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 t o know in particular their isoelectric points, their molecular weights , and their hydrophobic characters to determine which of these paramet ers are important for foam constitution. Champagne base wine proteins have a molecular weight between 9 600 and 60 000 daltons, with a major ity between 20 000 and 30 000 daltons. They have isoelectric points be tween 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 betwee n the foam wine and the remainder wine. These parameters do not seem t o have much importance. But hydrophobic interaction chromatography sho ws that hydrophobic proteins contribute more to foam constitution than hydrophilic proteins.