 IVES 9 IVES Conference Series 9 Impact and comprehension of nitrogen and lipid nutrition on the production of fermentative aromas with different S. Cerevisiae yeasts used for spirits

Impact and comprehension of nitrogen and lipid nutrition on the production of fermentative aromas with different S. Cerevisiae yeasts used for spirits

Abstract

In the Cognac appellation, the production of white wines is almost exclusively dedicated to elaborate Charentaise eaux-de-vie. In this sense, the quality of Cognac eaux-de-vie intrinsically depends on the quality of the base wines subjected to the distillation stage. In this context, the production of these base wines differs from those of classic white wines to release particular organoleptic properties during the distillation stage. Thus, the settling stage is one of the stages that most illustrates the identity of Cognac wines. The freshly pressed white grape juice is placed in a settling tank but without the presence of pectolytic enzymes, without sulfiting and for a relatively short period of time, contrary to conventional oenological practices. Under these operating conditions, Cognac musts reach very high turbidities in the order of 500 to 2000 NTU against 150 to 200 NTU in conventional oenology. These Charentais musts, rich in solid particles and therefore in lipids [1], allow to guarantee an organoleptic quality that is both delicate and full of character for future eaux-de-vie. Associated with lipids, nitrogen is a nutrient with a major role in alcoholic fermentation [2] that will also influence the aromatic profile of wines [3] intended for distillation. To understand the impact of these main nutrients on the desired organoleptic quality of Cognac, we studied their influence under natural fermentation conditions with three strains of S. cerevisiae commonly used for the Cognac appellation. To understand the influence of each nutrient and their interaction, an experimental plan called “Central Composite Design” (CCD) was developed. The CCD allows to model the aroma productions from the fermentation conditions. Fermentations were carried out with natural ugni blanc must at 23°C. Assimilable nitrogen concentrations ranged from 115 to 285 mg/L and turbidity from 500 to 2700 NTU. Finally, a statistical analysis of covariance (ANCOVA) was also performed to evaluate the strain effect. The main results showed that lipids and assimilable nitrogen have a significant impact on the aromatic quality of Cognac wines. Indeed, high lipids concentrations favor the production of organic acids but inhibit the synthesis of esters. The metabolism of the 3 yeast strains reacts in the same way to changes in nitrogen and lipid nutrition. However, each strain keeps its own aromatic profile whatever the fermentation conditions. This study made it possible to study and model the impact and interaction of two essential nutrients for alcoholic fermentation on the metabolism of yeast in natural conditions with excess lipids. In addition, it should be noted that, even if each strain of the Cognac appellation has its aroma properties, all strains respond in the same way to the variations of nitrogen and lipid nutrition.

DOI:

Publication date: September 7, 2021

Issue: Macrowine 2021

Type: Article

Authors

Charlie Guittin, Faïza, Montpellier Isabelle, Jean-Marie, Jean-Roch, SANCHEZ

UMR SPO, INRAE of Montpellier, MACNA, UMR SPO, INRAE Montpellier, , UMR MISTEA, INRAE Montpellier, SABLAYROLLES, UMR SPO, INRAE Montpellier Xavier, POITOU, Hennessy, Cognac, MOURET, UMR SPO, INRAE Montpellier Vincent, FARINES, UMR SPO, INRAE Montpellier

Contact the author

Keywords

cognac, nitrogen, lipids, centered composite design, alcoholic fermentation, Saccharomyces cerevisiae, metabolism, aromas

Citation

Climate, Viticulture, and Wine … my how things have changed!

The planet is warmer than at any time in our recorded past and increasing greenhouse emissions and persistence in the climate system means that continued warming is highly likely. Climate change has already altered the basic framework of growing grapes for wine production worldwide and will likely continue to do so for years to come. The wine sector can continue to play an important role in leading the agricultural sector in addressing climate change. From developing on…

Climate projections over France wine-growing region and its potential impact on phenology

Climate change represents a major challenge for the French wine industry. Climatic conditions in French vineyards have already changed and will continue to evolve. One of the notable effects on grapevine is the advancing growing season. The aim of this study is to characterise the evolution of agroclimatic indicators (Huglin index, number of hot days, mean temperature, cumulative rainfall and number of rainy days during the growing season) at French wine-growing regions scale between 1980 and 2019 using gridded data (8 km resolution, SAFRAN) and for the middle of the 21th century (2046-2065) with 21 GCMs statistically debiased and downscaled at 8 km. A set of three phenological models were used to simulate the budburst (BRIN, Smoothed-Utah), flowering, veraison and theoretical maturity (GFV and GSR) stages for two grape varieties (Chardonnay and Cabernet-Sauvignon) over the whole period studied. All the French wine-growing regions show an increase in both temperatures during the growing season and Huglin index. This increase is accompanied by an advance in the simulated flowering (+3 to +9 days), veraison (+6 to +13 days) and theoretical maturity (+6 to +16 days) stages, which are more noticeable in the north-eastern part of France. The climate projections unanimously show, for all the GCMs considered, a clear increase in the Huglin index (+662 to 771 °C.days compared to the 1980-1999 period) and in the number of hot days (+5.6 to 22.6 days) in all the wine regions studied. Regarding rainfall, the expected evolution remains very uncertain due to the heterogeneity of the climates simulated by the 21 models. Only 4 regions out of 21 have a significant decrease in the number of rainy days during the growing season. The two budburst models show a strong divergence in the evolution of this stage with an average difference of 18 days between the two models on all grapevine regions. The theoretical maturity is the most impacted stage with a potential advance between 40 and 23 days according to wine-growing regions.

Influence of a spontaneous cover crop on the vineyard and soil erosion under Mediterranean climate

Sixty five % of the agricultural area of the Basque Country located in the DO Ca Rioja corresponds to vineyards. More than 40% of it has an average slope greater than 10%, which makes it sensitive to erosive processes. Furthermore, it is foreseeable that extreme weather events (storms, hail, extreme heat and cold, etc.) will be favored due to climate change. Cover cropping can mitigate this risk, and therefore the objective of this work is to evaluate the impact that a vegetable cover has on the agronomic behavior of the vineyard, the quality of the grape and soil erosion. For this, a trial has been carried out with a Graciano variety vineyard with a slope between 10% -20% during the years 2020 and 2021. Conventional tillage management in the area has been compared (4-6 passes per year of tillage machinery) versus spontaneous vegetation cover management in the vineyard. This implies not tilling and allowing the grass of the land to colonize the range between the lines of vines, controlling their height through 1-3 mowing passes per year, always trying to affect the surface of the land as little as possible. The vegetative growth, yield and quality of the grape and wine was measured. Furthermore, erosion has been measured using Gerlasch boxes. The yield was lower in the second year of the trial in the cover crop treatment, but erosion was significantly reduced.

Influence of agronomic practices in soil water content in mid-mountain vineyards

In the context of LIFE project MIDMACC (LIFE18 CCA/ES/001099), several pilots have been installed in vineyards in mid mountain areas of Catalonia (NE Spain) to test well stablished agronomic practices to increase the adaptation of Mediterranean mid mountain to climate change. Soil water content (SWC) at three different depths (15, 30 and 45cm) was measured in continuum from August 2020. One pilot (WC) included a well-established green cover (GC), a new GC (NC) and a conventional soil management (CM, tilling+herbicides). NC presented an intermediate state between WC and CM, responding similarly to CM in autumn but quickly reaching similar SWC to WC, then following the same evolution till next spring, with CM presenting lower values along autumn and winter. Then vegetation activation decreased SWC in all plots, (much slower in CM, lacking GC). Sensibility to spring rains is again intermediate for NC, which joins SWC evolution of CM by the end of spring till next autumn. It is expected that NC will resemble WC more and more as its GC develops. In the pilot combining vine training (VSP vs Gobelet) and hillside management (slope vs terrace), no clear pattern could be related with these conditions. However, both terraces seem to be more sensitive to spring rains. A third pilot included new vineyards (7 and 1 year old). In the new vineyard (N), higher canopy development, a spontaneous green cover and row straw resulted in a slower SWC dynamic, not so sensitive to rains but conserving more soil water in spring and most of summer, even with presumably a higher water extraction by vines. In the newest vineyard (VN) the deepest sensor is still sensitive to rain events all over the year and SWC is always highest at this depth, revealing small water capture by vines.

Short-term relationships between climate and grapevine trunk diseases in southern French vineyards

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.19.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...