提取溶剂对青稞提取物总酚、黄酮含量及其抗氧化活性的影响

以3种不同的青稞为原料,采用不同的提取溶剂(水、60%乙醇、60%甲醇、60%丙酮、95%乙醇、100%甲醇、100%丙酮)对青稞进行提取。对各提取物的总酚、总黄酮进行测定,同时采用3种抗氧化方法:二苯代苦味酰自由基(DPPH)、2,2’-联氨-双(3-乙基苯并噻唑啉-6-磺酸)二胺盐自由基(ABTS)和总抗氧化能力(FARP)评价青稞提取物的抗氧化活性。结果表明,95%乙醇和60%丙酮更有利于青稞多酚的提取。藏青2000的各溶剂提取物的总酚、总黄酮及抗氧化活性普遍高于相应溶剂的循化蓝青稞和香格里拉绿青稞。藏青2000的60%丙酮提取物含有最高的总酚含量,达到211.92mg GAE/100g DW;在60%乙醇提取时具有最高的总黄酮含量,达到60.11mg RT/100g DW;在60%乙醇提取时具有最强的DPPH清除能力,达到80.08%;而用60%丙酮提取时,具有最强的ABTS清除能力和总抗氧化能力,分别达到了1.85,9.28 mmol TEAC/100g DW。总酚含量与抗氧化活性均具有显著的相关性,FRAP法与DPPH、ABTS法具有极显著的相关性。综上表明,青稞富含总酚成分,是一种潜在的天然抗氧化剂资源。

Effect of different solvents on total phenolic content, total flavonoid content and antioxidant activity of highland barley

The objectives of this study were to evaluate total phenolic, total flavonoid content and antioxidant activities of different extraction from three kinds of highland barley. The results showed that 95% ethanol and 60%acetone were better to extract phenolic compounds than other solvents. Total phenolic and total flavonoid contents, antioxidant activities of Zangqing 2000 using different solvents were higher than that of Xunhua and Shangri-la highland barley. Meanwhile, the highest total phenolic content of Zangqing 2000 was 211.92 mg GAE/100 g DW in 60% acetone, the highest total flavonoid content of Zangqing 2000 was 60.11 mg RT/100 g DW in 60% ethanol, the highest ABTS scavenging ability and total antioxidant activity of Zangqing 2000 were 1.85 and 9.28 mmol TEAC/100 g DW, respectively. Furthermore, there was a significant correlation between total phenolic content and antioxidant methods. FRAP method was significantly correlated to DPPH and ABTS methods. These results suggested that highland barley was rich in phenolic content and considered as a good natural antioxidant resource.