## 3 Results and Discussion
### Integrated Evaluation of Instrumental and Sensory Data Using PCA Analysis
PCA also confirmed the distinctly different composition of black currant cultivars, which (unlike red/white cultivars) show a strong correlation with aldehydes, ketones, acids, esters, and terpen. They are also characterized by their asringent and \"blackcurrant\" flavor notes [13; 19; 15], which were strongly correlated with each other. However, these properties correlated negatively with overall flavor, indicating that they are generally perceived negatively by consumers. The flavor of black currants is generally less preferred than that of red/white cultivars. As expected, flavor contributed most significantly to the overall acceptability of the samples. Sweetness correlated negatively with acidity and astringency (see Figure 2b), which, consequently, contributed negatively to sample acceptability. It can be inferred that assessors/consumers prefer sweeter, less acidic currants. To estimate which compounds contribute to sample flavor, odor activity values (OAVs)--the ratio of a compound's concentration to its odor threshold--were calculated. Because currant berries primarily consist of water, odor thresholds in water, obtained from the literature, were used. In black currants, the following compounds had OAVs \(\geq 1\) (exact values in parentheses) and were, therefore, considered to contribute to their aroma (aroma descriptions are provided in Table S1): \(\beta\)-damascenone (1520) \(>\) 1-octen-3-one (298) \(>\) \(\delta\)-3-carene (55) \(>\) 3-methylbutanan-1-ol (30) \(>\) (Z)-3-hexenal (17) \(>\) ethyl butanoate (12) \(\approx\) ethyl hex anoate (12) \(\approx\) rose oxide (12) > hexanal (9) > ethyl propanoate (8) > 1-octen-3-ol (6) > octanal (5) > nonanal (4) > ethyl heptanoate (2) \(\approx\) (E)-2-octenal (2). The remaining compounds with OAVs < 1 likely make minor or no contributions. This is comparable with [PERSON] [26], who, based on the OAV concept, detected the C\({}_{6}\) compounds hexanal, (Z)-3-hexenal, (E)-2-hexenal, and (Z)-3-hexenol; the short-chain esters ethyl butanoate and methyl butanoate; and the terpenes 1,8-cineole, \(\alpha\)-pinene, rose oxide, 1-octen-3-one, and 1-octen-3-ol as odor-active compounds. Of these, \(\beta\)-damascenone, 3-methylbutan-1-ol, octanal, nonanal, ethyl propanoate, and ethyl hexanoate were also recognized as key components in other studies on black current berries [12; 13; 16; 17]. In red/white currants, the following compounds showed OAVs \(\geq\) 1: \(\beta\)-damascenone (>1000) > 1-octen-3-one (>100) > ethyl propanoate (11) > ethyl hexanoate (5-6) > octanal (5) \(\approx\) hexanal (5) > ethyl butanoate (4-5) > 1-octen-3-ol (4) \(\approx\) nonanal (4). Consistent with our results, the only study dealing with OAV values in red currants [26] identified \(\beta\)-damascenone and 1-octen-3-one as odor-active. However, (E)-2-hexenal and acetic acid, which they found to be important, were detected in concentrations that were too low in our samples, and (Z)-3-hexenal was not detected in our cultivars at all. As shown, \(\beta\)-damascenone (0.002 \(\upmu\)g/L) and 1-octen-3-one (0.005 \(\upmu\)g/L), compounds with low odor thresholds, had the highest OAVs in all current variants. According to [PERSON] et al. [17], fruity, floral, and sweet notes are the major aroma features in currants, to which, according to our results, mainly terpenes and esters with high OAVs likely contribute.