Rheological and functional characterization of a biopolymer obtained from Beijerinckia sp

An exopolysaccharide producer, Beijerinckia sp. was isolated and identified from a sample of soil. A sample of 10.3 g (dry weight) of polysaccharide/L was obtained by fermentation on liquid Czapek culture media supplemented with yeast extract. The functionality of the biopolymer was characterized for its potential use by the food industry. It showed shear thinning behaviour (pseudoplastic). The effects of concentration, temperature and pH were evaluated; almost all of the salts had no effect on rheological parameters of the power law model. There was a linear relationship between the percent of remaining emulsion after centrifugation and the polysaccharide biopolymer concentration, demonstrating the stabilizing effect of biopolymer on the emulsion. In contrast, the biopolymer was not able to form a gel under various pH and temperature conditions, or with the addition of ions.