The Optimization of the Extraction-Purification Process of the Total Anthocyanin from the Purple-Fleshed Sweet Potato

To optimize the extraction and purification process of the total anthocyanin from the purple-fleshed sweet potato(PSP). The orthogonal experimental was design to optimize the extraction and purification process of the PSP. On the basis of single-factor experiments, the orthogonal experimental was design to optimize the extraction process of the PSP. The optimized process: the PSP was extracted by 70% ethanol (pH= 4) soulution at 60 C for 3 times (each time 30 min) under ultrasonic, and the solid-liquid ratio is 1: 20. Meanwhile, the most suitable macroporous, Diaion HP 2MGL, for separating and purification anthocyanins was selected. The optimized purification process: flow rate of sample was 1.0 mL/min, the pH value of the sample solution is 4, the eluent was 80% ethanol (pH= 3), the flow rate of elution was 0.6 mL/min. The total anthocyanin content can be as high as 9.36% by adopting this technique. This researching result provided a reference bases for the further processing of PSP and at same time, enlarged its application range and increased its practical and additional values.