Quality Characteristics of Dried Purple Sweet Potato with Heat Treatment and Enzymatic Saccharification

Abstract

In this study, purple sweet potato paste was obtained after subjecting to heat treatment and enzyme saccharification, and the quality characteristics of dried sweet potato paste were subsequently evaluated. The total sugar and reducing sugar contents were 12.66 and 6.85%, respectively, in the steamed sweet potato paste and 14.73 and 7.47%, respectively, in the baked sweet potato paste. After enzyme treatment, the total sugar of steamed and baked sweet potato paste increased to 16.04 and 20.72%, respectively, and the reducing sugar increased to 8.20 and 10.16%, respectively. The total sugar content of dried sweet potatoes was 47.25% for steamed sweet potatoes and 52.30% for baked sweet potatoes, and the reducing sugar content was 20.68 and 24.05%, respectively, both values were higher for baked sweet potatoes. The total sugar, reducing sugar, and free sugar contents of dried sweet potatoes increased under enzyme treatment conditions. No significant differences were obtained in the hardness of dried sweet potatoes, and was not dependent on the presence or absence of enzyme treatment. Results of this experiment indicate that baking is an excellent treatment when manufacturing dried sweet potatoes, and the sugar content can be increased through enzyme treatment.