Correlation between agronomic performance and resistance gene in PIWi varieties in the field

Studying the impact of reducing alcohol techniques in the chemical composition of the aromatic profile of rosé Tempranillo wines from the spanish region of Castilla-La Mancha INTRODUCTION: In the last decades there has been an increseasing demand of wines with low or non-existing alcohol concentration due to the negative effects that alcohol has in health. In spite of that, there are not laws that protect these products, and there is also a great difficulty in the elaboration of these type of wines due to the increasing temperatures because of climate change. This is why the oenological industry has made great advances in the development of different techniques that could satisfy consumers’ demands without modifying wine quality. The most used techniques have been post-fermentative ones.

Calcium-induced instabilities present a major challenge in bottled wines, with calcium tartrate (CaT) precipitation becoming increasingly common due to rising calcium levels in grape must, largely driven by climate change. Although CaT is an insoluble salt, its instability— although less frequent than potassium hydrogen tartrate (KHT) precipitation—is more difficult to predict and control, as it develops gradually over time.

Le lien fonctionnel entre typicité et terroir a été étudié en prenant en compte deux dimensions importantes : le type de sol et la date de vendanges. Ces deux facteurs sont, à des degrés divers

Fermentation derived sulfidic off-odors due to hydrogen sulfide (H2S) and low molecular weight thiols are commonly encountered in wine production and removed by Cu(II) fining. However, the mechanism underlying Cu(II) fining remains poorly understood, and generally results in increased Cu concentration that lead to deleterious reactions in finished wine. The present study describes a mechanistic investigation of the iron and copper mediated reaction of H2S, cysteine, 3-sulfanylhexan-1-ol, and 6-sulfanylhexan-1-ol with oxygen. The concentrations of H2S, thiols, oxygen, and acetaldehyde were monitored over time. It was found that Cu(II) was rapidly reduced by both H2S and thiols to Cu(I).

Astringency sensation decreases slowly during the aging of red wine. Complex reactions of condensation and precipitation of wine polyphenols are involved in this phenomenon. Wine composition and conditions of aging, such as temperature and oxygen availability, strongly influence evolution of the phenol matrix. Recently, a Post-Fermentative cold Maceration (PFM) technique was tested with the aim of accelerating reactions leading to the reduction of astringency and exploiting chemical compounds not extracted from the solid parts of grapes during the previous traditional maceration phase. To this purpose, an innovative maceration system was engineered and used to perform PFM trials on marc derived from vinification of different varieties of red grapes.