Macrowine 2021
IVES 9 IVES Conference Series 9 Impact of nitrogen addition timing on the synthesis of fermentative aromas in alcoholic fermentation

Impact of nitrogen addition timing on the synthesis of fermentative aromas in alcoholic fermentation

Abstract

Among the different compounds present in the must, nitrogen is an essential nutrient for the management of the fermentation kinetics but it also plays an important role in the synthesis of fermentative aromas. To address the problems related to nitrogen deficiencies, nitrogen additions during alcoholic fermentation have been developed. At present, they are mainly used to “secure” the fermentation process and avoid slow or sluggish fermentations. The consequences of such additions on the main reaction are well known (Beltran et al., 2005; Jiménez-Marti et al., 2007; Seguinot et al., 2018). However, their impact on the synthesis of aromas has been poorly studied. So, the main objective of this study was to compare the impact of nitrogen addition at different timings on both the kinetics and aroma synthesis. We also studied the effect of the initial nitrogen content of the must and the quantity of added nitrogen. To study the impact of these 3 parameters simultaneously, we used a Box-Behnken design and response surface modeling. Our results indicated that all three factors studied had important effects on fermentation kinetics and aroma production. The most remarkable points were the different regulation of the bioconversion of higher alcohols into acetate esters on one side and of fatty acids into ethyl esters on the other side. It was highlighted that the conversion of higher alcohols into acetate esters was maximum when nitrogen was added at the beginning of the stationary phase. Conversely, the highest conversion of acids into ethyl esters was reached when nitrogen was added close to the end of the stationary phase. This work enables to get a deeper understanding of the regulation of the yeast metabolism. It also underlines the possibility to refine the organoleptic profile of a wine by targeting the addition of nitrogen at a specific time during the stationary phase.

DOI:

Publication date: September 7, 2021

Issue: Macrowine 2021

Type: Article

Authors

Joséphine Godillot 

SPO, Univ Montpellier, INRAE, Institut Agro, Montpellier, France,Christian PICOU, SPO, Univ Montpellier, INRAE, Institut Agro, Montpellier, France Marc PEREZ, SPO, Univ Montpellier, INRAE, Institut Agro, Montpellier, France Isabelle SANCHEZ, MISTEA, INRAE, Institut Agro, Montpellier, France Jean-Marie SABLAYROLLES, SPO, Univ Montpellier, INRAE, Institut Agro, Montpellier, France Jean-Roch MOURET, SPO, Univ Montpellier, INRAE, Institut Agro, Montpellier, France

Contact the author

Keywords

alcoholic fermentation – nitrogen additions  – fermentative aromas – box-behnken design

Citation

Related articles…

Exploring resilience and competitiveness of wine estates in Languedoc-Roussillon in the recent past: a multi-level perspective

The Languedoc-Roussillon wineries are facing a decline in wine yields particularly PGI yields due to many factors. Climate change is just ones, but is expected to increase in the future. There is also structurally a large heterogeneity of yield profiles among terroirs, varieties and strategies. This work investigates the link between yield, competitiveness and resilience to explore how resilient winegrowers have been in the recent past. To this end two approaches have been combined; (i) an accountancy database analysis at estate scale and (ii) municipality level competitiveness analysis. A new resilience indicator that characterizes the capacity of an estate to absorb yield variation is also defined. The FADN database between 2000 and 2018 of ex-Languedoc-Roussillon (France) and other data are used to analyse the current situation and the past evolution of competitiveness and resilience by type of estate (type of farm: PGI and/or PDO & type of commercialization: bulk and/or bottles). The net margin, which defines competitiveness, is not correlated to yield for all types but depends on the type of commercialization and the level of specialisation. The resilience indicator shows that the net margin of estates specialized in PGI is particularly sensitive to yield declines. We also show that price evolutions seem to compensate the effect of yield losses for the majority of types. Municipality scale analysis shows the links between local pedoclimate, yield, commercialization strategies and price. Overlapping a PDO with a PGI does not always increase a municipality’s PGI competitiveness. It is difficult to make links between causes and effects due to the complexity of the wine production system. Production diversification may be a solution. Resorting to the two level of analysis helps resolving the data gap that is necessary to explore the links between yield and economic performance of the wine estates in the long term.

Bentonite fining in cold wines: prediction tests, reduced efficiency and possibilities to avoid additional fining treatments

Bentonite fining is widely used to prevent protein haze in white wines. Most wineries use laboratory-scale fining trials to define the appropriate amount of bentonite to be used in the cellar. Those pre-tests need to mimic as much as possible the industrial scale fining procedure to determine the exact amount of bentonite necessary for protein stability. Nevertheless it is frequent that, after fining with the recommended amount of bentonite, wines appear still unstable and need an additional fining treatment. It remains a major challenge to understand why the same wine, fined with the same dosage of the same bentonite, achieves stability in the lab, but not in the cellar.

For a phenomenology of terroir. A consumers’ perspective

This study investigates the notion of terroir by applying a phenomenological approach, focusing on the subjective experience of consumers. We will consider how terroir is described by consumers in order to gauge their subjective viewpoint and understand their way of describing and defining this spatiality.

Le pays du Brulhois

Depuis un an, nous essayons de mettre en place un projet de développement socio-économique et culturel d’une zone située essentiellement au sud de la Garonne et à cheval sur 3 départements (le Lot et Garonne, le Gers et le Tam et Garonne) et sur 2 régions (l’Aquitaine et Midi Pyrénées): le pays du Brulhois, “porte de la Gascogne”.

FLAVONOID POTENTIAL OF MINORITY RED GRAPE VARIETIES

The alteration in the rainfall pattern and the increase in the temperatures associated to global climate change are already affecting wine production in many viticultural regions all around the world (1). In fact, grapes are nowadays ripening earlier from a technological point of view than in the past, but they are not necessarily mature from a phenolic point of view. Consequently, the wines made from these grapes can be unbalanced or show high alcohol content. Dramatic shifts in viticultural areas are currently being projected for the future (2).