Phenolic Compounds Determined by LC-MS/MS and In Vitro Antioxidant Capacity of Brazilian Fruits in Two Edible Ripening Stages.

The aim of this study was to investigate the free individual phenolics and the in vitro antioxidant capacity of blackberry, acerola, yellow guava, guabiju, jambolan and jabuticaba fruits in two edible stages. Of the thirty-three phenolics investigated by liquid chromatography - tandem mass spectrometry (LC-MS/MS), twenty-five were quantified and the major ones were catechin, isoquercitrin, epicatechin and gallic acid. The highest values for the total phenolic content (in dry matter) were observed for acerola (83.6 to 97.7 mg gallic acid equivalents g-1 DM) and blackberry (18.9 to 28.3 mg gallic acid equivalents g-1 DM); however, acerola, jabuticaba, and blackberry showed the highest antioxidant capacities (134.6 to 1120.4 mg Trolox equivalents g-1 for 2,2-diphenyl-1-picrylhydrazyl and 43.6 to 501.8 μmol Trolox equivalents g-1 for ferric reducing antioxidant power). For most fruits, the antioxidant capacity decreased during the ripening, possibly due to a decrease in the concentration of most of the phenolics.