猕猴桃根总黄酮的超声提取及抗氧化活性

以湘西"米良猕猴桃"根为原料,采用超声波辅助乙醇提取总黄酮,通过单因素及正交实验优化提取条件,考察总黄酮对羟基自由基清除效果及对油脂氧化的抑制作用,并与常用抗氧化剂作比较。结果表明,以体积分数60%乙醇按照每1 g固体30 mL液体(即料液比1∶30,下同)在60℃水浴中超声提取40 min后,猕猴桃根中总黄酮得率为1.5%。该提取物对羟基自由基清除效果随质量浓度的增大而升高,对食用油脂的氧化有较好的抑制作用。

Ultrasonic-assisted Ethanol Extraction of Flavonoids from Kiwifruit Root and Their Antioxidant Activity

Flavonoids were extracted from "Miliang Kiwifruit" root under ultrasonic assistance,using ethanol as extraction solvent.The technical conditions were investigated based on single factor and orthogonal tests.The hydroxyl radical-scavenging capacity and the antioxidative activity against oils and fats of the flavonoids extracts were assessed and compared with those of citric acid and Vc.The results show that the optimal extracting conditions were obtained as follows:volume fraction of ethanol 60%,1∶ 30(g∶ mL) material-to-liquid ratio,40 min of ultrasonic extracting time and 60 ℃ water-bath of ultrasonic temperature.Under the optimal conditions,the extraction rate of total flavonoids was 1.5%.The scavenging capability on ·OH free radical increased with extracts concentration increasing.Furthermore,the antioxidant activity of flavonoids extracts against oils and fats was excellent.