## 3 Results and Discussion
### The Content of Organic Acids, Sugars, Ethanol, and Vitamin C  
During the mashing process, polysaccharides undergo hydrolysis under the influence of enzymes and acids (Table 3). Afterwards, the role of yeasts in the fermentation process is to convert sugar into alcohol and carbon dioxide [37; 38]. Therefore, at this stage of the experiment, control samples \"C\" (CL, CD) (CL--control light beer, CD--control dark beer,), i.e., basic beer, where the amount of ethanol was 3.79 mL 100 mL\({}^{-1}\) of light beer and 3.28 mL 100 mL\({}^{-1}\) of dark beer, this alcohol content is deduced by the mashing parameters used. Additionally, in unpasteurized beer samples with the addition of the AAB starter culture, the amount of ethanol was at a comparable level (Table 3). Significantly lower amounts of ethanol (\(p<0.05\)) were determined in pasteurized beer and inoculated with AAB starter culture. This demonstrates good environmental conditions in BPGL and BPGD samples for the growth of the AAB starter culture, as AAB utilized ethanol to grow. These differences were due to the pasteurization of the samples (BJP and BGP) and the inactivation of the yeast that produces ethanol. AAB tolerates the active acidity of the environment in the range of 3.6-6.3 [35; 36]. In the studied beverage variants, the pH values in samples with the addition of AAB  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multirow{2}{*}{**Ethanol** **[mL 100 mL\({}^{-1}\)]**} & \multirow{2}{*}{**Vitamin C** **[mg 100 mL\({}^{-1}\)]**} & \multirow{2}{*}{**Glucose**} & \multirow{2}{*}{**Fructose**} & \multirow{2}{*}{**Maltose**} & \multirow{2}{*}{**Sucrose**} \\ \cline{1-1} \cline{5-7}  & & & & & & \\ \hline BJPL & 2.82 \({}^{\text{a}}\)\(\pm\) 0.04 & 1.03 \({}^{\text{a}}\)\(\pm\) 0.06 & 1.13 \({}^{\text{a}}\)\(\pm\) 0.01 & 0.83 \({}^{\text{a}}\)\(\pm\) 0.01 & 0.27 \({}^{\text{a}}\)\(\pm\) 0.01 & 0.18 \({}^{\text{a}}\)\(\pm\) 0.02 \\ BPGL & 2.72 \({}^{\text{ab}}\)\(\pm\) 0.03 & 2.83 \({}^{\text{bf}}\)\(\pm\) 0.06 & 0.34 \({}^{\text{b}}\)\(\pm\) 0.02 & 0.03 \({}^{\text{b}}\)\(\pm\) 0.01 & 0.23 \({}^{\text{b}}\)\(\pm\) 0.01 & nd \({}^{\text{b}}\) \\ BGL & 3.14 \({}^{\text{c}}\)\(\pm\) 0.04 & 2.03 \({}^{\text{c}}\)\(\pm\) 0.06 & nd \({}^{\text{c}}\) & 0.01 \({}^{\text{cg}}\)\(\pm\) 0.00 & 0.24 \({}^{\text{b}}\)\(\pm\) 0.01 & 0.03 \({}^{\text{c}}\)\(\pm\) 0.00 \\ CL & 3.79 \({}^{\text{d}}\)\(\pm\) 0.09 & nd \({}^{\text{d}}\) & 0.05 \({}^{\text{d}}\)\(\pm\) 0.01 & nd \({}^{\text{cd}}\) & 0.33 \({}^{\text{c}}\)\(\pm\) 0.01 & nd \({}^{\text{b}}\) \\ \hline BJPD & 2.53 \({}^{\text{b}}\)\(\pm\) 0.02 & 1.57 \({}^{\text{e}}\)\(\pm\) 0.06 & 0.65 \({}^{\text{e}}\)\(\pm\) 0.02 & 0.02 \({}^{\text{bc}}\)\(\pm\) 0.01 & 0.39 \({}^{\text{d}}\)\(\pm\) 0.01 & nd \({}^{\text{b}}\) \\ BPGD & 2.94 \({}^{\text{ac}}\)\(\pm\) 0.03 & 2.43 \({}^{\text{f}}\)\(\pm\) 0.06 & 0.99 \({}^{\text{f}}\)\(\pm\) 0.02 & 0.67 \({}^{\text{e}}\)\(\pm\) 0.01 & 0.23 \({}^{\text{b}}\)\(\pm\) 0.01 & 0.03 \({}^{\text{c}}\)\(\pm\) 0.00 \\ BGD & 3.22 \({}^{\text{c}}\)\(\pm\) 0.13 & 2.60 \({}^{\text{bf}}\)\(\pm\) 0.20 & nd \({}^{\text{c}}\) & 0.09 \({}^{\text{f}}\)\(\pm\) 0.01 & 0.39 \({}^{\text{d}}\)\(\pm\) 0.01 & nd \({}^{\text{b}}\) \\ CD & 3.28 \({}^{\text{c}}\)\(\pm\) 0.08 & nd \({}^{\text{d}}\) & 0.03 \({}^{\text{cd}}\)\(\pm\) 0.01 & nd \({}^{\starter culture were significantly lower than in beer without the addition of _G. oxydans_ H32 (_p_ < 0.05). These results are confirmed by the number of AAB in each of the study beverage samples (Table 2). It additionally attests to the metabolic processes carried out by these microorganisms in the studied beers. The main metabolites produced by AAB are organic acids, including acetic acid. It is formed during the oxidation of ethanol, and this reaction is accompanied by enzymes that catalyse the entire process. Alcohol dehydrogenase (ADH), which accompanies the oxidation of ethyl alcohol to acetaldehyde, is responsible for the first stage of its entire production.