花生茎叶酚酸的提取纯化及其抗氧化活性研究

Extraction and purification of phenolic acid from Arachis hypogaea L.stems and leaves and its antioxidant activity

以花生茎叶(Arachis hypogaea L.stems andleaves,AHSL)为原料,采用60Coγ射线辐照结合溶剂法提取AHSL酚酸,Box-Behnken响应面法优化提取工艺参数,萃取纯化后进行AHSL酚酸的抗氧化性研究。结果表明:吸收剂量6.70 kGy,乙醇浓度70%,液料比(mL∶g)27∶1为最优提取工艺参数,AHSL酚酸得率最高可达(2.25±0.11)%;工艺参数中,吸收剂量对AHSL酚酸得率的影响最显著(p=0.0001)。经氯仿和乙酸乙酯萃取纯化后,AHSL酚酸含量可达萃取前的1.8倍。在抗氧化性方面,AHSL酚酸的自由基清除率和总还原力优于乙醇提取物,对羟基自由基的清除作用与同浓度的茶多酚无显著性差异(p>0.05)。其中AHSL酚酸浓度为100μg/mL时,可以清除50%以上的1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基和羟基自由基。以上结果表明,60Coγ射线辐照结合溶剂提取的工艺可行,获得的AHSL酚酸具有较强的体外抗氧化活性。

Arachis hypogaea L.stems and leaves(AHSL)were used as raw materials,to extract phenolic acids through 60 Coγirradiation and solvent synergistic method.The extraction conditions were optimized by the response surface methodology of Box-Behnken,following a separation;thereafter,the antioxidant activity of the phenolic acid AHSL was studied.The results showed that the optimal extraction process could be achieved at an absorbed dose of 6.70 kGy and 70%ethanol concentration with 27∶1 liquid-solid ratio(mL∶g).The highest AHSL phenolic acid yield was(2.25±0.11)%.Among the process parameters,the absorbed dose showed the most significant effect on the AHSL phenolic acid yield(p=0.0001).The phenolic acid content increased to 1.80 fold after extraction and purification with chloroform and ethyl acetate.Concerning the antioxidant activity,AHSL phenolic acid showed better free radical scavenging ability and ferric-reducing power than the ethanol extracts.Moreover,no significant difference could be observed in the hydroxyl radical scavenging effect between AHSL phenolic acid and tea polyphenols under the same concentration(p>0.05).More than 50%of DPPH free radicals and hydroxyl free radicals could be removed at the AHSL phenolic acid concentration of 100μg/mL.The results revealed that 60 Coγray irradiation combined with ethanol extraction is feasible,and the phenolic acid from AHSL has strong antioxidant activity in vitro.