Estudios de zonificación vitícola en España

A critical aspect of wine quality from a consumer perspective is the overall impression of wine flavour, which is formed by the interplay of volatile aroma compounds, their precursors, and taste and matrix components. Grapes contribute some potent aroma compounds, together with a large pool of non-volatile precursors (e.g. glycoconjugates and amino acid conjugates). Aroma precursors can break down through chemical hydrolysis reactions, or through the action of yeast or enzymes, significantly changing the aroma profile of a wine during winemaking and storage. In addition, glycoconjugates of monoterpenes, norisoprenoids and volatile phenols, together with sulfur-conjugates in wine, provide a reservoir of additional flavour through the in-mouth release of volatiles which may be perceived retro-nasally.

The light exposure of wine can be detrimental as a relevant loss of aromas takes place [1] and light-induced reactions can occur. The latter involves riboflavin (RF), a photosensitive compound, that is fully reduced by acquiring two electrons. When the electron-donor is methionine, the light-struck taste (LST) can appear leading to cooked cabbage, onion and garlic odours-like [2]. The use of oenological tannins can limit the appearance of LST in both model wine [3] and white wine [4]. This research aimed to evaluate the impact of certain oenological tannins, selected in a previous study as the most effective against LST [5], in both white and rosé wines.

Yeasts serve as highly versatile tools in oenology. They do more than just perform alcoholic fermentation. Nowadays, yeasts from various species, naturally present in grapes, are selected for specific non-fermentative applications. For example, the use of selected non-saccharomyces at the early stage of winemaking has become a common practice to limit the growth of unwanted microorganisms. When inactivated, yeasts can be fractionated into soluble and insoluble fractions providing a wide range of benefits related to structural components or specific metabolites.

Wine grapes breeding has been concentrating a lot of efforts within the grape research community over the last decade. The quick phenotyping of genotype quality traits including aroma composition remains challenging. Selected Ion Flow Tube Mass Spectrometry (SIFT-MS), a technology first available in 2008 and developing rapidly, could be particularly valuable for this usage. The aims of this study were i) to use SIFT-MS, to analyze the whole volatilome from different grape varieties, ii) to assess the ability of this technology to discriminate varieties according to their grape aroma composition, and iii) to study the stability of SIFT-MS signal over maturation to define a sampling strategy.

A major goal of modern grapevine (Vitis vinifera L.) breeding programs is the introgression of resistance genes along with desirable traits for better adaptation to climate change. Developmental stages have an impact on yield components and berry composition and are expected to shift towards earlier dates in the future. We investigated the genetic determinism of phenological stages in the progeny of a cross between two grapevine hybrids, each carrying several quantitative trait loci (QTL) for downy mildew and powdery mildew resistance.