1. Functional Foods Development Division, Kaneka Corporation, Takasago, Hyogo 676-8688, Japan
2. Life Science Research Laboratories, Life Science RD Center, Kaneka Corporation, Takasago, Hyogo 676-8688, Japan
3. Laboratory of Medicinal Plant Science, School of Pharmacy, Tokyo University of Pharmacy and Life Science, Hachioji 192-0392, Japan
4. Department of Molecular Metabolism and Diabetes, Department of Internal Medicine, Tohoku University School of Medicine, Sendai 980-8574, Japan
5. Laboratory of Nutrition Chemistry, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan