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…

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)

Adaptation to soil and climate through the choice of plant material

Choosing the rootstock, the scion variety and the training system best suited to the local soil and climate are the key elements for an economically sustainable production of wine. The choice of the rootstock/scion variety best adapted to the characteristics of the soil is essential but, by changing climatic conditions, ongoing climate change disrupts the fine-tuned local equilibrium. Higher temperatures induce shifts in developmental stages, with on the one hand increasing fears of spring frost damages and, on the other hand, ripening during the warmest periods in summer. Expected higher water demand and longer and more frequent drought events are also major concerns. The genetic control of the phenotypes, by genomic information but also by the epigenetic control of gene expression, offers a lot of opportunities for adapting the plant material to the future. For complex traits, genomic selection is also a promising method for predicting phenotypes. However, ecophysiological modelling is necessary to better anticipate the phenotypes in unexplored climatic conditions Genetic approaches applied on parameters of ecophysiological models rather than raw observed data are more than ever the basis for finding, or building, the ideal varieties of the future.

Projected changes in vine phenology of two varieties with different thermal requirements cultivated in La Mancha DO (Spain) under climate change scenarios

The aim of this work was to analyze the phenology variability of Tempranillo and Chardonnay cultivars, related to the climatic characteristics in La Mancha Designation of Origin, and their potential changes under climate change scenarios. Phenological dates referred to budbreak, flowering, veraison and harvest were analyzed for the period 2000-2019. The weather conditions at daily time scale, recorded during the same period, were also evaluated. The thermal requirements to reach each of these phenological stages were calculated and expressed as the GDD accumulated from DOY=60. Changes in phenology were projected by 2050 and 2070 taking into account those values and the projected temperatures and precipitation, simulated under two Representative Concentration Pathway (RCP) scenarios –RCP4.5 and RCP8.5– using an ensemble of models. The average phenological dates during the period under study were, April 16th ± 6.6 days and April 5th ± 6.0 days for budbreak, May 31st ± 6.0 days and May 27th ± 5.3 days for flowering, July 26th ± 5.6 days and July 25th ± 5.8 days for veraison, and Ago 23rd ± 10.8 days and Ago 17th ± 9.0 days for harvest, respectively, for Tempranillo and Chardonnay. The projected changes in temperature imply an average change in the maximum growing season (April-August) temperatures of 1.2 and 1.9°C by 2050, and 1.6 and 2.6°C by 2070, under the RCP4.5 and RCP8.5 scenarios, respectively. A reduction in precipitation is predicted, which vary between 15% for 2050 under RCP4.5 scenario and up to 30% by 2070 under RCP8.5. The advance of the phenological dates for 2050, could be of 6, 7, 7, and 8 days for Tempranillo and 4, 6, 6 and 9 days for Chardonnay, respectively for budbreak, flowering, veraison and harvest under the RCP4.5 scenario. Under the RCP8.5 emission scenario, the advance could be up to 30% higher.

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.

Rapid damage assessment and grapevine recovery after fire

There is increasing scientific consensus that climate changeis the underlying cause of the prolonged dry and hot conditions that have increased the risk of extreme fire weather in many countries around the world. In December 2019, a bushfire event occurred in the Adelaide Hills, South Australia where 25,000 hectares were burnt and in vineyards and surrounding areas various degrees of scorching and infrastructure damage occurred. The ability to coordinate and plan recovery after a fire event relies on robust and timely data. The current practice for measuring the scale and distribution of fire damage is to walk or drive the vineyard and score individual vines based on visual observation. The process is time consuming, subjective, or semi-quantitative at best. After the December 2019 fires, it took many months to access properties and estimate the area of vineyard damaged. This study compares the rapid assessment and mapping of fire damage using high-resolution satellite imagery with more traditional ground based measures. Satellite imagery tracking vineyard recovery in the season following the bushfire is being correlated to field assessments of vineyard productivity such as canopy health and development, fertility and carbohydrate storage. Canopy health in the seasons following the fires correlated to the severity of the initial fire damage. Severely damaged vines had reduced canopy growth, were infertile or had very low fertility as well as lower carbohydrate levels in buds and canes during dormancy, which reduced productivity in the seasons following the bushfire event. In contrast, vines that received minor damage were able to recover within 1-2 years. Tools that rapidly and affordably capture the extent and severity of damage over large vineyard area will allow producers, government and industry bodies to manage decisions in relation to fire recovery planning, coordination and delivery, improving the efficiency and effectiveness of their response.