响应面法优化南瓜籽中抗氧化物提取工艺

Response Surface Method for Optimizing the Extraction Process of Antioxidant from Pumpkin Seeds

南瓜籽用石油醚脱脂处理后,残渣经过乙醇回流得到抗氧化提取物。通过单因素试验和Box-Benhnken Design中心组合试验设计,以南瓜籽抗氧化提取物的提取率为检验指标,以乙醇浓度、液料比、提取时间、提取温度为自变量,采用4因素3水平响应面法(RSM),旨在优化南瓜籽中抗氧化物的提取工艺。确定南瓜籽中抗氧化提取物的提取率,研究了提取物的DPPH自由基的清除能力和还原能力。获得最佳提取条件为:乙醇70%,液料比20∶1 mL/g,提取时间120 min,提取温度80℃。在最佳提取条件下,进行了3次验证试验,南瓜子抗氧化物的提取率为15.11%,与预测值15.008%接近,说明该模型可以较好地反应南瓜籽提取物的最佳提取条件。南瓜籽提取物具有较好的自由基清除能力和还原能力,表现出较强的抗氧化活性。

After the pumpkin seeds degreased with petroleum ether,the residue was extracted by ethanol reflux.Based on the design principle of single factor experiment and box-benhnken design center combined experiment,the extraction rate was taken as the evaluation index.The independent variables were ethanol concentration,liquid-solid ratio,extraction time,and extraction temperature.The extraction process of pumpkin seeds was optimized by 4-factor 3-level response surface method(RSM).The extraction rate of antioxidant extracts from pumpkin seeds was determined and the scavenging capacity and reducing capacity of DPPH free radical were studied.The optimal extraction conditions were obtained as follows:70%ethanol,liquid/material ratio 20:1 mL/g,extraction time 120 min,extraction temperature 80℃.Under the optimal extraction conditions,three verification tests showed that the extraction yield of pumpkin seeds was 15.11%,which is close to the predicted value of 15.008%,indicating that the model could well reflect the optimal extraction conditions of pumpkin seed extract.Pumpkin seed extract has good DPPH free radical scavenging ability and reduction ability,and shows strong antioxidant activity.