Terroir 2004 banner
IVES 9 IVES Conference Series 9 Analytical and Chemometric Investigation of Phenolic Content of South African Red Wines

Analytical and Chemometric Investigation of Phenolic Content of South African Red Wines

Abstract

Phenolic compounds have been the focus of a lot of research in recent years for their important contribution to sensory characteristics of wine, their beneficial health effects, as well as the possibility they offer of characterising wines. In this contribution, a method is developed that allows the direct injection of wine samples followed by liquid chromatography-diode array-electrospray ionisation-ion trap mass spectroscopy (MS) for the quantitative and qualitative analysis of a wide range of non-coloured phenolics. Diode array detection was found to be more suitable for quantitative purposes, while on-line UV spectra in combination with mass spectra greatly facilitate the identification of phenolics. Although MS detection was characterised by relatively poor sensitivity (full scan mode) and linear response, this form of detection proved to be an exceedingly powerful identification tool, allowing identification of 20 non-standard compounds in wine. These include procyanidins, epigallocatechin, prodelphinidins (only the second time these compounds are identified in wine), tartaric acid esters of p-coumaric acid and caffeic acid, 3 resveratrol derivatives, myricetin and flavonol-glucosides. It is concluded LC-UV-MS currently represents the state-of-the art in analysis methods for wine polyphenols, combining quantitative and identification capabilities.
The LC-diode array method was subsequently used to quantify 16 phenolic compounds in 55 South African red wines. Values are compared to those reported in the literature for these compounds in wines from other countries. These data were used together with chemometric methods for the characterisation of these wines according to variety. Discriminant analysis allowed a 100% correct recognition of the 5 cultivars studied, independent of the vintage or geographical origin, based on non-coloured phenolic content.

DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

A. de Villiers (1), A. Crouch (1), Th. Heidemann (1), P. Majek (2), P. Sandra (1)

(1) University of Stellenbosch, Department of Chemistry, CENSSUS, Private Bag X1, Matieland 7602, South Africa
(2) Slovak University of Technology, Department of Analytical Chemistry, 812 37 Bratislava 1, Slovak Republic

Contact the author

Tags

IVES Conference Series | Terroir 2004

Citation

Related articles…

Adaptation of Lactobacilli towards low ph and SO2 to develop MLF in base musts for sparkling wines

In some white wines, malolactic fermentation (MLF) is very interesting, and for low pH wines this process is particularly difficult. Although MLF is generally not recommended for sparkling white wine, some winemakers prefer to promote MLF to contribute to organoleptic complexity. Oenococcus oeni is generally the bacterium of choice for MLF.

Impact of cover crop in vineyard on the musts volatile profile of Vitis vinifera L. Cv Syrah

rape aromatic characteristics are very important for the production of quality wines. The concentrations of volatile compounds in grape berries from vines with cover crops have been scarcely studied.

Genetic prospecting of rainfed viticulture in the region with the largest cultivated area in Chile

The Maule region hosts up to a third of the total area of vineyards in Chile, in an environment where ancient practices inherited from the colonial past coexist with modernity and dynamism that include technified irrigation and fine vines. In the dry land of Maule there is a viticulture that has subsisted with ancient vines and traditions transmitted over generations, and there is little clarity about the origin and classification of the Maule viticulture, giving rise to the use of different concepts as synonyms to describe the ancient, minority, patrimonial or Criollas vines. In order to characterize and protect the ancient material, we studied the genetic diversity of a territorial collection that covers 80% of the communes of the region, prioritizing plants established more than 40-60 years ago.

The start of Croatian grapevine breeding program

Modern viticulture in Croatia and the world is mainly based on the grapevine varieties susceptible to various diseases and pests, which leads to unsustainable use of large amounts of pesticides. The sustainable development of viticulture in the future will only be possible by increasing the resistance of the grapevine through the development of new resistant varieties. Breeding programs have been launched in the leading wine-growing countries with the aim of developing resistant varieties possessing high quality level. Coratia is rich in in native grapevine varieties that are the basis of wine production, and are not included in the breeding programs of other countries.

Discrimination of South Tyrol’s wines by their cultivation practices: A detailed mass spectrometric approach

Climate change is having a profound effect on viticulture by altering the conditions under which vines grow, leading to increased water stress and earlier harvests, which in turn affect the quality and character of wines [1].