Terroir 2020 banner
IVES 9 IVES Conference Series 9 Characterising the chemical typicality of regional Cabernet Sauvignon wines

Characterising the chemical typicality of regional Cabernet Sauvignon wines

Abstract

Aim: To define the uniqueness of Australian Cabernet Sauvignon wines by evaluation of the chemical composition (volatile aroma and non-volatile constituents) that may drive regional typicity, and to correlate this with comprehensive sensory analysis data to identify the most important compounds driving relevant sensory attributes.

Methods and Results: A range of specialised analytical methods have been optimised to quantify more than 70 volatile aroma compounds in Cabernet Sauvignon wine. These methods examine a diverse array of metabolites that originate from the grape, fermentation, maturation and oak maturation. Examination of a variety of non-volatile compounds such as tannins, basic chemistry and non-volatile secondary metabolites were also undertaken. These analytes were quantified in 2015 commercial Cabernet Sauvignon wines (n = 52) originating from Coonawarra, Margaret River, Yarra Valley and Bordeaux. Multivariate statistical analysis of chemical datasets and sensory ratings obtained by a trained descriptive analysis panel identified compounds driving aroma attributes that distinguished wines from the different regions. Some compounds, such as dimethyl sulfide, which arises from a grape amino acid and is described as ‘black currant or olive’ at low concentration and ‘canned vegetables’ at high concentration, were not statistically different amongst regions. In contrast, compounds such as 1,4-cineole (‘mint’ and ‘bay leaf’ aroma), 3-isobutyl-2-methoxypyrazine (‘green capsicum’ aroma) and 4-ethylphenol (‘earthy’ and ‘band-aid’ aroma) were able to differentiate the wines.

Conclusions: 

For the first time, this work has revealed various wine chemical constituents, both volatile and non-volatile, that have been linked with results from comprehensive sensory analysis to determine the important drivers of regional typicity of Australian Cabernet Sauvignon wines. Identifying these candidates will lead us to the next step of identifying which viticultural and/or winemaking practices can influence these compounds to meet target styles for wines of provenance.

Significance and Impact of the Study: Identifying the chemical markers that characterise Cabernet Sauvignon regional typicity will lead Australian producers one step closer to having the tools to preserve the ‘uniqueness’ of their regional wines. A greater understanding of chemical drivers of wine sensory traits will keep the industry at the forefront of the field internationally and will provide producers with knowledge that can be used for promoting their wines and enhancing sales.

DOI:

Publication date: March 17, 2021

Issue: Terroir 2020

Type: Video

Authors

Dimitra L. Capone1,2*, Paul Boss3, Lira Souza Gonzaga1,2, Susan E.P. Bastian1,2, David W. Jeffery1,2

1Australian Research Council Training Centre for Innovative Wine Production, Australia
2Department of Wine Science, The University of Adelaide, PMB 1, Glen Osmond, South Australia 5064, Australia
3CSIRO, Locked Bag 2, Glen Osmond, South Australia 5064, Australia

Contact the author

Keywords

Regional typicity, chemical markers, wine sensory traits, Cabernet Sauvignon

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

A spatial explicit inventory of EU wine protected designation of origin to support decision making in a changing climate

Winemaking areas recognized as protected designations of origin (PDOs) shape important economic, environmental and cultural values that are tied to closely defined geographic locations. To preserve wine products and wine-growing practices adopted in different PDOs these areas are strictly regulated by legal specifications. However, quality viticulture is increasingly under pressure from climate change, which is altering the local conditions of many winegrowing areas. Therefore, maintaining traditional wine products will require the adoption of tailored adaptation strategies, including possible changes in the legal regulation of protected wines. To this end, it is necessary to have a comprehensive knowledge on PDOs including their extension, products and allowed practices. While there have been efforts to build databases that summarize the characteristics for individual wine PDO areas and to quantify the related effects of climate change, much information is still included only in the official documentation of the EU geographical indication register and has never been collected in a comprehensive manner. With this study we aim at filling this gap by building a spatial inventory of European wine PDOs that supports decision making in viticulture in the context of climate change. To map and characterize European wine PDOs, we analysed their legal documents and extracted relevant information useful for climate change adaptation. The output consists of a comprehensive geographical dataset that identifies the boundaries of all 1200 European wine PDOs at unprecedented spatial resolution and includes a set of legally binding regulations, such as authorized vine varieties, maximum yields and planting density. The inventory will allow researchers to analyse the impacts of climate change on European wine PDOs and support decision makers in developing tailored adaptation strategies. This includes, among others, the evaluation of new vineyard site selection, the expansion of cultivated varieties or the authorization of irrigation in vineyards.

Drought effect on aromatic and phenolic potential of seven recovered grapevine varieties in Castilla-La Mancha region (Spain)

The effects of climate change are seriously affecting the quality of wine grapes. High temperatures and drought cause imbalances in the chemical composition of grapes. The result is overripe grapes with low acidity and high sugar content, which produce wines with excessive alcohol content, lacking in freshness and not very aromatic. As a consequence, the search of varieties with capacity of produce quality grapes in adverse climate conditions is a good alternative to preserve the sustainability of vineyards. In this work, quality parameters of seven Vitis vinifera L. cultivars (five whites and two reds) recently recovered from extinction and grown under two different hydric regimes (rainfed and irrigated) were analyzed during the 2020 vintage. At harvest time, weight of 100 berries, must physicochemical parameters (brix degree, total acidity, malic acid, pH), and carbon and oxygen isotope ratios (δ13C, δ18O) were determined. Subsequently, varietal aroma potential index (IPAv) and total polyphenol index (TPI) were analyzed. Quality parameters, IPAv and TPI, showed significant differences between varieties and water regimes. Both red varieties, Moribel and Tinto Fragoso, stood out for their high aromatic and phenolic potential, which was higher under rainfed regime. Regarding to white varieties, Montonera del Casar and Jarrosuelto stood out in terms of varietal aroma potential. Montonera del Casar high acidity in its musts and Jarrosuelto showed the highest berry weights.

Influence of weather and climatic conditions on the viticultural production in Croatia

The research includes an analysis of the impact of weather conditions on phenological development of the vine and grape quality, through monitoring of four experimental cultivars (Chardonnay, Graševina, Merlot and Plavac mali) over two production years. In each experimental vineyard, which were evenly distributed throughout the regions of Slavonia and The Croatian Danube, Croatian Uplands,

Short-term relationships between climate and grapevine trunk diseases in southern French vineyards

[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"...

An analytical framework to site-specifically study climate influence on grapevine involving the functional and Bayesian exploration of farm data time series synchronized using an eGDD thermal index

Climate influence on grapevine physiology is prevalent and this influence is only expected to increase with climate change. Although governed by a general determinism, climate influence on grapevine physiology may present variations according to the terroir. In addition, these site-specific differences are likely to be enhanced when climate influence is studied using farm data. Indeed, farm data integrate additional sources of variation such as a varying representativity of the conditions actually experienced in the field. Nevertheless, there is a real challenge in valuing farm data to enable grape growers to understand their own terroir and consequently adapt their practices to the local conditions. In such a context, this article proposes a framework to site-specifically study climate influence on grapevine physiology using farm data. It focuses on improving the analysis of time series of weather data. The analytical framework includes the synchronization of time series using site-specific thermal indices computed with an original method called Extended Growing Degree Days (eGDD). Synchronized time series are then analyzed using a Bayesian functional Linear regression with Sparse Steps functions (BLiSS) in order to detect site-specific periods of strong climate influence on yield development. The article focuses on temperature and rain influence on grape yield development as a case study. It uses data from three commercial vineyards respectively situated in the Bordeaux region (France), California (USA) and Israel. For all vineyards, common periods of climate influence on yield development were found. They corresponded to already known periods, for example around veraison of the year before harvest. However, the periods differed in their precise timing (e.g. before, around or after veraison), duration and correlation direction with yield. Other periods were found for only one or two vineyards and/or were not referred to in literature, for example during the winter before harvest.