Rheological study of xanthan and locust bean gum interaction in dilute solution

An oscillatory capillary rheometer was used to investigate visco-elastic properties of xanthan and locust bean gum (LBG) blends in dilute solution. Gums were evaluated for intrinsic viscosity and the elastic component. Molecular conformation of the complex of xanthan-LBG was assessed by the power law and the Huggins equations. A 60% xanthan-40% LBG blend exhibited the strongest attraction between xanthan and LBG molecules as evidenced by a greater intrinsic viscosity, the polymer miscibility coefficient alpha, the elastic component, and a positive Huggins coefficient K(m). The power-law model was successfully applied to predict the molecular conformation of xanthan and LBG alone in dilute solution and was exhibited as rod-like and random coil conformation. The power-law coefficient b increased as the LBG fraction increased in the blends, suggesting a more flexible xanthan-LBG complex dependent on LBG. (c) 2005 Elsevier Ltd. All rights reserved.