Ultrasound-assisted extraction and (U)HPLC-DAD-ESI-MSn analysis of phenolic compounds from black chokeberries cultivated in Turkey

Phenolic compounds from two black chokeberry cultivars 'Viking' and 'Nero' grown in Turkey were analyzed by high performance liquid chromatography-diode array detection-electrospray ioniza-tion-multistage mass spectrometry (HPLC-DAD-ESI-MSn). In the first step, five different solvents were compared to efficiently iso-late phenolic compounds by ultrasound-assisted extraction. Three sequential extraction cycles using methanol/formic acid (95:5, v/v) sufficed for exhaustive extraction of anthocyanins, hydroxycinna-mic acid derivatives, and flavonol glycosides from black chokeberry within merely 60 sec. A total of four cyanidin glycosides, two hy-droxycinnamic acids, and five quercetin mono-and di-glycosides were detected in both cultivars. Total anthocyanins (425-438 mg/ 100 g of fresh weight, FW), hydroxycinnamic acids (173-179 mg/ 100 g of FW), and flavonols (37 mg/100 g of FW) were determined in a similar range for both cultivars. Complementary, a rapid ultra-high performance liquid chromatography (UHPLC)-DAD method was developed, permitting a high throughput screening of choke-berry phenolics. The established methods were validated considering extraction recoveries, intra-and inter-day repeatability, calibration linearity, limit of detection (LOD), and limit of quantitation (LOQ). UHPLC provided a 2.3 times faster compound separation (30 min) and less solvent consumption than HPLC (68 min).