A comparison of the rheological behavior of xanthan gum and diutan gum aqueous solutions

It was conducted thorough rheology characterization of aqueous solutions of xanthan and diutan gums, obtaining the following rheological properties: viscosity; elastic modulus, viscous modulus, complex modulus and complex viscosity, in different temperatures. The Power Law model fits very well the pseudoplastic behavior of aqueous solutions of xanthan and diutan gums. The elastic modulus (G'), in the case of aqueous solution of xanthan gum, shows larger values compared to viscous modulus (G"), indicating a gel behavior. For the aqueous solution of diutan gum, there is a crossover of the curves of G' and G", in the frequency sweep test, corresponding to a gel structure formation (G' > G"). The aqueous solution of xanthan gum shows thermal degradation while aqueous solution of diutan gum shows good thermal stability. The study of rheology of aqueous solutions of xanthan gum and diutan gum can contribute to better understanding the flow behavior of these biopolymers that have many industrial and scientific applications.