Characterisation of phenolic compounds in wild fruits from Northeastern Portugal

This study aimed to analyse the phenolic composition of wild fruits of Arbutus unedo (strawberry-tree), Prunus spinosa (blackthorn), Rosa canina and Rosa micrantha (wild roses). Analyses were performed by HPLC-DAD-ESI/MS. Prunus spinosa fruits presented the highest concentration in phenolic acids (29.78 mg/100 g dry weight), being 3-O-caffeoylquinic acid the most abundant one, and flavone/ols (57.48 mg/100 g), among which quercetin3-O-rutinoside (15.63 mg/100 g) was the majority compound. (+)-Catechin was the most abundant compound in A. unedo (13.51 mg/100 g) and R. canina (3.59 mg/100 g) fruits. Arbutus unedo fruits presented the highest concentration in flavan-3-ols (36.30 mg/100 g). Cyanidin 3-O-glucoside was found in all the studied fruits, being the major anthocyanin in most of them, with the exception of P. spinosa samples, in which cyaniding 3-O-rutinoside and peonidin 3-O-rutinoside predominated; Prunus spinosa fruit presented the more complex anthocyanin profile among the analysed fruits and also the highest anthocyanin concentrations, which was coherent with its greater pigmentation. All in all, P. spinosa presented the highest levels of phenolic acids and flavonoids, including anthocyanins, flavonols and flavones, although no flavan-3-ols could be identified in its fruits. The present study represents a contribution to the chemical characterization of phenolic compounds from wild fruits with acknowledged antioxidant activity and traditionally used for several folk medicinal applications.PEst-OE/AGR/UI0690/2011 and PEst-C/QUI/UI0686/2011 for financial support to CIMO and CQ-UM, respectively. R. Guimarães and L. Barros thank to FCT, POPH-QREN and FSE for their grants (SFRH/BD/78307/2011 and SFRH/BPD/4609/2008, respectively). The GIP-USAL is financially supported by the Consolider-Ingenio 2010 Programme (FUN-C-FOOD, CSD2007-00063). M. Dueñas thanks the Spanish “Ramón y Cajal” Programme for a contract