## 3 Results and Discussion
### Characteristics of Obtained Preparations
The values of the initial tittatable acidity did not differ so clearly; only the dough with EOPP added directly to the dough was characterized by a much higher initial tittatable acidity, while differences were observed in the parameters of the tittatable acidity of the dough after fermentation. The tittatable acidity of the standard dough increased by about 0.5 TTA units during fermentation. In the case of the dough to which the preparation was added at the dough stage only, the increase was greater and ranged between 0.7 and 2.0 TTA units, while the dough with the EOPP preparation showed the smallest increase in acidity (0.74 TTA units). The greatest increase in acidity during fermentation was observed after adding the preparation to the sourdough (by 0.98-2.3 TTA units), especially in the case of E30 PP and E40 PP. Therefore, it can be inferred that the addition of the tested preparations accelerates its acidification. In the tested preparations, maltodextrin constituted a significant proportion, which in the context of the extrusion process resulted in higher availability for microorganisms [50]. The use of pomace additionally increased the acidification of the dough. Greater acid synthesis may be associated with the supply of proteins, minerals, and vitamins within the pomace, which promotes the growth of bacteria [51]. It could be expected that the TTA of the dough would increase due to the decreasing pH of the product. The additional apparent increase in acidity after fermentation could be related not only to the acidification directly influencing the pH, but also to the increase in the content \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{\begin{tabular}{c} **Type of Dough** \\ **and Bread** \\ \end{tabular} } & **Initial pH of** & **pH of Dough after** & \begin{tabular}{c} **Initial TTA of** \\ **Dough** \\ \end{tabular} & \
\begin{tabular}{c} **Dough TTA after** \\ **Permention** \\ \end{tabular} &
\begin{tabular}{c} **TTA of Bread** \\ **Crumb** \\ \end{tabular} \\ \hline SB & 4.33 \({}^{\text{b}}\)\(\pm\) 0.01 & 4.28 \({}^{\text{c}}\)\(\pm\) 0.01 & 6.65 \({}^{\text{bc}}\)\(\pm\) 0.65 & 7.11 \({}^{\text{c}}\)\(\pm\) 0.18 & 5.95 \({}^{\text{b}}\)\(\pm\) 0.26 \\ \hline EOPP\_T1 & 4.29 \({}^{\text{c}}\)\(\pm\) 0.00 & 4.28 \({}^{\text{c}}\)\(\pm\) 0.01 & 7.39 \({}^{\text{a}}\)\(\pm\) 0.47 & 8.13 \({}^{\text{b}}\)\(\pm\) 0.07 & 5.96 \({}^{\text{b}}\)\(\pm\) 0.01 \\ \hline E30 PP\_T1 & 4.32 \({}^{\text{b}}\)\(\pm\) 0.01 & 4.35 \({}^{\text{a}}\)\(\pm\) 0.01 & 6.65 \({}^{\text{bc}}\)\(\pm\) 0.37 & 8.62 \({}^{\text{ab}}\)\(\pm\) 0.13 & 6.49 \({}^{\text{a}}\)\(\pm\) 0.15 \\ \hline E40 PP\_T1 & 4.37 \({}^{\text{a}}\)\(\pm\) 0.01 & 4.33 \({}^{\text{ab}}\)\(\pm\) 0.01 & 6.27 \({}^{\text{c}}\)\(\pm\) 0.38 & 8.04 \({}^{\text{b}}\)\(\pm\) 0.42 & 6.60 \({}^{\text{a}}\)\(\pm\) 0.0 \\ \hline E0 PP\_T2 & 4.38 \({}^{\text{a}}\)\(\pm\) 0.01 & 4.34 \({}^{\text{a}}\)\(\pm\) 0.01 & 5.86 \({}^{\text{c}}\)\(\pm\) 0.23 & 6.84 \({}^{\text{c}}\)\(\pm\) 0.46 & 6.59 \({}^{\text{a}}\)\(\pm\) 0.0 \\ \hline E30 PP\_T2 & 4.32 \({}^{\text{b}}\)\(\pm\) 0.01 & 4.34 \({}^{\text{a}}\)\(\pm\) 0.01 & 6.77 \({}^{\text{bc}}\)\(\pm\) 0.15 & 8.98 \({}^{\text{a}}\)\(\pm\) 0.07 & 6.50 \({}^{\text{a}}\)\(\pm\) 0.14 \\ \hline E40 PP\_T2 & 4.37 \({}^{\text{a}}\)\(\pm\) 0.01 & 4.31 \({}^{\text{b}}\)\(\pm\) 0.01 & 6.32 \({}^{\text{c}}\)\(\pm\) 0.06 & 8.62 \({}^{\text{ab}}\)\(\pm\) 0.41 & 6.10 \({}^{\text{b}}\)\(\pm\) 0.15 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Results of pH and acidity determinations for dough and bread crumb. of weakly acidic NaOH-reactive compounds; hence, the change in the TTA of the dough during proofing is evident [52]. It should be noted, however, that the most acidic dough was obtained when using preparation E30 PP (Table S1). Probably, this composition of the preparation was the optimal substrate for bacteria growth, which resulted in better acidification of the dough. Regardless of the titratable acidity of the dough, the titratable acidity of the bread crumb has changed.