1. Ministry of Health, Labour and Welfare. Japan’s Specifications and Standards for Food Additives, 8th ed. Ministry of Health, Labour and Welfare: Tokyo, 2009; pp. 252–253.
2. Japan Food Additives Association. New Manual of Food Additives, 4th ed. Japan Food Additives Association: Tokyo, 2013; pp. 143–175.
3. Ministry of Health, Labour and Welfare. Manual of the Official Method for Food Additives, 8th ed. Ministry of Health, Labour and Welfare: Tokyo, 2007; pp. 316–318.
4. Genipin: A natural blue pigment for food and health purposes
5. The Pharmaceutical Society of Japan. Methods of Analysis in Health Authorized; The Pharmaceutical Society of Japan: Kanehara, Tokyo, 2015; pp. 380–390.