Discrimination of genetic and geographical groups of grape varieties (Vitis vinifera L.) based on their polyphenolic profiles

Abstract Relevant aspect of wine geographic origin is related to grapevine varieties used for wine production in specific wine country or region. The grapevine germplasm is highly variable and classified into geographic groups. These classifications were recently confirmed using genetic studies, and further classified varieties into geographic-genetic (GEN-GEO) groups. Polyphenolic compounds are important secondary metabolites in grapes and have an important impact on wine quality and sensory properties. The aim of this research was to investigate the polyphenolic profiles of 50 grape varieties from different GEN-GEO groups. The groups were C2 (varieties from Italy and France), C7 (varieties from Croatia), C8 (varieties from Spain and Portugal). Polyphenolic compounds analysed belonged to the classes of anthocyanins, flavan-3-ols, flavonols, phenolic acids, and stilbenes. The most abundant classes of polyphenols were anthocyanins, followed by flavan-3-ols and flavonols. Using discriminant analysis, the genetic-geographic groups were clearly separated based on their polyphenolic profiles, with all classes of compounds contributing to discrimination.