Antimicrobial activity and differentiation of anthocyanin profiles of rabbiteye and highbush blueberries using HPLC-DAD-ESI-MSn and multivariate analysis

This study aims to perform in vitro analyses of the antimicrobial activity of ten blueberry cultivars, to characterize the anthocyanin composition of these fruits, and to use multivariate analysis to compare the results. All blueberry cultivars presented anti-Escherichia coli activity. Furthermore, the complete series of six glycosides (galactoside, glucoside, arabinoside, xyloside, acetylgalactoside and acetylglucoside) of five anthocyanidins (delphinidin, cyanidin, petunidin, peonidin, and malvidin) were detected, together with six malonyl derivatives of the main anthocyanins. The rabbiteye cultivars showed higher proportions of cyanidin 3-galactoside than the highbush cultivars, the latter accounting for higher proportions of the 3-arabinosides of delphinidin and malvidin. The total anthocyanin content was between 10.8 and 26.5 g/kg of dry weight, and the concentration depended on the size of the berries, with the smaller rabbiteye cultivars exhibiting higher levels of anthocyanins.