Rheology of xanthan gum: Effect of concentration, temperature and high-pressure

Effects of concentration (0.25 and 1.25%), temperature (20 and 130 degrees C) and high-hydrostatic pressure (100 to 400 MPa) on rheological characteristics of xanthan gum were studied using a controlled stress rheometer. Xanthan gum exhibited pseudoplasticity with yield stress and flow was adequately described by the Herschel-Bulkley model. It was observed that concentration significantly affected rheological parameters (p < 0.05) of xanthan gum dispersion while temperature exhibited the least effect (p > 0.05). An empirical equation was developed to describe the variation of yield stress with gum concentration. High-hydrostatic pressure increased yield and consistency index while a decrease in flow behaviour index represented by more pseudoplasticity of xanthan gum dispersions.