浸提法、超声波法和微波法提取紫薯花色苷的抗氧化性比较研究

Comparative Antioxidant Activities of Anthocyanins Extracted from Purple Sweet Potato by Organic Solvent,Ultrasonic-Assisted and Microwave-Assisted Extraction

本实验通过羟自由基(·OH)清除率、1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率、还原力、超氧阴离子自由基(O_2^-·)清除率、总抗氧化性和金属螯合能力6个抗氧化测定方法对浸提法、微波辅助提取法和超声波辅助提取法提取的紫薯花色苷的抗氧化活性进行了综合评价。结果表明:除金属螯合能力较弱外,其余5种抗氧化活性检测结果均表明紫薯花色苷具有一定的抗氧化能力,且5种抗氧化活性检测结果一致性地表明微波辅助提取法、超声波辅助提取法和浸提法提取的紫薯花色苷抗氧化能力依次降低,它们都总体表现为对·OH、DPPH自由基、O_2^-·的清除能力较强,还原力和总抗氧化性次之,金属螯合能力最差;采用超声波或微波辅助提取有助于保持提取的紫薯花色苷的抗氧化活性,且微波辅助提取法效果最好;对紫薯花色苷抗氧化活性的检测和判定可以·OH、DPPH自由基和O_2^-·清除能力作为主要指标。

The antioxidant activity of anthocyanins extracted from purple sweet potato by organic solvent,ultrasonicassisted or microwave-assisted extraction was comparatively evaluated by radical scavenging activities against hydroxyl,DPPH and superoxide anion radicals,total antioxidant capacity（TAC）,reducing power and ferrous ion chelating activity.The results showed that the anthocyanins extracted from purple sweet potato,irrespective of the extraction method used,exerted antioxidant activities except for ferrous ion chelation.Moreover,the results from 5 antioxidant assays consistently indicated that the antioxidant capacity of anthocyanins extracted by microwave-assisted,ultrasonic-assisted and organic solvent extraction revealed a decreasing trend in turn.The extracted anthocyanins showed the strongest ability to scavenge free radicals followed by reducing power and total antioxidant capacity,and possessed the lowest ferrous ion-chelating activity.Both ultrasonic-assisted and microwave-assisted extraction are beneficial for maintaining antioxidant activity of anthocyanins extracted from purple sweet potato,with the latter being superior to the former.