## 3 Results and Discussion
Those fatty acids are associated with a sweet, rancid, and cheesy aroma note in wines. In our research, in all wines, only two of them, butanoic and hexanoic acid, were in concentrations higher than the odor detection threshold (173 and 420 \(\mu\)g/L, respectively) [49]. The L wines had a significantly higher concentration of 2,4-hexadienedioic, butanoic, decanoic, and dodecanoic acid in comparison to S wines and 3-methylbutanoic and butanoic acid in comparison to N wines. In L and N wines, the higher diversity between fatty acids and increase in fatty acids, higher alcohols, and esters could be due to a specific metabolic interaction between _L. thermotolerans_ and _S. cerevisiae_[6] and non-_Saccharomyces_ and _S. cerevisiae_ in comparison to monoculture. The N wines had the highest concentration of the total sum of lactones (933.80 \(\pm\) 32.44 \(\mu\)g/L), and the S wines were minimal (495.39 \(\pm\) 11.85 \(\mu\)g/L). In L and N wines, a higher concentration of butyrolactone over \(\gamma\)-heptalactone is seen, while in S wines, \(\gamma\)-heptalactone predominates. Lactones are formed during fermentation from fatty acids in _the_\(\beta\)-oxidation pathway [50], although some of them have been found in the over-ripe grape of Syrah [51]. Previously, the most abundant lactone in wines produced with different _Saccharomyces_ strains (three _S. cerevisiae_ and one _S. bayanus_) was butyrolactone [33]. The S wines had a maximum of volatile phenols (113.94 \(\pm\) 2.09), with a maximum of 4-ethyl guaiacol and 4-ethyl phenol, while none of the volatile phenols was detected in L wines. Differences in volatile phenols in _S. cerevisiae_ compared to non-_Saccharomyces_-produced wines were previously reported [52]. Production of volatile phenols is associated with a non-oxidative decarboxylation of the hydroxycinnamic acids early in fermentation steps after four to 48 h [10; 53]. In red wines, enzyme activity is inhibited by catechhin flavour-3-ol monomers and dimers [10]. It could be that in our case, _L. thermotolerans_ blockade this process early in fermentation steps, as the decarboxylase activity of _S. cerevisiae_ strain is maximal at the beginning of the stationary phase and decrease rapidly when the viability of the cells diminishes [10]. Those two compounds below 140 and 620 \(\mu\)g/L for 4-ethyl guaiacol and 4-ethyl phenol, respectively, positively contribute to red wine aroma [54]. In higher concentrations, those are carriers of barnyard, animal, and clove-like and smoke aromas associated with a \"Brett character\" found in wines contaminated with _Brettanomyces_ yeast [55]. Among other compounds, the most abundant was Methionol (3-(methylthio)-1-propanol), which was especially abundant in N wines (5978.68 \(\pm\) 107.43 \(\mu\)g/L) contrary to minimal concentrations in L wines (53.23 \(\pm\) 3.53 \(\mu\)g/L). This volatile sulfur flavor compound is derived from the amino acid methionine. It has a low odor threshold ranging from about one to 3 ppm (1000-3000 \(\mu\)g/L) and perception of baked cabbage [56]. Production of this compound depends on the methionine level in the yeast strain used and can be modulated by quantity and quality of nitrogen nutrient selection [43]. Polyphenic Profile of the Plavac Mali Wines Produced by Sequential L, Conventional S and Spontaneous N Fermentation  
Both sequential L and conventional S fermentation led to a significant reduction in non-flavonoid HCA acids, mainly the most predominant one, caftaric acid (Table 4). In berries caftaric, coutaric, and ferratic acids are tartaric esters of HCAs. In fermentation, those are released by the cinnamyl esterase enzymes and can be transformed by hydroxycinnamate decarboxylalase and vinylphenol reductase into volatile phenols. In S wines significant decrease in HCA and caftaric acid and an increase in volatile phenols is associated with a strong hydroxycinnamate decarboxylalase activity of _S. cerevisiae_[10].