Measurement of hydration of polysaccharides

Abstract

A small scale mixing rig for monitoring hydration behaviour of polysaccharides was developed consisting of a 20 l vessel into which powder was fed at a controlled rate. Agitation was carried out with a variable speed high shear mixer. The objective of this work was to quantify hydration rates from viscosity-time curves for various polysaccharide samples. Viscosity was measured empirically using a Brookfield Viscometer, on aliquots of solution removed from the vessel, Viscosity-time curves were obtained for guar gum and a range of xanthan gums. The data obtained was analysed using a simple exponential model to give a time constant which is a measure of hydration rate. This approach was used to obtain information about the effect of salt concentration on xanthan hydration rate and particle size on guar hydration rate.