RHEOLOGICAL PROPERTIES OF MESQUITE SEED GUM IN STEADY AND DYNAMIC SHEAR

The steady and dynamic shear rheological properties of mesquite seed g um (MSG) solutions were measured at various concentrations (0.4-2.0 g/ 100 mL). The intrinsic viscosity was 240.5 mL/g. The Cross flow model provided a better fit on the shear rate-apparent viscosity data than t he Carreau flow model. The coil overlap parameter, C[eta], correlated well with the zero-shear rate specific viscosities (eta(spo)) The tran sition at the critical concentration (C ) occurred at a value of the coil overlap parameter C[eta] = 2.7 close to that observed for other g alactomannan gums. Storage (G') and loss (G'') moduli increased with i ncrease in frequency (omega), while dynamic shear viscosity (eta) dec reased. G'' values showed elastic plateaus at high frequencies. The dy namic and steady-shear viscosities at several concentrations followed the empirical Cox-Merz rule.