| Abstract
| - Recently, it was found that the addition of chitosan, a cationic polymer, to whole or skim milk producesthe destabilization and coagulation of casein micelles which takes place without modifications in themilk pH or in the stability of most of the whey proteins. In the present work, Monte Carlo simulationsare employed to show that the phase separation of casein micelles induced by chitosan can beexplained by a depletion mechanism, where an effective attraction between the casein micelles isinduced by the presence of chitosan molecules. This interaction is described on the basis of Vrij'smodel, where the depletion of polymer from the gap between neighboring casein micelles originatesan effective attractive interaction that leads to a phase transition. This model, that considers volumerestriction effects, accounts for several qualitative and even quantitative aspects of the experimentaldata for the coagulation of casein through chitosan addition. Keywords: Casein micelles; chitosan; depletion mechanism; Monte Carlo simulation
|
