Foodborne illness and fresh produce

Aug 2 2007

Once was the day that beef was considered a primary source of foodborne illness.

Now fresh produce is increasingly responsible for the outbreaks, and receiving increased focus from people paid to protect public health.

“Produce is where much of the action has occurred,” said Michael Doyle, food safety expert with the Institute of Food Technologists and director of Center for Food Safety at the University of Georgia, speaking at the IFT Annual Meeting & Food Expo.

In the 25 years preceding 1997, there were 190 outbreaks of foodborne illness associated with fresh produce. In the five years that followed, that number jumped to 249. The list of offenders varied from lettuce, melons and seed sprouts to apple juice, orange juice and tomatoes.

Doyle predicts that produce and other foods from plants will be the dominant vehicles for foodborne illnesses, accounting for more than 50 percent of all illnesses currently estimated at more than 70 million cases a year.

The current trend of cutting fresh produce before selling it raises questions about whether the process has an acceptable safety level, according to Doyle.

He explained that when fresh produce is cut, nutrients begin leaking and more surface area is created that's attractive to harmful bacteria. The leaking juice can interfere with, and sometimes neutralize, disinfectants like chlorinated water that are applied to kill bacteria. If the product isn't properly refrigerated, then bacteria are more likely to grow.

“This is where I think there's going to have to be more emphasis,” Doyle said. “We really don't have a fully effective way to treat fresh cut fruits and vegetables.”

In 2006, 205 cases of E. coli O157:H7 illness were found in 26 states, all linked to bagged spinach and traced back to a central California ranch.

“The outbreak strain was confirmed in 26 of the 45 samples taken,” Doyle said. “This is as close to a smoking gun as I think you can get.”

Will Daniels, vice president at Earthbound Farm, which produced the bagged spinach implicated in the outbreak, says the company has instituted strong controls since that time that he believes are working.

“We came to the conclusion that, more than likely, we received a batch of contaminated raw product into our (processing) facility,” Daniels said.

For that reason, the company now tests lots of leafy greens before they enter the building. They are tested for two strains of E. coli as well as Salmonella, once before they enter the processing facility and once again as they are leaving. Daniels says the company also tests the seeds, soil and water for pathogens before the growing process begins.

“We don't have the capacity to test every leaf of lettuce. What we're looking for is gross contamination events,” Daniels said.

Daniels says the company has not looked at the financial impact of the testing which requires product be held in the processing facility for as long as 12 hours while awaiting test results. Whatever the cost, it's certainly less than the price of a recall, he said

Now in its 67th year, the IFT Annual Meeting + Food Expo is the world's largest annual scientific forum and exposition on food. Ranked among the largest U.S. conventions, the meeting delivers comprehensive, cutting-edge research and opinion from food science-, technology-, marketing- and business-leaders; online at IFT.org/amfe.

Scientific sessions conclude tomorrow with the IFT Global Food Safety & Quality conference, and IFT's Food Nanotechnology conference.

Founded in 1939, and with world headquarters in Chicago, IFT is a not-for-profit international scientific society with 22,000 members working in food science, technology and related professions in industry, academia and government. As the society for food science and technology, IFT brings sound science to the public discussion of food issues. For more on IFT, see IFT.org.

http://www.ift.org/