Prediction of the production kinetics of the main fermentative aromas in winemaking fermentations

Abstract

A novel dynamic model was developed for predicting the synthesis kinetics of the principal aroma compounds produced by yeasts during winemaking fermentations: isobutanol, isoamyl alcohol, isoamyl acetate, ethyl hexanoate and ethyl octanoate. The parameters of the model were identified from nine fermentations performed at temperatures between 18 and 30°C and with different initial nitrogen contents, in the range of 70 to 410mgN/L. The model was validated in six independent experiments with conditions in the same range. Predictions were accurate for these volatile compounds: the mean difference between experimental and estimated values for fermentative aroma synthesis throughout the process was below 10%, for both the fermentations used to build the model and those used for validation. This model is the first to simulate the production kinetics of fermentative aromas and provides new insight into the synthesis of these volatile compounds. It will facilitate the development of innovative strategies for controlling the production of those aromas in winemaking, through management of the principal control factors: assimilable nitrogen content and temperature during the alcoholic fermentation.