Contribución de las semillas y del raspón sobre la composición, color y calidad del vino tinto; influencia del sistema de vinificación y del tratamiento del racimo

Identificador:  TDX:2588

Handle: https://hdl.handle.net/20.500.11797/TDX2588

Autors:  Pascual García, Olga

Resum:
This work studies, as main objective, the influence of the tannin composition of the wine on their color and sensory quality. With this aim different experiments were performed in order to determine the influence of the winemaking system, as well as the importance of the contribution of the seeds and the stems on the composition, color and final quality of the red wine. The presence of stems either by vinification of the whole cluster without crushing or with crushing, generated significant differences on the composition and color of the wine. The presence of seeds or stems as the only source of phenolic compounds of the wine generated a significant increase of total phenolic compounds, proanthocyanidins and astringency. The proanthocyanidins released by the stems have a somewhat lower percentage of galoylation than those of the seeds, and a rather high percentage of (-)-epigallocatechin units. In addition, the kinetics of oxygen consumption by different oenological tannins in a model wine medium has been studied, proving that there is a direct relationship between the concentration of tannins, the oxygen consumption rate and temperature. Therefore, it can be asserted that oenological tannins are potent antioxidants that can help to protect the wine against oxidation.