Abstract
Small deformation oscillatory shear tests in the linear domain of viscoelasticity were carried out at 25°C in gels of gellan-iota carrageenan and gellan-xanthan, in order to determine the contribution of both polysaccharides to the viscoelastic behavior of the mixture. Admixtures having a constant total concentration of 0.5% (w/w) with different proportions were prepared in the presence of 0.01 mol/kg CaCl2. The storage and loss moduli of 0.5% gellan alone gels were the highest and moduli of the two-component gels decreased as the proportion of gellan was reduced. Mixed gels having a gellan concentration equal or lower than 50% mass of the total concentration were less stiff and brittle, hence more elastic, and exhibited a higher dependence of phase angle with frequency than 0.5% gellan alone gels. Presence of carrageenan and xanthan also reduced syneresis considerably. No enhancement of rheological properties was observed and results suggest that separate-phase systems are formed.