(563i) Kinetics of Soy Protein Adsorption at the Fluid Interface: Interfacial Rheology

In this work, we used interfacial rheology to probe the soy protein globulins adsorption at the water/oil interface. We determined different energy barriers against the protein adsorption: diffusion, surface pressure, and electrostatic repulsion. It was quite clear that at early stages of adsorption, the kinetics were diffusion-controlled, with interface concentration~t^0.5. However, as the protein continued to travel to the fluid interface, the energy barriers arising from surface pressure and electrostatic repulsion appeared to affect the process. The DLVO theory was used to explain the effect of pH and ionic strength on the adsorption kinetics. Also, by adjusting the centrifuge process, protein particles with four different average particle diameters (0.1-10.0 um) were prepared to examine the effect of the particle size on these energy barriers.