超声波提取核桃内种皮多酚的响应面优化及其抗氧化研究

摘要

以核桃内种皮酚类物质提取得率为响应值,设计提取温度、提取时间以及液固比3因素3水平的Box-Behnken试验,采用响应面法确定超声波提取核桃内种皮酚类物质的最佳工艺,同时通过自由基清除能力和还原力试验,评价内种皮酚类物质的抗氧化性能.结果表明:0.1g核桃内种皮粉末在固定超声波功率为100W下的最佳提取工艺为提取温度53℃,提取时间55 min,液固比58∶1 (mL∶g),总多酚得率为30.79％.相同浓度下的核桃内种皮酚类物质抗氧化性明显高于天然抗氧化剂Vc,其清除1,1-二苯基-2-三硝基苯肼(DPPH)自由基的半数抑制浓度(IC50)值为3.38 mg/L,小于Vc的4.72 mg/L;清除2,2′-联氮-双(3-乙基苯并噻唑-6-磺酸)(ABTS)自由基的IC50值为36.44 mg/L,小于Ve的82.23 mg/L.%Using temperature,time and liquid/solid ratio as independent variables,a Box-Behnken design was applied to optimise the extraction of phenolics from walnut pellicle by using response surface methodology.The results indicated that when the ultrasonic power was set at 100 W,the optimum ultrasonic extraction conditions for walnut pellicle phenolics were as follows:extraction temperature 53℃,extraction time 55 min,liquid/solid ratio 58∶1 (mL∶ g).Under this optimum condition,the extraction yield was 30.79％.It was found that the phenolics extracted from walnut pellicle behaved stronger antioxidant activities than ascorbic acid when they were under the same concentration.The IC5o values of scavenging activity of pellicle phenolics on DPPH free radicals and ABTS were 3.38 mg/L and 36.44 mg/L,respectively,while those of ascorbic acid were 4.72 mg/L and 82.23 mg/L,respectively.