The objective of this work was to evaluate the effect of NaCl and CaCl_2 salts addition, at a fixed ionic strength (150 mM), on the rheological properties of flaxseed gum (FG) solutions. FG was extracted from seeds by an aqueous extraction process and rheological properties (steady and dynamic measurements) of FG solutions were evaluated at three different gum concentrations (1, 1.5 and 2% w/w) without and with salts addition. Intrinsic viscosity of solutions (0.004-0.05% w/v) was also determined. FG solutions exhibited a shear thinning behavior without yield stress. Flow curves were fitted to the power law model, being that the salts addition led to an increase in flow behavior index (n) and a decrease in consistency index (k) values at the same FG concentration. The increase of FG concentration led to a higher viscosity (higher k values) and pseudoplasticity (lower n values). Intrinsic viscosity of FG solutions decreased with the salts addition, which is in agreement with results found by flow curves. In addition, a typical behavior of a solution (G" > G') and “weak gel” properties (G’ slightly greater than G") were observed at lower and higher FG concentration, respectively, for FG solutions without and with addition of salts. Samples without salts addition showed more pronounced elastic and viscous character than the solutions with salts addition. During the heating process, it was observed that the salts addition stabilized the network formed (G' increased), which was thermoirreversible. In general, it was not observed differences between rheological properties with mono or divalent (with different ionic radius) salts addition, which can be associated to an electrostatic screening between the negatively charged groups of FG and the positive salt ions.
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