Characterization of Foaming Proteins in a Champagne Base Wine

As proteins are the most important foam-active components in Champagne base wine, it was necessary to characterize them. It will be useful to know in particular their isoelectric points, their molecular weights, and their hydrophobic characters to determine which of these parameters are important for foam constitution. Champagne base wine proteins have a molecular weight between 9 600 and 60 000 daltons, with a majority between 20 000 and 30 000 daltons. They have isoelectric points between 3.5 and 7.6, with a majority between 3.5 and 4.5. No differences have been detected in molecular weight or in isoelectric point between the foam wine and the remainder wine. These parameters do not seem to have much importance. But hydrophobic interaction chromatography shows that hydrophobic proteins contribute more to foam constitution than hydrophilic proteins.