DETERMINATION OF DIFFERENT PHENOLIC COMPOUND CLASSES IN POMEGRANATE JUICES BY HPLC-DAD-ESI-QTOF-MS

Background and objectives: Traditionally, pomegranate (Punica granatum L.) has been consumed as fresh fruit or as pomegranate juice and it has been described as a rich source of phenolic compounds. Several recent studies have shown that drinking pomegranate juice contributes to significant potential health benefits, and, today, it is known, that the positive health properties of pomegranate are due to the presence of bioactive compounds like, flavonoids, phenolic acids and tannins contained in it. Therefore, in this work, the main phenolic compounds of 17 pomegranate varieties were determined by HPLC-DAD-ESI-qTOF-MS. Methods: A new chromatographic HPLC-DAD-ESI-qTOFMS method, using a C18 fused-core column, was established and the analyses were performed in less than 20 minutes. Results: Eight anthocyanins and fourteen other phenolic compounds were tentatively identified and quantified in the pomegranate juices. As far we are concerned, a new flavonolglycoside has been tentatively identified for the first time in pomegranate juices. Total phenolic content ranged from 573.6 to 2519.8 mg/mL. Anthocyanins varied between 110.9 to 1925.5 mg/mL and they represented the 17-86 % of total phenolic content.Flavonoids were the 1.6-24.4 % of total phenolic compounds. Phenolic acid and ellagitannins were in the range of 300.9-810.2 mg/mL. Conclusions: The results confirmed, as reported in literature, that the pomegranate variety influences substantially the phenolic composition. It is important to highlight that, as far we are concerned, a new flavonol-glycoside has been tentatively identified for the first time in pomegranate juices thanks to this method.