Predicting Organic Acid Variation in White Wine Malolactic Fermentation Using a Logistic Model

The variation in organic acids during malolactic fermentation (MLF) affects the wine’s quality, presenting a challenge for the wine industry. This study aimed to investigate the kinetics of organic acids during MLF using two Oenococcus oeni strains under different barrel conditions. The study examined the variation in pH, total and volatile acidity, and concentration of tartaric, malic, lactic, and citric acid during MLF in the identical initial wine. In addition, the aromatic profile of the final wines was evaluated. The fermentation occurred in new and used French oak barrels. Two strains of O. oeni were used: (a) citrate-negative O. oeni (CINE) and (b) O. oeni, commonly used in the wine industry. The experimental data obtained were fitted to the logistic model for each monitored parameter. The degree of fitting R2 was higher than 92.79%, indicating good predictive accuracy for substrate consumption (malic and citric acid), as well as product formation (lactic and acetic acid). The mean values of O. oeni and O. oeni CINE differ in acetic (0.29 and 0.15 g/L) and citric acid (0.13 and 0.18 g/L), respectively. The logistic model effectively predicted the change in acid content during fermentation, describing the changes in organic acid levels during the MLF conducted in barrels. Modeling can be useful in forecasting industrial-scale production.