1. Appalachian Fruit Research Station, Agricultural Research Service, U.S. Department of Agriculture, Kearneysville, WV 25430, USA
2. Food Quality Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705, USA
3. Statistics Group, Northeast Area, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705, USA