食品科学 ›› 2012, Vol. 33 ›› Issue (15): 166-170.

• 基础研究 • 上一篇    下一篇

大豆分离蛋白-麦芽糊精聚合物的结构特征

孙 鹏,程建军*   

  1. 东北农业大学食品学院
  • 收稿日期:2012-04-12 修回日期:2012-07-10 出版日期:2012-08-15 发布日期:2012-09-07
  • 通讯作者: 程建军 E-mail:cheng577@163.com

Structural Characterization of Soybean Protein Isolate-Maltodextrin Polymers

  • Received:2012-04-12 Revised:2012-07-10 Online:2012-08-15 Published:2012-09-07

摘要: 以大豆分离蛋白(SPI)和麦芽糊精(MD)为原料制备不同接枝度的SPI-MD聚合物,通过巯基含量测定、SDS-PAGE凝胶电泳、差式量热扫描、傅里叶红外光谱、电子扫描显微镜和圆二色谱分析SPI和不同接枝度(10%、20%、30%、40%)SPI-MD聚合物结构特征的变化。结果表明:随着接枝度的提高,SPI-MD聚合物的巯基含量逐渐降低、变性温度先提高后降低、α-螺旋和β-转角的结构含量减少以及β-折叠和无规则卷曲结构含量增多;并且证明了SPI和MD是以共价键的结合方式聚合及SPI中7S与MD反应活性较高;SPI-MD聚合物的微观结构松散,呈多孔状。

关键词: 大豆分离蛋白, 麦芽糊精, 聚合物, 结构特征

Abstract: The sulphydryl group contents of soy protein isolate (SPI) and its polymer complexes with maltodextrin (MD) at different degrees of grafting (10%, 20%, 30% and 40%) were determined. At the same time, SPI and four polymer complexes were analyzed by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE), differential scanning calorimeter, Fourier transform infrared spectroscopy, scanning electron microscope and circular dichroism. The results showed that SPI-MD polymers revealed a gradual decrease in sulphydryl group content, an initial increase and then a decrease in denaturation temperature, a reduction in α-helical and β-turn and an increase in β-sheet and random coil structure with increasing grafting level. SPI molecules could be grafted with MD molecules by covalent bonds between 7S in SPI molecules and MD. The structure of SPI-MD was porous and loose.

Key words: soyprotein isolate, maltodextrin, polymer, structural characterization

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