Food science professor Tianxi Yang with students Tzu-Cheng Chiu and Ling Guo working on the wash at the University of British Columbia. Credit: Sachi Wickramasinghe Many grocery shoppers know the routine: bring fruit and vegetables home, rinse them, dry them and hope they stay fresh long enough to be eaten. But fresh produce is delicate. Grapes shrivel, apple slices brown and berries can spoil quickly. At the same time, many people worry about what may remain on the surface of fruit they buy, including pesticide residues. Cleaning and freshness are usually treated as separate problems that require different treatments. Washing feels like a simple act of control. But it's not quite that simple. The U.S. Food and Drug Administration recommends rinsing produce under running water and says soap, detergent and commercial produce washes are not recommended. Water helps, but it does not solve every problem. Our new study suggests those goals may be combined.…