Preguntas frecuentes

Analyze the rheological behavior of native (high-acyl) gellan gum in solution compared to xanthan gum, especially regarding salt sensitivity and thixotropy.

Native gellan gum displays solution properties distinct from its deacylated form and other common thickeners. When dispersed in cold water, it provides extremely high viscosities. However, this viscosity is highly sensitive to salt concentration, showing a dramatic decrease as ionic strength increases—a much more pronounced effect than seen with xanthan gum, whose viscosity is famously stable to salt. Furthermore, solutions of native gellan gum are described as highly thixotropic; their high apparent viscosity results from the formation of a weak, shear-sensitive, gel-like network at rest. This structure breaks down under shear and rebuilds upon standing. Similar thixotropic behavior is observed in cold dispersions of low-concentration xanthan gum and locust bean gum mixtures. This makes native gellan gum a potential candidate for applications where high low-shear viscosity and suspension are needed, provided ionic strength is controlled.