超高压改性大豆蛋白与可溶性多糖复合物对乳液形成及稳定性的影响

Effect of Ultra-High Pressure Processing on the Formation and Stability of Emulsions Containing Soy Protein and Soluble Polysaccharide Complexes

通过研究超高压处理改性的柔性大豆蛋白与可溶性多糖复合物对乳液形成的影响,揭示复合物结构变化与乳状液稳定性的关系,采用激光共聚焦、动态激光散射、接触角测量仪和圆二色谱研究不同超高压处理改性大豆蛋白与可溶性多糖复合物形成乳液的微观结构、流体动力学半径、界面吸附特性和大豆蛋白超高压改性的空间结构变化。实验表明:随着压力的增加乳液粒径变小,乳滴形状规则、分布均匀,乳液表面负电荷增加;400 MPa处理的蛋白所形成复合物的乳化活性和乳化稳定性最大分别为18.33 m^2/g和30.2 min;不同超高压处理改变了大豆蛋白二级结构,影响了与可溶性多糖分子的键合,进而影响复合物在油-水界面吸附特性和乳液的界面压,结果证明超高压改性大豆蛋白与可溶性多糖复合物形成乳液的稳定性机制与乳液界面层分子结构的变化有关。

The present study was undertaken to explore the effect of ultra-high pressure(UHP)processing the formation of emulsions containing soy protein and soluble polysaccharide complexes and to reveal the relationship between the structural change and emulsion stability of the complexes.For this purpose,the changes in the microstructure,particle size distribution,interfacial adsorption properties and spatial structure of soy protein after UHP modification were studied using confocal laser technology,dynamic laser light scattering,contact angle measurement and circular dichroism.The experimental data showed that the droplet size of the emulsion became smaller,more regular in shape and more evenly distributed with increased pressure and the negative surface charge increased.UHP treatment at400MPa provided the maximum emulsifying activity and emulsion stability,which were18.33m2/g and30.2min,respectively.The secondary structure of soy protein changed after UHP treatments,thereby influencing its bonding with soluble polysaccharides and the adsorption properties of protein at the oil-water interface and the interface pressure of the emulsion.These results uncovered that the stability mechanism of emulsions containing ultra-high pressure-modified soy protein and soluble polysaccharides may related to the change in the molecular structure of the interfacial layer in emulsions.