BOSTON — The vegetable aisle in the supermarket may be riskier than consumers think.

“Microbes have been around for a long time,” said Ewen Todd, professor of advertising, public relations and retailing at Michigan State University. “But now we are seeing these problems are coming back: And they are harder than ever to control.”

Fresh produce like lettuce, spinach, and tomatoes and even processed food like chocolate, peanut butter and tahini are prone to harboring food-borne pathogens like E. coli O157:H7 and salmonella because of the risks of contamination in the field and the processing plant.

Todd is an organizer and member of the discussion in a team with four other scientists at a symposium, titled “How the Bugs Come Back and Bite Us: The Rise of Agricultural Pathogens,” at the American Association for the Advancement of Science annual meeting today.

Cooking used to be the last defense against harmful microbes in or on food, but people consume more fresh vegetables now than ever before. That makes for a healthier diet, but also creates new risks for food contamination, Todd said.

The dramatic increase in the amount of fresh vegetables that are produced and improved monitoring abilities have resulted in a spike in cases of food contamination. 

New awareness of contamination is partly due to the increased demand for such products year round, globalization of the food supply and increased ability to detect large outbreaks across many states or even countries with better surveillance technologies.

Outbreaks of salmonella from chocolate, peanut butter and tahini, as well as botulism outbreaks from canned chili sauce, show that processed foods also can be subject to the same kinds of contamination even with today’s industry food safety awareness. If a microbe enters the production process, it can contaminate entire batches of products.

“We have seen canker, salmonella and E. coli before, but now the bugs are unexpectedly coming back to bite us in new ways,” Todd said. “There are risks associated with food choices, but what should the public, industry and the government do about it?” 

For more information, go to http://special.newsroom.msu.edu/aaas/index.php.

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