Phase Separation and Gel Formation in Kinetically-Trapped Guar Gum/Acid Milk Gels

The main objective of this research was to explore more precisely various conditions of phase separation and gelation kinetics and gain knowledge on the most important factors influencing particle dynamics. Polysaccharides such as guar gum, locust bean gum, xanthan gum or pectin are often used in acid milk gels to modify the rheological properties. However, the addition of guar gum to skim milk at the natural pH of the mixture results in a segregative phase separation between the casein micelles and guar gum, described as a depletion-flocculation phenomenon. In order to ‘freeze’ the droplet evolution at an intermediate state of phase separation, gelation can be used: the gelation process freezes the development of the two-phase structure far from the thermodynamic equilibrium conditions.