Coping with extreme climatic events: some lessons from recent work on grapevine under heat peak

The chemical mechanisms involved in oxidation/reduction potential of wine during winemaking and aging are affecting its color, aroma and taste. Chemical oxidation is one of the major causes of development of off-flavors during ageing1. Thus, the chemical changes in wine during storage should be controlled to ensure the sensory quality of the product and avoid consumer rejection that will compromise the economic value of the product. The 1-hydroxyethyl radical has been recognized as the key radical intermediate in the oxidative reactions in wine2. Based on the kinetic study of POBN-1-hydroxyethyl spin adduct formation in wines initiated via the Fenton reaction, a novel tool was recently developed in our laboratory to quantify the resistance of wines against oxidation3.

Oloroso Sherry is a typical fortified wine from Jerez de la Frontera (south of Spain). It is one of the most used in the seasoning of oak barrels, called Sherry Cask, destined in this area for ageing brandies or condiments as wine vinegars. Brandy de Jerez is an European Geographical Indication for grape-derived spirits. Its special organoleptic characteristics are due to its traditional dynamic ageing in Sherry Casks. American oak is the most common wood employed in Jerez area, where Brandy de Jerez is exclusively manufactured. During ageing period of Sherry and brandies, the wood is not only a container, it is involved in several physicochemical process with the Sherry or the distillate. Oak wood is the responsible of the presence of many compounds in the products, affecting their aroma and chemical composition and having a high influence in their final quality. Moreover, the seasoned wood with Sherry wine could transfer the compounds from wine into the brandy, improving its aroma and flavor.

Arbuscular mycorrhizal fungi (AMF) form symbiotic associations with plant roots and can help plants acquire nutrients from the soil in exchange for photosynthetic carbon. Commercial bioinoculants containing AMF are widely available and represent a potential opportunity to reduce the dependence of grapevines on agrochemicals. However, which commercially available AMF species colonize vine roots and affect vine growth remains unknown. The aim of this study was to identify the AMF species from commercial bioinoculants that colonize grapevine roots using high-throughput sequencing, and to evaluate the performance of five commercial bioinoculants and their effects on own-rooted Cabernet sauvignon.

Adrenaline (epinephrine) belongs to catecholamine class. It is a neurotransmitter and both a hormone which is released by the sympathetic nervous system and adrenal medulla in response to a range of stresses in order to regulate blood pressure, cardiac stimulation, relaxation of smooth muscles and other physiological processes. Adrenaline exhibits an effective antioxidant capacity (1). However, adrenalin is capable to auto-oxidation and in this case it generates toxic reactive oxygen intermediates and adrenochrome. Under in vitro conditions, auto-oxidation of adrenaline occurs in an alkaline medium (2).

La producción vitícola es el resultado de una serie de factores influyentes (variedad, patron) dentro de un medio ecológico­-climatico-edafico, en el que se interactua por medio de técnicas de cultivo adecuadas.