IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Highlighting the several chemical situations of Dimethyl sulfide in wine

Highlighting the several chemical situations of Dimethyl sulfide in wine

Abstract

Dimethyl sulfide (DMS) is a compound that accumulate in wine for the early years of ageing 1. During this stage, which is often carried out in the bottle, the environmental conditions are conducive to the release of DMS from its precursors, already present in grapes2. DMS has long been associated with unpleasant odours of cabbage or green olives but technological advances in analytical methods have made it possible to quantify this compound in smaller quantities in wines, allowing scientists to consider it as an aromatically interesting molecule. Recently, DMS has been identified as a central component of ageing bouquets for participating to their complexity and typicity3,4. Indeed, it contributes to the “truffle” and “undergrowth” odours of wines and its presence intensifies the fruity aromas and more particularly of the blackcurrant notes5. Also during the tasting, DMS acts as an enhancer and an inhibitor of aromatic notes successively and alternatively6. On the other hand, recent laboratory tests have shown that a wine spiked with a known amount of DMS will not have the same smell as a wine naturally rich in the same amount of DMS. Thus, the hypothesis of the existence of weak bonds between DMS and some components of wine matrix was posed.

Several components whose combined effect may be possible was chosen for explore hypothesis. Model wine solutions were made with additions of the different target compounds and DMS. Free DMS was determined by SHS-FPD at different days according to established kinetics. Then, the sorption mode was characterized as well as the sensory impact of DMS in different matrices. 

Experiments showed that in the model solutions containing grapes tannins, the free DMS decreased over the days compared to the control without tannins where the amounts of DMS remained the same from 0 to 15 days. Differences in the decrease of free DMS in the headspace of the samples were observed and measured depending on the tannin fractions tested and the concentration added to the model solution. Then, the sorption mode employed between DMS and tannins studied would be a cooperation sorption. The characterisation of DMS in water, wine and according to its mode of service was carried out which made it possible to highlight the multiple odours of this compound and its essential contribution, whatever its form in the wine, to the aromatic characters of this one as of the opening of the bottle.

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

Laboyrie Justine1, Jourdes Michael1 and Marchand Stéphanie1

1University of Bordeaux, INRAE, Bordeaux INP, UR OENOLOGIE, EA 4577, USC 1366, 210 Chemin de Leysotte – CS50008, 33882 Villenave d’Ornon Cedex, France

Contact the author

Keywords

Wine ageing, Dimethyl sulfide, sorption, tanins, bounded form aroma

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Bioclimatic shifts and land use options for Viticulture in Portugal

Land use, plays a relevant role in the climatic system. It endows means for agriculture practices thus contributing to the food supply. Since climate and land are closely intertwined through multiple interface processes, climate change may lead to significant impacts in land use. In this study, 1-km observational gridded datasets are used to assess changes in the Köppen–Geiger and Worldwide Bioclimatic (WBCS)

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…

Assessing the climate change vulnerability of European winegrowing regions by combining exposure, sensitivity and adaptive capacity indicators

Winegrowing regions recognized as protected designations of origin (PDOs) are closely tied to well defined geographic locations with a specific set of pedoclimatic attributes and strictly regulated by legal specifications. However, climate change is increasingly threatening these regions by changing local conditions and altering winegrowing processes. The vulnerability to these changes is largely heterogenous across different winegrowing regions because it is determined by individual characteristics of each region, including the capacity to adapt to new climatic conditions and the sensitivity to climate change, which depend not only on natural, but also socioeconomic and legal factors. Accurate vulnerability assessments therefore need to combine information about adaptive capacity and climate change sensitivity with projected exposure to new climatic conditions. However, most existing studies focus on specific impacts neglecting important interactions between the different factors that determine climate change vulnerability. Here, we present the first comprehensive vulnerability assessment of European wine PDOs that spatially combines multiple indicators of adaptive capacity and climate change sensitivity with high-resolution climate projections. We found that the climate change vulnerability of PDO areas largely depends on the complex interactions between physical and socioeconomic factors. Homogenous topographic conditions and a narrow varietal spectrum increase climate change vulnerability, while the skills and education of farmers, together with a good economic situation, decrease their vulnerability. Assessments of climate change consequences therefore need to consider multiple variables as well as their interrelations to provide a comprehensive understanding of the expected impacts of climate change on European PDOs. Our results provide the first vulnerability assessment for European winegrowing regions at high spatiotemporal resolution that includes multiple factors related to climate exposure, sensitivity, and adaptive capacity on the level of single winegrowing regions. They will therefore help to identify hot spots of climate change vulnerability among European PDOs and efficiently direct adaptation strategies.

Downscaling of remote sensing time series: thermal zone classification approach in Gironde region

In viticulture, the challenges of local climate modelling are multiple: taking into account the local environment, fine temporal and spatial scales, reliable time series of climate data, ease of implementation and reproducibility of the method. At the local scale, recent studies have demonstrated the contribution of spatialization methods for ground-based climate observation data considering topographic factors such as altitude, slope, aspect, and geographic coordinates (Le Roux et al, 2017; De Rességuier et al, 2020). However, these studies have shown questions in terms of the reproducibility and sustainability of this type of climate study. In this context, we evaluated the potential of MODIS thermal satellite images validated with ground-based climate data (Morin et al, 2020). Previous studies have been encouraging, but questions remain to be explored at the regional scale, particularly in the dynamics of the massive use of bioclimatic indices to classify the climate of wine regions. The results at the local scale were encouraging, but this approach was tested in the current study at the regional scale. Several objectives were set: 1) to evaluate the downscaling method for land surface temperature time series, 2) to identify regional thermal structure variations. We used weekly minimum and maximum surface temperature time series acquired by MODIS satellites at a spatial resolution of 1000 m and downscaled at 500 m using topographical variables. Two types of analyses were performed:

Grape must quality and mesoclimatic variability in Fruška Gora wine-growing region, Serbia

The Fruška Gora mountain is a traditional wine-growing region in Serbia situated in the Pannonian Basin. Due to such a position, the vicinity of the Danube River and the presence of concave configuration, it is suitable for grape production. This paper provides analyses of spatial variations in meteorological parameters and grape juice quality within Fruška Gora wine region over three consecutive vintages (2018-2020). The examined period can be defined as warm with cool nights during September (AVG 18,9°C; GDD 1918°C; CI 12°CF) and with the presence of mesoclimatic variability. The East part of the study area was somewhat drier and hotter compared to other parts of the region. The analyses of grape must samples (190 in total) of five cultivars (Cabernet-Sauvignon, Merlot, Chardonnay, Sauvignon blanc and Grašac (Welschriesling)) commonly grown across the region (19 sites), were performed using Fourier Transform Infrared Technology (FTIR). Among all cultivars, Sauvignon blanc was harvested first in the East area (DOY=246±5, GDD at harvest=1552±74, 22.2±0.7 °Brix), while the latest harvest was recorded for Cabernet-Sauvignon in the West (DOY=283±5, GDD at harvest=1936±187, 23.4±1.0 °Brix ). Both the red and white cultivars had higher acidity and YAN in the grape must if the vines were grown in the North and East compared to South and West areas. According to PCA analysis, Grašac showed the lowest variation in grape must chemical composition. Thus, the results confirm that Grašac is the most stable cultivar in Fruška Gora. All monitored cultivars reached technological fruit ripeness by the end of the growing season. However, it was difficult to reach full ripeness of red cultivars, mostly beacuse of uncoupling of technolocical and phenolic ripeness. Thus, Cabernet-Sauvignon had higher variations in GDD sums at harvest compared to other cultivars, which probably increased variations in grape must quality.