I know from servsafe education, professional research, and personal experience that all food products should be received, stored, and handled with great care and consideration for haccp standards, and I insist that my prep cooks and line cooks are educated and follow safe food handling practices. That being said, I have always required my kitchen staff to memorize the 5 food products (beyond ready to eat items) that I consider mandatory for them to wear gloves when handling, regardless of how often they wash their hands or what temp it might be brought up to. Shellfish, tomatoes, rice, pasta, and dairy products. I know from experience that these 5 food products will have a shelf life of half as long if handled with bare hands. I have heard that this is because of a chemical reaction with the pH and natural body chemistry of human skin. Can anyone give me more information about the actual science behind this?