地皮菜总黄酮提取工艺优化及抗氧化活性评价

Optimization of Extraction and Antioxidant Activity Evaluation of Total Flavonoids from Nostoc Commune

以青海地皮菜为原料,确定超声波辅助法提取地皮菜总黄酮的最佳提取工艺,并对其抗氧化活性进行探究。在单因素试验的基础上,通过响应面分析法确定地皮菜总黄酮的最佳提取工艺条件为:乙醇体积分数75%、液料比45 mL/g、提取温度75 ℃、超声时间30 min,在此条件下,地皮菜实际总黄酮得率为(1.49±0.02)%,与模型预测值1.5135%基本相符,说明了响应面模型可较好地优化地皮菜总黄酮的提取工艺。抗氧化活性研究表明,地皮菜总黄酮对羟自由基、DPPH自由基、ABTS;自由基的清除能力随其质量浓度的增大而增强;当总黄酮含量为3.20 mg/mL时,其对DPPH、ABTS;和羟自由基的清除率分别为53.30%、76.05%和57.09%,此时总还原能力最强。相同质量浓度下,地皮菜总黄酮清除羟自由基的能力类似于抗坏血酸,特别是质量浓度大于0.8 mg/mL时,地皮菜总黄酮溶液对羟自由基的清除能力强于抗坏血酸,说明地皮菜总黄酮具备开发成新型天然抗氧化剂的潜力。

Using Nostoc commune from Qinghai as raw materials,optimization of the experimental conditions for extracting total flavonoids from Nostoc commune by ultrasonic-assisted method and evaluation of the antioxidant activities were performed.Based on single factor experiment,the optimum extraction conditions of total flavonoids from Nostoc commune were determined by response surface analysis as follows:ethanol concentration 75%,liquid to solid ratio 45 mL/g,extraction temperature 75 ℃,ultrasonic time 30 min.Under these conditions,the actual yield of total flavonoids was calculated to be (1.49±0.02)%.It was basically consistent with the predicted value of 1.5135%,indicating that the response surface model could better optimize the extraction process of total flavonoids from Nostoc commune.The results of antioxidant activity in vitro showed that the scavenging ability of total flavonoids on hydroxyl free radical,DPPH free radical and ABTS;free radical increased with the increase of their concentration;when the concentration of total flavonoids solution was 3.20 mg/mL,the scavenging rates of DPPH,ABTS;and hydroxyl radical were 53.30%,76.05% and 57.09%,respectively,and the total reducing power was the highest.At the same concentration,the scavenging ability of total flavonoids from Nostoc commune was similar to Vc,especially at high concentration,the hydroxyl radical scavenging ability of total flavonoids from Nostoc commune was stronger than Vc,indicating that total flavonoids from Nostoc commune had the potential to be developed into new natural antioxidants.