Article Isolation and Characterization of a Thermally Extracted Yeast Cell Wall Fraction Potentially Useful for Improving the Foaming Properties of Sparkling Wines

Two different yeast cell wall extracts were obtained using enzymatic digestion and thermal treatment. The effects of the extracts obtained on the foaming properties of a model wine and two sparkling wines were studied. The model wine and sparkling wines, supplemented with the thermal extract, presented better foaming properties than did the samples supplemented with the enzymatic extract. The fractioning (Con A chromatography) and characterization (SDS-PAGE, SEC, GC, and RP-HPLC) of both extracts showed that the fraction responsible for the foaming properties is constituted by mannoproteins with a relative molecular weight between 10 and 30 kDa, presenting an equilibrated composition of the hydrophobic and hydrophilic protein domains. This thermal extract did not modify the protein stability in both the model wine and the sparkling wines. These results demonstrate that the enrichment of a sparkling wine with mannoproteins extracted by mild heat procedures will contribute to improving its foaming propertiesThis work was funded through Project MERG-CT-2004-513472 from the European Union and Projects AGL2003-01762 and AGL2004-06933 from the Spanish Ministry of Science and Education (MEC).Peer reviewe