Phenolic, sugar and acid profiles and the antioxidant composition in the peel and pulp of peach fruits

In this study, antioxidant compounds (ascorbic acid; total phenolic, flavonoid and anthocyanin contents; and relative antioxidant capacity) and the profiles of sugars, organic acids, polyphenols and mineral composition were compared in the peel and pulp tissues of nine commercial peach cultivars. The antioxidant compounds, measured by a 96-well microplate reader, showed differences among cultivars. The phenolic profile determined by UPLC resulted in the quantification of hydroxycinnamates, flavonols (only in peel), flavanols and anthocyanins, which were differently distributed in both tissues. Peels contained the highest concentrations of phytochemicals, with the exception of sugars and organic acids. We found that the contents of flavonoids, anthocyanins and total phenolic compounds measured by spectrophotometry and UPLC MS methodologies were highly correlated. The Spanish cultivar Calanda Tardio showed the highest antioxidant and sorbitol contents. Venus had the highest contents of ascorbic and citric acids, and Big Top had the highest sucrose content.