Determining the gas-liquid partitioning ( Ki) of acetaldehyde during alcoholic fermentation is an important step in the optimization of fermentation control with the aim of minimizing the accumulation of this compound, which is responsible for the undesired attributes of green apples and fresh-cut grass in wines. In this work, the effects of the main fermentation parameters on the Ki of acetaldehyde were assessed. Ki values were found to be dependent on the temperature and composition of the medium. A nonlinear correlation between the evolution of the Ki and fermentation progress was observed, attributable to the strong retention effect of ethanol at low concentrations, and it was demonstrated that the partitioning of this specific molecule was not influenced by the CO2 production rate. A model was developed that quantifies the Ki of acetaldehyde with a very accurate prediction, as the difference between the observed and predicted values did not exceed 9%.
Keywords: acetaldehyde; gas−liquid transfer; modeling; online-gas-chromatography measurement; partition coefficient; wine fermentation.