Anthocyanin profile of two Italian Cichorium intybus L. cultivars

Cichorium intybus L. consists of many cultivars, two of the most representative in Italy are the red ('Radicchio Rosso di Treviso') and the red-spotted ('Radicchio di Castelfranco'), both belonging to the foliosum variety. Both cultivars are protected by the European Union with the PGI label (Protected Geographycal Indication) from the European Union, since they are very specific of a limited area in the north-eastern part of Italy. The aim of this study was to determine the qualitative and quantitative profile of anthocyanins, the main phytochemical compounds characterizing both cultivars. 'Radicchio Rosso di Treviso' was sampled in four different locations, and 'Radicchio di Castelfranco' in three, all of them within the PGI zone. Anthocyanins were separated by HPLC/PAD, and NMR spectroscopy was used to identify their molecular structure. The red cultivar showed a marked variability in anthocyanins concentration among the four localities studied. Cyanidin 3-O-glucoside was identified both by NMR and by UV-Vis spectra and was used for anthocyanins quantification. The main species found was attributed to cyanidin-3-O- (6"malonyl)-glucoside, in agreement with data reported in literature. The red-spotted cultivar ('Radicchio di Castelfranco') showed a similar anthocyanins profile with markedly lower concentration compared to the red cultivar.