Evaluation of residual immunoreactivity in red and white wines clarified with gluten or gluten derivatives.

Gluten or hydrolyzed gluten could be a suitable alternative to animal proteins in the wine clarification process, but their residues could represent a risk for individuals suffering from coeliac disease or allergic to cereal proteins. The aim of this study was to investigate the presence of gluten in wines treated with gluten or its hydrolysate in the clarification process and to assess its antigenicity in commercial products. The presence of residual immunoreactive gluten was evaluated by electrophoresis (SDS-PAGE) and immunoblotting. Data obtained in several red and white wine samples showed that no residue was detectable in any of the red wines. In white wines, gluten reduced the protein content less completely, but most samples showed no immunoreactivity after the wine had been treated with gluten or its derivatives, either alone or combined with bentonite, silica gel or tannins. The use of gluten derivatives coupled with bentonite was the most effective method of removing immunoreactive protein in white wines. In conclusion, the use of gluten derivatives in wine clarification seems to exclude a risk for subjects susceptible to coeliac disease or gluten allergy. However, it is recommended that wine producers continuously monitor the clarification process in order to protect the most sensitive individuals.