A RHEOLOGICAL MODEL FOR SODIUM CASEINATE

The rheological behaviour of commercial sodium caseinate was determined at various temperatures (25-65-degrees-C) and concentrations (10-16%), and was found to be most adequately described by the Bingham model. The effect of temperature on the viscosity followed an Arrhenius relationship, whereas the effect of concentration followed an exponential relationship. A model to predict the viscosity as a function of temperature and concentration is presented, which considers also the effect of concentration on the activation energy. Sodium caseinates from other commercial sources and one manufactured using extrusion were assessed and their rheological behaviour could be adequately predicted by the Bingham model. The model developed would be useful for sodium caseinate manufacture and applications.