Production of SO2 Binding Compounds and SO2 by Saccharomyces during Alcoholic Fermentation and the Impact on Malolactic Fermentation

  • A. Wells Department of Food Science and Technology, Oregon State University, Corvallis, OR, 97331, USA
  • J.P. Osborne Department of Food Science and Technology, Oregon State University, Corvallis, OR, 97331, USA

Abstract

The objective of this study was to investigate the production of SO2 and SO2 binding compounds by wineyeast and the impact of the production of these compounds on the MLF at various time points duringalcoholic fermentation. Fermentations were observed for a number of commercial wine yeasts in a syntheticgrape juice and Pinot gris juice and SO2, acetaldehyde, pyruvic acid and α-ketoglutarate. Measurementswere taken at multiple time points during the fermentation. Samples were taken from the fermentationsat weekly intervals, sterile filtered, and inoculated with O. oeni strain VFO to induce MLF. Significantdifferences between the amount of SO2, acetaldehyde and pyruvic acid produced by the various yeaststrains were noted. Some yeast strains such as FX10, CK S102, F15 and M69, produced significantly higherSO2 concentrations than other yeast strains and MLF was inhibited in these wines. Insignificant free SO2was measured, indicating that bound SO2 rather than free SO2 was responsible for inhibition. At almostall time points of the alcoholic fermentation, acetaldehyde bound SO2 was determined to be the dominantspecies of bound SO2 present, suggesting that MLF inhibition by bound SO2 was due to acetaldehydebound SO2.
Published
2011-12-07
Section
Articles