Résumé
Pectolytic enzymes act differently on the degradation of the cell wall of grape skin and on the libération of tannins. PG and PL degrade the pectin from the middle lamella and the primary wall which favours the liberation of granulate tannins present inside the vacuole only ones. Cellulase degrade the cellulose fibbers and allows the liberation of tannins bound to the cellular wall. These last ones being bound to cellulosic molecules.