Category Archives: Microbiology Investigations

NCSU

In a study aimed at assessing the impact of washing poultry on kitchen contamination, researchers found that more than a quarter of study participants contaminated salad with raw poultry – including many study participants who did not wash the poultry. The study highlights the importance of hand-washing and cleaning and sanitizing the kitchen in order to reduce the risk of foodborne illness when cooking at home.

Washing raw poultry is not recommended, due to concerns about inadvertently contaminating other foods and surfaces – and increasing the risk of foodborne illness.

“We wanted to know what effect an educational intervention would have on getting people to stop washing poultry before cooking, and what effect any resulting change in behavior might have on reducing contamination in the kitchen,” says Ellen Shumaker, corresponding author of the study and an extension associate at North Carolina State University. “We also wanted to get a better idea of how, if at all, washing poultry actually led to increased contamination in the kitchen.”

For the study, researchers recruited 300 home cooks who said they washed poultry before cooking it. The researchers sent food safety information to 142 of the study participants via email, outlining risk-reduction efforts – including the recommendation to not wash raw poultry during food preparation. The remaining 158 study participants did not receive the education intervention.

All 300 study participants were then invited to test kitchens equipped with video cameras that filmed meal preparation. Participants were asked to cook chicken thighs and prepare a salad. After preparing the chicken thighs, but before putting the chicken in the oven, participants were called out of the kitchen to conduct a short interview. Participants were then sent back into the kitchen to cook the chicken thighs, prepare the salad, and clean the kitchen as they would at home.

What the study participants didn’t know was that the chicken thighs were inoculated with a harmless strain of bacteria, which the researchers would be able to detect. This allowed researchers to swab surfaces in the kitchen to see whether any cross-contamination occurred during the food preparation and cooking process.

When study participants left the kitchen to conduct the interview, researchers swabbed the kitchen to identify any potential contamination. This process was repeated after each participant had completed cooking the meal and cleaned the kitchen. The prepared salad was also tested for possible contamination.

Ninety-three percent of the participants who received the intervention did not wash the chicken, as compared to 39% of the participants who did not receive the intervention.

However, the researchers were surprised to see that people who did wash the chicken and people who didn’t wash the chicken had similar levels of contamination from the raw chicken in their prepared salads.

AARP

During the journey from farm to table, the fruits, vegetables and other foods we eat are exposed to countless people, places, substances and surfaces before ever reaching our mouths. It would seem a given, then, that everything we bring home from the grocery store needs to be thoroughly washed and sanitized.

“Produce comes from the environment; it comes from the ground. The way that it’s grown and harvested, it can have dirt on it and other bacteria,” says Meredith Carothers, technical information specialist at the U.S. Department of Agriculture (USDA). “Unlike meat and poultry, which is packaged, a lot of times produce is just out in the grocery store on display.”

From a food safety standpoint, experts say it’s not necessary to wash all foods. In fact, washing some foods can actually increase the risk of contamination and illness. To help clear up any confusion, we asked Carothers to break down the do’s and don’ts of food washing.

Rules for washing produce

Do rinse fruits and vegetables under running water. After produce is harvested, it gets sorted, delivered and put on display in the grocery store. During this process there are many opportunities for produce to encounter a number of hands and surfaces. Before consuming fresh produce, remove any torn or bruised parts (bacteria that can cause illness thrive in these places) and rinse under running water to remove germs and dirt.

Do scrub hard produce with a clean brush. Foods like potatoes or apples can be scrubbed to thoroughly remove dirt from the exterior, including crevices that rinsing alone may not reach.

Do dry rinsed produce on a clean surface. That means spreading a clean cloth or paper towel on a clean surface to avoid recontamination. If you use a salad spinner, make sure it’s clean before you add greens to it, and clean it again between batches.

Don’t wash produce labeled “prewashed” or “ready to eat.” It is already safe to eat out of the package. Just make sure that prewashed produce doesn’t encounter unclean surfaces or utensils — especially if those surfaces have had raw meat or its juices on them.

Don’t use soap to clean produce. The USDA does not recommend any type of detergent on fruits or vegetables because it can leave behind a film that is not intended to be consumed. Some produce is also porous and may absorb the soap. Although you can buy commercial produce washes, they aren’t approved or labeled by the Food and Drug Administration (FDA) and are not recommended.

Don’t soak produce. Soaking may remove the germs initially, but the now-tainted water can recontaminate your produce as well as nearby surfaces. When produce is rinsed under running water, the dirt and germs go down the drain.