Colloidal and rheological behavior of aqueous dispersions of buriti tree (mauritia flexuosa) gum

The temperature, concentration and pH variables influence the aqueous dispersion of the gum properties. In this context, the aims of this research were to characterize the gum obtained from the buriti tree (Mauritia Flexuosa) trunk exudate, as well as to evaluate the colloidal and rheological behavior of the aqueous dispersions of this gum. Thus, the centesimal composition, absolute zeta (ζ) potential as a function of pH (1.2 to 4.0), particle size distribution, as well as the rheological properties of the gum at different temperatures (15, 20, 25, 30, and 40 °C) and concentrations (4, 5, 8, and 10% (m/v)) were studied. In addition, the Newton, Power Law, and Herschel-Bulkley models were fitted to the rheological data. Buriti tree gum (BG) was found to have 10.43% moisture, 5.05% ashes, 0.68% lipids, 3.09% proteins, and 80.76% carbohydrate. The aqueous dispersion of the gum (1%) had a ζ value of -17.1 mV with a tendency for greater stability at pH 0.99). Gum dispersion viscosity decreased with higher temperature and lower concentration. The activation energy (Ea) value for gum dispersion ranged from 9.07 to 17.35 kJ/mol.