The pyramidal organization of AOC in France: a process of identification and valorisation of terroirs

Grapevine downy mildew, caused by Plasmopara viticola, is a devastating disease worldwide. Most commercially important cultivars of the European grapevine are highly susceptible and therefore require the recurrent application of synthetic fungicides to control the disease, copper being the most frequently used. However, with European Union goals to lower their usage, there is a need to develop innovative and sustainable strategies. In this respect, seaweeds have proven to have great potential as phytosanitary agents, in addition to promoting plant growth and stress-tolerance.

Molecular markers of wine oxydation, such as sotolon or Strecker’s aldehydes that induce respectively nut or curry and boiled vegetables or wilted rose odors, can be percieved as a default by consumers. These volatile compounds are especially formed during the premature aging of wine, but it is likely that several contributing compounds are still unknown as is their combined contribution. This study was carried out to identify the markers of oxydation in Chardonnay wine by Gas Chromatography Olfactometry (GC-O) and to study the impact of these markers on the complex wine aromatic buffer using the Olfactoscan approach.A Chardonnay wine (2018-vintage), taken after malolactic fermentation without sulphites addition, was submitted to an artificial oxidation to simulate more or less prononced premature oxidation. Volatile compounds were extracted by Solid-Phase Extraction (SPE) and analysed by GC-O with a panel of 13 trained subjects. The same extract was also submitted to a second analysis based on the Olfactoscan technique, which allowed to evaluate the impact of each volatile compounds on the complex aromatic buffer of a non-oxidized wine delivered as background odor. Preliminary results revealed three types of behavior. On the one hand, several odor zones appeared only with the background odour, suggesting a synergy effect induced by the compounds in the aromatic buffer. Conversely, odor-active compounds could not be perceived within the background odor suggesting a masking effect. Finally several compounds were found to contribute as key odorants for wine oxydation once mixed with the aromatic buffer. These compounds are still to be identified using complementary techniques.

The effects of anthropogenic activities on vineyard (different plant protections) and in winery
(pressing/clarification step, addition of sulfur dioxide) on fungal populations from grape to wine were studied. The studied anthropogenic activities modify the fungal diversity. Thus, lower biodiversity of grapes from organic modality was measured for the three vintages considered compared to biodiversity from ecophyto modality and conventional modality. The pressing / clarification steps strongly modify fungal populations and the influence of the winery flora is highlighted.

Viral diseases are a significant cause of both decreased grape quality and vineyard production. Important agents include grapevine leafroll-associated virus (glravs) and grapevine rupestris stem pitting-associated virus (grspav). However, conducting phytosanitary analysis of vineyards for viruses on-site is challenging, and molecular testing is generally expensive.

Sauvignon blanc is the most important variety in cool valleys in central Chile accounting 15,522 ha which corresponds to 42.4% of the cultivated surface with white varieties in Chile