Rheological Analysis of the Aggregation Behavior of a Soymilk Colloidal System

Abstract

The applicability of Einstein's and Krieger-Dougherty's theories of viscosity was examined using soymilk. Under dilute conditions, the relative viscosity of the emulsion with suspended oil bodies was proportional to the volume fraction of oil bodies, and the slope increased to greater than 2.5. Under concentrated conditions, the oil body suspension showed a Krieger-Dougherty-like dependency on volume fraction. The oil bodies in soymilk behaved as suspended substances and it was possible for us to predict the relative viscosity from the volume fraction of oil bodies. We also focused on the coagulation of soymilk by magnesium chloride and examined the validity of the novel viscous model, combining the extended Einstein equation and the Krieger-Dougherty equation, on the effect of cross-linkers. At 10°C and 25°C, the equation could be applied to various soymilk samples. In addition, the viscosity during coagulation could be predicted when the parameter h_c of the dispersion system was utilized.