Modeling sugar accumulation dynamics of a wide variety of grape cultivars (Vitis vinifera L.)

The objective of the present work is to assess yeast effects on the development of wine varietal aroma throughout aging and on wine longevity. Three independent experiments were carried out; two fermenting semi-synthetic musts fortified with polyphenols and aroma precursors extracted from Tempranillo (1) or Albariño (2) grapes and with synthetic precursors of polyfunctional mercaptans (PFMs), and a third in which a must, mixture of 6 different grape varieties was used. In all cases, fermentations were carried out by different Saccharomyces cerevisiae strains and one S. kudriavzevii, and the obtained wines were further submitted to anoxic accelerated aging to reproduce bottle aging. The volatile profile of the wines was analyzed using several chromatographic procedures, in order to provide a comprehensive evaluation of wine aroma. Aroma compounds analyzed included fermentation volatile metabolites, grape-derived aroma compounds including PFMs, and Strecker aldehydes (SA). Results revealed that the effects of yeast on wine aroma throughout its self-life extend along three main axes: 1. A direct or indirect action on primary varietal aroma and on its evolution during wine aging. 2. The direct production of SA during fermentation and/or their delayed formation by producing the required reagents (amino acids + dicarbonyls) for Strecker degradation during anoxic aging. 3. Producing acids (leucidic, branched acids) precursors to fruity esters. More specifically, and leaving aside the infrequent de novo formation, the action of the different strains of yeast on primary varietal aroma takes four different forms: 1.- Speeding the hydrolysis of aroma precursors, which leads to early aroma formation without changing the amount of aroma formed. In the case of labile molecules, such as linalool, the enhancement of young wine aroma implies a short-living wine. 2.- Metabolizing the aroma precursor, reducing the amounts of aroma formed, which can be of advantage for negative aroma compounds, such as TDN or guaiacol; 3.- Transforming grape components into aroma precursors, increasing the amounts of aroma formed, as for ethyl cinnamate, leucidic acid or vinylphenols; 4.- Forming reactive species such as vinylphenols able to destroy varietal polyfunctional mercaptans. Overall, it can be concluded that the yeast carrying alcoholic fermentation not only influences fermentative wine aroma but also affects to the wine varietal aroma, to its evolution during aging and to the development of oxidative off-odors

According to the Kyoto Protocol objectives, it’s necessary to identify alternative carbon dioxide sinks, and vineyard soils could be a significant opportunity.

In questa nota viene analizzata l’importanza della conoscenza del territorio nel funzionamento del mercato dei prodotti alimentari di qualità e nella gestione delle denominazioni di origine.
La denominazione di origine si sta affermando in tutti i mercati alimentari, dopo l’esperienza secolare maturata nel mercato del vino. Iniziative nel campo del turismo, delle produzioni ecologiche, della promozione dello sviluppo, sono collegate alla dimensione territoriale, in risposta ad un generale orientamento della domanda.

Retrotransposons, particularly of the Ty-Copia and Ty-Gypsy superfamilies, represent the most abundant and widespread transposons in many plant genomes. Grapevine is no exception and it is clear that these mobile elements have played a major role in the evolution of Vitaceae genomes. While speculation abounds around the possible role of transposons in plant genomes, outside of the rather obvious involvement of retrotransposition in fueling genome expansion, there is little clarity of the actual role these elements have in both developing new genetic variation and in modulating epigenetic responses within genomes to changing climate. To this end we have been exploring de-novo assembled Sauvignon blanc and Pinot noir genomes with a view to catalogue retrotransposon loci to determine the structural intactness and thus age of insertion variation across a small number of clonal linages of these 2 varietals in an attempt to identify ‘live’ TE loci.

Increasing drought is the most important impact of the ongoing climate change in the Mediterranean Basin, and it is predicted to result in productivity decreases and changes in grape quality.