Extraction and Stability of Anthocyanin from Purple Sweet Potato

In this paper, the optimum extracting condition of anthocyanin from purple sweet potato and its stabilitiy were studied.The results showed that this kind of anthocyanin had spectral characteristics of the general anthocyan pigment. The optimum conditions of extracting were as follows: using 0.1% hydrochloric acid as extracting solution, the anthocyanin was extracted at 60℃ waterbath for 1h,with raw material-to-0.1% HCl ratio 1:30.The colors of anthocyanin in acidic, neutral and alkaline solution were red, purple and blue, respectively. The anthocyanin was sensitive to the oxidant, reducing agent and color protectant in common sweet potato,and was stable to potassium sorbate,metal ions and freeze -drying. Purple sweet potato might be a good source of extracting natural anthocyan.