1. Biochemistry Department (0308), Virginia Polytechnic Institute and State University, Blacksburg, VA 24061.
2. Corresponding author. Phone: (540) 231-9960. Fax: (540) 231-9070. E-mail: kmpvpi@vt.edu
3. Chemistry Department, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061.
4. Department of Food Science and Technology, University of Georgia, Athens, GA 30602.
5. USDA ARS, Beltsville Human Nutrition Research Center, Nutrient Data Laboratory, 10300 Baltimore Blvd., Bldg. 005, Room 107, Beltsville, MD 20705.