People are eating more raw and organically grown fruits and vegetables these days. And that has many consumers concerned whether they are properly cleaning their produce. Michael Doyle, a professor of food microbiology at the University of Georgia and director of its Center for Food Safety, offers his opinion on how to wash fresh food—and whether it's OK to rub an apple on your shirt.

Harboring Enemies

When it comes to anything plucked from the produce aisle, Dr. Doyle says there are two main concerns—pesticides, which he...