Macrowine 2021
IVES 9 IVES Conference Series 9 Revealing the origins of old bordeaux wines using terpene quantification

Revealing the origins of old bordeaux wines using terpene quantification

Abstract

The overall quality of fine wines is linked to the development of “bouquet” during wine bottle ageing (1). Bordeaux red wine ageing bouquet is defined by the association of several odours including fresh and fruity notes sometimes related to specific compounds. Some of those molecules, such as thiols or DMS are issued from precursors produced by the grapevine (2–5). On the another hand, several compounds such as terpenes are produced by the grape as precursors (6) and released during ageing. The aroma of aged wines , the “bouquet” could originate directly in grapes thanks to flavour precursors (7). In this study we addressed the questions: What is the most important between vintage and terroir in wine identity? And is there a molecular signature in the aroma of old wines linked to grape origin and revealed during ageing?Over 80 volatile molecules including DMS, esters, terpenes, mint terpenes, C13-norisoprénoïdes, volatiles oak wood compounds and off-flavors were quantified by GC/MS in 80 red Bordeaux wines (7 domains x 12 vintages between 1990 and 2007). A statistical analysis was performed on the dataset. First, the presence of most of the targeted molecules were identified in the 80 wines and the link between their contents and the wines’ ages was evaluated. After that, the hypothesis of wine identity being linked to wood contact or off-flavors was rejected. Next, principal component analysis (PCA) on the data showed a separation between the 7 vineyards studied. Each Bordeaux area and domain could be represented by one or several molecules. Then, a discriminant factor analysis (DFA) showed the weight of each compound in the separation. The terpenes, in particular terpinen-1-ol, terpinen-4-ol and α-terpinene, were implicated to the partitioning of vineyards. A degradation of the separation of the wines is observed if terpenes levels are excluded from the data set. Nevertheless, the separation is not effective based on solely terpene levels. The profile of terpenes in the molecular signature of these Bordeaux old wines is important but the signature of studied domains is incomplete without the other compounds.These results highlight the specificity of productions areas and the existence of a molecular identity unique to each domain beyond the effect of vintage and the passage of years. The terroir and blending practiced in Bordeaux are probably involved in this singular molecular identity.

DOI:

Publication date: September 14, 2021

Issue: Macrowine 2021

Type: Article

Authors

Justine Laboyrie

Unité de recherche Oenologie, EA 4577, USC 1366 INRAE, ISVV, University of Bordeaux, Bordeaux INP, F33882 Villenave d’Ornon France ,Davide Slaghenaufi, Department of Biotechnology, University of Verona 37029 San Pietro in Cariano, Italy Giovanni Luzzini, Department of Biotechnology, University of Verona 37029 San Pietro in Cariano, Italy Maurizio Ugliano, Department of Biotechnology, University of Verona 37029 San Pietro in Cariano, Italy Laurent Riquier, Unité de recherche Oenologie, EA 4577, USC 1366 INRAE, ISVV, University of Bordeaux, Bordeaux INP, F33882 Villenave d’Ornon France Stéphanie Marchand, Unité de recherche Oenologie, EA 4577, USC 1366 INRAE, ISVV, University of Bordeaux, Bordeaux INP, F33882 Villenave d’Ornon France

Contact the author

Keywords

red wines identity, ageing, gas chromatography analysis, terpenes, terroir

Citation

Related articles…

Water deficit differentially impacts the performances and the accumulation of grape metabolites of new varieties tolerant to fungi

The use of resistant varieties is a long-term but promising solution to reduce chemical input in viticulture. Several important breeding programs in Europe and abroad are now releasing a range of new hybrids performing well regarding fungi susceptibility and producing good quality wines. Unfortunately, insufficient attention is paid by the breeders to the adaptation of these varieties to climatic changes, notably to the increased climatic demand and water deficit (WD). Thus, prior to the adoption of such varieties by the wine industry in Mediterranean regions, there is a need to consider their suitability to WD. This study aimed to characterize the different drought-strategies adopted by 6 new resistant varieties selected by INRAE in comparison to Syrah. To allow the assessment of long-term impacts of WD, field-grown vines were exposed to contrasted WD from 2018 to 2021 under a semi-arid Mediterranean climate. A gradient of WD was applied in the field and controlled through plant measurements at the single plant level. Grape development was non-destructively monitored to determine the arrest of berry phloem unloading. The impacts of WD on berry composition, including water, primary metabolites (sugars, organic acids), secondary metabolites (anthocyanins, thiols precursors) and main cations contents, were assessed at this specific stage. Results showed different varietal responses during the year and inter-annual acclimation in terms of plant water use efficiency, biomass accumulation, as well as yield components and berry composition. WD differentially reduced the accumulation of primary metabolites at plant and berry levels, but it little changed their concentrations in the fruits at the ripe stage. Moreover, WD differentially impacted the accumulation of secondary metabolites and major cations between the varieties. In the talk, we’ll present the main results regarding the WD impacts on fruit metabolites and enlarge the reflection about the practical assessment of the grapevine acclimation to WD.

Effect of one-year cover crop and arbuscular mycorrhiza inocululation in the microbial soil community of a vineyard

The microbial composition of the soil is an important factor to consider in viticulture, since its influence on the “terroir” and on the organoleptic properties of the wine have been demonstrated. Different agronomic techniques have the potential to modify the composition and functionality of the soil microbial community. Maintaining green covers is known to increase soil microbial diversity. The direct application of inoculum of beneficial microorganisms to the soil has also been used to increase their abundance. However, the environmental conditions of each site seem to have a determining weight in the result of these practices. In this study, we compared the effect on the microbial community of a cover crop with legumes in autumn and the inoculation of grapevines with commercial inoculum bases on Rhizophagus irregularis and Funeliformis mosseae in the previous spring. The study has been carried out in a vineyard in Binissalem, Mallorca, Spain. After applying the treatments, we will analyze the soil microbial communities using the data obtained from Illumina amplification of soil DNA from the 16S and ITS regions to analyze bacteria and fungi community, respectively. In addition, we will record the physicochemical characteristics of the soil at each sampling point. The result showed that agronomic management, in the short term, has less influence than soil characteristics on the composition of the soil microbiome. With these results, we can conclude that in a vineyard, agricultural techniques should focus on improving the characteristics of the soil to improve the biodiversity of the soil microbiota.

austrianvineyards.com: online viewer of all designations of Austrian wine

To digitally record and present all the origins of Austrian wines in the same perfect and clear way was the motivation for the Austrian Wine Marketing Board (Austrian Wine) to start with the project in 2018. In June 2021 the results were presented to the public in an online viewer showing all the designations of Austrian wine, available at https://austrianvineyards.com in a largely barrier-free manner. The online viewer provides tailored individual maps fitted to the respective zoom level. The smallest unit of wine-origins in Austria is called Ried and is displayed in a plot-specific manner highlighting areas under vine. Information on the Ried include administrative district, winegrowing municipality, cadastral municipality, large collective vineyard site, specific winegrowing region, generic winegrowing region, winegrowing area and, in many cases, an illustrative picture. Complementary data on the size, elevation (minimum-maximum), orientation (in 8 sectors plus flat) and gradient (minimum, maximum, average) are based on the area under vine according to the EU’s Integrated Administration and Control System. Additional information covers climate data. The diagrams are taken from the monthly breakdown of data in the annals of the Central Institute for Meteorology and Geodynamics, Austria provide a display of values for air temperature, precipitation, and sunshine hours for the reference year and the long-term average. Seasonal aggregated data on temperature, precipitation, and sunshine hours complete the display. Short descriptions with emphasis on geology and soil, field name in historical maps, etymology of the denomination, and main planted variety complements the available information for the main designations in the online viewer. These descriptions are compiled by winegrowers, geologists, historians, and journalists. All the information and data can be extracted to a pdf-file. Printed vineyard maps are also available. Missing content regarding wine origins in Styria will be completed in winter 2021/22.

Climate modeling at local scale in the Waipara winegrowing region in the climate change context

In viticulture, a warming climate can have a very significant impact on grapevine development and therefore on the quality and characteristics of wines across different spatial scales, ranging from global to local. In order to adapt wine-growing to climate change, global climate models can be used to define future scenarios, but only at the scale of major wine regions. Despite the huge progress made over the last ten years in terms of the spatial resolution of climate models (now downscaled to a few square kilometres), they are not yet sufficiently precise to account for the local climate variability associated with such parameters as local topography, in spite of these parameters being decisive for vine and wine characteristics. This study describes a method to downscale future climate scenarios to vineyard scale. Networks of data loggers have been used to collect air temperature at canopy level in the Waipara winegrowing region (New Zealand) over five growing seasons. These measurements allow the creation of fine-scale geostatistical models and maps of temperature (at 100 m resolution) for the growing season. In order to model climate change at pilot site scale, these geostatistical models have been combined with regional climate change predictions for the periods 2031-2050 and 2081-2100 based on the RCP8.5 climate change scenario. The integration of local climate variability with regionalized climate change simulations allows assessment of the impacts of climate change at the vineyard scale. The improved knowledge gained using this methodology results from the increased horizontal resolution that better addresses the concerns of winegrowers. The results provide the local winegrowers with information necessary to understand current processes, as well as historical and future viticulture trends at the scale of their site, thereby facilitating decisions about future response strategies.

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.