Polyphenolic Composition of the Berry Skin of Six Fungus-Resistant Red Grapevine Varieties

Phenolic compound profiles were investigated by high-performance liquid chromatography-diode array detector in three vintages to assess genotypic variation in berry skins of six resistant grapevine varieties: “Cabernet Cortis,” “Chancellor,” “Leon Millot,” “Marechal Foch,” “Monarch,” and “Regent.” The research has revealed a significant difference among the varieties in the total phenolic content, anthocyanins, flavanols, and flavan-3-ols. A clear differentiation of all varieties by means of the polyphenol profile using discriminant analyses has been achieved. “Regent” reached the significantly highest total polyphenol content, as well as total anthocyanin and total flavonol content. The polyphenol profile of “Chancellor” was quite different from all of the other studied varieties. Although being closely related, “Marechal Foch” and “Leon Millot” showed qualitatively and quantitatively quite different polyphenol contents. No clear connection between the genetic origin of the varieties and their polyphenol...