What metabolomics teaches us about wine shelf life

Grapevine (Vitis vinifera) is amongst the world’s most cultivated fruit crops, and of global and economic significance, producing a wide variety of grape-derived products, including wine, and table grapes. The genus Vitis, encompassing approximately 70 naturally occurring inter-fertile species, exhibits extensive genetic and phenotypic diversity, highlighted by the global cultivation of thousands of predominantly Vitis vinifera cultivars. Despite the importance of harnessing its naturally occurring genetic diversity to pursue traits of interest, especially considering the continued and growing demand for sustainable high-quality grape production, the systematic characterization of available functional genetic variants remains limited.

The choice of sites for viticulture depends on natural environmental factors, particularly climate, as grapevines have specific climatic requirements for optimum physiological performance and berry quality achievement. In the Stellenbosch wine-producing region, the complex topography and the proximity of the ocean create a variety of topoclimates resulting in different growth conditions for vines within short distances.

Due to varietal factors, the formation of undesirable deposits of flavonols, especially quercetin (Q), occurs in several red wines.

In recent studies, several grapevine trunk pathogen complexes have been identified from grapevines in South Africa. These pathogens include Eutypa lata, Phaeomoniella chlamydospora, Phaeoacremonium sp., Botryosphaeria sp. and Phomopsis sp. Trunk diseases lead to reduced yield, and grape quality as well as a decline

Rootstocks are gaining importance in viticulture as a strategy to combat abiotic challenges, as well as enhancing scion physiology and attributes. Therefore, understanding how the rootstock affects photosynthesis is insightful for genetic improvement of either genotype in the grafted grapevines. Photosynthetic parameters such as maximum rate of carboxylation of RuBP (Vcmax) and the maximum rate of electron transport driving RuBP regeneration (Jmax) have been identified as ideal targets for breeding and genetic studies. However, techniques used to directly measure these photosynthetic parameters are limited to the single leaf level and are time-consuming measurements.