不同提取方法对南酸枣果胶多糖理化性质及抗氧化作用的影响

Effects of Different Extraction Methods on the Physicochemical Properties and Antioxidant Activities of Pectic Polysaccharides from Choerospondias axillaris Fruit

分别采用水提法、酸法、碱法、草酸铵法从南酸枣果肉中提取果胶多糖,并比较不同提取方法对多糖理化性质及抗氧化作用的影响。结果表明,4种方法制备的多糖得率分别为20.31%、25.33%、24.54%、21.71%;中性糖含量分别为21.21%、26.31%、35.53%、32.09%;半乳糖醛酸含量分别为35.78%、29.64%、45.35%、39.44%;蛋白质含量分别为2.99%、5.49%、3.34%、5.86%。红外光谱图显示4种多糖都具有果胶的特征吸收峰,属于果胶类多糖。抗氧化研究表明,4种果胶多糖的自由基清除力及还原力均随样品浓度升高而增加,基本呈正相关。其中碱提法制备的果胶多糖,表现出相对较好的抗氧化性,其对DPPH·和·OH的IC50分别为3077μg/mL和3694μg/mL。

Four pectic polysaccharides were extracted by distilled water,hydrochloric acid,sodium hydroxide and ammonium oxalate,respectively,and the effects of different extraction methods on their physicochemical properties and antioxidant activities were compared.The results indicated that the yields of them were 20.31%,25.33%,24.54%,21.71%,the neutral sugar contents were 21.21%,26.31%,35.53%,32.09%,the galacturonic acid contents were 35.78%,29.64%,45.35%,39.44%,and the protein contents were 2.99%,5.49%,3.34%,5.86%,respectively.Infrared spectra showed that all the four polysaccharides had characteristic absorption peaks of pectin,which indicated that they all belonged to the pectic polysaccharides.The antioxidant studies showed that the free radical-scavanging capacity and reducing power of the four pectic polysaccharides increased with the increasing concentration,displaying a positive correlation.Among them,pectic polysaccharides prepared by alkali method showed relatively good antioxidant activities,and the IC50 values of DPPH·and·OH scavenging experiments were 3077μg/mL and 3694μg/mL,respectively.