Grape juice consumption may prevent several chronic diseases owing to the presence of phenolic compounds, which have an important role in the reduction of oxidative stress. This study investigated the polyphenol content and antioxidant activities of grape juices from two cultivars: BRS‐Cora and Isabella. Total polyphenol content (TPC), anthocyanins, antioxidant capacity (oxygen radical absorbance capacity, ferric reducing antioxidant power and 1,1‐diphenyl‐2‐picrylhydrazyl), and phenolic profile (high‐performance liquid chromatography with diode array and fluorescence detection – HPLC‐DAD‐FLD) were determined. RESULTS BRS‐Cora grape juice showed higher concentrations of total polyphenols and anthocyanins, as well as higher antioxidant potential, than those of Isabella grape juice. A significant positive correlation was found in TPC or anthocyanin contents when correlated with the remaining antioxidant assays. In addition, HPLC‐DAD‐FLD showed a higher total phenolic content in BRS‐Cora grape juice compared to Isabella. CONCLUSION The present results show BRS‐Cora as a promising cultivar for grape juice production with an improved functional potential. © 2015 Society of Chemical Industry Ver menos