Free low-molecular weight phenolics composition and bioactivity of Vaccinium padifolium Sm fruits

Uveira-da-serra (Vaccinium padifolium Sm) is a native blueberry from Madeira Island (Portugal). In this study, the free low-molecular weight phenolic composition of Vaccinium padifolium berries (uva-da-serra - UdS), was established using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) strategy combined with liquid chromatography electrospray ionization tandem mass spectroscopy (LC-ESI-MSMS). Total phenolic content (TPC), total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical-scavenging activities and oxygen radical absorbance capacity (ORAC) were also evaluated. Twenty-six phenolic compounds were identified in the UdS, being chlorogenic acid (17.4 mg/g DW), epigallocatechin (2.33 mg/g DW), caffeic acid (0.66 mg/g DW), quercetin-3-glucoside (0.38 mg/g DW) and myricetin (0.33 mg/g DW) the predominant compounds. As far we are aware, this is the first time that the free low molecular weight phenolic composition of Vaccinium padifolium Sm is characterized, also unveiling (-)epigallocatechin gallate, o-coumaric acid and m-coumaric acids presence in a Vaccinium specie. TPC (3021.8 mg GAE/100 g DW), TFC (2645.2 mg QE/100 g DW), DPPH (20509.0 µmol TE/g DW), ORAC (18510.0 µmol TE/g DW) and ABTS (19338.0 µmol TE/g DW) suggest a high antioxidant potential which is to health benefits including on cardiovascular and neurodegenerative disease prevention, making UdS a useful biosource with potential applications in food, pharmaceutical and cosmetic industries.