多糖分子质量对大豆蛋白聚集体/葡聚糖混合体系微观结构的影响

Effect of Molecular Weight of Polysaccharide on Microstruc-tures of Heat Induced Soy Protein Aggregate/Dextran Mixtures

采用共聚焦激光扫描显微镜观察了室温下、pH 7.0时不同尺寸大小的大豆蛋白热聚集体和不同分子质量的葡聚糖混合体系的微观结构,并以天然大豆蛋白和葡聚糖混合体系的微观结构作对照。结果表明:葡聚糖分子链的排空相互作用使得蛋白质聚集体间产生了有效而不均匀的交联;蛋白质聚集体的尺寸增加和/或葡聚糖分子质量的增加促进了蛋白质富集区域的交联。对其共聚焦激光扫描图像进行灰度水平变化方差分析和灰度直方图分析表明,不同混合物间微观结构上具有显著性差异。

The microstructures of mixed systems of heat-induced soy protein aggregates with different size and dextran with different molecular weight have been observed by confocal laser scanning microscopy（CLSM） at room temperature（25 ℃） and pH 7.0,with native soy protein/dextran system as the comparison.Results：The depletion interaction of the dextran chains induces the inhomogeneous association of protein-rich areas.The increasing of the size of soy protein aggregates and/or the molecular weight of dextran accelerate the association of protein-rich areas.The image analysis based on the CLSM images shows that the variance of the grey values and the histograms of the grey values are different significantly among the different mixed systems.