Gilvanete Maria Ferreira
Federal Institute of Amapá, IFAP
Brazil
Title: Creep-recovery tests of polymers systems
Biography
Biography: Gilvanete Maria Ferreira
Abstract
The cupuassu (Theobroma grandiflorum Schum, Sterculiaceae) is a native Amazonian fruit. Its pulp has a pleasant acidic taste and a strong fragrance and is used in candies, ice cream, domestic jellies, and jams. In this work the rheological behavior of the cupuassu fruit pulp, xanthan and guar gums dispersed in the pulp was studied. The experiments were carried out in a Rheometer AR 2000, using cone-plate (2º, 60mm) geometry. The rheological behavior of xanthan gum in cupuassu fruit pulp was evaluated by means of oscillatory tests in the frequency range of 0.1 to 100 Hz. at temperatures 10, 30 and 50 ºC. In oscillatory tests all samples behaved as weak gel, with storage module greater than loss module (G' > G"), which increased as the gum concentration increased. In tests of creep of pure cupuassu more elastic behavior showed that the pulp with gums due to the wont of pectin jelling.