CORVALLIS, Ore. – To keep things safe, you should wash melons and other fruits and vegetables that grow in, on or near the ground in cold water before cutting, peeling or eating them.
"There is always a chance for bacteria to grow on the surface of a fruit or vegetable, so washing is important before cutting or peeling your produce, homegrown, or store bought," explained Nellie Oehler, family and community development faculty with the Oregon State University Extension Service.
Before cutting into them with a knife, hard fruits and vegetables should be scrubbed with a brush under running water, to rid them of soil particles and possible bacteria, viruses or parasites. To clean soft fruits like tomatoes, plums, apples or nectarines, hold them under running water and rub them all over. Berries should be gently washed in cool water and never soaked.
Using detergent to wash produce is a no-no. Oehler cites Cornell University Extension research, which concludes that while washing fruits and vegetables using detergents might remove more bacteria and some pesticides, the soaps may also contain chemicals not intended to be on food.
"Once detergent gets into some food it is more difficult to remove than from dishes and it can make people sick," Oehler explained. "In fact, the U.S. Department of Agriculture, the Environmental Protection Agency and the U.S. Food and Drug Administration – the three federal agencies involved in food safety activities – all recommend washing fresh fruits and vegetables with plain water and not with soap or other products."
Cornell Extension specialists also say that commercial rinse products that claim to remove all sorts of hazards from produce are not any more beneficial than plain water. They also state that chlorine solutions are no more beneficial than plain, potable water for cleaning produce.
"Chlorine may work well to purify clear water or to sanitize clean kitchen surfaces, it does not seem to work well in the complex chemical environment of fruit and vegetable surfaces," they point out in a publication. "Plus, a chlorine solution may leave residues of chlorinated compounds on the produce, and the amounts and safety of such possible residues have not been studied."
Basically, no washing method completely removes or kills microbes.
Oehler says that other studies have shown that bacteria like Salmonella can survive and grow on cut surfaces of tomatoes, cantaloupes, watermelons and honeydew melons. Microorganisms are more likely to survive in the stem scar, growth cracks, and any damaged parts of the produce, so it is important to trim away these parts before serving or eating them. Cut fruit should be refrigerated and not left at room temperature for more than two to three hours.
For answers to your questions about food harvest, preservation and storage, the OSU Extension Food Safety/Preservation hotline is in operation from July 17 to Oct. 13. Call 1-800-354-7319, Monday through Friday from 9 a.m. to 4 p.m. (except holidays). OSU Extension Family Food Education volunteers and Extension faculty and staff run the hotline.