WAC 2022 banner
IVES 9 IVES Conference Series 9 WAC 9 WAC 2022 9 3 - WAC - Posters 9 Eugenol:  a new marker of hybrid vines? The case study of Baco Blanc in Armagnac

Eugenol:  a new marker of hybrid vines? The case study of Baco Blanc in Armagnac

Abstract

Nowadays, winemaking is dealing with great challenges, notably climate change, disease resistance and low pesticide inputs, desire for more sustainable agricultural productions and permanent changing of consumer preference. Trying to propose practice improvements, scientists are exploring vine hybridization a paradoxically old but still actual way to take up such challenges (Pedneault & Provost, 2016). Phylloxera crisis in Europe (XIXth century) was a crucial step for improving hybridization in grapevine. Unfortunately some of the wines produced then presented redibitory sensorial default and were finally excluded for getting the PDO (Protected Designation of Origin) wine label in France.

 However, one grape variety from Armagnac vineyard resisted despite the ban: the Baco blanc, a complex hybrid of Vitis labrusca x Vitis riparia x Vitis vinifera. Baco was created to be a disease tolerant vine and productive vine of white wine intended for distillation (Baco, 1925).

Armagnac white brandies elaborated with only Baco Blanc present an atypical chemical profile. Eugenol, a phenylpropenic compound, usually known to be released by contact with oak, is significantly more concentrated in white brandies made with Baco than same products made with V.vinifera cultivars. Moreover, eugenol has been identified in other hybrid vines (Sun et al., 2011). Pure form of eugenol has a clove aroma and a noticeable and well-known antiseptic action, a gustative impact including an anesthesic power. These observations raises plenty of questions but the main ones are: “Is there a link between tolerance of the Baco to diseases and the presence of eugenol?”; “What is the dynamic of eugenol levels during spirit making?”; “Is there a link between the eugenol presence and the typicity of Baco?”.

Thus, we quantified eugenol in plants, grapes, musts, wines and distillates by HS-SPME-GC/MS. In grapes, a greater eugenol concentration and accumulation during maturation occurred in Baco Blanc than in other V.vinifera cultivars we tested (Ugni Blanc and Folle Blanche). In Baco Blanc wines, the use of enzymes increases the eugenol content during first steps of winemaking and highlights the existence of both eugenol forms, bounded and free fractions. Furthermore, eugenol amounts seemed to increase along with the storage duration on lees (before distillation). Finally, alambic characteristics may influence the alcohol content which may also impact eugenol concentration.

DOI:

Publication date: June 27, 2022

Issue: WAC 2022

Type: Article

Authors

Xavier Hastoy, Céline Franc, Laurent Riquier, Stéphanie Marchand-Marion, Marie-Claude Ségur, Marc Fermaud, Gilles De Revel

Presenting author

Xavier Hastoy – Université Bordeaux, Unité de recherche Œnologie, EA 4577, USC 1366 INRAE, ISVV, 33882 Villenave d’Ornon cedex, France

Université Bordeaux, Unité de recherche Œnologie, EA 4577, USC 1366 INRAE, ISVV, 33882 Villenave d’Ornon cedex, France | Université Bordeaux, Unité de recherche Œnologie, EA 4577, USC 1366 INRAE, ISVV, 33882 Villenave d’Ornon cedex, France | Université Bordeaux, Unité de recherche Œnologie, EA 4577, USC 1366 INRAE, ISVV, 33882 Villenave d’Ornon cedex, France | Bureau National Interprofessionnel de l’Armagnac (BNIA), 32800 Eauze, France | INRAE, UMR SAVE, Bordeaux Science Agro, ISVV, F-33882, Villenave d’Ornon, France | Université Bordeaux, Unité de recherche Œnologie, EA 4577, USC 1366 INRAE, ISVV, 33882 Villenave d’Ornon cedex, France

Contact the author

Keywords

Eugenol-Baco blanc-Brandies-Armagnac-Hybrid vines

Tags

IVES Conference Series | WAC 2022

Citation

Related articles…

VINIoT: Precision viticulture service for SMEs based on IoT sensors network

The main innovation in the VINIoT service is the joint use of two technologies that are currently used separately: vineyard monitoring using multispectral imaging and deployed terrain sensors. One part of the system is based on the development of artificial intelligence algorithms that are feed on the images of the multispectral camera and IoT sensors, high-level information on water stress, grape ripening status and the presence of diseases. In order to obtain algorithms to determine the state of ripening of the grapes and avoid losing information due to the diversity of the grape berries, it was decided to work along the first year 2020 at berry scale in the laboratory, during the second year at the cluster scale and on the last year at plot scale. Different varieties of white and red grapes were used; in the case of Galicia we worked with the white grape variety Treixadura and the red variety Mencía. During the 2020 and 2021 campaigns, multispectral images were taken in the visible and infrared range of: 1) sets of 100 grapes classifying them by means of densimetric baths, 2) individual bunches. The images taken with the laboratory analysis of the ripening stage were correlated. Technological maturity, pH, probable degree, malic acid content, tartaric acid content and parameters for assessing phenolic maturity, IPT, anthocyanin content were determined. It has been calculated for each single image the mean value of each spectral band (only taking into account the pixels of interest) and a correlation study of these values with laboratory data has been carried out. These studies are still provisional and it will be necessary to continue with them, jointly with the training of the machine learning algorithms. Processed data will allow to determine the sensitivity of the multispectral images and select bands of interest in maturation.

Making sense of available information for climate change adaptation and building resilience into wine production systems across the world

Effects of climate change on viticulture systems and winemaking processes are being felt across the world. The IPCC 6thAssessment Report concluded widespread and rapid changes have occurred, the scale of recent changes being unprecedented over many centuries to many thousands of years. These changes will continue under all emission scenarios considered, including increases in frequency and intensity of hot extremes, heatwaves, heavy precipitation and droughts. Wine companies need tools and models allowing to peer into the future and identify the moment for intervention and measures for mitigation and/or avoidance. Previously, we presented conceptual guidelines for a 5-stage framework for defining adaptation strategies for wine businesses. That framework allows for direct comparison of different solutions to mitigate perceived climate change risks. Recent global climatic evolution and multiple reports of severe events since then (smoke taint, heatwave and droughts, frost, hail and floods, rising sea levels) imply urgency in providing effective tools to tackle the multiple perceived risks. A coordinated drive towards a higher level of resilience is therefore required. Recent publications such as the Australian Wine Future Climate Atlas and results from projects such as H2020 MED-GOLD inform on expected climate change impacts to the wine sector, foreseeing the climate to expect at regional and vineyard scale in coming decades. We present examples of practical application of the Climate Change Adaptation Framework (CCAF) to impacts affecting wine production in two wine regions: Barossa (Australia) and Douro (Portugal). We demonstrate feasibility of the framework for climate adaptation from available data and tools to estimate historical climate-induced profitability loss, to project it in the future and to identify critical moments when disruptions may occur if timely measures are not implemented. Finally, we discuss adaptation measures and respective timeframes for successful mitigation of disruptive risk while enhancing resilience of wine systems.

Assessing the relationship between cordon strangulation, dieback, and fungal trunk disease symptom expression

Grapevine trunk diseases including Eutypa dieback are a major factor in the decline of vineyards and may lead to loss of productivity, reduced income, and premature reworking or replanting. Several studies have yielded results indicating that vines may be more likely to express symptoms of vascular disease if their health is already compromised by stress. In Australia and many other wine-growing regions it is a common practice for canes to be wrapped tightly around the cordon wire during the establishment of permanent cordon arms. It is likely that this practice may have a negative effect on health and longevity, as older cordons that have been trained in this manner often display signs of decay and dieback, with the wire often visibly embedded within the wood of the cordon. It is possible that adopting a training method which avoids constriction of the vasculature of the cordon may help to limit the onset of vascular disease symptom expression. A survey was conducted during the spring of two consecutive growing seasons on vineyards in South Australia displaying symptoms of Eutypa lata infection when symptomless shoots were 50–100 cm long. Vines were assessed as follows: (i) the proportion of cordon exhibiting dieback was rated using a 0–100% scale; (ii) the proportion of canopy exhibiting foliar symptoms of Eutypa dieback was rated using a 0–100% scale; (iii) the severity of strangulation was rated using a 0–4 point scale. Images were also taken of each vine for the purpose of measuring plant area index (PAI) using the VitiCanopy App. The goal of the survey was to determine if and to what extent any correlation exists between severity of strangulation and cordon dieback, in addition to Eutypa dieback foliar symptom expression.

Climate ethnography and wine environmental futures

Globalisation and climate change have radically transformed world wine production upsetting the established order of wine ecologies. Ecological risks and the future of traditional agricultural systems are widely debated in anthropology, but very little is understood of the particular challenges posed by climate change to viticulture which is seen by many as the canary in the coalmine of global agriculture. Moreover, wine as a globalised embedded commodity provides a particularly telling example for the study of climate change having already attracted early scientific attention. Studies of climate change in viticulture have focused primarily on the production of systematic models of adaptation and vulnerability, while the human and cultural factors, which are key to adaptation and sustainable futures, are largely missing. Climate experts have been unanimous in recognising the urgent need for a better understanding of the complex dynamics that shape how climate change is experienced and responded to by human systems. Yet this call has not yet been addressed. Climate ethnography, coined by the anthropologist Susan Crate (2011), aims to bridge this growing disjuncture between climate science and everyday life through the exploration of the social meaning of climate change. It seeks to investigate the confrontation of its social salience in different locations and under different environmental guises (Goodman 2018: 340). By understanding how wine producers make sense of the world (and the environment) and act in it, it proposes to focus on the co-production of interdisciplinary knowledge by identifying and foreshadowing problems (Goodman 2018: 342; Goodman & Marshall 2018). It seeks to offer an original, transformative and contrasted perspective to climate change scenarios by investigating human agency -individual or collective- in all its social, political and cultural diversity. An anthropological approach founded on detailed ethnographies of wine production is ideally placed to address economic, social and cultural disruptions caused by the emergence of these new environmental challenges. Indeed, the community of experts in environmental change have recently called for research that will encompass the human dimension and for more broad-based, integrated through interdisciplinarity, useful knowledge (Castree & al 2014). My paper seeks to engage with climate ethnography and discuss what it brings to the study of wine environmental futures while exploring the limitations of the anthropological environmental approach.

Vineyards and clay minerals: multi-technique analytical approach and correlations with soil properties

Purpose of this research is to quantitatively assess the mineral component of vineyard soils, with particular attention to the mineralogical analysis of clays, which represent an element of high importance in the vineyard culture as well as in general agriculture. An X-ray diffraction (XRD) / thermogravimetric (TG) multi-technique analytical approach was developed, tested on soil samples taken from vineyards around the world. This codified analytical procedure was necessary to obtain precise qualitative and quantitative mineralogical data, globally comparable to distinguish the geopedological identity of the vineyards. Soil samples from vineyards of various locations were analysed, in very different geological conditions. The bulk-rock quantitative phase analysis (QPA) was obtained by the Rietveld method while the detailed composition of the clay-sized fraction was determined by modelling of the oriented X-ray diffraction patterns. The research provided a precise classification of the mineral component of soils, distinguishing the mineral phases of the clays and the so-called mixed-layer clay minerals. We found that the content in mixed layers can be directly correlated with the water retention and the cation exchange capacity ​​of the soil, while the presence of other clayey minerals and phyllosilicates in this research did not affect this CEC parameter, which codes the fertility level of the soils. The study demonstrates that terroir, in particular soils formed in complex or very different geological conditions, can only be effectively interpreted by properly analysing its mineral phases, in particular the mixed-layer clay component. These are characteristic abiotic ecological indicators, which may have specific eco-physiological influences on the plant.