## 4 Discussion
The group of polyphenolic compounds, anthocyanins, were present only in the elderflower WWVs, and were not detected in rosemary, thyme, or unflavored WWVs. Among anthocyanins, malvidin was the compound with the highest concentration. The most abundant group of phenolic compounds in the WWVs flavored with elderflower were flavonols, while flavones were found in significantly higher concentrations in WWVs flavored with rosemary (apigenin-4-O-glucose and apigenin-7-O-glucose) and thyme (luteolin-7-O-glucose). The highest polyphenolic compound concentrations (7 of 19 detected flavonoids) were detected in the elderflower compared to other flavored WWVs, probably because of the higher dose of the added plant material (20 g/L) compared to the other WWVs (4 g/L). Among flavonoles, quercetin and chlorogenic acid were most abundant in elderflower-flavored WWV, among flavonoles and hydroxycinnamic acids, respectively. Previous investigations of the elderflower phenolic profile demonstrated caffeoylquinic acid (chlorogenic acid) and quercetin-3-rutinoside (rutin) [26; 38] as the main phenolic compounds. In our research, chlorogenic acid and quercetin were the main phenolics in the WWVs flavored with elderflower. Chlorogenic acid was not detected in the unflavored WWV, and this phenolic compound is related to the plant material used for the WWV flavoring. Total flavonoids, followed by total hydroxycinnamic acids, were the groups of phenolic compounds with the highest concentration in elderflower methanol extracts and sabesa (a beverage made of water with added sucrose and citric and acetic acid) in [PERSON] et al. [26], as well as in our research. The variations in aromatic and phenolic compound concentrations between our and other studies could be attributed to differences in the growing [34; 35; 39] or drying conditions [23], extraction or maceration solvent [26], detection method, and variations in the chemotypes [21] of aromatic plants. As the PCA has shown, the main contribution of elderflower to WWV was the substantial increase in all polyphenolic groups, except for flavones, which is consistent with the increased dosage used in its preparation as well as the polyphenolic profile of elderflower as shown by [PERSON] et al. [40]. Besides the increase in polyphenolic compounds, the sensory analysis has shown a distinct floral aroma of the elderflower-infused WWV compared to the other investigated WWVs, which is a direct effect of aroma compounds present in elderflower [41]. Similarly, the PCA showed that thyme and rosemary maceration contributed to the elevated terpenes, esters, and alcohols, as well as flavones and dihydroflavonols in WWV, but with distinct volatile and sensory profiles, characteristic for each plant species. In our investigation, thyme-infused WWV exhibited spicy and herbaceous notes characteristic of the herb and described by [PERSON] and [PERSON] [42]. On the other hand, rosemary-infused WWV is characterized by pinewood and herbal notes, which is in line with the work of [PERSON] et al. [43]. Consistent with the smaller dosage of thyme and rosemary compared to elderflower, the polyphenolic enrichment of the herb-infused WWV is evident compared to the control WWV, albeit in lower abundance if compared to the elderflower macerated WWV in our study. Both thyme and rosemary macerated WWVs were shown to be rich in flavones, more precisely in luteolin, apigenin, baicalein, and their glycosides. This is in line with the investigation by [PERSON] et al. [21] on rosemary and [PERSON] et al. [44] on both rosemary and thyme polyphenic profiles. To the best of our knowledge, this is the first research that uses dried herbal parts of black elder, rosemary, and thyme as a material for maceration in white wine vinegar and analyzes the volatile and polyphenolic compounds, as well as the sensory profile of the obtained flavored vinegas.