提取方法对马铃薯渣果胶结构特征及特性的影响

对酸处理提取(acid-treated extraction,ATE)、酶处理提取(enzyme-treated extraction,ETE)和盐沉析提取(salt-treated extraction,STE)的马铃薯渣果胶抗氧化活性及其特性进行研究,发现3种提取方法中,STE果胶提取率最高。流变特性结果显示,ATE果胶具有最高的初始黏度。结构特征表明,STE多糖呈光滑致密的块状结构;ETE果胶呈不规则褶皱的形状;ATE多糖呈棉絮片状,较其他2种其表面结构松软。3种多糖的单糖组成各不相同,ATE的果胶主要由葡萄糖、半乳糖、阿拉伯糖以及少量的鼠李糖和木糖组成;ETE的果胶主要的单糖组成为葡萄糖和半乳糖;STE的果胶主要的单糖组成为葡萄糖、半乳糖、阿拉伯糖。ATE果胶(51481 Da)分子质量最大,其次为ETE果胶(14593 Da)、STE果胶(11669 Da)。抗氧化特性显示,ATE果胶表现出较高的清除DPPH自由基的能力,STE具有较高的清除·OH和·O₂^-的能力。

Extraction methods on structure and properties of pectin from potato residue

The effects of salt-extraction(STE),acid-treated extraction(ATE),and enzyme-treated extraction(ETE)on the antioxidant activities and characteristics of pectin from potato residue were investigated in this study.Among different methods,the extraction rate of pectin from STE was the highest.And the results of rheological properties showed that ATE pectin had the highest initial viscosity.The STE pectin showed smooth and dense block structure,and ETE pectin exhibited an irregular fold shape;meanwhile,the ATE pectin showed a cotton wadding sheet shape,as observed by scanning electron microscopy(SEM).The surface structure of the ATE pectin was softer than the other two.The monosaccharide composition of the three pectins was different.The pectin of ATE was mainly composed of glucose,galactose,arabinose and a small amount of rhamnose and xylose;the main monosaccharide groups of ETE pectin were glucose and galactose,and STE pectin mainly consisted of glucose,galactose and arabinose.The ATE pectin had the largest molecular weight(51481 Da),reduced by the order of the ETE pectin(14593 Da)and STE pectin(11669 Da).The antioxidant properties showed that ATE pectin showed higher DPPH scavenging ability,and STE had higher scavenging capacity of hydroxyl radical and superoxide anion.