食品科学

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高压均质对大豆蛋白-磷脂复合体系结构及理化/功能性质的影响

毕 爽,李 杨,隋晓楠,王中江,齐宝坤,江连洲*   

  1. 东北农业大学食品学院,黑龙江 哈尔滨 150030
  • 出版日期:2017-03-15 发布日期:2017-03-28

Effect of High Pressure Homogenization on Structural, Physicochemical and Functional Properties of Soybean Protein-Lecithin Composite System

BI Shuang, LI Yang, SUI Xiaonan, WANG Zhongjiang, QI Baokun, JIANG Lianzhou*   

  1. College of Food Science, Northeast Agricultural University, Harbin 150030, China
  • Online:2017-03-15 Published:2017-03-28

摘要: 以大豆蛋白-磷脂复合体系为研究对象,采用圆二色谱表征复合体系构象变化,采用乳化性及乳化稳定性测定、表面疏水性及粒度分析等解析高压均质对复合体系中大豆蛋白二级结构的变化与理化/功能性质表达的影响。结果显示:高压均质会显著改善复合体系的功能性质如乳化性和乳化稳定性。随着均质压力升高,体系中大豆蛋白表面疏水性显著提高,说明疏水基团暴露明显,蛋白质与磷脂间的相互作用程度增加。复合体系的体积平均粒径由未均质时的33.21 μm降至3.61 μm,粒径分布均匀,整体向小粒径方向移动。圆二色谱结果显示高压均质改变了蛋白质-磷脂复合体系的构象,说明蛋白质和磷脂间发生相互作用,但当均质压力进一步增加,和未经处理的样品相比,样品中的α-螺旋含量略有下降,同时功能性质稍有提高。

关键词: 高压均质, 大豆蛋白, 卵磷脂, 结构性质, 功能性质

Abstract: The objective of this research was to reveal the effect of high pressure homogenization on the change in protein secondary structure and physicochemical and functional properties of soybean protein isolate (SPI)-lecithin system through characterizing conformational changes by circular dichroism spectroscopy and through measuring emulsifying capacity, emulsion stability, surface hydrophobicity and droplet size distribution. The results showed that high pressure homogenization improved emulsion activity index and emulsion stability index of the complex system significantly. The surface hydrophobicity of SPI significantly increased at higher pressure of homogenization, implicating considerable exposure of surface hydrophobic groups and increased interaction between soybean protein and phospholipid. After the homogenization treatment, the average droplet diameter of the composite system decreased from 33.21 to 3.61 μm, and the droplet size distribution was uniform with a slight shift towards smaller droplet sizes. Circular dichroism spectral results showed that high pressure homogenization resulted in conformational changes of the composite system, implying the occurrence of interaction between protein and lecithin. However, with further increasing homogenization pressure, only a little reduction in α-helix content was observed compared with untreated samples.

Key words: high pressure homogenization, soybean protein, lecithin, structural properties, functional properties

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