 28, 2008 02:34:56 AM

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 of a temperature difference can make a tomato literally suck water inside the fruit through the scar where its stem used to be. If salmonella is lurking on the skin, that's one way it can penetrate and have time to multiply, if the tomato isn't eaten right away.

That doesn't mean people shouldn't wash their tomatoes. They should. Just probably not in cold water.

As the Food and Drug Administration investigates the nation's outbreak of salmonella from tomatoes, the example shows the farm isn't the only place contamination can occur. Checking water quality and temperature control in packinghouses and other supply stops, among other things, is 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 more 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.

Florida's agriculture department on Tuesday begins enforcing "tomato best practices," farming and handling guidelines that leading growers pushed the state to adopt formally, 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 acted on that request.

"We need them, we've asked for them, and we don't yet have them," said Dr. David Acheson, the agency's food safety chief, who is directing the hunt for the tainted tomatoes.

Further complicating the picture, budget trouble means the FDA's inspections of food-producing facilities have plummeted by 56 percent from 2003 to last year. Acheson said the drop has continued this year; the FDA plans to hire more inspectors with a pending budget boost from Congress.

But inspections aren't the solution for food poisoning, insists Acheson, who hopes to double or triple the 10 percent of the FDA's budget historically devoted to prevention.

The FDA "is not arguing that you can inspect your way out of these problems," he said. "The critical point is to build safety upfront, not load up inspection at the end."

There are common themes when fresh produce sickens, either from salmonella -- bacteria that live in the intestinal tracts of humans and animals -- or other microbes: water sources, worker hygiene, and wildlife or domestic animals near fields are frequent culprits because they involve points where safety systems easily can break down.

Washing fresh produce under running water is a common sense consumer defense.

"We know you can wash off some salmonella," said Virginia Tech food microbiologist Robert Williams, who accompanied FDA scientists to Virginia farms as part of the tomato initiative. But, "nobody's ever shown it washes off all salmonella."

Water is an automatic suspect. Was clean water used to irrigate, mix pesticides sprayed on crops, wash down harvest and processing equipment, and wash field workers' hands? Then in packinghouses, tomatoes often go straight into a dump tank with flumes of chlorinated water for a first wash. To guard against salmonella washed into the water in turn being sucked into the tomatoes, producers often keep wash water 10 degrees warmer than the incoming crop, said food safety scientist Keith Schneider of the University of Florida.

Beyond packinghouses, the industry points to cases in which suppliers were shipped unwashed, warm tomatoes and dunked them in ice water to firm them for further processing.

How often does the water have to be changed? Dirt, leaves and other sediment reduce the chlorine's effectiveness.

Studies never have shown that plant roots can suck salmonella up and inside the tomato, where it can't be washed out, said Virginia Tech's Williams, whose lab is working to confirm that. Still, if contaminated water is sprayed onto the leaves or blooms, or bird droppings fall onto the foliage, salmonella might be absorbed, he said.

In fact, salmonella may be particularly hard to prevent in a variety of crops because birds, reptiles and amphibians carry it. "You're not going to stop a bird going through a field. You're not going to stop a frog," Schneider said.

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