Production of purple sweet potato (Ipomoea batatas L.) juice having high anthocyanin content and antioxidant activity

The purpose of the study was to retrieve procedure of production of purple sweet potato ( Ipomoea batatas L.) juice with the best total anthocyanin and antioxidant activity. Purple sweet potato was processed into purple sweet potato juice through a process of heating with temperature variations of 70 0 C, 80 0 C, and 90 0 C and various duration of heating, which are 5 mins, 10 mins, and 15 mins. The total anthocyanin was determined by using pH differential method. The antioxidant activity was determined by using DPPH (2,2-Diphenyl-l-picrylhydrazyl) method. Total anthocyanin of purple sweet potato juice declined in the range between 215.08 mg/L - 101.86 mg/L. The antioxidant activity of purple sweet potato juice declined in the range between 90.63% - 67.79%. Antioxidant activity and total anthocyanin purple sweet potato juice decreases with increasing temperature and duration of heating. The best characteristics found in purple sweet potato juice were made with warming temperatures of 800C. The product with the highest antioxidant activity, total anthocyanins, and good durability was prepared at 800C heating temperature for 5 mins.