Effect of xanthan structure on its interaction with locust bean gum: Toward prediction of rheological properties

Xanthan (X) and locust bean gum (LBG) are well known to exhibit strong rheological enhancement when mixed as a result of specific interactions between both gums. On the one hand, the present work deals with the influence of the thermal treatment of xanthan/LBG mixtures on their interactions. The rubber elasticity theory evidences that the viscoelasticity enhancement after heating is related to an increase of the cross-linking density between smooth region of LBG and disordered segment of xanthan (from 1 per 62 to 1 per 10 repeating units of xanthan molecules for unheated and heated systems, respectively). Additionally, based on different xanthan samples with various acetate and pyruvate rates, we clearly illustrate how rheological properties and thus interactions evolve with both acetate and pyruvate contents.