Early and late ripening sweet cherries were characterized for phenolic acids, and also their antioxidant capacity and potential antifungal effects were investigated. Free, conjugated, and bound phenolics were identified and quantified using ultra performance liquid chromatography-tandem mass spectrometry. Our results indicated that the early ripening cultivars contained higher free phenolic acids, which was positively related to remarkable antioxidant properties and the inhibition effects on Alternaria alternata and tenuazonic acid (TeA) accumulation. However, conjugated phenolics of the late ripening cultivars, mainly including caffeic, 2,3,4-trihydroxybenzoic, p-coumaric, and pyrocatechuic acids, achieved the highest antifungal effects and almost completely inhibited the A. alternata and TeA production. 2,2-Diphenyl-1-picrylhydrazyl testing and ferric ion reducing antioxidant power assay showed strong positive correlation with total phenolics and specific phenolics such as free epicatechin and conjugated 2,3,4-trihydroxybenzoic acids and also with antifungal activity. Results from this study provide further insights into the health-promoting phenolic compounds in sweet cherries.
Keywords: antifungal activity; antioxidant; early and late ripening sweet cherries; mycotoxin; phenolics.