1. Laboratory of Functional Food Science and COE Program in the 21st Century, Department of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, and Central Research Laboratories, Food Research Laboratories, Mitsui Norin Co., Ltd., 223-1 Miyabara, Fujieda, Shizuoka 426-0133, Japan