响应面法优化提取藜麦种子黄酮及抗氧化活性

Optimization of Extraction Technology of Flavonoids from Quinoa Seeds by Response Surface Methodology and Its Antioxidant Activities

研究藜麦种子总黄酮的最佳提取工艺及体外抗氧化活性。以藜麦种子为原料,在单因素试验的基础上,利用响应面分析法优化提取条件,得到具有显著性的拟合回归方程。探讨乙醇体积分数、料液比、浸提时间3个因素对藜麦种子总黄酮热回流提取的影响,对藜麦种子总黄酮的DPPH·清除能力和·OH自由基能力进行分析。结果表明,藜麦种子总黄酮的最佳提取工艺:提取时间59.42 min、料液比1∶29.46、乙醇浓度79.77%。在此条件下,藜麦种子黄酮提取率的理论值达0.2649 g/100 g。抗氧化性试验表明,藜麦种子中提取的总黄酮对DPPH·和·OH的清除率分别达90.89%和44.90%,其IC50(半抑制浓度)值分别为9.996μg/m L和56.639μg/m L。藜麦种子品种间总黄酮含量存在明显差异,其中品种"Shelly 25 Black"的总黄酮含量最高,达0.316 g/100 g。

The suitable extraction condition of flavonoids from quinoa seeds and the antioxidant activities of the ex- tracts were investigated in the study. On the basis of single factor test, the response surface methodology was applied to optimize the extraction conditions and the significant fitted regression equation was： consequently obtained. Meanwhile, the ethanol concentration, solid-liquid ratio and extraction time were selected to investigate the effects on the method of ethanol reflux extraction of flavonoids from quinoa seeds Additionally, the scavenging effects of flavonoids on free radicals such as DPPH. and .OH were subsequently analyzed. The results suggested that optimum extracting conditions consisted of extraction time 59.42 minutes, a ration of the powder to reagent of 1：29.46 and extracting reagent 79.77% ethanol. The extraction yields of flavonoids from quinoa seeds reached 0.2649 g/100 g under the above conditions. Moreover, the antioxidant experiment showed that flavonoids extracted from quinoa leaves exhibited a strong scavenging effect on DPPH. and .OH free radicals, with the removal rate 90.89% and 44.90% respectively, and its IC50 （half inhibitory concentration） was respectively up to 9.996 μg/mL and 56.639 μg/mL. Meanwhile, great variation in flavonoids content has been found in quinoa seeds among different varieties, of which variety ＇Shelly 25 Black＇ had the highest flavonoids content, reaching 0.316 g/100 g.