野葛总黄酮的提取工艺优化及抗氧化活性研究

通过单因素试验及正交试验确定野葛总黄酮的最佳提取工艺，并采用紫外分光光度法对野葛总黄酮的1,1-二苯基-2-三硝基苯肼（DPPH）自由基清除能力、总还原能力和羟基（OH）自由基清除能力进行测定。结果表明，野葛总黄酮的最佳提取工艺条件为：体积分数40%的乙醇、料液比1∶20（g∶mL）、80 ℃水浴提取2 h，提取2次。在此优化条件下，野葛总黄酮的提取率3.06%。抗氧化试验结果表明，野葛总黄酮质量浓度分别为0.8 mg/mL、0.4 mg/mL、0.8 mg/mL时，DPPH自由基清除能力、OH自由基清除能力、总还原能力（OD700 nm值）最大值分别为72.98%、65.38%、0.16，表明野葛中总黄酮具有一定的抗氧化能力，且在一定浓度范围内，浓度越高抗氧化能力越强。

Optimization of extraction process of total flavonoids from Pueraria lobata and its antioxidant activity

The optimal extraction process of total flavonoids from Pueraria lobata was determined by single factor tests and orthogonal tests, and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, total reducing ability and hydroxyl (OH) radical scavenging ability of total flavonoids from P. lobata were determined by ultraviolet spectrophotometry. The results showed that the optimal extraction conditions of total flavonoids from P. lobata were as follows: ethanol 40%vol, solid and liquid ratio 1∶20 (g∶ml), extraction in 80 ℃ water bath for 2 h, and extraction 2 times. Under the optimal conditions, the extraction yield of total flavonoids from P. lobata was 3.06%. The results of antioxidant tests showed that when the mass concentrations of total flavonoids from P. lobata were 0.8 mg/ml, 0.4 mg/ml, and 0.8 mg/ml, respectively, the maximum value of DPPH radical scavenging ability, OH radical scavenging ability, and total reducing ability (OD700 nm value) were 72.98%, 65.38%, and 0.16, respectively, indicating that the total flavonoids in P. lobata had a certain antioxidant ability, and within a certain concentration range, the higher the concentration, the stronger the antioxidant capacity.