## 2 Results and Discussion
### Ethyl Fatty Acid Esters
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & & **Ethyl Lactate** & \begin{tabular}{c} **Ethyl** \\ **Propanoate** \\ \end{tabular} & \begin{tabular}{c} **Ethyl** \\ **Hexanoate** \\ \end{tabular} & \begin{tabular}{c} **Ethyl** \\ **Octaoate** \\ \end{tabular} & \begin{tabular}{c} **Diethyl** \\ **Succinate** \\ \end{tabular} \\ \hline \multirow{8}{*}{\
\begin{tabular}{c} White \\ wine \\ \end{tabular} } & \multicolumn{1}{c}{
\begin{tabular}{c} Chardonnay \\ AF \\ COI \\ SEQ \\ SPONT \\ \end{tabular} } & \(8.54\pm 0.31\) & \(0.31\pm 0.03\) & \(0.83\pm 0.07\) & \(1.17\pm 0.09\) & \(0.68\pm 0.01\) \\  & \(134.97\pm 3.93\) & \(0.36\pm 0.05\) & \(0.36\pm 0.05\) & \(0.86\pm 0.04\) & \(1.11\pm 0.09\) & \(2.63\pm 0.02\) \\  & \(15.63\pm 5.59\) & \(0.42\pm 0.04\) & \(0.79\pm 0.09\) & \(1.14\pm 0.04\) & \(1.42\pm 0.06\) \\  & \(72.43\pm 2.64\) & \(0.39\pm 0.05\) & \(0.81\pm 0.05\) & \(1.12\pm 0.06\) & \(0.89\pm 0.03\) \\  & \(\mathrm{Kerling}\) & & & & \\  & \(\mathrm{AF}\) & \(8.62\pm 0.68\) & \(0.14\pm 0.04\) & \(0.53\pm 0.03\) & \(0.88\pm 0.05\) & \(0.32\pm 0.05\) \\  & \(\mathrm{COI}\) & \(132.57\pm 4.04\) & \(0.27\pm 0.07\) & \(0.57\pm 0.05\) & \(0.93\pm 0.04\) & \(1.14\pm 0.03\) \\  & \(\mathrm{SEQI}\) & \(111.66\pm 5.84\) & \(0.23\pm 0.03\) & \(0.53\pm 0.04\) & \(0.89\pm 0.06\) & \(0.55\pm 0.05\) \\  & \(\mathrm{SPONT}\) & \(71.04\pm 3.61\) & \(0.21\pm 0.04\) & \(0.55\pm 0.04\) & \(0.85\pm 0.08\) & \(0.49\pm 0.05\) \\ \hline \multicolumn{8}{c}{Pinot nor} \\ \multicolumn{8}{c}{A} \\ \multicolumn{8}{c}{A} \\ \multicolumn{8}{c}{AF} & \(14.44\pm 0.86\) & \(0.51\pm 0.03\) & \(0.74\pm 0.06\) & \(1.23\pm 0.04\) & \(0.54\pm 0.03\) \\  & \(\mathrm{COI}\) & \(151.25\pm 4.23\) & \(0.73\pm 0.05\) & \(0.77\pm 0.07\) & \(1.31\pm 0.03\) & \(2.07\pm 0.09\) \\  & \(\mathrm{SEQI}\) & \(97.32\pm 6.59\) & \(0.77\pm 0.03\) & \(0.74\pm 0.05\) & \(1.26\pm 0.02\) & \(1.32\pm 0.07\) \\  & \(\mathrm{SPONT}\) & \(64.97\pm 4.44\) & \(0.74\pm 0.03\) & \(0.71\pm 0.05\) & \(1.22\pm 0.05\) & \(0.76\pm 0.06\) \\  & \(\mathrm{Pinot}\) & & & & \\ \(\mathrm{Red wine}\) & \(\mathrm{AF}\) & \(11.43\pm 0.41\)[FOOTNOTE:3]Footnote 3: footnotemark: [ENDFOOTin concentration. Similar to our results, a significant increase in the concentration of ethyl lactate, ethyl propanoate, and diethyl succinate was also observed after MLF during viinification of Riesling wine [9; 17; 29], Aglianico wine [16], and Tempranillo and Merlot wine [12; 15].  
A second important group of wine esters is the acetate esters group. For this study, we selected: Ethyl acetate, isoamyl acetate, and 2-phenethyl acetate.  
Ethyl acetate is synthesized from ethanol and acetic acid, which are key metabolites in the viinification process. When its concentration does not exceed 100 mg/L, a desirable and fruity aroma enriches the wine. Its presence in higher concentrations leads to solvent, nail, varnish, and chemical aromas [4; 14; 30]. Isoamyl acetate introduces pleasant fruity notes (mostly banana) to wine aroma profiles. This ester is formed from isoamyl alcohol and acetic acid, intermediate metabolites of alcoholic and malalactic fermentation. The highest concentrations of both ethyl acetate (88.13-119.33 mg/L) and isoamyl acetate (0.76-0.94 mg/L) were always noted with spontaneous MLF (Table 3). This may be due to the notably higher concentrations of volatile acidity (as acetic acid) for this variant of viinification, as described in our previous research [13]. The different inoculation methods significantly affected the final concentration of ethyl acetate and isoamyl acetate in the white and red wines, but the concentrations did not exceed 86.87 and 0.66 mg/L, respectively (Table 3). [PERSON] et al. [14] found additionally that the production of these compounds was dependent on the MLB strain. In their study, the concentrations after MLF varied from 36.94 to 216.04 mg/L of ethyl acetate, and from 0.25 to 0.68 mg/L of isoamyl acetate.  
2-phenethyl acetate is a volatile metabolite which gives wine floral, honey, and raspberry aromas. In all the examined wines, malalactic bioconversion significantly increased (by almost a factor of two)  
* The data are the mean of triplicates \(\pm\) SD; AF—only alcoholic fermentation; COI—coinculation of yeast and bacteria; SEQI—sequential inoculation: bacteria at the end of AF; SPONT—spontaneous MLF; a, b, c, d—denotes statistically significant differences (\(p\) < 0.05) between the different inoculation techniques.
* \end{table}