Evaluation of mannoprotein formation by different yeast strains by enzymatic analysis of mannose and tribological estimation of astringency

Context and purpose of the study. To date over 3,000 grapevine accessions have been collected at Fondazione Edmund Mach (FEM).

In viticulture, climate change significantly impacts the plant’s development and the quality and characteristics of wines. These variations are often observed over short distances in a wine-growing region and are linked to local features (slope, soil, seasonal climate, etc.). The high spatial variability of climate caused by local factors is often of the same order or even higher than the temperature increase simulated by the different IPCC scenarios.

Brettanomyces bruxellensis is an ubiquitous yeast associated with different fermentation media such as beer and kombucha, where its presence is beneficial to bring an aromatic typicity. However, it is a main spoilage yeast in wines, in which it produces volatile phenols responsible for organoleptic deviations causing significant economic losses (Chatonnet et al., 1992). Cellar and winery equipment’s are considered as the first source of contamination, during fermentation and wine ageing process (Connel et al., 2002). Indeed, it is possible to find B. bruxellensis in the air, on walls and floors of the cellars, on small materials, vats and barrels.

Top quality sparkling wines (SW) are mostly produced using the traditional method that implies a second fermentation into the bottle[1]. That is the case of sparkling wines of reputed AOC such as Champagne, Cava or Franciacorta. However, it seems that the first SW was elaborated using the ancestral method in which only one fermentation takes place[2]. That is the case of the classical SW from the AOC Blanquette de Limoux[3]. In both cases, SW age in the bottle during some time in contact with lees favoring yeast’s autolysis[4]. There is a lot of information about traditional method but only few exists about ancestral method. The aim of this work was to compare SW made by the ancestral method with SW made by the traditional method.

The “Geoviticulture Multicriteria Climatic Classification (MCC) System” was developed to characterize the climate of the wine producing regions of the world.