Migration of phenolic compounds from different cork stoppers to wine model solutions: antioxidant and biological relevance

Considering the enological interest of cork, this study aimed to identify and quantify the phenolic compounds able to migrate from different classes (natural cork stoppers Flor and Third quality and microagglomerate cork stopper) of cork stoppers into bottled wine model solutions. Another aim was to evaluate some antioxidant and biological features of cork phenolics that migrated into the wine model solutions. The main phenolic acids and aldehydes detected were as follows: gallic and protocatechuic acid detected both around 3.5 mg/L and vanillin and protocatechuic aldehyde detected around 2.5 and 1.5 mg/L after 27 months of bottling, respectively. Trace amounts of more complex polyphenols, namely hydrolysable tannins (castalagin/vescalagin and mongolicain A/B), were also detected. Two antioxidant features of the wine model solutions bottled with different wine cork stoppers were studied, namely the antiradical capacity and the reducing capacity, being the natural cork stoppers the ones with the higher activities. The intestinal absorption of the compounds in each wine model solution after 27 months in bottled was evaluated. The simpler phenolic compounds were able to cross Caco-2 cell model. The antiproliferative activity of the same wine model solutions was also evaluated against gastric and breast cancer cells. All samples were active against the two cell lines, which highlight the possible health outcomes of wine sealed with cork stoppers.