Macrowine 2021
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

Related articles…

Copper contamination in vineyard soils of Bordeaux: spatial risk assessment for the replanting of vines and crops

Copper (Cu) is widely and historically used in viticulture as a fungicide against mildew. Cu has a strong affinity for soil organic matter and accumulates in topsoil horizons. Thus, Cu may negatively affect soil organisms and plants, consequently reducing soil fertility and productivity. The Bordeaux vineyards have the largest vineyard surfaces (26%) within French controlled appellation and a great proportion of French wine production (around 5 million hl per year). Considering the local context of vineyard surfaces decreasing (vine uprooting) and possible new crop plantation, the issue of Cu potential toxicity rises. Therefore, the aims of this work are firstly to evaluate the Cu contamination in vineyard soils of Bordeaux, secondly to produce a risk assessment map for new vine or crop plantation. We used soil analyses from several local studies to build a database with 4496 soil horizon samples. The database was enhanced by means of pedotransfer functions in order to estimate the bioaccessible (EDTA-extractable) Cu in soils of samples without measurements. From this database, 1797 georeferenced samples with CuEDTA concentrations in the topsoil (0-50 cm depth) were used for kriging interpolation in order to produce the spatial distribution map of CuEDTA in vineyard soils. Then, the spatial distribution of Cu was crossed with vine uprooting surfaces and municipality boundaries. CuEDTAconcentrations ranged from 0.52 to 459 mg/kg and showed clear anomalies. Our results from spatial analysis showed that almost 50% of vineyard soil surfaces have CuEDTA concentrations higher than 30 mg/kg (moderate risk for new plantation) and 20% with concentrations higher than 50 mg/kg (high risk for new plantation). A decision-support map based on municipalities was realised to provide a simple tool to stakeholders concerned by land use management.

Grapevine yield estimation in a context of climate change: the GraY model

Grapevine yield is a key indicator to assess the impacts of climate change and the relevance of adaptation strategies in a vineyard landscape. At this scale, a yield model should use a number of parameters and input data in relation to the information available and be able to reproduce vineyard management decisions (e.g. soil and canopy management, irrigation). In this study, we used data from six experimental sites in Southern France (cv. Syrah) to calibrate a model of grapevine yield limited by water constraint (GraY). Each yield component (bud fertility, number of berries per bunch, berry weight) was calculated as a function of the soil water availability simulated by the WaLIS water balance model at critical phenological phases. The model was then evaluated in 10 grapegrowers’ plots, covering a diversity of biophysical and technical contexts (soil type, canopy size, irrigation, cover crop). We identified three critical periods for yield formation: after flowering on the previous year for the number of bunches and berries, around pre-veraison and post-veraison of the same year for mean berry weight. Yields were simulated with a model efficiency (EF) of 0.62 (NRMSE = 0.28). Bud fertility and number of berries per bunch were more accurately simulated (EF = 0.90 and 0.77, NRMSE = 0.06 and 0.10, respectively) than berry weight (EF = -0.31, NRMSE = 0.17). Model efficiency on the on-farm plots reached 0.71 (NRMSE = 0.37) simulating yields from 1 to 8 kg/plant. The GraY model is an original model estimating grapevine yield evolution on the basis of water availability under future climatic conditions.  It allows to evaluate the effects of various adaptation levers such as planting density, cover crop management, fruit/leaf ratio, shading and irrigation, in various production contexts.

How can historical cultivars mitigate the effects of climate change?

IFV, INRAe and the national network “Partenaires de la Sélection Vigne” representing 37 organizations from the different wine regions, have been working increasingly closely over the last 2 decades towards the preservation of the French varietal patrimony. There are approximately 600 patrimonial varieties according to INRAe and SupAgro Montpellier experts, including ancient cultivars (400) and intravarietal crossbreeds obtained since the 19th century. In the context of a drastic reduction in such varieties from the mid 1980’s in favor of mainstream varieties, it was essential to carry out an inventory of old vines and vineyards. INRAe Vassal collection plays a key role here as it holds the largest diversity available, along with a rich bibliography and herbariums, offering us the opportunity to document and double check the identity of a cultivar, consolidating the expertise of ampelographers. The work is carried out in several stages, from verifying the existence of a variety in a small region, through to rehabilitation. During this session, the authors present the process that leads to the official registration of a variety. After this, IFV selection center takes over to initiate the process of selection and propagation. A specific focus within regions such as the Alps, Champagne and the South-West will provide details of the full procedure. Bia, Bouysselet, Chardonnay rose, Mecle and the aptly named Tardif, are some of the cultivars that have followed this procedure. Furthermore, a recent regulation established by INAO on “varieties of interest for adaptation purposes” might boost uptake by growers. Since 2006, 36 historical cultivars have been registered. Most of these have been neglected in the past due to late maturity, lack of sugar and high titratable acidity at harvest time. Such characteristics are today considered as positive qualities, not only in mitigation of the effects of climate change, but also as an opportunity for restoring diversity…

A predictive model of spatial Eca variability in the vineyard to support the monitoring of plant status

[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"...

Effect of the commercial inoculum of arbuscular mycorrhiza in the establishment of a commercial vineyard of the cultivar “Manto negro

The favorable effect of symbiosis with arbuscular mycorrhizal fungi (AMF) has been known and studied since the 60s. Nowadays, many companies took the chance to start promoting and selling commercial inoculants of AMF, in order to be used as biofertilizers and encourage sustainable biological agriculture. However, the positive effect of these commercial biofertilizers on plant growth is not always demonstrated, especially under field conditions. In this study, we used a commercial inoculum on newly planted grapevines of a local cultivar grafted on a common rootstock R110. We followed the physiological status of vines, growth and productivity and functional biodiversity of soil bacteria during the first and second years of 20 inoculated with commercial inoculum bases on Rhizophagus irregularis and Funeliformis mosseaeAMF at field planting time and 20 non-inoculated control plants. All the parameters measured showed a neutral to negative effect on plant growth and production. The inoculated plants always presented lower values of photosynthesis, growth and grape production, although in some cases the differences did not reach statistical significance. On the contrary, the inoculation supposed an increase of the bacterial functional diversity, although the differences were not statistically significant either. Several studies show that the effect of inoculation with AMF is context-dependent. The non-favorable effects are probably due to inoculation ineffectiveness under complex field conditions and/or that, under certain conditions, AMF presence may be a parasitic association. This puts into question the effectiveness of its application in the field. Therefore, it is recommended to only resort to this type of biofertilizer when the cultivation conditions require it (e.g., very low previous microbial diversity, foreseeable stress due to drought, salinity, or lack of nutrients) and not as a general fertilization practice.