Terroir 2020 banner
IVES 9 IVES Conference Series 9 Application of fluorescence spectroscopy with multivariate analysis for authentication of Shiraz wines from different regions

Application of fluorescence spectroscopy with multivariate analysis for authentication of Shiraz wines from different regions

Abstract

Aim: To investigate the possibility of utilising simultaneous measurements of absorbance-transmittance and fluorescence excitation-emission matrix (A-TEEM) combined with chemometrics, as a robust method that gives rapid results for classification of wines from different regions of South Australia according to their Geographical Indication (GI), and to gain insight into the effect of terroir on inter regional variation.

Methods and Results: Additionally, to obtaining various colour parameters, the A-TEEM technique enables the “fingerprint” of wine samples to be attained in response to the presence of fluorophoric compounds. This is accomplished by recording a three-dimensional excitation-emission matrix (EEM) over multiple excitation and emission wavelengths, which can then be analysed using multivariate statistical modelling to classify wines. Shiraz wine samples (n = 134) from six different GIs of South Australia (Barossa Valley, Clare Valley, Eden Valley, Langhorne Creek, McLaren Vale, and Riverland) were analysed and absorbance spectra, hue, intensity, CIE L*a*b, CIE 1931, and EEMs were recorded for each sample. EEM data were evaluated according to the cross-validation model built with extreme gradient boost discriminant analysis (XGBDA) using score probability to assess the accuracy of classification according to the region of origin. Preliminary results have shown a high prediction ability and the data extracted from A-TEEM could be used to investigate phenolics as potential chemical markers that may provide effective regional discrimination.

Conclusions: 

The molecular fingerprinting capability and sensitivity of EEM in conjunction with multivariate statistical analysis of the fluorescence data using the XGBDA algorithm provided sufficient chemical/spectral information to facilitate accurate classification of Shiraz wines according to the region of origin. A-TEEM coupled with XGBDA modelling appears to be a promising tool for wine authentication according to its geographical origin.

Significance and Impact of the Study: Having tangible evidence that Australian fine wines may be discriminated on the basis of geographical origin, will help to improve the international reputation of Australian wines and increase global competitiveness. Understanding of the important regional chemical parameters would allow grape growers and winemakers to optimise their viticultural and winemaking practices to preserve these characteristics of their terroir. Moreover, verifying the content in the bottle according to the label descriptions with a rapid method, has the potential to verify product provenance and counteract fraud in cases where wine of inferior/questionable quality or contaminated wine is presented as originating from Australia.

DOI:

Publication date: March 25, 2021

Issue: Terroir 2020

Type : Video

Authors

R.K.R. Ranaweeraa, A. M. Gilmoreb, D.L. Caponea, c, S.E.P. Bastiana,c, D.W Jefferya, c*

aDepartment of Wine and Food Science, The University of Adelaide, South Australia, Australia
bHORIBA Instruments Inc., 20 Knightsbridge Rd., Piscataway, NJ 08854, United States
cAustralian Research Council Training Centre for Innovative Wine Production, The University of Adelaide

Contact the author

Keywords

Geographical origin, chemometrics, modelling, excitation-emission matrix

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

Building of a hierarchy of wines based on terroirs: an initiative from the producers of Muscadet

The Muscadet area is situated in the southeast of Nantes, close to the Atlantic coast. It constitutes the western extension
of the French vineyard “Loire Valley”. The Muscadet is renowned and often spontaneously linked to a white wine.
However it remains misconceived as an ordinary wine, lacking authenticity.

How the physical components of the terroir can differently intervene in French wines DPO definitions.Example of Côte de Nuits in Burgundy

European regulations describe what elements must be given in the specifications of DPO determination ; mainly production conditions, links between quality and products characteristics and the physical traits of the production area. These elements are given in the “link to terroir” paragraph relating natural and human factors, detailed product characteristics linked to the geographical area and at last interactions between product originality and the geographical area.

Vignobles sur les pentes en Bourgogne : l’aube d’un nouveau modèle de l’Antiquité au Moyen Âge

La découverte d’une vigne gallo-romaine en plaine à Gevrey-Chambertin (Côte-d’Or) constitue un point important pour la compréhension de la construction des terroirs viticoles de Bourgogne. Sa situation en plaine constitue pour nous le point de départ d’une large réflexion sur la mise en place du modèle de viticulture de coteau qui prévaut en Bourgogne et sur les facteurs de ce changement de norme de qualité viticole. Les sources mobilisées pour cette approche interdisciplinaire et diachronique sont géomorphologiques, archéologiques et textuelles.

Everything else, it’s work ”Socio-cultural dimensions of terroir among Bordeaux winemakers

In 2010, the OIV adopted a resolution that defines ‘terroir’. The OIV definition understands terroir as the result of the interactions between the physical specificities of a space and human labor, with an emphasis on the subsequently produced collective knowledge (OIV-VITI 333-2010); by doing so, it alludes to the social and cultural dimensions of terroir.

Swiss program for the creation of fungal disease resistant grape varieties in Switzerland

Grapevine breeding is part of the research program of Agroscope in Switzerland since 1965. From 1965 to 1995, the aim of the Vitis vinifera crosses was to obtain a high resistance to grey rot (Botrytis cinerea), one of the most virulent fungal pathogens in the Swiss vineyard. In 2021, the grape varieties released from this first breeding program covered 936 ha of the 15’000 ha of the Swiss vineyard.
In 1996, a second breeding program aimed at obtaining, by classical interspecific hybridization, grape varieties resistant to downy mildew (Plasmopara viticola) and powdery mildew (Erisyphe necator) and less sensitive to grey rot (Botrytis cinerea). In order to accelerate and make the selection process more reliable, an early biochemical test was developed based on the natural defense mechanisms of the vine against downy mildew (stilbene phytoalexins). The synthesis of stilbenes (i.e., resveratrol and its oxidized dimers - and -viniférine) and pterostilbenes (methylated derivative) is among the most efficient induced defense mechanisms of grapevine against fungal pathogens on both the leaves and the clusters.