芒果皮渣多酚的提取分离及抗氧化活性分析

以芒果皮渣为原料,通过单因素实验优选粗多酚的提取方法和工艺参数;采用不同极性有机溶剂萃取粗多酚,筛选多酚含量最高的组分,并通过HPD100型大孔树脂分离纯化;进一步,采用LC-Q-TOF-MS法对纯化组分初步定性并比较了不同溶剂萃取相和纯化组分的体外抗氧化活性。结果表明,超声辅助法对芒果皮渣多酚的提取效果较好,最佳提取条件为:乙醇浓度80%、浸提时间1.5 h、浸提温度60℃、超声功率250 W、液料比30:1 mL/g,在此条件下,多酚得率为9.68%;乙酸乙酯相所得多酚含量最高,达到254.41 mg/g;从树脂纯化组分中共鉴定出17种化合物,主要包括黄酮、黄酮醇、酚酸和鞣质等,具有优异的抗氧化活性,其清除DPPH自由基、ABTS+自由基、羟自由基和超氧阴离子自由基的IC50值分别为0.191×10-3 mg/m L、0.081 mg/mL、0.43 mg/mL和0.63mg/m L。表明乙酸乙酯相中的纯化组分是深入挖掘芒果皮渣抗氧化功效的物质基础。

Extraction, Separation and Antioxidant Activity of Polyphenols from Mango Pomace

Using mango pomace as the raw material, the extraction method and process conditions of crude polyphenols were determined by single factor experiments. Crude polyphenols were extracted with organic solvents of different polarities to screen the components with the highest contents. These screened components were separated and purified by HPD100 macroporous resin. Furthermore, the purified components were qualitatively analyzed by LC-Q-TOF-MS, and comparison was made on the in vitro antioxidant activities of the extraction phases obtained by different solvents and the purified components. The results showed that ultrasonic-assisted extraction was more effective, with the optimal extraction conditions as: ethanol concentration 80%, extraction time was 1.5 h, extraction temperature was 60 ℃, ultrasonic power was 250 W, and the liquid-to-material ratio 30:1(V/W). Under these conditions, the yield of polyphenols was 9.68%. The content of polyphenols extracted by ethyl acetate was the highest(254.41 mg/g). A total of 17 compounds were identified from the purified components obtained by resin, which mainly included flavones, flavonols, phenolic acids and tannins, and had excellent antioxidant activities. The IC50 values for the DPPH, ABTS+, hydroxyl and superoxide anion radical scavenging assays were 0.191×10-3, 0.081, 0.43 and 0.63 mg/mL, respectively. These results indicated that the purified components in the ethyl acetate phase were the material basis for the antioxidant activities of mango pomace.