## 2 Results and Discussion
### Hydrolates
& (_E_)-2-decanal & 26.424 & 1261 & 1260 & nd & tr & GC, MS \\
30. & perillaldehyde & 26.800 & 1269 & - & nd & tr & GC, MS \\
31. & bornyl acetate & 27.492 & 1284 & 1283 & 0.38 \(\pm\) 0.01 & 2.04 \(\pm\) 0.25 & GC, MS \\
32. & \(p\)-cymen-7-ol & 27.631 & 1287 & 1287 & 0.68 \(\pm\) 0.04 & 3.54 \(\pm\) 0.87 & GC, MS \\
33. & thymol & 27.899 & 1293 & 1289 & 0.38 \(\pm\) 0.02 & 0.97 \(\pm\) 0.04 & GC, MS \\
34. & carvacrol & 28.306 & 1301 & 1298 & 2.62 \(\pm\) 0.02 & 4.32 \(\pm\) 0.02 & GC, MS \\
35. & \(p\)-vinyl guaiacol & 28.719 & 1311 & 1309 & 1.63 \(\pm\) 0.25 & nd & GC, MS \\
36. & (_E_,_E_)-2,4-decanalanal & 28.879 & 1315 & 1315 & nd & 0.47 \(\pm\) 0.01 & GC, MS \\
37. & mytrivel acetate & 29.431 & 1327 & 1324 & 1.63 \(\pm\) 0.13 & 0.49 \(\pm\) 0.03 & GC, MS \\
38. & longipinence & 29.666 & 1333 & 1350 & 1.76 \(\pm\) 0.06 & nd & GC, MS \\
39. & 1H-indene,2,3-dihydro-1,1,4,5- & & 30.383 & 1349 & - & 1.22 \(\pm\) 0.03 & nd & GC, MS \\
40. & (_Z_)-\(\beta\)-damascenone & 31.859 & 1383 & 1387 & 4.80 \(\pm\) 0.34 & tr & GC, MS \\
41. & 10-(acetylmethyl)-3-carene & 32.121 & 1390 & - & 13.45 \(\pm\) 0.61 & nd & GC, MS \\
42. & \(a\)-ionone & 33.245 & 1416 & 1428 & 10.04 \(\pm\) 0.33 & tr & GC, MS \\
43. & \(a\)-copan-11-ol & 37.739 & 1527 & 1539 & nd & 0.52 \(\pm\) 0.10 & GC, MS \\
44. & cypreene epoxyde & 38.136 & 1537 & - & tr & 1.99 \(\pm\) 0.11 & GC, MS \\
45. & pathulenol & 39.648 & 1575 & 1577 & 1.50 \(\pm\) 0.12 & 8.78 \(\pm\) 0.37 & GC, MS \\
46. & \(ar\)-tumerol & 39.767 & 1579 & 1582 & 0.88 \(\pm\) 0.06 & 3.66 \(\pm\) 0.89 & GC, MS \\
47. & \(\beta\)-copan-4-a-ol & 39.870 & 1581 & 1590 Following the previously stated conclusions from the study by [PERSON] et al. (2018), the chemistry of sea fennel hydrolates differed significantly from the composition of EOs, as expected. Of the 51 compounds detected in both samples (isolated by HD and MHD), only a few were non-oxygenated and present in relatively low amounts (4.64 and 1.23%, respectively). The content of limonene in the hydrolate HD was almost twice that in the MHD sample (1.16 and 0.61%, respectively). \(\gamma\)-Terpinene was found in trace amounts in both samples, while the presence of \(\alpha\)-ionene (0.5%) and longipinene (1.76%) was confirmed only in HD hydrolate. Terpinen-4-ol was the predominant compound in both HD and MHD samples, with yields of 13.86 and 17.45%, respectively, Figure 2. HD hydrolate was characterised by the presence of (\(Z\))-\(\beta\)-damascenone (4.80%), 10-(acetylmethyl)-3-carene (13.45%), and (\(E\))-\(\alpha\)-ionone (10.04%), the presence of which was either not confirmed or detected in trace amounts in the MHD sample. The contents of benzacetaldehyde (5.34%) and linalool (1.29%) were significantly higher in the HD than in the MHD sample. Among the other compounds, the most significant increase in yield in the MHD sample compared to the HD sample was observed for spathulenol (5.8-fold higher amount) and \(ar\)-tumerol (4.16-fold higher amount). The yields of (\(E\))-carveol, isocarveol, and \(\alpha\)-terpineol were also higher in the MHD hydrolates with proportions of 4.92 and 5.70%, 1.23 and 4.17%, and 2.92 and 3.85%, respectively. Other dominant components such as (\(Z\))-sabinene hydrate, (\(E\))-sabinene hydrate, (\(E\))-sabinene hydrate, (\(E\))-\(p\)-mentha-2,8-dienol, (\(Z\))-\(p\)-mentha-2,8-dienol, and carvacrol were found in about twice the amounts in the MHD hydrolate. It is interesting that among the compounds detected in the hydrolates there was also dillapiol, which has not been found so far in Croatian sea fennel (14; 19; 20). This compound was interesting because, according to [PERSON] et al. (2014), two different chemotypes of sea fennel can be distinguished in terms of its content, and, according to their report, Croatian sea fennel belongs to the chemotype II, with a content of 0-6% dillapiol. In this study, the content of dillapiol in hydrolates was also quite low, 1.12% in HD hydrolate and 1.56% in MHD hydrolate, while its presence in EOs was again not confirmed.