Phenolic Diversity in Local Germplasm of Sweet Cherry by LC-ESI-Orbitrap HRMS

Sweet cherry is a widely appreciated fruit crop, valued for its sensory properties and recognised as a rich source of health-promoting phenolic compounds. Despite the extensive diversity of Italian sweet cherry germplasm, many traditional landraces are threatened by genetic erosion, while detailed metabolomic characterization, particularly in underexplored regions, remains limited. This study comprehensively characterized the phenolic composition of 34 autochthonous sweet cherry genotypes from the Basilicata region using targeted liquid chromatography–high resolution mass spectrometry (LC–ESI–HRMS). Hydroxycinnamic acids, flavan-3-ols, flavonols, and anthocyanins were identified by accurate mass measurements and MS/MS fragmentation patterns and quantified by matrix-matched standard addition calibration. An LC–ESI–HRMS method was developed to separate and identify several pairs of isomeric compounds indistinguishable by mass spectrometry alone, enabling simultaneous quantification of multiple phenolic classes in a single run, with detection limits of 0.53–7.28 mg/kg fresh weight. Among the detected compounds, 5-caffeoylquinic acid (5-CQA) was the predominant phenolic in most genotypes, irrespective of fruit pigmentation, whereas anthocyanin and flavan-3-ol profiles showed marked genotype-dependent variability. These findings reveal the unique phenolic diversity of geographically restricted traditional varieties and provide a robust qualitative and quantitative reference dataset for southern Italian sweet cherry germplasm.]