The incorporation of sweet potato application in the preparation of a rice beverage

To increase the industrial applications of sweet potato, a rice beverage was prepared by adding barley sprouts, sweet potato, or a mixture of barley sprouts and sweet potato (1:1). Amylases from barley sprouts and sweet potatoes had a similar hydrolysis pattern to β-amylase. Heat stability of this enzyme in sweet potato was higher than that in barley. Reducing sugar content in the mixture of barley sprouts and sweet potato was higher than in either barley sprouts or sweet potato alone. After the preparation of the rice beverage, the maltose content of the mixture with barley sprouts, either barley sprouts and sweet potato, or sweet potato was 37.2, 44.1 and 40.3 mg mL ^-1 after 6 h, respectively. The amylase activity in the mixture with barley sprouts and sweet potato decreased more than that of the mixture with only sweet potato. The use of sweet potato resulted in an increase of sweetness, flavour and improved preference in rice beverage.