Influence of shear rate and concentration ratio on viscous synergism. Application to xanthan—Iocust bean gum— NaCMC mixtures Influencia de la velocidad de cizalla y la relación de concentraciones en la sinergia viscosa. Aplicación a mezclas de xantana-garrofín-CMCNa

A method is described that allows the development of an empirical approach to quantify synergistic interactions and their variations with shear rate. The approach is based on the definition of a viscous synergism index, I v . The method is applied to xanthan-locust bean gum gels, and an equation is developed for relating the synergism index to shear rate, γ, and the locust bean gum/xanthan gum concentration ratio, z. The value of at which that function has a maximum, I M V , is calculated. This value of z provided an estimation of the proportion of gums at which maximum synergism occurs. A decreasing exponential dependence of these I M V on γ is shown. The influence of the addition of a fixed proportion of a third gum (NaCMC) is also analyzed. The results obtained for the higher γ values are analogous to those of other authors.