Scientific publications
Michèle N. Fanwa* (Corresponding author)
Other affiliations: Université Le Havre Normandie · Normandie Université
Arnaud Maxime Cheumani Yona
Nicolas Hucher
Other affiliations: Normandie Université · Unité de Recherche en Chimie Organique et Macromoléculaire
Catherine Malhiac
Other affiliations: Normandie Université · Unité de Recherche en Chimie Organique et Macromoléculaire
Michel Grisel* (Corresponding author)
Other affiliations: Normandie Université
International Journal of Biological Macromolecules
The polyelectrolyte gum from Triumfetta cordifolia stem bark has recently come to the fore for its remarkable potential as an emulsifier and stabilizer for aqueous formulations. This paper presents the rheological study of T. cordifolia gum aqueous solutions in the concentrated regime (C > C** = 0.14 % w /w). To this end, both flow and oscillation tests were performed on T. cordifolia gum solutions at two distinct concentrations belonging to the concentrated regime: at 0.2 % w /w (close to C**) and at 0.7 % w/w (far above C**). The effect of temperature, pH and added salts (NaCl, CaCl 2 and AlCl 3 ) on gum viscoelastic parameters were investigated, revealing associative interactions. Under specific conditions, several remarkable and complex phenomena were observed, such as over-structuring induced by temperature, anti-thixotropy, gelation , syneresis and salting-out induced by salt addition. The charged structure of T. cordifolia gum (weak polyelectrolyte), the high divalent metal content and the presence of associative groups in its network were demonstrated as the major factors responsible for these phenomena. These findings form the basis for the structure-property relationships of T. cordifolia gum and may open up to further investigations for this gum of great potential in many fields of applications.
