Ripening of Mencía grape cultivar in different edaphoclimatic situations (D.O. Ribeira Sacra, Spain)

Stomata are microscopic pores mainly located in leaf epidermis, allowing gas exchanges between plants and atmosphere. Stomatal initiation relies on the transcription factor SPEECHLESS which is mainly regulated by the MAP kinase cascade, in turn controlled by small signaling peptides, the Epidermal Patterning Factors (EPF and EPF-Like), namely EPF1, EPF2 and EPFL9. While EPF1 and EPF2 induce the inhibition of SPEECHLESS, their antagonist, EPFL9, stabilizes it, leading to stomatal formation. In grapevine, there are two paralogs for EPFL9, VviEPFL9-1 and VviEPFL9-2. Despite their structural similarity, it remains unclear whether they are differentially regulated and have distinct roles.

Aim: This work studies how successive O2 saturations affects the color and hydroxycinnamic
acids concentration in the absence and presence of laccase from B. cinerea with the aim of better understanding the browning processes.

Materials and methods: Grapes of Muscat of Alexandria were harvested and pressed with a vertical press to extract 60% of their juice. Aliquots of 30 mL of this must were placed in 60 mL flasks equipped with a pill (PreSens Precision Sensing GmbH) for measuring oxygen by luminescence (Nomasense TM O2 Trace Oxygen Analyzer).

Una de las biotecnologías más potentes para disminuir el pH en vinos de zonas cálidas y en variedades de pH elevado es el uso de la levadura no-saccharomyces lachancea thermotolerans. Esta especie es capaz de formar ácido láctico a partir de azúcares, reduciendo al mismo tiempo ligeramente el grado alcohólico. Por lo tanto, mejora dos de los principales problemas de los vinos de regiones afectadas por el calentamiento global. El ácido láctico es un ácido orgánico con una buena integración sensorial en el sabor del vino, y también química y biológicamente estable durante el envejecimiento del vino.

Specific inactivated yeast derivatives (SYDS) are obtained from s. cerevisiae yeasts by various processes (thermal, mechanical, and enzymatic) and have diverse oenological applications to improve wine quality. However, different impacts on wine sensory and aromas were reported, depending on syds types and fractions, wine matrices, and experimental settings. Few works have examined the impact of SYDS on aromas considering also those on wine macromolecules influencing organoleptic properties.

Wine cellars are affected by seasonally fluctuating workloads and face challenges especially in the harvest period connected to the required timely processing of the harvested grapes.