Characterization of different cultivars of Algerian date palm (Phoenix dactylifera L.) leaves and pollen by comprehensive two-dimensional liquid chromatography of phenolic compounds extracted with different solvents

[Display omitted] •Different TPC, TFC, TCTC were obtained for date palm leaves and pollen extracts.•21 and 23 phenols were identified by HPLC-MS in leaves and pollen extracts, respectively.•Different LC × LC profiles were observed for the different samples.•LC × LC optimized method gave 33 common polyphenolic peaks.•Extracts were correctly classified according to their cultivar with good resolution. The polyphenolic composition of Algerian date palm (Phoenix dactylifera L) leaves (in Hamray, Safray, Ghars, Horra, Deglet Nour (DN) cultivars), and pollen (in DN cultivars), were investigated for the first time in these cultivars. The polyphenolic fractions were extracted using three solvents (acetone, methanol and ethanol), and characterized in terms of antioxidant activity and contents of total polyphenols (TPC), flavonoids (TFC), and tannins (TCTC). All the extracts exhibited high antioxidant activity and TPC, TFC and TCTC values, DN being the cultivar that provided the best results without significant differences among the three solvents. When the extracts were analyzed by HPLC-MS, 21 and 23 phenols were identified in leaf and pollen extracts, respectively. Furthermore, polyphenolic fingerprints of leaf extracts were obtained by comprehensive two-dimensional liquid chromatography (LC × LC), which made it possible to discriminate samples according to their cultivar by linear discriminant analysis.