Investigation of rheological behaviors of aqueous gum Arabic in the presence of crystalline nanocellulose

Abstract

An investigation on the effects of addition of crystalline nanocellulose (CNC) on both the intrinsic viscosity and rheological behavior of gum Arabic (GA) is undertaken. An adapted, facile method of CNC synthesis from microcrystalline cellulose (MCC) is used. At low concentrations of both CNC and GA, intrinsic viscosity of GA appears unaffected. However, the rheological behavior of 20 wt% and 40 wt% GA solutions is markedly affected by the introduction of CNC, even at very low concentrations. Enhanced viscosity and shear thinning properties are demonstrated with increased addition of CNC within the range studied, as are similar increases in storage modulus. Mechanisms are proposed for interactions between GA and CNC that may cause the observed effects, based on previous studies found in the literature. The use of CNC as a food grade viscosity modifier of GA and likely other polymer solutions is confirmed, and suggestions for further investigation are provided.