Synergistic interaction of Locust Bean Gum and Xanthan investigated by rheology and light scattering

The use of synergistic interactions between polysaccharides can represent an important approach for the preparation of physical networks with a wide range of industrial applications, such as in the food and biomedical fields. Locust Bean Gum and Xanthan, two biocompatible polymers, are able to form gels when mixed together. A detailed study was carried out on three samples, prepared at different weight ratios and two temperatures, by means of light scattering and rheological techniques. The solid-like character of each sample was evaluated by measurements of the viscoelastic spectrum and intensity autocorrelation function. The contribution of fast and slow fluctuations to the static light scattered intensity was also evaluated at different angles. The power law exponents for the sol-gel transitions were estimated together with the fractal dimensions. The scattering results were found in good agreement with the mechanical ones in revealing a strong dependence of the structural properties of the different samples on their preparation conditions. Indeed, results show that a fine tuning of the properties of the mixed gels is possible through the change of the temperature preparation and/or the polymer weight ratio. (C) 2010 Elsevier Ltd. All rights reserved