Effect of different winemaking technologies on phenolic composition in Tinta Miúda red wines.

The influence of different types of winemaking technology on the contents of catechins, proanthocyanidins, and anthocyanins in Tinta Miúda red wines was studied. The Tinta Miúda red wines were made by fermentation with carbonic maceration, fermentation with stem contact, and fermentation without stem contact, respectively. The analysis of individual catechins, procyanidins, and anthocyanins in these wines was performed by HPLC, and quantification of total catechins, total oligomeric proanthocyanidins, total polymeric proanthocyanidins, and total anthocyanins was carried out by spectrophotometric methods. The wine made by carbonic maceration contained the highest amounts of both catechins and oligomeric and polymeric proanthocyanidins, followed by the wine made by fermentation with stem contact, whereas the wine made by fermentation without stem contact contained the lowest of these compounds. On the other hand, the concentrations of total anthocyanins and nearly all individual anthocyanins in the carbonic maceration wine were lower than those in the wines made by fermentation with stem contact and fermentation without stem contact. These results indicated that, although the carbonic maceration technique could retain higher amounts of catechins and proanthocyanidins in wine, it did not favor retaining or stabilizing anthocyanins in wine.