本研究目的是确定辣木籽多酚的最佳提取工艺,并对其抗氧化活性进行初步研究。利用响应面法对辣木籽多酚的提取工艺进行了优化,以多酚提取量为指标,就乙醇体积分数、浸提温度、浸提时间和料液比进行了单因素实验,基于Box-Behnken和Design-Expert V8.0.6,进行了四因素三水平响应面法优化,并测定了辣木籽多酚提取物中植物活性成分含量以及其体外抗氧化活性。结果表明,回归模型极为显著(p<0.0001),可以对辣木籽多酚含量进行很好的分析和预测;优化后的最佳提取条件为:乙醇体积分数66.78%、浸提温度75.9 ℃、料液比1:12 g/mL、浸提时间1.24 h,此条件下模型预测的最大提取量为4.134 mg/g,实测值为(4.125±0.017) mg/g,与预测值无显著性差异。辣木籽多酚提取物具有较强的体外抗氧化活性,其总抗氧化活性、DPPH·和ABTS+·清除能力、FRAP还原力分别为(43.52±8.47)、(0.571±0.017)、(1.413±0.032)、(0.731±0.040) mg TEs/g extract。此优化工艺可行,辣木籽多酚具有一定的抗氧化能力。
The objective of this study is to determine the optimum extraction conditions of polyphenols from Moringa oleifera Lam. seeds and preliminarily evaluate their antioxidant activities. The optimum extraction conditions of polyphenols from Moringa oleifera Lam. seeds were investigated by response surface methodology. With the extraction of polyphenols as the target,the single factor test was carried out on the alcohol concentration,extraction temperature,extraction time and solid/liquid radio. Based on Box-Behnken and Design-Expert V8.0.6,four-factor three-level response surface methodology was carried out,and the phytochemicals in the extract of Moringa oleifera Lam. seeds were measured and their antioxidant activities in vitro were also determined. The results suggested that the regression model was very significant(p<0.0001),which could be used for the analysis and prediction of the polyphenol content of Moringa oleifera Lam. seeds. The optimal extraction conditions were as follows:66.78% ethanol as extraction solvent,an extraction temperature of 75.9℃,a solid/liquid radio of 1:12 (g/mL)and an extraction time of 1.24 h. Under these optimized conditions,the extraction yield of polyphenols was 4.134 mg/g,and the measured value was(4.125±0.017) mg/g,which was not significantly from the predicted value. The extract of Moringa oleifera Lam. seeds showed antioxidant activity in vitro. The total antioxidant activity,DPPH·free radical and ABTS+·free radical scavenging ability,and FRAP reducing force were separately(43.52±8.47),(0.571±0.017),(1.413±0.032)and(0.731±0.040) mg TEs/g extract. This optimization process is feasible,the polyphenols from Moringa oleifera Lam. seeds have a certain antioxidant activities.