Effect of egg albumin fining, progressive clarification and cross-flow microfiltration on the polysaccharide and proanthocyanidin composition of red varietal wines.

The effect of egg albumin fining, progressive clarification and cross-flow microfiltration on the polysaccharide and proanthocyanidin composition of four red varietal wines was studied in this work. Discriminant analyses were applied to achieve a possible differentiation of the wines according to treatment or grape variety. Egg albumin fining did no produce a significant decrease in the content of wine polysaccharides. Progressive clarification caused a significant reduction of mannoproteins, homogalacturonans and polysaccharides rich in arabinose and galactose in Graciano wines. However, both treatments reduced the total content of proanthocyanidins in all varietal wines. Cross-flow microfiltration produced the highest retention of polysaccharides and proanthocyanidins in all the wines, mainly polysaccharides rich in arabinose and galactose, yeast mannoproteins and highly polymerized phenols. Polysaccharides rich in arabinose and mannoproteins were more retained on the ceramic membrane than polysaccharides rich in galactose and proanthocyanidins. Discriminant analyses allowed a clear differentiation of cross-flow microfiltrated wines from the rest of the wines.