# Influence of Technological Parameters on Sourdough Starter Obtained from Different Flows
## 3 Results
### Assessment of the Nutritional Profile of Dry Raw Materials
#### 3.2.1 pH and Total Titractable Acidity  
All sourdough variants showed, during the fermentation period at 25 \({}^{\circ}\)C and 35 \({}^{\circ}\)C, respectively, a decrease in pH values and an increase in acidity as a result of the production of lactic and acetic acid by the lactic bacteria from the spontaneous microflora of the tested flours. In the case of both variants of the fermentation temperature, the maximum acidity values were identified at 48 h of fermentation. The sourdough made from 100% Einkorn wheat flour presented the highest TTA value (13.4 \(\pm\) 0.05 degrees) at 48 h of fermentation at 25 \({}^{\circ}\)C, which decreased considerably until the last day of testing, reaching 10.7 \(\pm\) 0.12-degree acidity. This course was also observed in the case of the other variants of sourdough, less so in the case of the sourdough made of 100% corn flour and the mixture of corn flour 50% + rye flour 50%, the acidity constantly increasing until the last day of fermentation, reaching 11.7 \(\pm\) 0.01 degrees and 12.4 \(\pm\) 0.34 degrees, respectively. Figure 1 shows that the acidity variations of different variations of spontaneous sourdough were influenced by the fermentation temperature used. A dough should be warm enough, at the optimum temperature for yeast growth, usually 29-32 \({}^{\circ}\)C, to encourage massive spontaneous fermentation and flavor creation. The highest values of TTA were determined at 48 h of fermentation at 35 \({}^{\circ}\)C, with the 100% Einkorn wheat dough having the highest value (27.4 \(\pm\) 0.0 degrees), followed by the 50% Einkorn + rye flour dough 50%, respectively 24.8 \(\pm\) 0.29 degrees. One of the major characteristics of sourdough fermentation is a decrease in pH proportional to the maturation of the LAB community that produces lactic and acetic acid, eventually reaching a pH of about 4.0. The pH of the dough changes depending on the stage of fermentation it is in; the values determined in the case of the two fermentation temperatures are presented in Table 2. Since changes in pH can induce stress on cultures of lactic acid bacteria, evaluation of pH conditions is necessary to understand and control the evolution of microorganisms in dough. In addition, pH can influence the degree of lactic \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Samples**} & **Moisture** & **Acidity** & **Fat** & **Protein** & **Ash** & **Fiber** \\ \cline{2-7}  & **\%** & **Grade** & **\%** & **\%** & **\%** & **\%** \\ \hline Einkorn wheat flour & 10.04 \(\pm\) 0.02 & 8.33 \(\pm\) 0.29 & 2.59 \(\pm\) 0.03 & 19.18 \(\pm\) 0.18 & 2.45 \(\pm\) 0.00 & 2.93 \(\pm\) 0.00 \\ \hline Whole wheat flour & 10.87 \(\pm\) 0.01 & 3.65 \(\pm\) 0.14 & 1.59 \(\pm\)0.02 & 9.40 \(\pm\) 0.00 & 1.73 \(\pm\) 0.02 & 3.66 \(\pm\) 0.00 \\ \hline Corn flour & 13.70 \(\pm\) 0.02 & 6.25 \(\pm\) 0.29 & 1.98 \(\pm\) 0.01 & 6.11 \(\pm\) 0.05 & 0.68 \(\pm\) 0.01 & 1.70 \(\pm\) 0.02 \\ \hline Rye flour & 10.05 \(\pm\) 0.00 & 6.46 \(\pm\) 0.29 & 1.28 \(\pm\) 0.01 & 7.91 \(\pm\) 0.12 & 1.74 \(\pm\) 0.01 & 3.08 \(\pm\) 0.01 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Quality and nutritional profile of raw materials (flours). (Results are presented as mean of two determinations \(\pm\) SD). acid fermentation in the dough. The optimum pH of the dough should be between 4.2 and 4.5 [2], and therefore, the fermentation time required at 25 to 35 \({}^{\circ}\)C will be somewhere between 6 and 24 h.  
Surveying the changes in the pH until it reached a value of about 4.3 allowed us to discover the optimal fermentation period for each of the two temperatures. It was observed that samples fermented at 35 \({}^{\circ}\)C reached a pH of 4.2 after 24 h, while samples maintained at 25 \({}^{\circ}\)C took 48 h to reach a pH of 4.1.