外场强化提取银杏总黄酮及抗氧化性能研究

目的]寻求银杏叶总黄酮外场辅助提取法的最佳提取工艺。方法]用正交试验设计优选出银杏叶总黄酮的外场(微波场、超声波场)辅助提取工艺,并采用DPPH检测法对最佳工艺条件下的微波、超声波提取物的抗氧化性进行了比较研究。结果]微波辅助提取银杏总黄酮的最佳工艺条件为:提取时间15min,乙醇浓度80%,提取温度70℃,料液比1∶25;超声波辅助提取银杏总黄酮的最佳工艺条件为:提取温度50℃,乙醇浓度80%,料液比1∶20,提取时间40min。在最佳工艺条件下微波法和超声波法提取得率分别为4.09%和3.68%,微波法所用时间仅为超声波法的1/3。结论]微波法是提取银杏叶总黄酮的较好方法,超声波法提取物的抗氧化能力强于微波提取物。

Studies on the Outfield Assisted Extraction of Total Flavonoids from Gingko Biloba and Its Antioxidant Capability

Objective The aim of this research was to seek for optimum extracting technology of the extraction method assisted by outfield of total flavonoids from Ginkgo biloba leaves.Method The technologies of outfields(microwave field and ultrasonic field)assisted extraction of total flavonoids from G.biloba leaves were optimized and screened out through orthogonal experimental design and the antioxidant performance of the extractives from G.biloba leaves by microwave and ultrasonic extractions under the optimum technological conditions were conducted for comparative study by DPPH detection.Result The optimum technological condition of microwave assisted extraction of total flavonoids from G.biloba leaves was ethanol concentration of 80 %,extraction time of 15 min and temperature of 70 ℃ and ratio of material to liquid of 1:25.The optimum technological condition of ultrasonic assisted extraction of total flavonoids from G.biloba leaves was ethanol concentration of 80 %,extraction time of 40 min and temperature of 50 ℃ and ratio of material to liquid of 1:20.Under the optimum technological condition,the yields of microwave and ultrasonic extractions were 4.09 % and 3.68 % resp.The extraction time used by microwave extraction was just one third of that by ultrasonic extraction.Conclusion Microwave extraction is the better method for extracting flavonoids from G.biloba leaves,while the antioxidant capability of extractives by ultrasonic extraction was stronger than that of extractives by microwave extraction.