食品科学 ›› 2010, Vol. 31 ›› Issue (19): 157-160.doi: 10.7506/spkx1002-6630-201019033

• 基础研究 • 上一篇    下一篇

不同直链/ 支链比的玉米淀粉分子质量及其构象

张攀峰,陈 玲,李晓玺* ,李 琳,刘国琴,苏健裕   

  1. 华南理工大学轻工与食品学院
  • 收稿日期:2010-06-30 修回日期:2010-09-27 出版日期:2010-10-15 发布日期:2010-12-29
  • 通讯作者: 李晓玺 E-mail:xxlee@scut.edu.cn
  • 基金资助:

    科技部农业科技成果转化基金项目(2009GB23600523);国家“863”计划项目(2007AA10Z312);
    中央高校基本科研业务费专项(2009ZZ0021);中国博士后基金项目(20070420775)

Molecular Mass and Conformation of Corn Starches with Ddifferent Amylose/Amylopectin Ratios

ZHANG Pan-feng,CHEN Ling,LI Xiao-xi*,LI Lin,LIU Guo-qin,SU Jian-yu   

  1. College of Light Industry and Food Science, South China University of Technology, Guangzhou 510640, China
  • Received:2010-06-30 Revised:2010-09-27 Online:2010-10-15 Published:2010-12-29
  • Contact: LI Xiao-xi E-mail:xxlee@scut.edu.cn

摘要:

采用凝胶渗透色谱(GPC)和十八角度激光光散射(MALLS)技术,以二甲基亚砜为流动相测定蜡质玉米淀粉、普通玉米淀粉、直链/ 支链比1:1 的高直链玉米淀粉(G50)、直链/ 支链比4:1 的高直链玉米淀粉(G80)的分子质量及其分布以及在二甲基亚砜(DMSO)溶液中的均方根旋转半径和构象。结果表明:分子质量最大的是蜡质玉米淀粉,其重均分子质量达到了1.416 × 108g/mol,其次是普通玉米淀粉2.744 × 107g/mol 与G50 1.026 × 107g/mol,最小的是G80 的3.992 × 106g/mol;均方根旋转半径也是随着直链淀粉含量的增加依次减小;蜡质玉米淀粉在DMSO 溶液中的构象是较为紧密的无规则卷曲型,其他3 种玉米淀粉的构象均为球型。

关键词: 玉米淀粉, 凝胶渗透色谱, 激光光散射, 分子质量分布, 分子构象

Abstract:

The determination of molecular mass, molecular mass distribution, mean square radius of gyration and conformation using gel permeation chromatography coupled with multi-angle laser light scattering (GPC-MALLS) with refractive index detector with DMSO as the mobile phase was carried out for waxy, common, G50 (with 50% amylase content) and G80 (with 80% amylase content) corn starches. The results showed that the weight-average molecular masses (Mw) of waxy, normal, G50 and G80 corn starches were 1.416 × 108, 2.744 × 107, 1.026 × 107, 3.992 × 106 g/mol, respectively. Similarly, higher-amylose corn starch had smaller mean square radius of gyration. The conformation of waxy corn starch was compact random coil and the three others were compact globular structure in DMSO.

Key words: corn starch, gel permeation chromatography, laser light scattering, molecular mass distribution, molecular conformation

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