AB-8大孔树脂纯化绿豆皮黄酮工艺优化及纯化前后抗氧化能力比较

采用AB-8大孔树脂初步分离纯化绿豆皮黄酮。分别对上样条件和洗脱条件进行优化，考察上样液质量浓度、上样液pH值、上样流速、以及洗脱剂体积分数、洗脱剂用量、洗脱流速对吸附解吸性能的影响，最终确定AB-8大孔树脂的分离纯化绿豆皮黄酮工艺为上样液质量浓度1.5?mg/mL、上样液pH5.0、上样流速1.0?mL/min；洗脱液乙醇体积分数70%、洗脱剂用量225?mL、洗脱流速2.0?mL/min，在此条件下分离纯化，绿豆皮黄酮纯度由27.95%提高到62.38%。经紫外-可见光谱扫描，出现黄酮类化合物特征峰带，经红外光谱扫描，光谱具备黄酮类物质特征官能团，验证了黄酮类物质的存在；利用扫描电镜对纯化前后黄酮类物质进行微观分析，得出被包裹的片状和粉粒状颗粒大部分被释放出来，这可能是导致纯化后黄酮类化合物纯度增高的原因。纯化后的绿豆皮黄酮与粗提物相比具有较高的抗氧化能力。

Optimization of Purification of Flavonoids from Mung Bean Coat by AB-8 Macroporous Resin and Comparison of Antioxidant Capacity of crude and purified Flavonoids

In this study, AB-8 macroporous resin was used to separate and purify flavonoids from mung bean coat. To establish optimized sample loading and the elution conditions, the influence of sample concentration, pH and flow rate as well as eluent concentration, volume and flow rate on the adsorption and desorption efficiencies was investigated. The optimal conditions determined were as follows: sample concentration, 1.5 mg/mL; pH, 5.0; flow rate, 1.0 mL/min; and 225 mL of 70% ethanol as eluent at a flow rate of 2.0 mL/min. Under these conditions, the purity of mung bean coat flavonoids increased from 27.95% to 62.38%. The existence of flavonoids were confirmed by their characteristic peaks in UV-visible spectra and characteristic functional groups identified by infrared spectroscopy. Scanning electron microscopy (SEM) showed that most flaky and powdery particles were released, which might contribute to the increased purity of flavonoids after initial purification. Compared with crude extract, the purified flavonoids had higher antioxidant ability.