With all the food-borne illness information in the news, I wondered what the best way was to wash produce to reduce the risk from harmful microorganisms.
I asked our University of Nevada Cooperative Extension's nutrition specialist, Kerry Seymour, what she knew. She sent me some information from Cornell University Cooperative Extension.
Surprisingly enough, washing fresh vegetables and fruits with plain water is the procedure recommended by the U.S. Department of Agriculture, the Environmental Protection Agency and the U.S. Food and Drug Administration. These agencies do not recommend washing food with soap. While detergents may sometimes remove bacteria that cause food-borne illnesses more effectively than water alone, and possibly reduce pesticide residue, soap can also make people sick. It is difficult to get all the soap off many kinds of produce.
There are produce-rinse products on the market, but there doesn't seem to be scientific data to support their benefits over plain water. I have heard people suggest rinsing off food with white or apple cider vinegar. This probably can't hurt anything.
Others say that a weak bleach and water solution can be used, but there is no research proving that it is better at removing bacteria on vegetables and fruits than water. And, it is quite possible the bleach residue would stay on the surfaces of the produce and be ingested. However, washing the sink, the vegetable brush and all kitchen surfaces with a bleach solution is an excellent idea.
It is essential that you scrub fruits such as melons, citrus fruits and avocados and vegetables such as cucumbers before you cut them. Otherwise, you risk contamination from the dirty surface of the fruit as you cut into the uncontaminated interior.
Salmonella readily survives and grows on the cut surfaces of honeydew, watermelon, cantaloupes, tomatoes and other fruits and vegetables. Smooth-skinned fruits, such as nectarines and tomatoes, can't be scrubbed, so rub their entire surface with your hands while holding them under running water. Remember to wash the stem area well, as bacteria seem to collect there. Also, cut away growth cracks and any damaged parts of produce because these are likely places for microorganisms to survive. It is still unclear how best to wash strawberries or raspberries, with their many porous surfaces.
Scientists are constantly researching harmful microorganisms on fresh produce, but there are still a lot of unknowns. The chances of contracting an illness from fresh fruit and vegetables are relatively low, even though they seem to be on the rise. Washing in clean tap water is the recommended practice to reduce risk.
For more information, e-mail skellyj@unce.unr.edu or call me at 887-2252. You can "Ask a Master Gardener" by e-mailing mastergardeners@unce.unr.edu or call your local University of Nevada Cooperative Extension office. Check out many useful horticulture publications at www.unce.unr.edu.
• JoAnne Skelly is the Carson City/Storey County Extension educator for University of Nevada Cooperative Extension.