What's the best way to wash microbes off your produce?

June 9, 2014 by Matt Shipman, North Carolina State University
Credit: Bartlomiej Berczynski (barthetzk), via freeimages.com

Short version: You can use water to wash off your fruits and veggies – but it may not make a big difference, in terms of food safety.

Here's the question we got: "What is the most effective means of cleaning at home to remove micro-organisms that could make you sick?"

"Vigorously rinsing the produce under running water is the most effective way of removing the that cause – you don't need soap or any special cleaning products," says Ben Chapman, a researcher at NC State. "But while washing your produce may remove some pathogens, it doesn't eliminate risk altogether."

"At best you get a two log reduction – that's a 99 percent reduction in microbes," Chapman says. "That seems good, but it's not great. While washing can help reduce pathogen contamination, it shouldn't be relied on as the only control measure."

By comparison, cooking food results in a six log reduction in viable microbes. That means the population of viable microbes gets cut by 99.9999 percent(!).

The difference between 99 percent and 99.9999 percent is important because some fruits and vegetables can be contaminated with thousands of microbes. And we know that, on average, most microbial food-borne illnesses are caused by foods that are contaminated by only 20-30 organisms. So washing off 99 percent of the microbes doesn't help much if a food was carrying thousands of microbes to start with.

This is why people who are immunocompromised, such as some chemotherapy patients, are often discouraged from eating raw produce; there is no way to make raw produce as safe as cooked fruits or vegetables in terms of microbial contamination.

Your best bet for reducing risk is to be an educated consumer and buy from a reliable producer that understands how to minimize the chances that produce will be contaminated.

Don't be afraid to ask questions at the farmer's market or in the produce section of your grocery store! Here's a list of food safety questions that could help. If they don't know the answer to your questions, you may want to shop elsewhere.

Explore further: Keep food safety in mind this memorial day weekend

Related Stories

Food handlers cause most food-poisoning cases

June 3, 2014

(HealthDay)—Norovirus, the so-called "cruise ship virus," is more often caused by infected restaurant workers than outbreaks on the high seas, U.S. health officials said Tuesday.

Recommended for you

Bright lighting encourages healthy food choices

May 26, 2016

Dining in dimly lit restaurants has been linked to eating slowly and ultimately eating less than in brighter restaurants, but does lighting also impact how healthfully we order?

Big Data can save lives, says leading cancer expert

May 16, 2016

The sharing of genetic information from millions of cancer patients around the world could be key to revolutionising cancer prevention and care, according to a leading cancer expert from Queen's University Belfast.

New soap to ward off malaria carrying mosquitoes

May 13, 2016

(Medical Xpress)—Gérard Niyondiko along with colleagues Frank Langevin and Lisa Barutel has posted a project on the crowd source funding site ulule for a product called Faso Soap. They claim the soap can cut in half the ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.