## 3 Results
### Experiment II  
Experiment II was conducted on mixed bread and Okin bread, with oncom starter and _P. freudentreichii_ DSM 20271, as presented in Scheme 2. 3.1 Changes in Dry Mass, pH, Titratable Acidity, and _P. freudentreichii_ Amounts after Oncom Fermentation  
The dry mass content in the obtained oncom products was similar, averaging 40%. After fermentation, large dry mass losses were again determined, although slightly smaller than in Experiment I, reaching a maximum of 43% (Tables 2 and 4). The pH values determined in the oncom ranged from 5.35 to 5.7 (Table 4) and again were higher by over 1 unit in the case of mixed bread compared to the initial value, while in the case of Okin bread, they were at the level indicated in the substrate (Table 1). The titratable acidity in the products was at a similar level of about 10-11 degrees. The highest value, significantly higher than the others, was determined in the oncom obtained with mixed bread after the co-fermentation process with a lower dose of bacteria. It is worth noting at this point that in Experiment II, slightly higher titratable acidity levels were determined for oncom from mixed bread than in Experiment I, with similar indications of pH values. This may be indicative of the higher buffering capacity of the resulting products. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{2}{c}{**Oncom 1** & **Dry Mass (\%)**} & **Dry Mass Loss (\%)** & **pH** & **Titratable Acidity (Degrees) 2** \\ \hline \multirow{3}{*}{Mixed bread} & control & 40.17 \(\pm\) 0.97 a & 41.69 \(\pm\) 2.07 c & 5.57 \(\pm\) 0.03 cd & 10.19 \(\pm\) 0.48 ab \\  & c-f 1 & 42.15 \(\pm\) 0.74 a & 38.69 \(\pm\) 2.23 ab & 5.50 \(\pm\) 0.10 bc & 13.06 \(\pm\) 1.52 c \\  & c-f 2 & 38.12 \(\pm\) 1.36 a & 43.27 \(\pm\) 1.64 c & 5.67 \(\pm\) 0.01 d & 9.55 \(\pm\) 0.60 a \\ \hline \multirow{3}{*}{Okin bread} & control & 42.62 \(\pm\) 1.03 a & 37.33 \(\pm\) 2.01 a & 5.41 \(\pm\) 0.09 ab & 10.10 \(\pm\) 0.13 ab \\  & c-f 1 & 40.50 \(\pm\) 2.37 a & 41.33 \(\pm\) 0.94 bc & 5.35 \(\pm\) 0.06 a & 11.68 \(\pm\) 0.93 bc \\ \cline{1-1}  & c-f 2 & 38.96 \(\pm\) 1.36 a & 43.34 \(\pm\) 1.37 c & 5.70 \(\pm\) 0.00 d & 10.19 \(\pm\) 0.31 ab \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Dry mass, pH, and titratable acidity after mixed bread and Okin bread fermentation. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multicolumn{2}{c}{**Oncom 1** & **Protein** & **Lipids** & **Ash** & **Carbohydrates** & **Reducing** & **Vitamin B12** \\  & **(g/100 g DM)** & **(g/100 g DM)** & **(g/100 g DM)** & **(g/100 g DM)** & **(g/100 g DM)** & **(g/100 g DM)** \\ \hline control & 22.74 \(\pm\) 0.20 a 2 & 5.51 \(\pm\) 0.10 b & 7.08 \(\pm\) 0.16 b & 65.01 & 12.99 \(\pm\) 0.68 a & 0.41 \(\pm\) 0.00 \\ c-f 1 & 22.38 \(\pm\) 1.71 a & 3.61 \(\pm\) 0.15 a & 7.76 \(\pm\) 0.10 c & 66.48 & 11.98 \(\pm\) 1.10 a & 0.72 \(\pm\) 0.0 \\ c-f 2 & 21.06 \(\pm\) 2.89 a & 3.49 \(\pm\) 0.13 a & 6.79 \(\pm\) 0.05 a & 68.88 & 13.26 \(\pm\) 1.44 a & 0.56 \(\pm\) 0.0 \\ \hline \hline \end{tabular}  
* control—oncom fermented with _N. sitophila_; c-f 1—oncom after fermentation by _N. sitophila_ and 2 \(\times\) 10\({}^{8}\) CFU/g FW of _P. freudentreichii_; c-f 2—oncom after fermentation by _N. sitophila_ and 10\({}^{9}\) CFU/g FW of _P. freudentreichii_. 2 Data are shown as the mean \(\pm\) SD. Mean values within a column followed by different letters differ significantly (\(p\leq 0.05\)).  
\end{table} 
Table 3: Chemical composition of oncom obtained from mixed bread. After fermentation, in oncom products obtained from mixed bread, 2.6 \(\times\) 10\({}^{8}\) CFU/g FW was determined in the c-f 1 variant, and 3 \(\times\) 10\({}^{8}\) CFU/g FW in the c-f 2 variant. Similar amounts of CFU were determined in fresh 5-day oncom made from Okin bread, in the c-f 1 variant it was 2.2 \(\times\) 10\({}^{8}\) CFU/g FW, and in c-f 2 2.6 \(\times\) 10\({}^{8}\) CFU/g FW.