Rheology of Sodium Alginate-Low Methoxyl Pectin Mixtures in Solution

M.V. PÉREZ; J.E. LOZANO; M.A. VILLAR

Gramado, Brasil

Simposio; X International Macromolecular Colloquium; 2005

Instituto de Química, UFRGS y ABPol

The interaction between sodium alginate and low methoxyl pectin was studied and their rheological properties were obtained by steady state measurements. First of all, critical concentration of both biopolymers was determined and the  analyses of the mixtures were performed, in the semi-concentrated regime, using 2 wt% solutions.  The effect of temperature on rheological behavior was also studied and the flow activation energy was calculated by the Arrhenius empirical relationship between the shift factor aT and temperature. It was observed that while alginate solution is “quite” thermorheologically simple, low methoxyl pectin introduces certain complexity. It was found that blends of the two biopolymers in aqueous solutions follow the widely used “log-aditive rule”.