ORIGINAL PAPER Phenolic Compounds Determined by LC-MS/MS and In Vitro Antioxidant Capacity of Brazilian Fruits in Two Edible Ripening Stages Fabiana Della Betta 1 & Priscila Nehring 1 & Siluana Katia Tischer Seraglio 1 & Mayara Schulz 1 & Andressa Camargo Valese 2 & Heitor Daguer 2 & Luciano Valdemiro Gonzaga 1 & Roseane Fett 1 & Ana Carolina Oliveira Costa 1 # Springer Science+Business Media, LLC, part of Springer Nature 2018 Abstract 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. Keywords Brazilian fruits . Antioxidant activity . Maturation . Native and cultivated fruits Abbreviations DM Dry matter DPPH 2,2-diphenyl-1-picrylhydrazyl FRAP Ferric reducing antioxidant power LC-MS/MS Liquid chromatography - tandem mass spectrometry Introduction Many beneficial properties have been attributed to the regular consumption of fruits, most of them due to their phytochem- ical compounds. Among these, the phenolic compounds are the most extensively investigated because of their antioxidant capacity and potential for the prevention of cancer as well as inflammatory and cardiovascular diseases [1, 2]. In this re- gard, there is a constant search for underexploited fruits such as blackberry ( Rubus ulmifolius ), acerola ( Malpighia emarginata), yellow guava (Psidium cattleianum), guabiju (Myrcianthes pungens), jambolan (Syzygium cumini), and jabuticaba (Myrciaria cauliflora), which are produced and consumed mainly by local populations, however, have been suggested as fruits of growing commercial interest. There are still a few published studies on the beneficial effects of these fruits, however, the first reports have shown positive results. Guabiju has demonstrated a positive effect on the decrease of glucose and cholesterol levels in rats [3], while jabuticaba prevents prediabetes and liver steatosis in high-fat-fed aging mice [4]. For acerola, Alvarez-Suarez et al. [5] showed a pro- tective effect against oxidative damage, improved antioxidant Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11130-018-0690-1) contains supplementary material, which is available to authorized users. * Ana Carolina Oliveira Costa ana.costa@ufsc.br Fabiana Della Betta fabianadb@gmail.com 1 Department of Food Science and Technology, Federal University of Santa Catarina, Florianopolis, SC 88034-001, Brazil 2 National Agricultural Laboratory (SLAV/SC/LANAGRO-RS), Ministry of Agriculture, Livestock and Food Supply, São José, SC 88102-600, Brazil Plant Foods for Human Nutrition https://doi.org/10.1007/s11130-018-0690-1