1. Contribution from the Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan, Division of ESR, Bruker Biospin K. K., Ibaraki 305-0051, Japan, Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan, and Research Team for Molecular Biomarkers, Tokyo Metropolitan Institute of Gerontology, Tokyo 173-0015, Japan