“Hydrodynamic properties of chañar gum from geoffrea decorticans fruit”

LISMET LAZO DELGADO; M.A. MASUELLI

IASI

Conferencia; CONFERENCE ON RHEOLOGY; 2022

"Petru Poni" Institute of Macromolecular Chemistry

Currently, there is a growing interest in the use of natural resources in a sustainable manner. Finding the Geoffroea decorticans tree, popularly known as Chañar, a good target to cover this interest, since it is not cultivated or harvested, rather is little exploited in its natural habitat. Chañar gum (CHG), a polysaccharide type, is obtained from Chañar fruit flour. Two extraction methods were used, hydrothermal and acid extraction. The resulting polysaccharides (CHT and CHA) were characterized with density, viscosity, and diffusion coefficient measurements to obtain their properties in aqueous solution (intrinsic viscosity, shape factor, partial specific volume, hydration value, molecular weight, and hydrodynamic radius). From the intrinsic viscosity data, it can be concluded that both macromolecules, obtained by different extraction techniques, differ in the molecular weight, size, and shape. Both gums were quasi-spherical where the va/b value of CHA is less than CHT, and Mv and RH of CHT were greater than CHA. These data were corroborated with the intrinsic diffusion coefficient data. This phenomenon can be explained by the nature of the hydrolysis. The partial specific volume was slightly higher for CHA. Regarding the Mark-Houwink parameters, CHA presents values of k = 0.01810 cm3/g, a = 0.5522, which affirms its quasi-spherical shape (va/b of 2.80). CHT values where k = 0.00611 cm3/g, a = 0.6249 which is a boundary between spheroid and ellipsoid shape (va/b of 3.42). The study of these properties is critical to demonstrate the functionality of biopolymers and their application. The obtained results represent an advantage and evidence that Chañar is an interesting source for extract polysaccharides. We have not yet elucidated the structure of these polysaccharides, but it has a high molecular weight that guarantees its application in the food industry as a thickening agent, film, and gel former.