南瓜多糖的分级醇沉与抗氧化活性研究  

Ethanol Fractional Precipitation and Antioxidant Activity of Pumpkin Olysaccharides

作　　者：李璐[1,2] 梁莉 李全宏[1,2] LI Lu;LIANG Li;LI Quanhong(College of Food Science and Nutritional Engineering, China Agricultural University （Beijing 100083;Fruits and Vegetables Processing Key Laboratory （Beijing 100083)

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083 [2]国家果蔬加工重点实验室,北京100083

出　　处：《食品工业》2018年第5期223-226,共4页The Food Industry

基　　金：公益性行业(农业)科研专项经费项目(201303112)

摘　　要：以新鲜南瓜为原料,经热水浸提后以不同体积分数乙醇溶液(60%,70%,80%和90%)分级沉淀,依次得到4种南瓜多糖样品(PPA-60,PPA-70,PPA-80和PPA-90),为探究不同组分间的差异,分别测定其总糖含量、蛋白含量、半乳糖醛酸含量及单糖组成,并利用红外和紫外光谱进一步分析分级醇沉产物之间的特性差异。结果表明,南瓜多糖PPA-60,PPA-70,PPA-80和PPA-90均为结合蛋白的多糖复合物,其中70%,80%乙醇沉淀的多糖含量较高(PPA-70>PPA-80>PPA-90>PPA-60),60%乙醇沉淀的样品蛋白含量显著高于其他组;单糖检测结果显示4种多糖样品均由阿拉伯糖、木糖、甘露糖、葡萄糖和半乳糖组成,但单糖组成比例存在差异;4种多糖样品均具有一定的抗氧化活性,抑制羟自由基的能力随着乙醇体积分数的升高逐渐增大(PPA-90>PPA-80>PPA-70>PPA-60)。With fresh pumpkin as the raw material,pumpkin polysaccharides which were extracted with hot water were fractionated by different gradient concentrations of ethanol（60%,70%,80% and 90%） into four precipitation fractions.To explore the differences between different components,the contents of sugar,protein,galacturonic acid and monosaccharide composition were determined,UV and IR spectroscopy analysis were run simultaneously to determine their spectroscopy properties.The results indicated that all four fractions were combined with a certain amount of protein and the samples precipitated by 70% and 80% ethanol had higher sugar content,the samples precipitated by 60% ethanol had the highest protein content.All four fractions were composed of arabinose,xylose,mannose,glucose and galactose,but their proportion of monosaccharide had some differences.All four fractions had certain antioxidant activity,and the ability of inhibiting hydroxyl free radicals were gradually increasing with the increase of ethanol concentration.

关 键 词：南瓜多糖 分级醇沉 单糖组成 抗氧化 

分 类 号：TS201.2[轻工技术与工程—食品科学]