1. Florida State Department of Agriculture and Consumer Services, Tallahassee, Florida
2. Department of Nutrition and Food Science, University of Maryland, College Park, Maryland 20742-7521
3. Produce Quality and Safety Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, USDA, 10300 Baltimore Avenue, Bldg. 002, Room 117, BARC-W, Beltsville, Maryland 20705-2350