Elimination of Suspended Cell Wall Material in Musts Improves the Phenolic Content and Color of Red Wines

Some studies have shown that the transfer rate of phenolic compounds from grape to must may be limited, among other reasons, because of interactions between phenolic compounds and the cell wall. One hypothesis is that after grapes are crushed to obtain the fermenting must, part of the skin and seed proanthocyanidins and anthocyanins are bound to skin and pulp cell walls present in the must in large concentrations, preventing these pigments from contributing to the final wine phenolic compounds. To test this assumption in a real vinification, a control red wine vinification was compared with a modified red wine vinification, in which a settling step similar to that commonly used for production of white and rose wines was included. The chromatic characteristics and the tannin content of the wines were measured, revealing that the wine obtained with the modified method contained a significantly higher quantity of phenolic compounds (23% increase in anthocyanin concentration and 43% increase in tannin concentration), and had improved chromatic characteristics.