玫瑰茄黄酮超声波辅助提取及其抗氧化活性

采用超声波辅助乙醇浸提法提取玫瑰茄花萼中的黄酮。先通过单因素试验,考察乙醇体积分数、超声时间、超声温度和料液比对玫瑰茄花萼中黄酮得率的影响;再通过正交试验,确定提取玫瑰茄花萼中黄酮的最佳工艺。结果表明:乙醇体积分数为80%,超声时间为45 min,超声温度为70℃,料液比为1∶20(g∶m L),在此条件下,玫瑰茄花萼中黄酮得率为3.78%。通过测定清除1,1-二苯基-2-苦肼基自由基(DPPH)的能力考察玫瑰茄花萼中黄酮的抗氧化性,表明玫瑰茄花萼中黄酮具有抗氧化性,且优于维生素C。

Ultrasonic-aided Extraction and Antioxidant Activity of Flavonoids from Hibiscus sabdariffa

The aim of this study is to research the optimum extraction process conditions of fla-vonoids from Hibiscus sabdariffa by the method of ethanol extraction with ultrasonic. The extraction process conditions contained concentration of ethanol, ultrasonic time, ultrasonic temperature, and ratio of material to liquid. Through single factor experiments, effects of extraction process conditions on extraction rate were researched. Orthogonal experiment was applied for optimizing parameters. The results showed that the optimum concentration of ethanol, ultrasonic time, ultrasonic temperature, and ratio of material to liquid were 80%, 45 min, 70℃, 1 : 20 ( g : mL) , respectively. The high-est extraction rate of flavonoids was 3. 78%. Antioxidant activity of Hibiscus sabdariffa flavonoids was characterized in terms of 1, 1-diphenyl-2-picrylhydrazyl free radical ( DPPH) scavenging activity. The results indicated that antioxidant activity of Hibiscus sabdariffa flavonoids was better than vitamin C.