Polysaccharide families of lyophilized extracts obtained from unfermented varietal grape pomaces

In the Bordeaux vineyards, press wine represents approximately 15% of the total volume of wine produced[1]. Valuing this large volume of wine is necessary from an economic point of view, but also because of their organoleptic contribution to the blend, and their contribution to the construction of wines for laying down. Therefore, this study was developed considering the lack of recent scientific knowledge on the composition of red press wines. The aim of this study is to establish an initial assessment of their chemical composition including aromatic compounds and a phenolic part.

Using grapevine genetic diversity is one of the strategies to adapt viticulture to climate change. In this sense, assessing the plasticity of cultivars in their responses to environmental conditions is essential. For this purpose, the drought tolerance of Grenache, Tempranillo and Semillon cultivars grafted onto SO4 was evaluated at two experimental vineyards, one located in Valencia (Spain) and the other in Bordeaux (France). This was done by assessing gas exchange parameters, water relations and leaf hydraulic traits at the end of the season.

Vineyards from mild temperature, high humidity locations receive often treatments with fungicides to prevent damages produced by fungi responsible for mildium, oidium and botrytis infections. In addition, insecticides are also applied to vineyards to fight again pests, which affect directly, or indirectly (as vectors of different diseases), their productivity. A fraction of the above compounds reaches the soil of vineyards, either during application, or when released from the canopy of vines due to rain-wash-off. Thereafter, depending on soil conditions (pH, organic matter) and environmental variables (regimen of rain, slope of vineyards), they might persist in this compartment, be degraded and/or transferred to water masses, modifying the biodiversity of soils and/or affecting the quality of water reservoirs.

Climate change has numerous detrimental consequences and creates new challenges for viticulture around the world. Transitory or constant high temperatures frequently associated with an excess of sunlight (UV) can cause a variety of physiological disorders, such as sunburn. Diverse environmental factors and the plant’s response mechanisms to stress determine the symptoms. Grapevine berry sunburn leads to a drastic reduction in yield, and may eventually decline berry quality. Consequently, this poses a significant risk to the winegrowers.

Vine growth circumstances are becoming warmer and drier because of climate change. Higher temperatures advance ripening to a point in the season less conducive to the production of fine wine, while drought reduces yields (Van Leeuwen et al., 2019). Several wine-producing regions around the world have already recognized threats to their viticultural viability (Santos et al., 2020). An economical and cost-effective strategy for adaptation is the employment of late-ripening, drought-resistant plant material (varieties, clones, and rootstocks).