As progress is made in fermentation technology and the brewing industry, many kinds of alcoholic beverages are being
produced each year to catch the interest of consumers. In Japanese sake brewing, the cooking of rice grains is an
important process. Rice bran, which contains proteins, lipids,vitamins, and minerals, is usually removed from the rice
grains by polishing before fermentation to produce an alcoholic beverage of good quality.
Purple rice , however,contains anthocyanin pigments, such as cyanidin and peonidin glucosides, in the bran layer. Anthocyanin is known to have physiological functions, as it has antioxidative activities, contributes to the prevention of arterial sclerosis, and is a type of functional food. Furthermore, anthocyanins in purple-fleshed sweet potato are known to have physiological functions, such as antioxidant properties