1. 1) Japan Society of Nutrition and Food Science: 〈http://www.jsnfs.or.jp/database_aminoacid.html〉, cited 5 May, 2016.
2. 2) Non-Profit Organization Umami Information Center: 〈http://www.umamiinfo.jp〉, cited 17 May, 2016.
3. 3) Young V. R., Ajami A. M., J. Nutr., 130, 892S-900S (2000).
4. 4) Ikeda K., Japan. Patent 14805 (1908).
5. 5) Ikeda K., Tokyo Chem. Soc., 30, 820-836 (1908).