Quelles cibles moléculaires pourraient expliquer l’effet du terroir sur la composition des baies en sucres et acides?

Le vigneron est confronté à une variabilité naturelle omniprésente, liée au millésime et aux facteurs pédoclimatiques. Depuis 10 ans, en Champagne, la relation qu’entretient le vigneron avec l’espace a évolué. Les exemples d’entreprises collectives à vocation territoriale se sont multipliés : gestion de l’hydraulique viticole, maillages de groupements de conseil viticole (Magister), sites en confusion sexuelle, réseau maturation, analyses de sols par secteur, …

Global climate change is exerting an influence on vine phenology, leading to a decoupling of technological and phenolic maturity of grapes. This results in the modification of berry chemical composition, which can translate into wines with excessive astringency. The addition of mannoproteins (MP) to wine has been proposed as a way of mitigating this problem, since some studies have shown that MPs can modulate wine astringency. However, the mechanism underlying the astringency modulation effect of MPs is not well known and it seems to be dependent on the compositional and structural characteristics of the MP.

In Portugal, the prospection and conservation of representative samples of intra-varietal variability of grapevine has been carried out for 46 years, and in 2010 an infrastructure was created for the conservation of all these genetic resources – the portuguese association for grapevine diversity (porvid) experimental centre for the conservation of grapevine diversity. the aim is to save the genetic identity of ancient varieties to prevent their imminent loss and to preserve the raw material for current and future selections, thus adding economic value and sustainability to the vine and wine sector.

Aim: The aim of this work is educating people about soil variability and terroir. Soil monoliths are used to educate the wine industry about how to describe a soil profile, interpret the soil formation processes operating in a particular soil profile and consequently the impact of soil properties on vine growth, fruit quality and wine production. Soil monoliths are a permanent artistic tool for educating, research and management of soil variability.  

Fungal bunch rots of grapes cause major losses to grape yield worldwide, yet the impact these moulds have on grape and wine quality is not well characterised. We sought to investigate the formation of unwanted volatile compounds of fungal origin in both synthetic grape juice culture media and in inoculated grape berries. Botrytis cinerea, Aspergillus niger, Aspergillus carbonarius, or Pencillium expansum were grown in synthetic grape juice medium and the culture homogenates analysed 4 and 7 days post inoculation. HS-SPME-GC-MS analysis of the culture homogenates 4 days post inoculation demonstrated that each of the fungi examined produced varying quantities of the mushroom or fungus-like aroma compounds, 1-Octen-3-ol, 1-Octen-3-one and 3-Octanone with A. carbonarius producing up to ten times the amounts of all three metabolites per mg of dry mycelium.