Characterization of polyphenols in Vaccinium berries and evaluation of their chemopreventive properties

This study was aimed at the complete metabolite profiling of polyphenols in Vaccinium floribundum Kunth berries from Ecuador by means of HPLC-UV/DAD, HPLC-ESI-MS and MS2, using an ion trap mass analyzer. As a comparison, Vaccinium myrtillus L. berries from the Italian Northern Apennine were analyzed in parallel. A sequential selective extraction procedure was developed to maximize the yields of the secondary metabolites from the berries, using ethyl acetate for flavonoids and phenolic acids, followed by acidified methanol for anthocyanins. The results of the HPLC analyses indicated several representative differences in both the quali- and quantitative composition of flavonoids and anthocyanins in the berry extracts obtained from V. floribundum and V. myrtillus, which showed typical fingerprints of their phenolic secondary metabolites. Thanks to its unique polyphenol composition, V. floribundum can be easily differentiated from common bilberries using the proposed techniques. The chemopreventive activity of these berries and their fractions was evaluated by the determination of their antioxidant activity using a panel of in vitro tests (DPPH, ABTS) and their antimutagenic properties against dietary and environmental, direct and indirect, mutagens. The results of these biological assays were correlated with the chemical composition of the two investigated Vaccinium species, to establish the potential application of V. floribundum as a source of phytochemicals in the nutraceutical and functional food ambit.