Production and antioxidative activity of alcoholic beverages made from Thai ou yeast and black rice (Oryza sativa var. Indica cv. Shiun)
Fermentation yeast was isolated from a Thai traditional alcoholic beverage called Thai ou, which is drunk through bamboo tubes. The isolated yeast was identified as a strain of the genus Saccharomyces cerevisiae. The alcoholic beverage made with the isolated yeast designated as S. cerevisiae NP01 from black rice grains had an ethanol concentration of 12.4 to 13.1% (v/v) and a large amount of phenolic compounds. The resulting alcoholic beverages made from black rice grains were red in color, especially those made from uncooked black rice, which had a brilliant red hue similar to that of red or rosé wine. The amount of anthocyanin in the beverages made from uncooked black rice with NP01 and industrial wine yeast W-4 was 118 and 131 μg/ml, respectively. The anthocyanin content of beverages made from uncooked black rice was higher than that of the beverages made from the cooked black rice. The antioxidative activity of alcoholic beverages made from uncooked black rice was also higher than that of beverages made from cooked black rice. In the course of this study, the use of NP01 yeast produced black rice wine that was red in color and exhibited antioxidative activity.
Key words: Antioxidative activity, ou, black rice, anthocyanin, alcoholic beverage.