芦柑叶总黄酮的提取工艺优化及其抗氧化活性研究

为得到芦柑叶总黄酮的最佳提取工艺,利用响应面法对芦柑叶总黄酮的提取工艺进行优化,并测定芦柑叶总黄酮的抗氧化活性。在单因素试验基础上,根据Box-Behnken试验设计原理,以芦柑叶总黄酮为响应值,选取液料比、乙醇浓度、超声温度和超声时间进行四因素三水平的响应面试验,建立二次回归方程模型,并利用总黄酮对·OH和DPPH·的清除作用来评价其抗氧化活性。结果表明,最佳的提取工艺条件为:液料比38∶1(mL/g)、乙醇浓度74%、超声温度71℃和超声时间26 min,在该条件下进行3次重复试验,得到总黄酮的平均提取率为(53.19±0.28)mg/g,与预测值的相对误差为0.6%,说明该二次回归方程模型具有一定的准确性与可靠性。芦柑叶总黄酮对·OH和DPPH·的清除试验表明,芦柑叶总黄酮有一定的抗氧化活性,与·OH和DPPH·的清除率之间存在量效关系,其对·OH和DPPH·清除率的IC50分别为146.41 mg/L和66.56 mg/L,说明芦柑叶总黄酮是一种潜在的天然抗氧化剂。

Optimization of Extraction Technology of Total Flavonoids from Ponkan Leaves and Its Antioxidant Activity

The aim was to obtain the optimal extraction technology of total flavonoids from ponkan leaves,the extraction technology of total flavonoids from ponkan leaves was optimized by response surface methodology and the antioxidant activity of total flavonoids in ponkan leaves was determined.Based on the single-factor and the Box-Behnken design,taking the total flavonoids of ponkan leaves as response values,the liquid-to-material ratio,ethanol concentration,ultrasonic temperature,and ultrasonic time were selected to perform a four-factor and three-level response surface experiment and a quadratic regression equation model was established.The anti-oxidant activity of total flavonoids on scavenging effects of·OH and DPPH·was evaluated.The results showed that the optimal process conditions were:liquid-to-material ratio 38∶1(mL/g),ethanol concentration of 74%,ultrasonic temperature 71℃,and ultrasonic time 26 min.Three repeated experiments under this condition showed that the average extraction yield of total flavonoids was(53.19±0.28)mg/g,and the relative error with the predicted value was 0.6%,indicated that the quadratic regression equation model had certain accuracy and reliability.The scavenging test of total flavonoids on·OH and DPPH·showed that total flavonoids had a certain antioxidant activity,and there was a dose-effect relationship between total flavonoids and the·OH and DPPH·clearance rates.The IC50 of clearance rates were 146.41 mg/L and 66.56 mg/L,indicated that the total flavonoids of ponkan leaves was a potential natural antioxidant.