微波萃取法提取紫心甘薯总黄酮及其抗氧化活性研究

研究了紫心甘薯总黄酮的微波提取工艺及其抗氧化活性．以芦丁为标准品，通过选用L9（3^4）正交表设计实验，确立提取总黄酮的最佳条件并以Vc为对照品，采用DPPH·（二苯代苦味酰自由基）法研究提取物的抗氧化活性．紫心甘薯总黄酮的最佳提取条件为：乙醇浓度70％，提取温度80℃，料液比1：20，提取时间35min；测得紫心甘薯薯肉和薯皮中总黄酮含量分别为1．55％和3．30％，二者抗氧化活性以半数抑制浓度（IC50）表示分别为0．0204，0．0192mg·mL^-1．微波提取紫心甘薯薯皮总黄酮的含量是薯肉的2．13倍，紫心甘薯薯皮的抗氧化性高于薯肉．

Study on microwave-assisted extraction and anti-oxidation activity of flavonoids from purple sweet potato

To study the microwave-assisted extraction and anti-oxidation activity of flavonoids from purple sweet potato. The optimum extraction conditions of flavonoids from purple sweet potato were investigated with L9 （3^4 ） orthogonal experimental design by using rutin as standard compound and the antioxidant activity of the extract with the optimum condition was evaluated by using the system of DPPH · method with Vc as reference substance. The best condition for procedure was extracting for 35 min at 80 ℃ with 20 times of 70% ethanol. The flavonoids extracted from pulp and peel by MAE were 1.55 % and 3.30 %, the anti-oxidation activity of flavonoids for DPPH · radical were 0. 020 4 mg · mL^- 1 and 0. 019 2 mg · mL^- 1 by IC50 respectively. The optimum extraction conditions of flavonoids from purple sweet potato were investigated. The quanlity of flavonoids in peel was about 2. 13 times as that in pulp. The scavenging capacity of DPPH · radical by flavonoids from peel was higher than that of from pulp.