1. Functional Food Creation Research Institute, 1056-7 Tsudaka, Kita-ku, Okayama 701-1152, Japan.
2. Department of Nutritional Science, Faculty of Health and Welfare Science, Okayama Prefectural University, 111 Soja, Okayama 719-1197, Japan.
3. Faculty of Agriculture, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan.
4. Department of Life Science, Okayama University of Science, 1-1 Ridai-cho, Kita-ku, Okayama 700-0005, Japan.