Estimation of Rheological Coefficients of Acacia nilotica Gum: A Versatile Biopolymer for Biomedical and Food Industries

Abstract

Polysaccharides are widely used in the biomedical and food industries as thickening, gelling, emulsifying, hydrating, and suspending agents. Polysaccharides have adequate viscoelastic properties and flow characteristics. The purpose of this study was to determine various rheological parameters of Acacia nilotica (Babool) gum. Understanding the influence of temperature on rheological properties is quite important for polymeric materials to be considered as pharmaceutical excipients. Thus, a polymeric solution of purified Babool gum was prepared, and the influence of temperature on its rheological behaviour (viscosity and surface tension) was investigated to develop a better understanding of the structural organization of the gum. Furthermore, viscosity, surface tension, temperature coefficient, activation energy, Gibbs free energy, Reynolds number, and entropy of fusion were calculated using the Arrhenius, Gibbs–Helmholtz, Frenkel–Eyring, and Eotvos equations, respectively. The activation energy of the gum was 3.81 ± 0.18 kJ/mol. Changes in entropy and enthalpy were 0.56 ± 0.23 and 4.27 ± 0.81 kJ/mol, respectively. The calculated amount of entropy of fusion was found to be 0.014±0.01 kJ mol−1 K−1. The study outcomes showed that the viscosity and surface tension increased as the temperature decreased. The good rheological properties of Babool gum make it a suitable excipient for its applications in the food and pharmaceutical industries.