# Gluten-Free Sourdough Based on Quinoa and Sorghum: Characterization and Applications in Breadmaking
## 3 Results
### Sourdough Properties
#### 3.3.2 Effect of Sourdough Addition on Thermo-Mechanical Properties of Dough
This can be explained through the potential exopolysaccharideradic production, which ensures good proteolysis in the dough obtained using pseudocereals [61], with beneficial effects on the quality of bakery products. [PERSON] et al. [61] showed that even _Lb plantarum_, which does not produce exopolysaccharidesradides on MRS-m, was able to biosynthesize and release exopolysaccharidesradides in the sourdough from quinoa flour. [PERSON] and [PERSON] [29] studied the effect of sourdough addition on the thermomechanical properties of wheat flour dough and noted that the main modification in the behavior of the dough appears during heating and cooling. In our study, except for the samples with higher levels of sorghum flour, the sourdough addition produced a delay in the C3 and C4 values (Tables 6 and 7). Additionally, regardless of the sourdough, the C3 and C4 torque values increased with the amount of sorghum flour in the dough. The retrogradation behavior of the starch was also mainly influenced by the level of sorghum flour, regardless of the sourdough addition. Thus, the C5 and (C5\(-\)C4) significantly increased (\(p<0.05\)) with the sorghum flour addition (Table 8). The lowest (C5\(-\)C4) values of 0.51\(-\)0.54 Nm were registered for the Q100-based dough with sourdough addition. On the other hand, in the case of the sorghum-containing dough samples, the (C5\(-\)C4) values significantly increased (\(p<0.05\)) with the sourdough addition (Table 8). [PERSON] and [PERSON] [29] reported an increase in the C4 and C5, from 1.68 to 2.27 Nm and  
Figure 4: The Mixolab curves for the dough samples prepared with quinoa flour (Q100) and quinoa flour substituted with 25 (Q75) and 50% (Q50) sorghum flour and 20% sourdough fermented with starter culture (SC2). from 2.51 to 3.45 Nm, respectively, while C3 varied within small limits, between 1.97 and 2.02 Nm, for wheat flour dough with sourdough addition. Similar results were obtained by [PERSON] et al. [60] on the millet dough properties prepared with different strains of lactic acid bacteria. Thus, authors reported higher C3, C4, C5 and (C5\(-\)C4) values of the millet dough fermented with lactic acid bacteria compared to the dough fermented with yeasts. Moreover, [PERSON] et al. [60] observed important variations in those parameters depending on lactic acid bacteria strains used for preparing the sourdough. Thus, sourdough fermented with _Lb acidophilus_ had C3, C4 and C5 values much higher compared to the sourdough prepared with _Lb rhamnus_ and _Lb plantarum_, while (C5\(-\)C4) was much lower. On the other hand, _Lb plantarum_ led to a dough with the highest (C5\(-\)C4) value and the lowest C4 value, whereas the C3 and C5 values were closer to _Lb rhamnus_. [PERSON] et al. [31] studied the baking properties of quinoa and sorghum flours supplemented with sourdough and noted that although viscoamylographic properties of quinoa flour are superior to the sorghum flour, both pseudocereals are suitable to increase the shelf life of the bread. Moreover, the authors observed that, although the sourdough sorghum bread had higher initial crumb firmness compared to quinoa bread, the crumb firmness of both bread samples doubled after 7 days. The high shelf life of sourdough breads can be explained by the presence of important concentrations of compounds with antimicrobial activity, such as phenolic compounds, formed during sourdough fermentation [62].