Macrowine 2021
IVES 9 IVES Conference Series 9 Chemical and sensory diversity of regional Cabernet-Sauvignon wines

Chemical and sensory diversity of regional Cabernet-Sauvignon wines

Abstract

AIM: To investigate chemical and sensory drivers of regional typicity of Cabernet Sauvignon from different geographical regions of Australia.

METHODS: Commercial Cabernet wines (n = 52) from Coonawarra, Margaret River, and Yarra Valley Geographical Indications of Australia, and from Bordeaux, France, were selected for extensive chemical and sensory analysis.1 A range of analytical methods were optimised to quantify a comprehensive array of volatile compounds (> 70) originating from different sources, including grape, fermentation, oak maturation, and ageing. Along with basic chemical data, measurement of non-volatile compounds such as tannins and other secondary metabolites and elements was also undertaken. Multivariate statistical analysis using partial least squares regression was applied to the combined chemical data and the sensory analysis ratings obtained through a trained descriptive analysis panel of the same wines, to determine important compounds driving relevant sensory attributes.

RESULTS: The compound 1,4-cineole, described as ‘mint’ and ‘bay leaf’, was partly responsible for separation of the Cabernet Sauvignon wines from the Australian regions, particularly from Margaret River, whereas compounds such as 4-ethylphenol and 4-ethylguaiacol were linked to the aromas of ‘earthy’ and ‘yeasty’, which drove some of the separation of Bordeaux wines from the others. Varietal thiol, 3-mercapto-1-hexanol, which is mainly associated with Sauvignon Blanc and other white wine varieties, was measured in concentrations above its aroma detection threshold in all of the wines analysed, with similar concentrations present in Bordeaux and Coonawarra wines, and significantly higher concentrations in Margaret River and Yarra Valley wines. Additionally, non-volatiles such as particular elements drove some the separation between the regions; for example strontium was present in highest concentration in the Coonawarra wines and was found at lowest concentration in the Bordeaux wines. Free anthocyanins were also found to differ between Coonawarra and Bordeaux regions, with higher concentration being measured in the latter.

CONCLUSION

In determining the influential drivers of sensory properties of regional Cabernet Sauvignon wines, this study has uncovered various volatile and non-volatile constituents that are associated with specific sensory attributes. This is an important step in being able to define and subsequently help preserve the distinctive characters associated with regional Cabernet Sauvignon wines.

 

DOI:

Publication date: September 7, 2021

Issue: Macrowine 2021

Type: Article

Authors

Dimitra L. Capone 

Australian Research Council Training Centre for Innovative Wine Production, The University of Adelaide,Paul BOSS, CSIRO, and Australian Research Council Training Centre for Innovative Wine Production  Lira SOUZA GONZAGA, Australian Research Council Training Centre for Innovative Wine Production, and The University of Adelaide  Susan E. P. BASTIAN, Australian Research Council Training Centre for Innovative Wine Production, and The University of Adelaide Ruchira RANAWEERA, Department of Wine Science, The University of Adelaide David W. JEFFERY, Australian Research Council Training Centre for Innovative Wine Production, and The University of Adelaide

Contact the author

Keywords

volatile compound, non-volatile compound, sensory analysis, partial least squares regression, regionality, terroir

Citation

Related articles…

A multidisciplinary approach to evaluate the effects of the training system on the performance of “Aglianico del Vulture” vineyards

Vineyards are complex agro-ecosystems with high spatial and temporal variability. An efficient training system may counteract the adverse effects of this variability. Moreover, considering the climate change issues, choosing an efficient training system that enhances water use and protects the vines from radiative thermal stress has become a priority for the farmers. A multidisciplinary approach that assesses the soil-crop-yield-wine relationships of vineyards in a distributed and holistic way could bring added knowledge on the behavior of the different training systems. This ongoing research aimed to implement a multidisciplinary approach to study the behavior of “Aglianico del Vulture” grapevines trained with two different systems: a spurred cordon (SC) and an “Alberello in parete” (AL), grown in a high-quality wine production area of Basilicata region (Italy). The approach merged several methods and scales of soil, ecophysiology, must/wine quality, and spectral data collection to assess the influence of the training system. Homogeneous zones (HZs) in both training systems were defined through a procedure based on geomorphological classification, unmanned aerial vehicles (UAV) images analysis, and a traditional soil survey supported by geophysical scanning. During the 2021 season, TDR probes monitored soil water content, while grapevine health status was assessed using eco-physiological measurements (LWP, chlorophyll content, PSII photosynthetic efficiency, LAI, and point-based field spectroscopy). These grapevine in-vivo measurements validated the spectral vegetation indexes (NDVI, RENDVI, CVI, and TVI) derived from the UAV multispectral imagery, which monitored the grapevine status in a distributed and non-invasive way. Grape yield, quality of berries, must and wine were measured to assess the effects of the training systems. The first experimental year results showed the variability of the vineyards and revealed relationships among soil parameters, crop characteristics, and vegetation indices of the SC and AL training systems. This multidisciplinary study could bring new insights into the vineyard training system’s effects on grape yield and wine quality.

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"...

Current climate change in the Oplenac wine-growing district (Serbia)

Serbian autochthonous vine varieties Smederevka (for white wines) and Prokupac (for rosé and red wines) are the primary representatives of typical characteristics of wines and terroir of numerous wine-growing areas in Serbia. In the past, these varieties were the leading vine varieties, however, as the result of globalization of winemaking and the trend of consumption of wines from widely prevalent vine varieties, they were replaced by introduced international varieties. Smederevka and Prokupac vine varieties are characterized by later time of grape ripening, and relative sensitivity to low temperatures. Climate conditions can be a restrictive factor for production of high-quality grapes and wine and for the spatial spreading of these varieties in hilly continental wine-growing areas.
This paper focuses on the spatial analysis of changes of main climate parameters, in particular, analysis of viticultural bioclimatic indices that were determined for the purposes of viticulture zoning of wine-growing areas in the period 1961-2010, and those same parameters determined for the current, that is, referential climate period (1988-2017). Results of the research, that is, analysis of climate changes indicate that the majority of examined climate parameters in the Oplenac wine-growing district improved from the perspective of Smederevka and Prokupac vine varieties. These studies of climate conditions indicate that changes of analyzed climate parameters, that is, bioclimatic indices will be favorable for cultivation of varieties with later grape ripening times and those more sensitive to low temperatures, such as the autochthonous vine varieties Smederevka and Prokupac, therefore, it is recommended to producers to more actively plant vineyards with these varieties in the territory of the Oplenac wine-growing district.

The concept of terroir: what place for microbiota?

Microbes play key roles on crop nutrient availability via biogeochemical cycles, rhizosphere interactions with roots as well as on plant growth and health. Recent advances in technologies, such as High Throughput Sequencing Techniques, allowed to gain deeper insight on the structure of bacterial and fungal communities associated with soil, rhizosphere and plant phyllosphere. Over the past 10 years, numerous scientific studies have been carried out on the microbial component of the vineyard. Whether the soil or grape compartments have been taken into account, many studies agree on the evidence of regional delineations of microbial communities, that may contribute to regional wine characteristics and typicity. Some authors proposed the term “microbial terroir” including “yeast terroir” for grapes to describe the connection between microbial biogeography and regional wine characteristics. Many factors are involved in terroir including climate, soil, cultivar and human practices as well as their interactions. Studies considering “microbial terroir” greatly contributed to improve our knowledge on factors that shape the vineyard microbial structure and diversity. However, the potential impact of “microbial terroir” on wine composition has yet not received strong scientific evidence and many questions remain to be addressed, related to the functional characterization of the microbial community and its impact on plant physiology and grape composition, the origins and interannual stability of vineyard microbiota, as well as their impact on wine sensorial attributes. The presentation will give an overview on the role of microbiota as a terroir component and will highlight future perspectives and challenges on this key subject for the wine industry.

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.