Background: In the scope of the wine vinegar production, this paper provides comprehensive information about the evolution of some volatile compounds during the biological acetification cycle. These data were compared with the acidity, cell concentration and ethanol concentration. Such information may allow a better understanding of the complex biological processes involved.
Results: The volatile compounds 2-phenylethanol, diethyl succinate (diethyl butanedioate), meso-2,3-butanediol (meso-butane-2,3-diol), levo-2,3-butanediol (levo-butane-2,3-diol), methanol and ethyl acetate exhibited no significant changes between the starting wine and produced vinegar, whereas the rest [acetoin (3-hydroxybutan-2-one) excepted] ethyl lactate (ethyl 2-hydroxypropanoate), isoamyl alcohols (3-methylbutan-1-ol and 2-methylbutan-1-ol), isobutanol (2-methylpropan-1-ol), 1-propanol (propan-1-ol), and acetaldehyde were consumed in substantial amounts during the process. Additionally, their specific evolution patterns alongside bacterial cell concentrations, acidity and ethanol concentration are shown.
Conclusion: Concentrations of acetic acid bacteria at the end of the acetification cycle were found to vary because of cell lysis, a result of the high acidity and low ethanol concentration of the medium. Variations were similar to those in some volatile compounds, which suggests their involvement in the metabolism of acetic bacteria. The results testify to the usefulness of this pioneering study and suggest that there should be interest in similar, more detailed studies for a better knowledge of the presence of certain volatile compounds and metabolic activity in cells effecting the acetification of wine.
Copyright © 2010 Society of Chemical Industry.