The use of viticultural and oenological performance of grapevines to identify terroirs: the example of Sauvignon blanc in Stellenbosch

Colour is an important quality parameter in wines and is the result of a complex mixture of pigments (including anthocyanins and their derivatives, quinones, xanthyllium compounds, etc.). Red wine colour changes over time as pigments react between themselves and with other wine macromolecules (particularly polyphenols). During wine tasting, colour is normally assessed on the outer rim of the wine profile in a tilted glass, since most wines are too opaque to be analysed in the middle of the glass. Therefore, depending on the depth of observation considered, the perception of wine colour can be different.

Mycobiota encountered from vine to wine is a complex and diversified ecosystem that may impact grape quality at harvest and the sensorial properties of wines, thus leading to off-flavors [1-3]. Among known off-flavors in wine, fresh mushroom aroma (FMA) has been linked to some mold species, naturally pre-sent on grapes, producing specific volatile organic compounds (VOC) [4-5]. The most well-known are 1-octen-3-ol and 1-octen-3-one, although many other VOC are likely involved. To better understand the FMA defect, biotic and abiotic factors impacting growth kinetics and VOC production of selected fungal species in must media and on grapes were studied.

An experimental vineyard with a radial array was planted in 2018, to provide valuable information on the relationship between orientation and planting density on plant physiology and cluster microclimate, and the consequent impacts on grape secondary metabolites, including aromas and polyphenols.

Fifteen nepoviruses are able to induce fanleaf degeneration in grapes. Grapevine fanleaf virus (GFLV) is the main causal agent of this disease

AIM: Red grape varieties are characterized by different phenolic contents (prominently tannins and anthocyanins) found in skins and seeds.