Physicochemical Parameters for Brea Gum Exudate from <i>Cercidium praecox</i> Tree

Abstract

Brea gum (BG) is a hydrocolloid obtained as an exudate from the Cercidium praecox tree. The physicochemical properties of brea gum are similar to those of the arabic gum and, in many cases, the former can replace the latter. The brea gum was incorporated in 2013 into the Argentine Food Code because of its ancestral background and its current food uses. Brea gum could be also used as additive or excipient for pharmacological formulations. This work reports intrinsic viscosity, coil overlap, and Mark⁻Houwink⁻Kuhn⁻Sakurada (MHKS) parameters of BG solutions. Partially hydrolyzed BG solution was analyzed using intrinsic viscosity measurements, dynamic light scattering and size-exclusion chromatography (SEC). The MHKS parameters, a and k, were determined for BG at 25 °C, with values of 0.4133 and 0.1347 cm3 g−1, respectively. The viscometric molecular weight of BG was 1890 kg mol−1. The hydrodynamic parameters of BG were indicative of a hyperbranched structure and spherical conformation. The knowledge obtained on the physicochemical properties of brea gum favors its use in food and pharmaceutical applications.

Keywords

• brea gum
• intrinsic viscosity
• Mark–Houwink–Kuhn–Sakurada parameters
• molecular weight