Carbon isotope ratio (Δ13C) and phenolic profile used to discriminate wines from Dealu mare and Cotnari regions (Romania)

AIM: The composition and quality of wine are directly linked to microorganisms involved in the alcoholic fermentation. Several studies have been conducted on the impact of Saccharomyces cerevisiae on volatile compounds composition after fermentation. However, if different studies have dealt with combined sensory and volatiles analyses, few works have compared so far the impact of distinct yeast strains on the global metabolome of the wine.

Le comportement de la vigne en terme de fonctionnement thermique et hydrique, influe de manière directe sur la qualité des baies de raisin. L’effet du terroir peut être perçu à travers l’étude de paramètres tels que la précocité, la mise en place de la surface foliaire ou la vigueur. Une expérimentation a été conduite en Val de Loire sur le cépage chenin dans le but de mieux comprendre le rôle des variables liées au terroir sur la croissance et le développement de la vigne et in fine sur la qualité des baies.

In viticulture, the concept of terroir is often used to enlighten the environmental-based typicity of grapevines grown in a local area however its scientific basis remains under debate. Grape polyphenols as key player of the plant defense system enables adaptation to environmental changes and so far, form a unique metabolic component to investigate the terroir influence.

Newer sequencing technologies have allowed for the addition of microbes to the story of terroir. The same environmental factors that influence the phenotypic expression of a crop also shape the composition of the microbial communities found on that crop. For fermented goods, such as wine, that microbial community ultimately influences the organoleptic properties of the final product that is delivered to customers. Recent studies have begun to study the biogeography of wine-associated microbes within different growing regions, finding that communities are distinct across landscapes. Despite this new knowledge, there are still many questions about what factors drive these differences. Our goal was to quantify differences in yeast communities due to management style between seven pairs of conventional and biodynamic vineyards (14 in total) throughout Oregon, USA. We wanted to answer the following questions: 1) are yeast communities distinct between biodynamic vineyards and conventional vineyards? 2) are these differences consistent across a large geographic region? 3) can differences in yeast communities be tied to differences in metabolite profiles of the bottled wine? To collect our data we took soil, bark, leaf, and grape samples from within each vineyard from five different vines of pinot noir. We also collected must and a 10º brix sample from each winery. Using these samples, we performed 18S amplicon sequencing to identify the yeast present. We then used metabolomics to characterize the organoleptic compounds present in the bottled wine from the blocks the year that we sampled. We are actively in the process of analysing our data from this study.

Aim: The main goal of this study was to find an efficient canopy management to limit the high temperature-related aroma losses of White Muscat grapes, and consequently to preserve the quality standards of Asti DOCG wines.