Proteins influencing foam formation in wine and beer: the role of yeast

This review focuses on the role of proteins in the production and maintenance of foam in both sparkling winesand beer. The quality of the foam in beer but especially in sparkling wines depends, among other factors, on the presence ofmannoproteins released from the yeast cell walls during autolysis. These proteins are hydrophobic, highly glycosylated, andtheir molecular masses range from 10 to 200 kDa- characteristics that allow mannoproteins to surround and thus stabilizethe gas bubbles of the foam. Both the production and stabilization of foam also depend on other proteins. In wine, theseinclude grape-derived proteins such as vacuolar invertase; in beer, barley-derived proteins, such as LTP1, protein Z, andhordein-derived polypeptides, are even more important in this respect than mannoproteins