Metatranscriptomic analysis of “aszú” berries: the potential role of the most important species of the grape microbiota in the aroma of wines with noble rot

Several Eurasian wild grapevine populations were found along Extremadura region (southwestern Spain). For conservation and study, one individual from four different populations (named L1, L2, L5 and L6) was vegetatively propagated and planted at Instituto de Investigaciones Agrarias Finca La Orden (CICYTEX), Badajoz. The aim of the present work was to characterize those conserved individuals from four different populations based on both an ampelographic description and a molecular analysis. Three vines per individual were studied.

Grape skin has a barrier and protective function in grapes. Cell wall of grape skins is mainly composed of polysaccharides such as pectins, celulloses and hemicelluloses and structural proteins. Terroir, variety and changes during ripening can affect the content of polysaccharides in grapes. The aim of this study was to evaluate the content of polysaccharides (PS) in grapes along the ripening process. Three red grape varieties were studied: Garnacha (G), Tempranillo (T) and Prieto Picudo (PP).

Many works have been carried out to identify the key aroma volatile compounds of oak wood (e.g., whisky-lactone, furfural, maltol, eugenol, guaiacol, vanillin) using conventional gas chromatography coupled with olfactometry and mass spectrometry (GC-O-MS). Inspired by recent untargeted approaches in the field of food “omics”, this work aims to extend our knowledge on the impact of cooperage process on the volatile composition of oak wood using two-dimensional comprehensive gas chromatography coupled with time of flight mass spectrometry (GCxGC-ToFMS).

The use of oenological additives is becoming a common practice due to the technological and sensory properties they provide to the wines. However, the number of studies focused on the impact that these additives might induce on wine flavor perception during wine tasting is still quite scarce. The aim of this work was to evaluate the effect of three different types of common oenological additives: two oenotannins (ellagitannin and gallotannin) and a commercial preparation of yeast mannoproteins on the long-lasting flavor perception (aroma and astringency).

Modern agriculture employs large amounts of plastics, such as mulching and greenhouse films, thermal covers, plant protection tubes and tying tape. The latter two types are very common in viticulture. Guard tubes are employed to protect young vines from mechanic and atmospheric damage, whilst polymeric tying tape has replaced natural-origin materials to hold the canopy of vines. Both materials are made on synthetic polymers, which include a range of additives to improve their environmental stability remaining in the environment of vineyards for years. During this time, they are exposed to the range of pesticides (fungicides, insecticides and in a lesser extend herbicides) applied to vines.