# Characterization of Berry Skin Phenolic Profiles in Dalmatian Grapevine Varieties
## 3 Results and Discussion
### Flavonols  
Grape berries contain almost exclusively flavonol glycosides [27]. Flavonols detected in the present study include myricetin-3-O-glucose, rutin, quercetin-3-O-galactoside, quercetin-3-O-glucose, kaempfer-3-O-glucose, and isorhamtein-3-O-glucose. The total flavonol content in berry skin and its relative profile during three-year research, together with the comparison of mean values by [PERSON]'s multiple range test, is represented in Table 2.  
Significant differences between varieties in content of all investigated flavonols glycosides were detected. Posip crni (1742.08 mg kg\({}^{-1}\)), Plavac mali (1526.32 mg kg\({}^{-1}\)), Zadarka (661.46 mg kg\({}^{-1}\)), and Trnjak (624.13 mg kg\({}^{-1}\)) showed the highest amount of total flavonols among investigated varieties. A very low amount of total flavonols has been detected in varieties Crljenak viski, Babic, and Plavina, 219.49 mg kg\({}^{-1}\), and 249.56 mg kg\({}^{-1}\), respectively. These observations were in close agreement with previously findings. The determined total content of flavonoid glycosides is in the range of 232.2 mg kg\({}^{-1}\) for Vinhao [28] up to 1542.83 mg kg\({}^{-1}\) for Syrah [25].  
Looking at the pattern of flavonols, the main aglycon in the investigated varieties by far was quercetin (quercetin-3-O-galactoside, quercetin-3-O-glucose, rutin). The portion of quercetin derivatives in the total flavonols content determined in Croatian varieties was in the range from 29.92% (Svrdlovina) up to 93.70% (Trisnjavac). These results are in close agreement with previous findings. During analysis of 64 red grape varieties, [PERSON], et al. [29] determined a range of quercetin derivatives portion from 12.34% up to 87.76%. All Croatian grape varieties that were analyzed contained quercetin-3-O-glucose as a dominant flavonol glycoside. Quercetin-3-O-galactoside was not identified in Crljenak viski, Dobrivic, Nincusa, Tribidrag, and Vranac. Many studies concerning the content and composition of phenolics in grapes did not find rutin in high concentrations. [PERSON], et al.'s [30] investigation of content of flavonols in ten grape varieties showed that two of them did not contain rutin (Malvasia Nera and Alphonse Lavalle). The second most abundant flavonol in the most of the examined grape varieties was myricetin-3-O-glucose (Dobricic 38.77%, Trnjak 29.48%, Svrdlovina 28.15%). The small percentage of this flavonol was observed in pink color grape varieties, Trisnjevac (4.56%) and Posip crni (1.24%). When it comes to red grape varieties, myricetin derivatives can be present in range from 2.35% up to 81.61% [29]. Third most abundant flavonol was isorhametin 3-O-glucose. Levels ranged from 14.35 mg kg\({}^{-1}\) (Lasina) to 129.98 mg kg\({}^{-1}\) (Trnjak). These values were like those obtained in Verdelho (21 mg kg\({}^{-1}\)) and Cabernet Sauvignon (261.25 mg kg\({}^{-1}\)) [17; 28]. Isorhamnetin 3-O-glucose was not identified in Trisnjavac. Moreover, low levels of isorhametin 3-O-glucose were detected in other varieties with pink color of berries, such as Posip crni and Gustopupica. Some authors have showed that myricetin and isorhamnetin glycosides are specific to the red grape varieties [31], and the obtained results for pink color grape varieties agreed with their genotype. The levels of kapmpferol-3-O-glucose ranged from 2.25 mg kg\({}^{-1}\) (Babica) to 114.82 mg kg\({}^{-1}\) (Plavac mali crni) with the average percentage of 4.52%. The highest portion was determined in Posip crni (12.24%). This flavonol was not detected identified in Crljenak viski, Dobricic, Lasina, Tribidrag, and Svrdlovina. [PERSON], et al. [17] did not identify kaempfer-3-O-glucose in Zinfandel. The obtained results agree with earlier studies, which determined that kaempfer derivatives are minor flavonols with a percentage range from 0% to 17.52% [29].