Towards a relationship between institutional clonal selection, mass selection and private clonal selection of grapevine cultivars

Dans la Région de la Bairrada (Litoral-Centre du Portugal), on a étudié au 1999, l’influence des différents systèmes de conduite sur le cépage rouge “Baga”, le plus important de la Région.

Under oenological conditions, when yeasts grow simultaneously during alcoholic fermentation, they often do not coexist passively, and in most cases, physiological and metabolic interactions are established between them. They interact by producing unpredictable compounds and fermentation products that can affect the chemical composition of the wine and therefore alter its aromatic and sensory

Wine aroma descriptors are important tools for wine evaluation. The present well-known wine aroma descriptor system was created and based on Western culture, which makes difficult for Chinese consumers to recognize and learn wine. AIM: The aim of this study was to update the wine aroma descriptor system for Chinese.

Methods: Fifty-four wine aroma descriptors of ‘Le nez du vin’ was used as substitution candidates. Firstly, a survey on unfamiliar aromas was distributed to 150 untrained Chinese wine consumers. Twenty attributors, such as blackcurrent buds, quince, linden, were selected as the most 17 unfamiliar. Then, a descriptive analysis was performed by trained tasting panel to substitute the targeted twenty aromas perfume. Furthermore, reference standards were looked and new le nez du vin were made. Finally, a substitution analysis was performed to replace the unknown wine aroma to the Chinese local aromas.

Elevated temperature during the grape maturation period is a major threat for grape quality and thus wine quality. Therefore, characterizing the grape composition response to temperature at a larger scale would represent a crucial step towards adaptation to climate change. In response to changes in temperature, various physiological mechanisms regulate grape composition. Primary and secondary metabolisms are both involved in this response, with well-known effects, for example on anthocyanins, and lesser known effects, for example on aromas or aroma precursors. At the field scale or at the regional scale, however, numerous environmental or plant-specific factors intervene to make the effects of temperature difficult to distinguish from overall variability. In this study, it was attempted to overcome this difficulty by selecting well-characterized situations with differing temperatures.
A long-term study of air temperature variability across several Merlot vineyards in the Saint-Emilion and Pomerol wine producing area found significant temperature differences and gradients at various time scales linked to environmental factors. From this study area, a few sites were selected with similar age, soil and training system conditions, and with repeated and contrasted temperature differences during the maturation period. The average temperature difference during the maturation period was about 2°C between cooler and warmer sites, a difference similar to that expected under future climate change scenarios. In close vicinity to the temperature sensors at each site, grape berries were sampled at different times until full maturity during 2019 and 2020. Also, berries from bunches on either side of the row were analyzed separately, allowing an investigation of bunch exposure effect associated with the coupling of berry temperature and solar radiation. Four replicates of pooled berries for each time – site – bunch exposure combination were obtained and analyzed for biochemical composition. Analyses of variance of the biochemical composition data collected at different sampling times reveal significant effects associated with temperature, site, and bunch azimuth. For instance, anthocyanins in grape skins are clearly influenced by temperature and solar radiation exposure, with up to 30% reduction in warmer conditions.

With alcohol consumption steadily declining, the growing popularity of dry january, a fiercely competitive environment, high dry matter inflation, economic upheavals, commercial uncertainties… The wine industry must adapt and offer products that meet consumer expectations, without denying their historical singularities.