黄秋葵黄酮的提取工艺和体外抗氧化活性研究

Extraction and Antioxidant Activity in vitro of Okra Flavonoids

研究黄秋葵黄酮的超声辅助提取工艺和体外抗氧化活性。在单因素试验基础上,采用响应面法优化黄秋葵黄酮的超声辅助提取工艺,并以VC为对照,对其还原力及羟自由基(?OH)、超氧阴离子自由基(O2-?)、1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除能力进行探讨。结果表明,在超声功率250 W的条件下,最佳提取工艺为料液比1∶25(g/mL)、提取时间21 min、提取温度75℃、乙醇体积分数50%,此条件下黄酮得率的验证实验平均值为4.85%,与预测值4.88%相近,最佳工艺切实可行,制得的黄秋葵黄酮对?OH、O2-?、DPPH自由基的IC50分别为6.00、3.28、2.98 mg/mL,最大清除率分别达31.49%、64.40%、62.22%,且具有较强的还原力,表现出较好的体外抗氧化活性。

This paper reports the results obtained for the ultrasonic-assisted extraction and antioxidant activity in vitro of flavonoids from fresh okras. The extraction process was optimized using response surface methodology. The evaluation of antioxidant activity was carried out by reducing power, hydroxyl, superoxide anion and DPPH radical scavenging assays in comparison to VC. The optimum extraction conditions were determined as 250 W, 1：25 （g/mL）, 21 min, 75℃ and 50% for ultrasonic power, solid-to-solvent ratio, extraction time, temperature and ethanol concentration, respectively. The experimentally observed yield of flavonoids under the optimized conditions was 4.85% on average, which approximated the predicted value of 4.88%, showing the reliability of the optimized process. In hydroxyl, superoxide anion and DPPH radical scavenging assays, the IC50 of the flavonoids extracted from okra were 6.00, 3.28 and 2.98 mg/mL, and the maximum scavenging rates were 31.49%, 64.40% and 62.22%, respectively. Moreover, strong reducing power was observed. These results support strong antioxidant activity in vitro for okra flavonoids.