## 4 Discussion  
In this experiment, oncom was obtained from stale bread using a cultivation method previously developed. Co-fermentation products were prepared using a standard procedure, except that at the inoculation stage, _P. freudenreichii_ cells were additionally introduced into the substrate. It should be noted that the oncom obtained by co-fermentation did not differ in appearance, smell, or taste from the control oncom. While a sensory test was not conducted, the above observations were made by individuals conducting this experiment and familiar with the typical characteristics of the bread-based oncom produced in the unit's laboratory. Figure 1 shows the appearance of a typical oncom from mixed bread after fermentation on a Petri dish. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**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 \multirow{3}{*}{Mixed bread} & control & 18.51 \(\pm\) 0.46 b \({}^{2}\) & 1.72 \(\pm\) 0.06 a & 5.96 \(\pm\) 0.05 e & 73.79 & 11.81 \(\pm\) 0.72 b & 0.25 \(\pm\) 0.00 a \\  & c-f 1 & 17.55 \(\pm\) 0.38 a & 2.75 \(\pm\) 0.27 c & 5.70 \(\pm\) 0.09 d & 73.98 & 11.73 \(\pm\) 1.48 b & 0.37 \(\pm\) 0.0 b \\  & c-f 2 & 18.34 \(\pm\) 0.39 b & 4.14 \(\pm\) 0.12 d & 5.42 \(\pm\) 0.01 c & 72.24 & 11.61 \(\pm\) 0.22 b & 2.22 \(\pm\) 0.0 d \\ \hline \multirow{3}{*}{Okin bread} & control & 21.08 \(\pm\) 0.35 c & 2.32 \(\pm\) 0.05 b & 4.62 \(\pm\) 0.05 a & 71.95 & 6.20 \(\pm\) 0.016 a & 0.25 \(\pm\) 0.0 a \\  & c-f 1 & 22.46 \(\pm\) 0.27 d & 2.75 \(\pm\) 0.12 c & 5.04 \(\pm\) 0.03 b & 69.74 & 6.15 \(\pm\) 0.60 a & 0.78 \(\pm\) 0.0 c \\ \cline{1-1}  & c-f 2 & 22.87 \(\pm\) 0.40 d & 1.76 \(\pm\) 0.10 a & 6.08 \(\pm\) 0.03 f & 69.28 & 12.52 \(\pm\) 0.15 b & 3.31 \(\pm\) 0.0 e \\ \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. freudenreichii_; c-f 2—oncom after fermentation by _N. sitophila_ and 10\({}^{8}\) CFU/g FW of _P. freudenreichii_. 2 Data are shown as the mean \(\pm\) SD. Mean values within a column followed by different letters differ significantly (\(\wp\leq\) 0.05).  
\end{table} 
Table 5: Chemical composition of oncom. The level of protein in products after 5-day fermentation was around 20%, regardless of the experiment and the kind of bread. This was in line with the observations of [PERSON] et al. [31], who determined 21% (total amino acid residues) after a 6-day fermentation of stale bread with _N. intermedia_, and with those of [PERSON] et al. [32], who measured 19.6 to 21.9% (laboratory Petri dish culture, in household conditions). Mycelial activity contributes to the enrichment of the final product in protein. Similar changes in protein levels in the grain products were determined by [PERSON] et al. [33], from 13 to 21%, after fermentation of red quinoa with _N. intermedia_. In this experiment, an increase in the level of fat was noted. [PERSON] et al. [31] also observed such a tendency, an increase from 2.4% in stale bread to as much as 10.5% in 6-day oncom. [PERSON] et al. [32] noted an increase, from roughly 1% in the substrate to 4-5% depending on the culture type. The increase in lipid content in high-carbohydrate substrates is not surprising, as moulds produce lipids, which they incorporate into cellular structures, utilizing other carbon and energy sources--primarily carbohydrates in this case. The rise in lipid content observed after the fermentation might also result from the utilization of non-lipid components, altering the percentage contribution of basic components in the dry mass of the product [34]. Although moulds of the _Neurospora_ genus exhibit lipolytic properties, the utilization of lipid substrates depends on their level in the material. In contrast to the bread experiment, flaxseed oil-cake fermentation with _N.