溶剂与提取方式对苦荞提取液抗氧化性能的影响

Effects of Extraction Solvents and Methods on Antioxidant Activity of Tartary Buckwheat Bran Extracts

目的:比较不同溶剂体系和提取方式对苦荞抗氧化活性物质含量及活性的影响,寻找适宜实验室使用的高效、便捷的苦荞抗氧化活性物质的提取方法。方法:以苦荞麸皮为试材,对比不同溶剂(80%丙酮、50%丙酮、80%甲醇、60%甲醇、80%乙醇和纯乙醇)和提取方式(均质、回流、超声波助提、浸泡法及振摇法)对苦荞麸皮提取物的总酚、总黄酮含量及抗氧化活性(清除ABTS·+、DPPH·能力及在β-胡萝卜素-亚油酸体系中的护色效果)的影响。结果:不同溶剂体系中,80%丙酮提取液的总酚和总黄酮含量最高,分别为(2370.27±137.94)mg GA eq/100gDW、(3361.28±132.95)mg RU eq/100g DW,其次依次为50%丙酮>80%甲醇>60%甲醇>80%乙醇>乙醇;80%丙酮提取物在3个抗氧化模型评价中排序较高。以80%丙酮为溶剂,对比不同提取方式研究中,总酚含量由高到低依次为回流提取>均质提取、超声波30min提取及浸泡提取>超声波10min提取与振摇提取。其中,超声波30min提取液在3个抗氧化模型中表现出最强的抗氧化能力。提取时间顺序:浸泡15h>回流2h、振摇2h>均质10min/次(3次)、超声波30min>超声波10min。结论:80%丙酮是适于苦荞抗氧化物质提取的溶剂体系,同时辅助超声波30min处理,是实验室便捷、高效的提取方法。

Objective：In order to search a efficient method for extracting antioxidant from tartary buckwheat bran,which applies to laboratory.Methods：The effects of different solvent systems （80% methanol,60% methanol,80% ethanol,absolute ethanol,80% acetone,50% acetone） and extraction procedures （homogenization extraction,heat reflux extraction,ultrasound extraction,maceration extraction and agitation extraction） on total phenol and total flavonoids contents and antioxidant activities in bran extracts of tartary buckwheat were investigated by Folin-ciocalteu＇s methods and three different bioassays：2,2＇-azino-bis（3-ethylbenzothiazo-line-6-sulfonic acid）diammonium salt（ABTS）,2,2＇-diphenyl-1-picrylhydrazyl（DPPH） radical scavenging assays and β-carotene-linoleic acid antioxidant system,respectively.Result：80% acetone extracts exhibited highest total flavonoids contents （3 361.28 mg Rutin eq/100 g DW） and the strongest antioxidant activities in DPPH· assays （24.53 mmol Trolox eq/100g DW）.Antioxidant activities of ultrasound extracts was found to be higher than others measured in the terms of trolox equivalent antioxidant capacity（30.34 mmol Trolox eq/100g DW,30.47 mmol Trolox eq/100 g DW） with ABTS·.＋,DPPH· assays and in terms of inhibition using β-carotene-linoleic acid assay （antioxidant activity coefficient,AAC=912.15）.Conclusion：80% acetone and ultrasound extract,which were a better choice for extracting antioxidants from buckwheat bran,showed relatively high phenolic contents and strong antioxidant activities.