Think you don’t need to wash that organic apple from the farmers’ market? Think again. It’s organic and locally grown, sure, but that apple has developed over many days in an uncontrolled environment, was harvested and packed by hands that were not your own, and has come in contact with surfaces untold. It’s had many chances to interact with harmful microbes that could potentially cause a food-borne illness.
“Fresh produce is a raw agricultural product,” says Catherine Strohbehn, PhD, RD, CP-FS, hospitality management extension specialist and professor at Iowa State University. “As part of production, it is exposed to potential contaminants from environmental and human sources. It is pretty hard to control the birds flying overhead or animals, so it is always a good idea to wash a product before eating.”
Whether local, organic or even out of your own garden, a quick wash is the best way to ensure you’ll healthfully enjoy your fruits and vegetables with less risk of ingesting harmful bacteria or chemicals. This goes for produce you peel before eating, too. “The knife blade can pull contaminants from the outside through the flesh, so even if the avocado peel is not eaten, the utensil used to fabricate it will have contact with [both] the soiled or outside portion and the clean or edible portion, thus resulting in cross-contamination. That is why handling contact surfaces—hands, knives, cutting boards, containers, sinks, et cetera—should all be clean and sanitized before having contact with fresh produce,” says Strohbehn.
You’ll find products on the grocery-store shelves marketed as fruit and vegetable washes, but those aren’t necessary.
“Research has found little significant difference between running water and commercial cleaners,” Strohbehn says. “Many producers use some type of post-harvest cleaning/sanitizing agent to reduce microbial loads … but for consumers, free-running water is still just as effective as purchased products.”
There’s debate in the food-safety community about the ideal wash-water temperature. Most sources, including the USDA and Council for Agricultural Science and Technology, recommend using water 10 degrees F warmer than the produce to prevent microbial transfer into the produce.
For some fruits and vegetables, a good rinse will do. Use these tips to further clean these types of produce:
- Immerse lettuce and other leafy greens in cool water for a few minutes to help loosen and remove soil and dirt. Use a large, clean bowl instead of the sink, which might contain more pathogens. “If using the ‘bath’ rather than ‘shower’ approach, be sure to repeat a few times, or use a colander/strainer insert in the bowl,” Strohbehn says.
- The Food and Drug Administration recommends scrubbing firm produce, such as root vegetables, melons or cucumbers, with a clean produce brush under running water to remove as much dirt and bateria as possible.
- To remove dirt from mushrooms, the Colorado State University Extension suggests using a soft brush under running water or wiping mushrooms with a wet paper towel.
The only produce that you should not wash before consuming is produce that is sold as “ready to eat,” such as bagged salad mix, having been washed by the producer or packager. Rewashing this already-clean produce has a greater potential to introduce bacteria than it does to rinse it away, according to Strohbehn.
To prolong its storage life, don’t wash your produce until you’re ready to use it unless it’s really dirty.
Proper handling doesn’t stop at the sink. “Some fresh produce items need to be kept refrigerated after washing and/or cutting,” Strohbehn says. “Sliced melons, cut tomatoes and leafy greens should be kept below 41 [degrees] F.” Store refrigerated fruits and vegetables away from raw meat and ensure meat drippings cannot contact your produce.
In the Garden
For homegrown produce, reducing the risk of contamination begins in the garden. Follow these guidelines for growing the safest produce:
- Once the edible portion emerges, irrigate food crops only with potable water.
- Don’t apply untreated compost or manure to the soil of food crops within 120 days of harvest if the edible portion is in contact with the soil; don’t apply to other crop soils within 90 days of harvest.
- Keep pets and wildlife out of the garden.
- Site your garden as far from animal pens and compost piles as possible.
- Prevent rainwater and irrigation runoff from animal pens and compost piles into your garden.
- Wash your hands, harvesting gloves, knives and containers before harvesting.
With many environmental and handling factors outside of your control, you can reduce the risk of food-borne illness for yourself and your family with a little effort and thoughtful produce preparation.
This article originally appeared in the March/April 2014 issue of Hobby Farm Home.