FUNCTIONAL-CHARACTERIZATION OF THE EXOPOLYSACCHARIDE FROM ENTEROBACTER-AGGLOMERANS GROWS ON LOW-GRADE MAPLE SAP

The exopolysaccharide (EPS312) produced by Enterobacter agglomerans wh en grown oil low-grade maple sap was isolated and its functional prope rties were compared to xanthan in order to assess its suitability to n ew applications or ifs use in place of currently economically viable p olymers. The polysaccharide exhibited shear thinning properties at hig h shear rates and a Newtonian behavior at low shear rates, while xanth an polymer showed shear thinning behavior over the entire range of she ar rates tested. EPS312 polymer was sensitive to homogenization and sh owed lower viscosity after the treatment. However, homogenization indu ced shear thinning behavior at low shear rates. At low concentration, EPS312 polymer increased the interfacial area and decrease the stabili ty of whey protein stabilized emulsions. At higher concentrations, the interfacial area of the emulsion decreased and the stability improved . Similar results were observed with xanthan, except that no increase of the interfacial area was observed at low xanthan concentration. Pro tein foam overrun was reduced by the addition of xanthan, but EPS312 p olymer had no significant effect. Foam firmness decreased but stabilit y increased by the addition of both polymers. Foams supplemented with xanthan were, however, stiffer and more stable than protein foams with added EPS312 polymer. The latter could find applications for the stab ilization of emulsions requiring low viscosity.