Caractérisation et gestion de la maturation par terroir en Champagne

La véraison, stade intermédiaire du développement de la baie de raisin, correspond au début de la maturation. Aux modifications de coloration de la pellicule sont associées une perte de fermeté, une diminution de l’acidité et une augmentation des teneurs en sucres et pigments ainsi que du volume de la baie. Le stade de véraison des cépages blancs reste difficile à apprécier visuellement. Son évaluation par palpation est subjective et donc sujette à caution.

Non-saccharomyces yeasts play a crucial role in fermentation, producing a variety of secondary metabolites and enzymes that contribute to aromatic and sensory complexity compared to saccharomyces yeasts. It is crucial to understand and control the dynamics of non-saccharomyces yeasts to produce distinctive and high-quality fermented beverages.

Grapevine, Vitis vinifera, requires grafting on Phylloxera tolerant rootstocks of American origin in most viticultural areas of the world. The most commonly used species in rootstock creation are V. berlandieri, V. riparia and V. rupestris. Rootstocks not only provide tolerance to Phylloxera but assure the supply of water and mineral nutrients to the scion. The objective of this work was to determine to what extent rootstocks of different parentages alter the mineral composition of petioles of grapevine.

Climate change presents increasing challenges to viticulture, particularly with rising water stress contributing significantly to yield losses and damages. The identification of the MYB60 transcription factor, which regulates stomatal opening and closing in Arabidopsis thaliana and Vitis vinifera, offers potential solutions. Notably, knockout studies in Arabidopsis have shown reduced stomatal opening and increased drought tolerance in myb60 mutants. Additionally, the grapevine ortholog, VviMYB60, can restore the wild-type phenotype of Arabidopsis myb60 mutants. Further investigation of the Arabidopsis promoter region has revealed that mutations in DOF motifs lead to reduced expression of AtMYB60.

Grape by-products (including skins, seeds, stems and vine shoots) are rich in health promoting polyphenols. Their extraction from winery waste and their following purification are of special interest to produce extracts with high added value compounds. Meanwhile, the growing concern over environmental problems associated with economic constraints, require the development of environmentally sustainable extraction technologies. The extraction using semi-continuous subcritical water, as a natural solvent at high temperature and high pressure a technology is promising “green” technology that is environmentally friendly, energy efficient and improve the extraction process in plant tissues.