Inelastic rheokinetic model for whey protein suspensions

CLAUDIO L. A. BERLI, JULIO A. DEIBER

LATIN AMERICAN APPLIED RESEARCH

UNS-CONICET

Año: 1997 vol. 27 p. 219 - 227

0327-0793

This work is concerned with the thermal evolution of the aqueous suspensions of whey proteins from commercial whey protein concentrates. The viscosity of a semiconcetrated suspension (protein volume fraction around 10%) at different shear rates is studied experimentally when the temperature is varied linearly with time. The structure of the suspension changes through different temperature ranges. An inelastic rheokinetic model is proposed, which is based on the concept of flow-induced variation of the microstructure. In addition to Brownian diffusion, our model considers denaturation kinetics of protein fractions, rapid molecular aggregation due to protein denaturation and mechanical breakdown of microstructure. The model predicts well the viscosity as a function of temperature, global degree of protein denaturation and shear rate.