The Effect of Adding Supplementary Quantities of Seeds During Fermentation on the Phenolic Composition of Wines

Several studies have suggested that a group of phenolic compounds present in grapes and wines, known as catechins and proanthocyanidins, may play a positive role in human nutrition, related to their protective action towards coronary heart disease and the scavenger properties of their free radicals. These molecules are accumulated in the most lignified parts of grape clusters, specially in the seeds. Several microvinification experiments were carried out with different red and white grapes to elucidate the effect of adding supplementary quantities of seeds during fermentation on the phenolic composition of wines. The presence of a higher quantity of seeds in contact with the must during fermentation resulted in wines with a higher content of phenolics, especially catechins and proanthocyanidins, and their varietal characteristics were more pronounced than in control wines. The addition of a quantity of supplementary seeds, which doubled the original quantity of seeds in pomace, appeared to stabilize wine color.