# How Different Fermentation Type Affects Volatile Composition of Plum Jerkums
## 3 Results and Discussion
### Chemical Composition of Fresh Plum Musts and Jerkums
Succinic acid could originate from either sugar or amino acid catabolism of yeast; however, it is connected to growth conditions and available nitrogen sources. Therefore, higher concentration of that organic acid in fermented musts produced from Wegierka Dabrowicka and Cacanska Lepotica could be related to a higher concentration of free amino nitrogen in those plum cultivars. Moreover, reactions of tricarboxylic acid cycle determine its direct formation [19]. Volatile acidity of wines is mostly built up by the acetic acid. That substance could be formed in biochemical reaction during fermentation or could be directly produced by acetic or lactic acid bacteria (LAB). When acetic acid is present above a certain concentration (1.2 g/L volatile acidity expressed as acetic acid), it decreases the quality of wine and it also inhibits the performance of yeasts [20; 21]. A slightly higher amount of this compound was present in samples obtained from Stanley cultivar fermented with Ethanol RED and from Cacanska Lepotica fermented spontaneously. We did not notice any correlation between concentrations of acetic and lactic acids--low concentrations of acetic acid was determined in samples that contained significant quantities of lactic acid and the other way around. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Plum** & **Type of** & **Citric** & **Malic** & **Succinic** & **Lactic** & **Actic Acid** & **Glycerol** & **Fructose** & **Sucrose** & **Glucose** \\ \cline{2-10}
**Cultvar** & **S. cerevisiae** S1 & 0.29 \({}^{\text{a}}\) & 0.99 \({}^{\text{c}}\) & 2.01 \({}^{\text{a}}\) & 9.38 \({}^{\text{a}}\) & 0.28 \({}^{\text{c}}\) & 3.10 \({}^{\text{d}}\) & 0.47 \({}^{\text{d}}\) & 1.44 \({}^{\text{b}}\) & 2.79 \({}^{\text{bc}}\) \\ \cline{2-10}
**Wegierka** & _H. uavrum_ H2 & 0.00 \({}^{\text{d}}\) & 0.00 \({}^{\text{d}}\) & 1.39 \({}^{\text{b}}\) & 0.48 \({}^{\text{d}}\) & 0.59 \({}^{\text{bc}}\) & 2.54 \({}^{\text{d}}\) & 1.69 \({}^{\text{c}}\) & 0.42 \({}^{\text{d}}\) & 0.00 \({}^{\text{d}}\) \\ \cline{2-10}
**Zwykha** & Spontaneous & 0.00 \({}^{\text{d}}\) & 0.00 \({}^{\text{d}}\) & 0.12 \({}^{\text{d}}\) & 0.75 \({}^{\text{d}}\) & 0.47 \({}^{\text{c}}\) & 5.42 \({}^{\text{c}}\) & 1.01 \({}^{\text{c}}\) & 0.16 \({}^{\text{d}}\) & 0.00 \({}^{\text{d}}\) \\ \cline{2-10}  & Ethanol RED & 0.00 \({}^{\text{d}}\) & 0.00 \({}^{\text{d}}\) & 0.17 \({}^{\text{d}}\) & 0.89 \({}^{\text{d}}\) & 0.69 \({}^{\text{b}}\) & 5.14 \({}^{\text{c}}\) & 0.22 \({}^{\text{d}}\) & 0.59 \({}^{\text{d}}\) & 2.16 \({}^{\text{b}}\) \\ \hline \multirow{5}{*}{Dbrowicka}{Dbrowicka} & _S. cerevisiae_ S1 & 0.19 \({}^{\text{b}}\) & 3.50 \({}^{\text{a}}\) & 2.15 \({}^{\text{a}}\) & 6.94 \({}^{\text{b}}\) & 0.84 \({}^{\text{b}}\) & 6.92 \({}^{\text{bc}}\) & 0.61 \({}^{\text{d}}\) & 0.32 \({}^{\text{d}}\) & 2.63 \({}^{\text{bc}}\) \\ \cline{2-10}  & _H. uavrum_ H2 & 0.24 \({}^{\text{b}}\) & 3.21 \({}^{\text{a}}\) & 2.26 \({}^{\text{a}}\) & 5.39 \({}^{\text{bc}}\) & 0.93 \({}^{\text{ab}}\) & 6.25 \({}^{\text{bc}}\) & 0.00 \({}^{\text{e}}\) & 2.46 \({}^{\text{a}}\) & 4.14 \({}^{\text{b}}\) \\ \cline{2-10}  & Spontaneous & 0.34 \({}^{\text{a}}\) & 1.07 \({}^{\text{c}}\) & 1.29 \({}^{\text{b}}\) & 4.62 \({}^{\text{c}}\) & 0.34 \({}^{\text{c}}\) & 5.01 \({}^{\text{c}}\) & 6.58 \({}^{\text{b}}\) & 1.16 \({}^{\text{c}}\) & 1.45 \({}^{\text{c}}\) \\ \cline{2-10}  & Ethanol RED & 0.29 \({}^{\text{a}}\) & 3.32 \({}^{\text{a}}\) & 1.91 \({}^{\text{ab}}\) & 3.19 \({}^{\text{d}}\) & 0.57 \({}^{\text{bc}}\) & 8.88 \({}^{\text{ab}}\) & 2.35 \({}^{\text{c}}\) & 0.00 \({}^{\text{d}}\) & 9.85 \({}^{\text{a}}\) \\ \hline \multirow{5}{*}{Stanley} & _S. cerevisiae_ S1 & 0.14 \({}^{\text{c}}\) & 1.23 \({}^{\text{c}}\) & 1.57 \({}^{\text{b}}\) & 6.38 \({}^{\text{b}}\) & 0.25 \({}^{\text{c}}\) & 7.93 \({}^{\text{b}}\) & 11.28 \({}^{\text{a}}\) & 0.85 \({}^{\text{cd}}\) & 0.65 \({}^{\text{cd}}\) \\ \cline{2-10}  & _H.