## 3 Results and Discussion
### Dongh Rheology Characterization  
#### 3.2.1 Gluten-Free Dough Flow Behavior  
Figure 1 shows the impact of Cc additions, on steady-shear flow behavior of gluten-free doughs, in comparison to control dough (CD).  
The flow curves indicated that all these systems behaved as typical structured materials, showing a Newtonian plateau region at low shear rates and dough viscosity began to decrease as the shear rate values increase, reflecting a typical shear-thinning behavior. These results agree with those obtained by other authors [19; 20], using different gluten-free flours and hydrocolloids on GFB formulations.  
Carreau equation was adjusted to the experimental data from Figure 1 (R\({}^{2}\) > 0.975) and the obtained rheology fitted parameters, summarized in Table 3, were used to characterize the dough flow behavior: Cc incorporations to dough promoted a significant reduction on apparent viscosity values (\(\eta_{0}\)) ranging from 390.2 k Pa s for CD to 37.3 k Pa s for CdD20% (higher Cc level tested), representing a decrease in viscosity of around 90.0%. Considering the significant reduction in dough viscosity observed, promoted by the Cc addition to dough, the dilution effect of starch-proteins-xanthan gum linkage density, of the GFB reference, should be invoked to support these findings.  
Based on the values of critical shear rate (\(\gamma_{\text{c}}\)), the transition of the Newtonian to shear-thinning behavior of all systems occurred around \(3.4\times 10^{-3}\) s\({}^{-1}\).  
Concerning the dough flow index (slope), the addition of Cc up to 10% did not significantly (\(p>0.05\)) change the dough's flow behavior, presenting values like CD (0.27-0.23). Nevertheless, as the amount of Cc increases, the flow index was significantly reduced, varying from 0.27 (CD) to 0.18  
Figure 1: Flow rheology behavior of the control dough (CD) and Cc doughs (CcD): 5% up to 20%, _w/w_.  
\begin{table}
\begin{tabular}{c c c c c} \hline  & \(\eta_{0}\) **(k Pa s)** & \(\gamma_{\text{c}}\) **(s\({}^{-1}\))** & **s (Slope)** & **R\({}^{2}\)** \\ \hline CD & 390.2 \(\pm\) 8.7 \({}^{\text{a}}\) & \(3.3\times 10^{-3}\) \(\pm\) 1.3 \(\times 10^{-4}\) \({}^{\text{a}}\) & 0.27 \(\pm\) 0.06 \({}^{\text{a}}\) & 0.987 \\ CcD5\% & 166.4 \(\pm\) 5.0 \({}^{\text{b}}\) & \(3.1\times 10^{-3}\) \(\pm\) 4.0 \(\times 10^{-4}\) \({}^{\text{a}}\) & 0.26 \(\pm\) 0.03 \({}^{\text{a}}\) & 0.987 \\ CcD10\% & 178.0 \(\pm\) 6.6 \({}^{\text{b}}\) & \(3.2\times 10^{-3}\) \(\pm\) 2.3 \(\times 10^{-4}\) \({}^{\text{a}}\) & 0.23 \(\pm\) 0.03 \({}^{\text{ab}}\) & 0.980 \\ CcD15\% & 101.5 \(\pm\) 1.7 \({}^{\text{c}}\) & \(3.6\times 10^{-3}\) \(\pm\) 4.8 \(\times 10^{-4}\) \({}^{\text{a}}\) & 0.21 \(\pm\) 0.04 \({}^{\text{b}}\) & 0.996 \\ CcD20\% & 37.3 \(\pm\) 4.0 \({}^{\text{d}}\) & \(3.6\times 10^{-3}\) \(\pm\) 2.3 \(\times 10^{-4}\) \({}^{\text{a}}\) & 0.18 \(\pm\) 0.09 \({}^{\text{b}}\) & 0.975 \\ \hline \end{tabular} Different superscripts (\({}^{\text{a}}\), \({}^{\text{b}}\), \({}^{\text{c}}\), \({}^{\text{d}}\)) indicate significant statistical differences between CD and CdD (at \(p\leq 0.05\), Tukey test).  
\end{table}
Table 3: Fitted rheology parameters estimated for control dough (CD) and cured cheese doughs (CcD5% up to CcD20%), by applying Carreau Model.  
for high Cc level tested (CcD20%). This increase in shear thinning behavior is probably due to the formation of longer and more flexible polymer-chains [21].  
Similar findings were reported by other researchers [22] to evaluate the effect of other hydrocolloids addition on the rheology features of the GF cakes. According to a previous study [23], lower flow indexes led to a quick decrease in dough viscosity, which can improve the capacity of dough to expand and retain more gas during baking.