Characterization and quantification of flavonoids and organic acids over fruit development in American cranberry (Vaccinium macrocarpon) cultivars using HPLC and APCI-MS/MS

Abstract

Cranberry flavonoids, including anthocyanins, flavonol glycosides and proanthocyanidins, and organic acids were characterized and quantified by HPLC and LC–MS/MS during fruit development and ripening in eight cranberry cultivars. Anthocyanin biosynthesis initiated at early fruit development and reached highest level in mature fruit, with significant differences between cultivars. Major flavonol glycosides, including the most abundant quercetin-3-galactoside and myricetin-3-galactoside, showed consistent concentrations during the season with moderate fluctuation, and were at similar levels in mature fruits of the eight cultivars. Proanthocyanidins declined during fruit development and then increased slightly in later maturation stages. Levels of various proanthocyanidin oligomers/polymers with different degree-of-polymerization were highly correlated within a cultivar during fruit development. Cultivars with coancestry exhibited similar levels (high/low) of anthocyanins or proanthocyanidins, indicating genetic effects on biosynthesis of such flavonoids. All cultivars showed similar levels of malic and citric acids, and declining levels of quinic acid during fruit development. Benzoic acid was extremely low early in the season and increased sharply during fruit ripening. Levels of quinic and citric acids were significantly different among cultivars in the mature fruit. Concentrations of proanthocyanidins, anthocyanins, quinic acid and benzoic acid have a strong developmental association in developing ovaries.