## 3 Results and Discussion
### Physicochemical Properties of JSP
#### 3.3.2 Rheological Behavior of JSP  
The steady-shear flow curves for the JSP aqueous solutions at different concentrations from 0.25% to 2.0% (_w/v_) at 25 \({}^{\circ}\)C are presented in Figure 6. JSP solutions in water exhibited shear-thinning behavior since the apparent viscosity (\(\eta\), Pa. s\({}^{-1}\)) decreased with the increasing shear rate (\(\dot{\gamma}\), s\({}^{-1}\)). As illustrated in Figure 6, increasing JSP concentrations from 0.25% to 2.0% (_w/v_) led to an increase in the apparent viscosity of the aqueous solutions, suggesting that polymer chains adopted a more intertwined network. This flow property was in agreement with previous results obtained for other sulfated galactans extracted from _G. birdiae_ and _H. durvillei_ since the authors described a pseudoplastic behavior for two sulfated galactans, considering the same range of concentrations [12; 16]. The Ostwald-de Waele model was used to fit the rheological data of the JSP solutions at different concentrations ranging from 0.25% to 2.0% (_w/v_) at 25 \({}^{\circ}\)C over the shear rate from 0.001 to 1000 s\({}^{-1}\) (Table 4). Note that the flow behavior index (\(n\)) takes the value \(n<1\) for fluid exhibiting pseudoplastic or shear-thinning behavior, \(n=1\) for Newtonian liquid and \(n>1\) for swelling plastic or shear-thickening fluid [57]. As seen in Table 4, the values of the flow behavior index for solutions of JSP in water were lower than 1, confirming the property of a shear-thinning (pseudoplastic) fluid. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \(\mathbf{M_{w}}\) 1 (g/mol) & \(\mathbf{M_{n}}\)2 (g/mol) & PDI 3 [FOOTNOTE:3]Footnote 3: M\({}_{w}\): Weight average molecular weight was measured by SEC-MALLS-DRI, 3[FOOTNOTE:3]Footnote 3: M\({}_{w}\): Weight average molecular weight was measured by SEC-MALLS-DRI, 3[FOOTNOTE:3]Footnote 3: M\({}_{w}\): Weight average molecular weight estimated by SEC-MALLS-DRI, 3[FOOTNOTE:3]Footnote 3: M\({}_{wThe effects of temperature and salts (NaCl and KCl) on the flow properties of JSP solutions (1.0-2.0%, _w/v_) are illustrated in Figure 7. The \(\eta\) was found to decrease with the increase in temperatures (Figure 7B) and when adding salts (Figure 7A). The increase in heat was able to increase the energy dissipation of polysaccharide molecules, which resulted in a breakdown of the weak energy bonds (hydrogen and electrostatic bonds), a decrease in the intermolecular interactions and, consequently, the drop of the flow polymer activation energy (\(E_{a}\)) [34; 57]. In monovalent salts NaCl or KCl solutions (0.5 mol/L), intermolecular electrostatic repulsions as well as the number and/or complexity of junction zones between JSP molecules decreased, showing that JSP adopted a more compact conformation because of its weak polyelectrolyte character (low uronic acids content) [16; 33; 34]. As shown in Table 4, the values of \(n\) increased in NaCl and KCl solutions (0.5 mol/L), by increasing the temperature (from 20 \({}^{\circ}\)C to 60 \({}^{\circ}\)C) or decreasing the polymer concentration (from 0.25% to 2.0% (_w/v_)). The consistency index \(k\) (Pa.s\({}^{n}\)) increased with concentration