Addition of glutathione-rich inactivated yeasts to white musts: effects on wine composition and sensory quality

The use of grapevine genetic diversity is a way to mitigate the negative impacts of climate change on viticulture systems. Leaf epidermal flavonoids (including flavonols and anthocyanins) are involved in plant defense mechanisms against environmental stresses, like high temperatures or excessive solar radiation [1,2]. Among other factors, they modulate light absorption, which reduces photoinhibition processes in photosynthetic tissues [1]. Therefore, the identification of grapevine cultivars with an increased content on leaf epidermal flavonoids arises as a potential avenue to improve grapevine tolerance to some detrimental environmental stresses.

Mendoza is one of Argentina’s most important and outstanding wine regions producing the renowned Malbec wines due to its optimal soil and weather conditions. However, the effects of 21st-century climate change would negatively impact Malbec wines quality. This study investigated the effect of temperature increase and the impact of plant hormone abscisic acid (ABA) used to mitigate the negative effect of temperature increase on Malbec wines aromatic composition through GC-MS. Four treatments were applied on vines at field condition: Control, Control + 3 ºC, ABA and ABA + 3 ºC.

Terroir encompasses environmental (climate, geology, soil and topography), genetic (cultivar and clone) and human factors (oenological and viticultural practices). Climate change brings about shifts in the suitability of a region for the growth of specific grapevine cultivars. This study focused on climatic and fruit parameters (berry size, weight, pH, total acidity (TA) and phenolics) to characterise the terroir effect in Vitis vinifera L. cultivars Chardonnay and Pinot Noir vineyards in the Cape South Coast region (Walker Bay and Elgin).

Arbuscular mycorrhizal fungi (AMF) symbiosis is probably the most widespread beneficial interaction between plants and microorganisms. AMF has been widely reported to promote grapevine growth, water and nutrient uptake as well as both biotic and abiotic stress tolerance[1]. However, the impact of AMF on grape composition has been less studied. The aim of this work was to evaluate the effects of the association between two commercial grapevine cultivars (Tempranillo and Cabernet Sauvignon grafted onto 110 rootstock) and AMF on the anthocyanin, flavonol and amino acid concentrations and profiles of grapes.

Improving our knowledge on biotic and abiotic factors that influence the composition of the grapevine mycobiome is of great agricultural significance, due to potential effects on plant health, productivity, and wine characteristics. Among the various environmental factors affecting the morphological, physiological, biochemical and molecular attributes of grapevine, drought stress is one of the most severe, becoming increasingly an issue worldwide.