Emulsifying and Rheological Properties of Acacia tortilis var. spirocarpa Gum from Sudan

Abstract

This work aims to study the emulsification and rheological properties of Acacia tortilis var spirocarpa gum. A composite sample of the gum was prepared from samples collected from Aboshmal forest Sharq Elneel, Khartoum state. Emulsions, of two samples, concentrations (5 and 10% w/w) and dioctanoic decanoic glycerol (Octanoic Decanoic triglyceride oil) (ODO), were prepared, by homogenization at 75MPa and stored for 3 and 7 days at 60C. The emulsifying stability was determined by the change in droplet size using a Mastersizer 3000 laser diffraction analyzer. The Emulsification study showed that A. tortilis var. spirocarpa gum is grade 1 emulsifier. The Flow behaviour and dynamic properties for two gum samples, at 25 and 50% w/w concentrations, were determined by applying a shear rate of 0.1-100S-1. Rheological studies of A.tortilis var..spirocarpa showed that the gum had formed a Newtonian fluid at high shear rate and high concentration and the result of oscillatory test of the gum solution revealed a solid-like more than a liquid-like behaviour.