## 3 Results and Discussion
### Contents of Phenolic Compounds in Croatian Wines
#### 3.1.2 Flavan-3-ols, Anthocyanins, and Stilbenes in Selected Red and White Wines
Looking at the composition of flavan-3-ol in the Chardonnay samples studied, only one difference can be observed, namely that the sample from Istria (wCR) contained more catechin than the sample from the Croatian Danube region (wCB). The first sample was similar to the sample from northern Italy from the 2014 vintage [57]. Traminer wine (wTI) contained twice as much catechin as the Croatian sample from the 2008 and 2009 experimental vintages [22]. Rhine Riesling from Slavonia (wRD) contained 8.1 mg/L procyanidin B2, which was significantly higher than that of the previously studied sample from northwestern Croatia [53]. There was no statistically significant difference in the other six white wine samples in which 3.0-3.8 mg/L procyanidin B2 was determined (Table 4). No tested anthocyanins were detected in the white wines, while their content varied widely in the red wines (Table 4). The content of delphindin-3-glucoside was low, reaching a maximum of 0.5 mg/L in the Cabernet Sauvignon from southern Dalmatia (rCD). The same wine also contained a high concentration of 20.2 mg/L malvidin-3-glucose, which was not the case in other Cabernet Sauvignon wines from Istria, Dalmatia, and the Croatian Danube. A similar malvidin-3-glucose content to rCD was also found in the Blauer Portugieser from the Croatian Uplands (rPM) at 21.4 mg/L. The other red wines contained 1.4-6.0 mg/L malvidin-3-glucose. As mentioned above, Blauer Portugieser from the Croatian Uplands (rPM) and Cabernet Sauvignon from southern Dalmatia (rCD) contained the most anthocyanins, but these are still lower values compared to the results of [PERSON] et al. [58] and [PERSON] et al. [59], who analyzed Czech and Brazilian wines, respectively. As the most abundant anthocyanin in grapes, malvidin-3-glucose was predominant in all the red wine samples, but its content in the wines studied was significantly lower compared to most previously published results. Thus, its content in Merlot from various European countries was 4.49-41.9 mg/L [38; 60], while our samples from the Dalmatian Hinterland (rMK) and Croatian Istria (rMA) contained only 1.6-2.1 mg/L of malvidin-3-O-glucose, which is also much lower than the samples from Croatia studied by [PERSON] et al. [16]. This was very similar in the other red wines studied, such as Syrah and Pinot Noir. Our samples contained significantly less malvidin-3-glucose than the Brazilian [42; 46; 59] or Hungarian [60] wines. It is interesting to note that not only the examined non-autochthonous but also the Croatian autochthonous red wines had unexpectedly low anthocyanin contents. In comparison with our results, many times higher levels of malvidin-3-glucose were previously found in Plavac Mali [16; 17] and Teran [16] wines. As shown in Table 4, unlike white wines, red wines contained silbenes and the proportion of _trans_-resveratrol was generally much higher than that of _cis_-resveratrol in all the wines studied, which is consistent with numerous previous relevant studies [2]. In addition to anthocyanins, the Blauer Portugieser from Croatian Uplands (rPM) contained the highest levels of _trans_-resveratrol (6.8 mg/L) and _cis_-resveratrol (1.6 mg/L). By contrast, previously studied Portugieser young wines from the same Croatian wine subregion and after 12 months of bottle aging contained significantly less _trans_-resveratrol (0.6-3.4 mg/L and 0.8-2.0 mg/L, respectively), the concentration of which decreased with aging [43]. Portugieser wine originating from south Hungary [60] and the Czech region of Moravia [61] also contained significantly less resveratrol than the sample studied. In Plavac Mali (rPD and rPI), Babic (rBS), Merlot (rMK and rMA), and Pinot Noir (rPK) a common stilbene content between 1.8 and 4.6 mg/L was found, while the content in the other studied red wines was <LOQ--1.9 mg/L. [PERSON] et al. [62] determined the free resveratrol monomers in wine varieties from the Dalmatian region, including Plavac Mali, Babic, and Merlot.