Experimental results regarding the effect of ionic strength on the viscous properties of mucilage (concentration of 0.06 g/mL) are shown in Fig. 4. Viscosity values are taken from the flow curve at a shear rate of 0.25 s1. The effect of the ionic concentration on the viscosity is important to determine the dependence of rheological properties on the presence of functional ions. Charged molecules show a strong viscosity dependence of ionic strength. Medina-Torres et al., (2000) represented this functionality by using the following Equation (4):