多抗氧化指标响应面法优化茶枝柑皮提取工艺

Optimization of extraction process for Citrus reticulata 'Chachi'peel by multiple antioxidative indexes of response surface methodology

以清除羟自由基能力、清除1,1-二苯基-2-苦肼基自由基(DPPH自由基)和还原铁离子能力(FRAP值)作为提取工艺的评价指标。单因素实验考察提取时间、提取温度、乙醇浓度和液料比对茶枝柑皮提取物体外抗氧化能力的影响。在单因素实验的基础上,采用软件Design-Expert7.0以Box-Behnken法设计4因素3水平6中心点响应面实验研究响应值以及最佳变量的组合。得出茶枝柑皮抗氧化物的最佳提取工艺为:液料比17:1,42%(V/V)乙醇于62℃下水浴回流3.1h。三次重复实验所得提取物产率为(37.32±1.21)g/100g,羟自由基清除率为67.83%±7.87%,DPPH自由基清除率为54.00%±3.42%,总抗氧化能力值(FRAP值)为(44.62±2.67)μmol/L。测定提取物的总黄酮含量为18.84mg/100g,总多糖含量为4.024mg/100g。所得茶枝柑皮抗氧化物的提取条件可靠。

Hydroxyl radical scavenging ability,1,1-diphenyl-2-picrylhydrazyl（DPPH radical）scavenging ability and the reducing power to Fe3＋（ferric reducing/antioxidant power assay,FRAP value）as the evaluation indexes of extraction process,the effects of extraction time,extraction temperature,ethanol concentration and liquid to solid ratio on the in-vitro antioxidant ability of Citrus reticulata ’Chachi’ peel extract were determined by single factor tests.Based on the single-factor tests,the Design-Expert 7.0 software was used with Box-Behnken method（4 factors and 3 levels 6 center response surface experiments）to study the response values and the best combination of variables.The optimum antioxidant extraction conditions were obtained as following：17：1 as liquid/solid ratio,42%（V/V）ethanol concentration,62℃ water-bath and refluxed 3.1h.The results of three repeated experiments indicated that the extraction yield as（37.32±1.21）g/100g,hydroxyl radical scavenging rate as 67.83%±7.87%,DPPH radical scavenging rate as 54.00%±3.42%,the reducing power to Fe3＋（FRAP value）as（44.62±2.67）μmol/L.The contents of extract were determined that total flavonoids of 18.84mg/100g,total polysaccharide of 4.024mg/100g.The extraction conditions of Citrus reticulata ’Chachi’peel antioxidant extracts were reliable.