不同流体界面上大豆11S球蛋白吸附膜膨胀黏弹性的比较研究

采用轴对称滴形分析法(ADSA)检测了空气/水、正十二烷/水和大豆油/水界面上不同浓度(0.001%~0.1%)的大豆11S球蛋白吸附膜的表面膨胀黏弹性随吸附时间的变化。研究表明,在体相蛋白溶液pH8.0和离子强度0.05mol/L的恒定条件下,随着吸附时间的延长,表面膨胀弹性增大,膨胀弹性明显大于膨胀黏性。从表面流变学的角度分析,空气/水和大豆油/水界面上大豆11S球蛋白吸附膜实际上是弹性的,膨胀弹性随液滴体相蛋白浓度的增加而增大,受界面类型的影响很大。空气/水界面上吸附膜的膨胀黏弹性最大,而大豆油/水界面上吸附膜的膨胀黏弹性最小。

Comparison of dilatational elasticity and viscosity of soy 11S globulin adsorbed films at different fluid interfaces

Surface dilatational elasticity(Ed) and viscosity (Ev) of soy 11S globulin films adsorbed at air-water,n-dodecane-water,and soy oil-water interface were measured as a function of adsorption time by axisymmetric drop shape analysis method(ADSA).The experiments were performed at various concentration (from 0.001% to 0.1%,W/W).The pH and ionic strength in the drop bulk phase were maintained at 8 and 0.05 mol/L respectively.The results indicated that Ed increased with adsorption time for all interfaces studied,adsorption films exhibited larger dilatational elasticity than Ev and thus were practically elastic from the surface rheological point of view.Ed increased with the protein concentration in the drop bulk phase,significantly depended on the nature of the interfaces.Ed and Ev were the largest at the air/water interface,and they were the smallest at soy oil-water interface.