Evaluation of cross-flow filtration and electrodialysis in four wine varieties under industrial conditions

The turbidity of wines needs to be reduced through filtration, with the other advantage of performing wine stabilization. Among the available techniques, cross-flow filtration is largely applied today because it does not require conventional filter media or filter aids, it can be applied during all the stages of winemaking and shows very high efficiency. Electrodialysis consists of separating differently charged ions, by the use of selective permeable membranes under the action of an electric field. It is used to apply tartrate stabilization on wines. These two techniques were applied to two red and two white wines, respectively cv. Nero d’Avola and Syrah and Catarrato and Grillo in an experimentation performed in Sicily (Italy) to evaluate the influence of these procedures on the quality of the wines ready to be bottled. Samples of wines were analyzed to evaluate the most important quality parameters (alcohol, pH, total acidity, volatile acidity, malic acid, lactic acid, citric acid, tartaric acid, ashes, color intensity and Hue, absorbance at 420, 520 and 620 nm, polyphenols, catechins, free sulfur dioxide, total sulfur dioxide, conductivity) and the aromatic profile by gas chromatography. Red wines showed greater sensitivity to quality change after the treatments, with particular reference to color.