Profiling of polyphenolic compounds using LC-ESI-QTOF-MS/MS in fruits of the Sorbus subgenus as a valuable source of polyphenolic compounds

The fruits of four Sorbus subgenera (Sorbus × arnoldiana 'Copper Glow', Sorbus hupehensis 'White Swan', Sorbus intermedia and Sorbus 'Alaya Krupnaya') were identified and subjected to quantitative analysis of polyphenolic compounds using LC-ESI-QTOF-MS/MS and UPLC-PDA. In the studied Sorbus subgenera, 101 polyphenolic compounds were identified classified into four groups: flavan-3-ols (2), phenolic acids (21), flavonols (66) and anthocyanins (12). Of the 101 compounds identified, 59 were reported for the first time in Sorbus fruit. Flavonols (66 %), derivatives of quercetin and kaempferol, including diglycosides (55 %), monoglycosides (31 %), triglycosides (14 %), and acylated forms (27 %) were dominant in the tested fruits. The polyphenol content was highest in Sorbus × arnoldiana 'Copper Glow' (531.25 mg/g), followed by Sorbus hupehensis 'White Swan' (210.67 mg/g), Sorbus intermedia (131.07 mg/g), and Sorbus 'Alaya Krupnaya' (81.43 mg/g). Sorbus × arnoldiana 'Copper Glow' with its characteristic orange fruit colour, was notable for its rich qualitative profile, in particular flavonols, and contained the highest levels of these compounds among the tested subgenera.