## 3 Results and Discussion
### Volatile Composition of Wines
The total amount of esters (with the OAV over 1) in the control samples was twice lower than in both the samples fermented with \(H\). _uvarum_ S-2 and 2.5 times lower than in both samples produced by \(C\). _famata_ WB-1. Although each ester follows different patterns and their concentration is dependent on the yeast strain and fermentation protocol, generally higher content was present in samples produced in sequential fermentation protocol. Another researcher also reported higher contents of esters in wine samples produced in sequential fermentations for different non-_Saccharomyces_ species [13; 47]. Independently of the yeast strain and fermentation protocol, ethyl hexanoate expressed the highest contribution to the aroma of all analyzed Tamjanika wine samples (ROC up to 50%), followed by ethyl decanoate (ROC up to 15.95%), ethyl octanoate (ROC up to 5.53%), and phenylethylacetate (ROC lower than 5%). Compared to the control sample, the total ethyl ester content was significantly higher in wines fermented by native \(C\). _famata_ WB-1 (from 9 to 28% higher for pure and sequential inoculation) and \(H\). _uvarum_ S-2 (from 52 to 42% higher for pure and sequential inoculation) yeasts. Furthermore, in our experiments, the commercial yeast strain produces Tamjanika wine with the lowest content of higher alcohol acetates, while sequential inoculation of selected yeast isolates resulted in an increase in the production of these compounds known to contribute to fruity notes (mainly banana and apple odor) of wine. These results indicate that the \(C\). _famata_ WB-1 and \(H\). _uvarum_ S-2 yeasts were able to esterify present higher alcohols better than the used commercial strain, providing about 7- and 2.5-times higher alcohol acetates than in a control sample, respectively. Knowing that the enzymatic formation of ethyl and acetate esters required specific enzymes (acyl-CoA synthetase, alcohol acetyltransferasease) [3], such results were evidence that the used native yeast strains were able to produce ester-synthesizing enzymes in higher content compared to the commercial \(S\). _cerevisiae_ QA23 strain. Therefore, the significant differences in the OAV and ROC for each compound confirmed the influence of the yeast strains on the wine's aromatic profile and justified the need to find the best possible match of the yeast species and grape variety. For the recognizability of the characteristic and unique aroma of the Muscat grape, such as Tamjanika grape variety, different terpen play a fundamental role. Linalool and geraniol are recognized as predominant terpenic aroma compounds present in Muscat grapes, along with citral, citronello1, nerol, and \(\alpha\)-terpinee [57; 58]. In accordance with the literature data, seven terpen, p-cymene, \(\gamma\)-terpinene, terpinolene, linalool, (Z) and (E)-\(\beta\)-ocimene, and one C13-norisoprenoid (\(\beta\)-ionone), were present above the ODT and contribute to the overall aroma of analyzed Tamjanika wine samples (Table 2). The average total concentration of terpen ranged between 0.25 and 0.98 mg/L, for control and pure fermentation with \(C\). _famata_ WB-1, while only p-cymene and terpinolene were present in all samples. The concentration of individual terpen quantified in analyzed Tamjanika wine samples was similar to the levels of p-cymene (5-35 \(\upmu\)g/L), \(\gamma\)-terpinene (6-35 \(\upmu\)g/L), nerol (3-43 \(\upmu\)g/L), and linalool (6-375 \(\upmu\)g/L) averagely present in different Muscat wines [59]. According to their ROC values of up to 12%, these compounds could significantly affect the wine aroma and sensory profile of Tamjanika wines regardless of their low concentration in the samples. Linalool, which positively contributes to the floral notes, was presented with OAV > 1 (from 3.2 to 4.8 for sequential and pure fermentation, respectively) in wines fermented by \(H\). _uvarum_ S-2, but was not detected in wines fermented by \(C\). _famata_ WB-1 and commercial \(S\). _cerevisiae_ QA23 strain.