确定辣木叶中总抗氧化物质的最佳提取条件，并评价其体外抗氧化活性。在单因素试验结果的基础上，以DPPH自由基清除率为评价指标，通过采用正交试验研究乙醇体积分数、提取温度、料液比和提取时间4个因素对辣木叶抗氧化物质抗氧化活性的影响。结果表明：最佳提取条件为提取温度为90 ℃、料液比为1:30、乙醇体积分数为60%、提取时间为1.5 h，在此条件下，辣木叶中多酚含量为69.36±0.58 mg/g，黄酮含量为53.72±0.48 mg/g，DPPH自由基清除率为57.83%±0.14%。辣木叶抗氧化物质粗提物对DPPH、ABTS和·OH自由基具有具有较好的清除效果，还原能力较弱，其EC50值分别为86、31和140 μg/mL，对DPPH、ABTS和·OH自由基清除率分别达到相同质量浓度BHT的98.26%、99.04%和96.63%，并与辣木叶粗提物质量浓度存在一定的量效关系。

To optimize the extraction conditions of antioxidant components from Moringa oleifera leaves and evaluate the antioxidant activity. Based on the results of univariate experiments, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging rate was used as the evaluation index. Effects of ethanol concentration, extraction temperature, the ratio of liquid to material and extraction time on the antioxidant activity of the antioxidant components from Moringa oleifera leaves were studied by orthogonal test. The results showed that the optimal parameters of extraction were as follows: extraction temperature of 90 ℃, the ratio of liquid and material of 1:30, ethanol concentration of 60% and extraction time of 1.5 h. Under these conditions, the flavonoids and polyphenol content were 69.36±0.58 mg/g and 53.72±0.48 mg/g, respectively, and the clearance of DPPH free radical was 57.83±0.14%. The crude extracts obtained from Moringa oleifera leaves had strong scavenging capacity on DPPH, 2,2’-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and hydroxyl radical (·OH) free radical in a dose-dependent manner, but its reducing power was weak. The EC50 values of crude extracts were 86, 31 and 140 μg/mL, respectively. The scavenging impact of the three radicals accounts for 98.26%, 99.04% and 96.63% of butylated hydroxytoluene (BHT), respectively.

广西科学研究与技术开发计划（桂科攻15248003-18）；中国热带农业科学院基本科研业务费专项资金（1630122017016）；中国热带农业科学院基本科研业务费专项资金（1630122016007）