## 3 Results and Discussion
### Volatile Compounds (VCs) Analysis  
The results are shown in Table 2. The analysis was carried out only for the samples of 25% EtOH treated with PEF at 100 \(\upmu\)s, which displayed the highest percentage increase in Y\({}_{\text{TP}}\) and oxidation temperature between PEF and the reference extracts. The peak area obtained by HS-SPME/GC-MS was used to semi-quantify the concentration of different VCs.  
Due to the large number of synonyms available, matching compounds by name tags was difficult, as was an accurate and thorough search using chemical IDs (e.g., CAS numbers). The identify compounds show strong MS similarity with library entries, without further information available.  
The main components of SOLL previously identified were \(\alpha\)- and \(\beta\)-thujone [34], \(\alpha\)- and \(\beta\)-pinene, camphor and \(\alpha\)-humulene [35], and 1,8-cineole, \(\beta\)-caryophyllene, camphene, myrcene, \(\gamma\)-terpinene, and \(p\)-cymene [36; 37]. In our study, the principal VCs identified were eucalypt, \(\beta\)-thujone, d- and l-camphor, 2-bornanol, bornel (endo-borneol), and l-borneol. These main compounds were identified in PEF-treated and reference extracts at about the same total percentage (65.51% and 67.58%, respectively). However, important differences appeared in the percentage of each of the above VCs between the differently treated samples. Specifically, d-camphor, bornel, and L-borneol showed an increase in PEF-treated extract, while eucalypt, \(\beta\)-thujone, l-camphor, and 2-bornanol decreased. Differences also appeared in many other compounds (Table 2). Additionally, some compounds (\(p\)-cymen-8-ol, (\(-\))_trans_-pinocarveol, piperitone, \(\alpha\)-santalene, calarene, (\(+\))-epizonarene, (\(+\))-longifolene and (\(-\))-\(\gamma\)-cadinene) appeared only in the PEF treated extract. The compounds \(p\)-cymen-8-ol and (\(-\))-\(\gamma\)-cadinene were previously identified in _S. officialis_ L. leaves extracted by supercritical CO\({}_{2}\)[38] or distillation-extraction [37]. Calarene and (\(-\))_trans_-pinocarveol were also previously reported [39; 40].  
The above results indicate that PEF effects can influence the aroma of SOLL extracts. Another study in line with the above conclusion is that of [PERSON] et al. [41]. These authors studied the result of PEF technique on the flavor profile of red-fleshed sweet cherries and concluded that PEF-treated extracts produced higher amounts of volatile compounds that characterize the flavor, and that no adverse compounds appeared because low energy intensities were applied.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Extraction Solvent** & **PEF Pulse** & **T\({}_{\text{max}}\) (\({}^{\circ}\)C) of PEF** & **T\({}_{\text{max}}\) (\({}^{\circ}\)C) of** & **Increase** \\
**Synthesis** & **Duration (\(\upmu\)s)** & **Treated Extract** & **Reference Extract** & **(\%)** \\ \hline \multirow{2}{*}{0\% EtOH} & 10 & 237\(\pm\) 3 \({}^{\text{1}}\) & \multirow{2}{*}{203 \(\pm\) 2} & 16.7 \\  & 100 & 221 \(\pm\) 2 & & 8.9 \\ \hline \multirow{2}{*}{25\% EtOH} & 10 & 280 \(\pm\) 3 & \multirow{2}{*}{182 \(\pm\) 3} & 53.8 \\  & 100 & 294 \(\pm\) 3 & & 61.5 \\ \hline \multirow{2}{*}{50\% EtOH} & 10 & 350 \(\pm\) 2 & \multirow{2}{*}{312 \(\pm\) 5} & 12.2 \\  & 100 & 362 \(\pm\) 4 & & 16.0 \\ \hline \multirow{2}{*}{75\% EtOH} & 10 & 487 \(\pm\) 7 & \multirow{2}{*}{387 \(\pm\) 8} & 25.8 \\  & 100 & 462 \(\pm\) 8 & & 19.4 \\ \hline \multirow{2}{*}{100\% EtOH} & 10 & 294 \(\pm\) 6 & \multirow{2}{*}{257 \(\pm\) 7} & 14.4 \\  & 100 & 310 \(\pm\) 7 & & 20.6 \\ \hline \hline \end{tabular} \({}^{\text{1}}\) Values are means of triplicate determinations \(\pm\) Standard deviation.  
\end{table}
Table 1: Oxidation temperature (T\({}_{\text{max}}\)) of the various samples during DSC determination.