Cell wall anthocyanin adsorption by different Saccharomyces strains during the fermentation of Vitis vinifera L. cv Graciano grapes

This work reports the adsorption of anthocyanins by the cell walls of different strains of Saccharomyces during the production of red wine from Vitis vinifera L. cv Graciano grapes. The anthocyanin derivative contents of the yeast cell walls were substantially different to those of their corresponding wines. Cinnamoyl derivatives (6-p-coumaroyl and 6-caffeoyl) were strongly adsorbed while vitisins (adducts of pyruvic acid and acetaldehyde) were weakly adsorbed. The mean total anthocyanin concentration of the wines was 507.64 mg L-1 with the following distribution: 3-glucosides (3G), 82.2%; vitisins, 0.97%; 6-acetyl derivatives, 7.44%; 6-caffeoyl derivatives, 1.81%; and 6-p-coumaroyl derivatives, 7.54%. A mean of 18.57 mg of anthocyanins were adsorbed by the lees corresponding to 1 L of wine; this quantity was distributed: 3G, 52.60%; vitisins, 0.15%; 6-acetyl derivatives, 4.06%; 6-caffeoyl derivatives, 6.61%; and 6-p-coumaroyl derivatives, 36.58%. Large differences were seen between the different yeast strains examined with respect to the quantities of anthocyanins adsorbed. The mean adsorption percentage was 3.67%, but this varied between 1.60% (strain 3VA) and 5.85% (strain 9CV). The adsorption percentage of 6-p- coumaroyl derivates for strain 3VA (7.61%) was fourfold less than that of 9CV (28.37%). Strains 2EV and 3VA showed no vitisin adsorption.