Polymerization model for prediction of heat-induced protein denaturation and viscosity changes in milk

A bicomponent polymerization model for heat-induced protein denaturation and viscosity changes in milk is presented. The model recognizes denaturation kinetics of beta-lactoglobulin (beta-lg) and the association between denatured beta-lg and casein micelles. The aim of the study was to develop a mathematical model based on physical and chemical fundamentals for prediction of the theology of milk products during thermal processes. The model reproduces both the degrees of denaturation of beta-lg and the viscosity change of skim milk heated at temperatures between 80 and 120 degrees C very well. In contrast td the volume fraction model of Snoeren, the polymerization model accounts for higher viscosities of milk heated at a higher temperature at the same denaturation degree of beta-lg. This confirms that, in addition to heat load, heating rate and temperature contribute to the theological properties of dairy products. The model developed will be a basis for future research in describing the relation between process variables and the functional properties of milk products.