Project Number
WW 08-28
Project title
Provenance determination of South African wines
Project leader
Coetzee, P P
Institution
Rand Afrikaanse University
Project description
A lack of knowledge exists on the phenol composition of local red grapes and wine and on the impact these colour and taste compounds have on wine quality. This knowledge is essential in the optimisation of viticultural and enological techniques to produce optimal quality wines.
One of the main goals of this project, i.e. to determine the phenol composition of a spectrum of red grapes and wines, has already been realized in part by the analyses of Pinotage, Shiraz and Cabernet Sauvignon wines from the 2002 season. Wines were sampled from the Young Wine and Veritas Wine shows according to cultivation distribution in wine producing areas. A liquid chromatographic technique, that is able to determine 38 individual phenols per wine, has been implemented for the analysis of these wines.
Interesting cultivar differences have been noted in the levels of certain phenols. The levels of caffeic acid and its tartaric acid derivative, caftaric acid, are significantly higher in Pinotage compared to Shiraz and Cabernet Sauvignon. Notably higher levels of total analysed flavonols were observed in Shiraz compared to the other two cultivars. These findings agree with those from the 2001 season, but need to be verified further by the analysis of more wines and also grapes over a number of seasons to determine possible seasonal effects.
Cultivar differences in phenol composition can be used in identifying colour and taste impact phenolic compounds. Identification of such compounds will be an important tool in realizing another main goal of this project, i.e. to apply the knowledge obtained from the phenol composition determination in optimising viticultural and enological techniques to produce wines of high quality. In so doing technology will be developed which can improve South Africa’s competitiveness on the international markets.
This is true especially seen in the light that the local wine production pattern is turning from white to red wine. The ratios of the main anthocyanins relative to one another in wines are increasingly being used as a measure of wine authenticity. These ratios were determined for the analysed wines from the 2002 season. The data indicate slight distinctions between Pinotage, Shiraz, and Cabernet Sauvignon wines based on these ratios. These data could be of value in setting a standard of characteristic anthocyanin ratios in South African wines
Presentation(s)
Van der Linde, G, Fischer and Coetzee, P P. 2005. Correlation of the trace element fingerprint of grapes, grape juice and the final wine. Paper presented at the 34th Colloquium Spectroscopium Internationale. 4-9 September, University of Antwerpen, Antwerpen, Belgium.
Coetzee, P P. 2005. Fingerprinting of South African wines using ICP-MS multi-element data and multivariate statistics. Paper presented at the Symposium and Workshop NRF-Flandres Collaboration. Het Pand, Ghent University. 10 September, Ghent, Belgium.
Coetzee, P P. 2005. ¹¹B/¹ºB ratio measurements by ICP-MS for wine authentication. Paper presented at the Symposium and Workshop NRF-Flanders Collaboration. 10 September, Het Pand, Ghent University, Ghent, Belgium.
Coetzee, P P. 2006. Multi-element analysis and boron isotope ratio measurements in South African wines by ICP-mass spectrometry and their classification according to geographical origin. Paper presented at the 29th National Congress of the South African Society for Enology and Viticulture. 14-17 November, Somerset West, South Africa.
Coetzee, P P, De Bruyn, R, Greeff, L and Vanhaecke, F. 2007. Boron isotope ratio measurements by ICP-MS for classification of wine according to geographical origin. Paper presented at the 34th Colloquium Spectroscopium Internationale. 4-9 September, University of Antwerpen, Antwerpen, Belgium.
Coetzee, P P. 2008. Provenance determination of agricultural products using isotope ratio and multi-element data by QICP-MS. Paper presented at the 10th Rio Symposium on Atomic Spectrometry. 7-12 September, Salvador-Bahia, Brazil
Vorster, C, Van der Walt, T N and Coetzee, P P. 2008. Ion exchange separation of Sr and Rb on Dowex 50W-X8, using the complexion properties of EDTA and DCTA. Paper presented at the South African Association for Mass Spectrometry Symposium. 12-17 October, Warmbaths, South Africa.
Coetzee, P P. 2008. 11B/10B and 87Sr/86Sr isotope ratio determination by Q-ICP-S for fingerprinting of South African wines. Paper presented at the 39th Convention of the South African Chemical Institute.1-5 December, University of Stellenbosch, Stellenbosch, South Africa.
Coetzee, P P. 2009. About wine and its origin: Tracing the authenticity of wine by chemical analysis. SACI Merck Award Lecture, University of Johannesburg. 29 May, Johannesburg, South Africa.
Article
Coetzee, P P, Vanhaecke, F. 2005. Classifying wine according to geographical origin via based ICP-mass spectrometry measurements of boron isotope ratios, Analytical and Bioanalytical Chemistry, v. 383 (6) (p. 977-984)
Coetzee, P P, Steffens, F E, Eiselen, R J, Augustyn, O P H, Balcaen,L, Vanhaecke, F. 2005. Multi-element analysis of South African wines by ICP-MS and their classification according to geographical origin, Journal of Agricultural and Food Chemistry, v. 53 (13) (p. 5060-5066)
http://doi.org/10.1021/jf048268n
Coetzee, P P, Augustyn, O P H. 2006. Classification of South African wines according to geographical origin using multi-element chemical analysis, WineLand, Mnth Jan (p. 92-95)
Coetzee, P P, Augustyn, O P H. 2008. Classifying South African wines according to geographical origin using multi-element chemical analysis, Chemical Technology, Mnth Jan (p. 21-25)
Vorster, C, Coetzee, P P. 2008. Ion exchange separation of Sr and Rb on Dowex 50W-X8, using the complexation properties of EDTA and DCTA, Analytical and Bioanalytical Chemistry, v. 392 (1/2) (p. 287-296)
Thesis
De Bruyn, R. 2008. Provenance determination of South African wines with quadrupole-based ICP-MS measurements of ¹¹B/10B ratios. MSc (Chemistry) University of Johannesburg, Johannesburg, South Africa.
Van de Linde, G. 2009. Multi-element analysis of South African wines and their provenance soils by ICP-MS and their classification according to geographical origin using multivariate statistics. MSc (Chemistry) University of Johannesburg, Johannesburg, South Africa.
Vorster, C. 2009. Precise 87Sr/86Sr isotope ratio measurement by quadrupole-based ICP-MS after ion exchange separation of Rb for provenance determination of agricultural products. MSc (Chemistry) University of Johannesburg, Johannesburg, South Africa.