Mannoproteins are complex glycoproteins extracted primarily from the cell walls of Saccharomyces cerevisiae yeast. They consist of mannose polysaccharide chains (α-1,6 backbone with α-1,2 and α-1,3 branches) covalently linked to proteins via N- or O-glycosidic bonds. In winemaking, they act as natural stabilizers preventing protein haze and potassium bitartrate precipitation while improving mouthfeel, reducing astringency, and enhancing aroma persistence. They are also used in food applications as emulsifiers and texture modifiers. Molecular weights typically range from 20-200 kDa. They are highly water-soluble due to hydrophilic mannose residues and are approved for oenological use by the OIV.