Polyphenol content examination of Tokaji Aszú wines

Vineyards are highly variable and this variation is largely driven by environmental conditions and seasonal variation. For example, warm temperatures

The risk of wildfires is increasing as the frequency and severity of drought and heat waves continue to rise. Wildfires are associated with the combustion of plant materials and emit smoke. In the atmosphere, smoke may spread readily across large areas. Smoke is composed of solid and liquid phase particulates and gases and has been identified as a causal agent of “smoke taint” in wine. On a smoky day, the intensity of direct light decreases because these particulates scatter sunlight. Even though this effect is frequently assumed to decrease plant photosynthesis, this assumption ignores the potential changes in diffuse light and may be based on scant evidence.

Phenolic compounds are among the most important quality factors of wines. They contribute to the organoleptic characteristics of wine such as colour, astringency, and bitterness. Although tannins found in wine can come from microbial and oak sources, the main sources of polyphenols are skin and seed from grapes. Yet, the link between grape seed phenolic content and wine composition, or even the link between seed maturity stage and wine composition are poorly studied. This work describes and explains the seed tannins kinetics release in wine, but also the impact of seed maturity stage on seed tannins extractability.

Among the different strategies used in vine growing to fight against mold diseases, it can be pointed out the hybridation of traditional grape varieties with others, presenting a genetic resistance to pathogen attack. The research in this field has been encouraged in recent years due to the increased concern about human safety and environmental pollution linked to the use of agrochemicals. This approach allows to limit the number of treatments and the type of active compounds used in vine management. The environment determines the pressure degree of the diseases on vines and the biologic response of the plant to their attack.

Wine produced under Designation of Origin (DOP) Ribeiro, the oldest DOP in Galicia (NW Spain), are elaborated using local grape cultivars, grown at the valleys of Miño, Avia and Arnoia rivers. The landscape formed by slopes and terraces and the peculiar climate of continental character, softened by the proximity of Atlantic Ocean, make it an area of excellent aptitude for vine cultivation. In addition, small-scale farming and the use of traditional techniques for vineyard management provide a great diversity to Ribeiro wines. This study presents the evaluation of red and white wines (bottled or bulk wines) from DOP Ribeiro, produced between years 2018-2022.