Characterisation of anthocyanidins in grape berry skin of Babica, Ljutun and Crljenak varieties by High-Performance Liquid Chromatography - HPLC method

Anthocyanins are large group of water soluble plant pigments responsible for the red, purple, and blue colours of many fruits, vegetables, flowers and grains. Chemically they are subdivided into the sugar-free anthocyanidine aglycons and the anthocyanin glycosides. In nature, there are 6 common anthocyanidins: pelargonidin, cyanidin, peonidin, delphinidin, petunidin, and malvidin. The colour of anthocyanins depends on their structure which can vary by glycosidic substitution at the positions 3 and 5 on the rings A and C as well as by acylation of the sugar groups with organic acids. Anthocyanins are responsible for the colour of red grapes and wine, so different authors have used their profile to classify the grape cultivars and wine authenticity. Thereby, the aim of this study was to investigate the profile of anthocyanidins (malvidin, delphinidin, cyanidin, pelargonidin and peonidin) in grape skin extracts of autochthonous Dalmatian cultivars: Babica, Ljutun and Crljenak. The extracts of anthocyanins were acid-hydrolyzed to release the corresponding anthocyanidins that were analysed by HPLC. HPLC analysis of the acid hydrolysis products of the grape berry skin extracts showed malvidin to be the major anthocyanidin in all extracts (ranged from 52 to 60%). Extract of Ljutun contained also high amounts of delphinidin (22%) while the lowest amounts of peonidin (from 5 to 6%) were found in all extracts. Obtained results on anthocyanidin profile of investigated grape skin extracts could be useful in chemotaxonomy for classifying red grape cultivars and wines.