Total proanthocyanidins were estimated according to Chira, Jourdes, & Teissedre (2011). This method is based on the Bate–Smith reaction, in which the proanthocyanidins in acid medium release anthocyanidins by heating. The wines were diluted to 1:50 in a 10% ethanol solution. One milliliter of the samples was added to 0.5 mL of water and 1.5 mL of 12 M HCl