Effect of refermentation conditions and micro-oxygenation on the reduction of volatile acidity by commercial S. cerevisiae strains and their impact on the aromatic profile of wines

Abstract

Herein, we evaluate the applicability of previously characterized commercial and indigenous Saccharomyces cerevisiae strains and non-S. cerevisiae species for the deacidification of white and red wines at a pilot scale. The effect of the refermentation process (mixture of acidic wine with musts from freshly crushed grapes or with residual marc) as well as micro-oxygenation (MO) on acetic acid removal efficiency and wine aromatic composition was also assessed in a red wine. The commercial strains S26 and S29 efficiently reduced both acetic acid (43 and 47%, respectively) and sugar (100%) after 264 h of refermentation of an acidic white wine that was supplemented with grape must. Similar results (60-66% of acetic acid removal) were observed for red wine deacidification using grape must, independently of MO. When residual marc was used for deacidification, strain S26 removed 40% of acetic acid, whereas strain S29 did not initiate refermentation with or without MO. Wines obtained by refermentation with the must had significantly lower acetic acid and a higher total SO(2) concentration in comparison to the wines deacidified by the grape marcs. The volatile aroma compound's composition of deacidified red wines was dependent on the refermentation process used, rather than on MO. Themarc-deacidified wine obtained by the use of strain S26 and without MO achieved the best sensory classification.When data from all analytical and sensory evaluation were combined, Principal Component Analysis (PCA) separated the wines into three distinct groups according to the strain and the refermentation process independently of MO. We successfully established an efficient and cheap enological solution for the rectification of volatile acidity of wines.

Lachancea thermotolerans, the Non-Saccharomyces Yeast that Reduces the Volatile Acidity of Wines

“…More modern techniques have been explained and studied in enological, biochemical, and microbiological terms [20,[29][30][31]. Under aerobic conditions, acetate can be used as a sole source of carbon and energy for the purposes of energy generation and cellular biomass [32].…”

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“…Titratable acidity of the fermented fruit juice was determined by titration method of a strong base against sample to an end point of pH 8.2 using potentiometric titration [11]. Volatile acidity of samples was determined by distillation of fermented fruit juice and the distillate was titrated against NaOH using phenolphthalein as indicator to determine volatile acid content [12]. The radical scavenging activity of fermented fruit juice samples were analysed by the 2, 2-diphenylpicrylhydrazyl (DPPH) method [13].…”

Biological Demalication and Deacetification of Musts and Wines: Can Wine Yeasts Make the Wine Taste Better?

“…cerevisiae is able to metabolize acetic acid during a refermentation process [14,56]. According to the authors and the work done by Vilela-Moura et al [7,15,16,56] and Vasserot et al [57], excessive volatile acidity can be removed by re-inoculating (performing a refermentation) with an appropriate S. cerevisiae wine yeast. Under aerobic conditions, acetate can be used as a carbon and energy source for the generation of energy and cellular biomass [58].…”

“…The influence of different combinations of the initial concentration of acetic acid, ethanol, SO 2 and MO on acetic acid removal from wines with an excessive volatile acidity, by two commercial yeasts strains (S26 and S29) was evaluated [16,56]. Both strains (S. cerevisiae S26 and S29) reduced by 78% and 48%, respectively, the volatile acidity of an acidic wine with an initial concentration of 1.0 g/L in acetic acid.…”