## 3 Results and Discussion
### Gc-Ms
Four of them, \(\beta\)-damascenone, \(\beta\)-ionone, 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN), and _trans_-1-(2,3,6-trimethylphenyl)buta-1,3-diene (TPB), were commonly found in wine at concentrations surpassing their odor perception thresholds, meaning they can have a direct impact on wine aroma [34]. Especially important is \(\beta\)-damascenone with its pleasant odor reminiscent of honey, dried plum and stewed apple, and a very low perception threshold, which ranks it among the most important wine odorants [37]. \(\beta\)-Ionone, characterized by a threshold of the similar order of magnitude, also significantly contributes to wine aroma with an odor reminiscent of violets, while the contribution of TDN and TPB becomes relevant mostly in aged wines [34]. The concentrations of the majority of C\({}_{13}\)-norisoprenoids were generally higher in Dalmatian Posip and Marastina, and the lowest in Kraljevina wines, although in particular cases with no statistical significance (Table 1). According to [PERSON] and [PERSON] [54] the concentration of \(\beta\)-damascenone is principally dependent on vicitcultural and winemaking conditions, while variety has less influence. Nevertheless, particular differences were observed: Malvazija wines were found to contain the highest concentration, although not different from that found in Posip, while Skrlet had the lowest, not different from that found in Marastina wine. Malvazija was also characterized by the lowest concentration of vitispiranes together with Kraljevina wine. Among benzenoids, ethyl cinnamate emerged as a prominent marker of Posip varietal origin, since it was found in the highest concentration in this wine. C\({}_{6}\)-alcohols are formed mainly in pre-fermentation vinicitation steps by degradation of unsaturated fatty acids by the action of enzymes, as well as by liberation from glycosidic precursors. They may have an effect on wine aroma with their so-called green and herbal odors, but luckily have relatively high odor perception thresholds, such as 8000 ug/L for 1-hexanol [37], so only very high concentration can produce negative effects. Certain authors include C\({}_{6}\)-compounds among varietal aromas [16] and their concentrations were found useful in differentiation of particular wines based on variety [43; 55]. The highest concentration of 1-hexanol was found in Skrlet, while Kraljevina contained the lowest amount (Table 1). Marastina, and especially Posip wines were characterized by the highest concentration of unsaturated C\({}_{6}\)-alcohols. It is possible that the mentioned differences were a consequence of different enzymatic potentials and fatty acid precursor loads in grapes of these varieties [55]. Concentrations and the composition of fermentation aroma compounds are mainly affected by fermentation conditions, but may also be influenced by grape composition [56]. Many studies proved that the composition of volatile compounds formed in fermentation can be useful in differentiating wines of mostly neutral varieties equally or even more successful than by using, e.g., monoterpeneconcentrations [11; 14; 20; 29]. This is more characteristic for C6-C10 fatty acids and the corresponding ethyl esters which, in contrast to acetates, are more dependent on the concentration of precursors and therefore on variety and conditions in vineyard, and less on the activity of yeast [57]. The average concentration of 2-phenylethylanol was higher than the corresponding odor perception threshold of 10,000 ug/L in all the studied monovarietal wines, meaning this alcohol contributed significantly with its odor reminiscent of roses [37]. Pospip and Marastina had approximately 50% higher concentration of 2-phenylethylanol in relation to the other investigated wines (Table 1). The concentrations of major volatile fatty acids (C6-C10) surpassed the corresponding odor perception thresholds of 420, 500, and 1000 ug/L, respectively [58], in all the investigated wines.