Philippine rice wine (Tapuy) made from Ballatinao black rice and traditional starter culture (Bubod) showed high alcohol content, total phenolic content, and antioxidant activity

Abstract This study described and evaluated the acidity, alcohol content, total phenolic content, antioxidant activity, and sensory attributes of rice wine (Tapuy) made from black, red, brown and white rice during a 7-day fermentation. Acidity of Tapuy made from the different pigmented rice had similar pH profiles characterized by a steep decrease at day 1 from 6.38 ± 0.4 to 3.38 ± 0.2, and remained relatively unchanged until the end of fermentation. Tapuy made from black rice (Ballatinao) contained 16.07% alcohol, second to white rice (Bongkitan) that contained 18.58% alcohol, although they were not significantly different from each other (p>0.05). At the end of fermentation, the total phenolic content and antioxidant activity of Tapuy made from black rice was significantly higher (p<0.05 and p<0.01, respectively) than Tapuy made from the other pigmented rice. Total phenolic content of Tapuy made from black rice was at 9.73 mg GAE/mL and antioxidant activity leveled-off at 70.63% DPPH radical scavenging activity; whereas Tapuy made from the other pigmented rice were declining. Thus, Ballatinao black rice is a suitable rice variety for making Tapuy and has the potential to be a health-promoting functional food.