梨中碱溶性果胶纳米结构在纯氧贮藏中的变化

Changes in Nanostructure of Alkaline-Soluble Pectin in Pear Stored in Pure Oxygen

利用原子力显微镜观察了贮藏在2℃和95%相对湿度下0、10和30 d的皇冠梨中碱溶性果胶(ASP)纳米结构的变化。原子力显微图像结果显示,ASP分子及聚集体在贮藏中逐渐分离,果胶小链宽出现的频率在空气和纯氧贮藏中都呈增加趋势,但是对照组的增加趋势更为明显,表明纯氧贮藏可抑制ASP分子的降解。ASP果胶链宽度基本单元为:23.538、19.531和15.625 nm;基本单元之间的平行交联或缠绕结构是梨中ASP分子结构的基本信息。

The changes of nanostructure degradation of alkaline-soluble polyuronides（ASP） in pears（Pyrus bretschneideri Rehd cv. Huangguan） were examined during 30 days of storage in air（control） and pure oxygen at 2℃and 95%relative humidity.Qualitative and quantitative information of ASP polymers was determined by atomic force microscopy（AFM） on day 0,10 and 30.Results showed that the frequency of small width ASP increased in all treatments over storage time,but was higher in control,indicating pure oxygen treatment inhibited the degradation of ASP molecules and the aggregate separation.Widths of ASP chains consisted of three basic units with widths of 15.625,19.531 and 23.538 obtained from the AFM determination.These conclusions also revealed that parallel linkages or intertwists between the basic units are fundamental structural conformations of ASP molecules.