Abstract: Extracting technology by ultrasonic method and frozen-melt method was studied for extracting anthocyaninsn frompurple sweet potatoes. The conditions for extracting anthocyanins from purple sweet potatoes witn ultrasonic method werestudied.Extracting technology with ultrasonic method was combined with frozen-melt method to get the better result for thefirst time. The result of combining ultrasonic method was better than that of traditional extracting technology. The totalamount of anthocyanins from purple sweet potatoes was determined by pH differential method.The extracting rate reachedas high as 89.2%.

Key words: purple sweet potato, anthocyanins, extracting technology with ultrasonic method and frozen-melt method, pH differential method