超声辅助离子液体提取人参多糖工艺及其抗氧化活性

Ultrasonic-assisted ionic liquid extraction of ginseng polysaccharide and its antioxidant activity

摘要:

采用超声辅助离子液体提取人参中的人参多糖，通过单因素实验和正交实验确定了人参多糖的最优提取工艺条件；利用苯酚-硫酸法测定提取的人参多糖中总糖含量；以抗坏血酸为对照组，采用1,1-二苯基-2-三硝基苯肼自由基（DPPH·）、羟基自由基（·OH）、2,2′-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐自由基（ABTS·）测定提取的人参多糖的抗氧化活性。结果表明，超声辅助离子液体提取人参多糖的最佳工艺为：选择质量浓度为8 g/L的1-己基-3-甲基咪唑溴盐水溶液为提取溶剂，料液比（人参和离子液体水溶液之比）为1:40（g：mL），在80 ℃下超声辅助提取30 min，人参多糖提取量为172.89 mg/g，提取的人参多糖总糖含量（质量分数）为65.9%。采用高效液相色谱法对纯化后的人参多糖的单糖组成进行测定，得到人参多糖的单糖组成为：甘露糖，核糖，半乳糖醛酸，葡萄糖，半乳糖，阿拉伯糖，岩藻糖，物质的量比为4.8∶6.43∶10.13∶15.71∶0.5∶4.3∶1.1。人参多糖对DPPH·和·OH以及ABTS·具有一定的清除力，其抗氧化能力随质量浓度增大而增强，但弱于抗坏血酸。

Abstract:

Ginseng polysaccharide was extracted from ginseng under ultrasound, with ionic liquid as extraction solvent. The technical conditions were investigated based on single factor and orthogonal tests. The total sugar content in ginseng polysaccharide was determined by phenol sulfuric acid method. Meanwhile, compared with ascorbic acid, the antioxidant activity of ginseng polysaccharide was evaluated by scavenging DPPH free radical, hydroxyl free radical and ABTS free radical. The optimal extraction conditions of ginseng polysaccharide were shown as follows: the mass concentration of 1-hexyl-3- methylimidazolium bromide solution was 8 g/L which was used as extraction solvent, material-to-liquid ratio (ratio of ginseng to aqueous solution of ionic liquid)of 1:40 (g：mL), extratction time of about 30 min and extraction temperature at 80 ℃. The extraction amount of ginseng polysaccharide reached 172.89 mg/g. The total sugar content (mass fraction) in ginseng polysaccharide was 65.9%. The monosaccharide composition of ginseng polysaccharide was determined by HPLC after further purification，the monosaccharide groups of ginseng polysaccharide are: mannose, ribose, galacturonic acid, glucose, galactose, arabinose and fucose, the mass ratio of them was 4.8∶6.43∶10.13∶15.71∶0.5∶4.3∶1.1. The ginseng polysaccharide exhibited a certain ability of scavenging DPPH free radical, hydroxyl free radical and ABTS free radical. The antioxidant activity increased with the increase of the concentration of ginseng polysaccharide, which was inferior to ascorbic acid.