Are dicysteinyl polysulfanes responsible for post-bottling release of hydrogen sulfide?

Yeast species S. cerevisiae, S. uvarum, S. kudriavzevii and their hybrids present clear metabolic differences, even when we compared S. cerevisiae wine versus wild strain. These species and hybrids produced significantly higher amounts of glycerol, organic acids, 2,3-butanediol, and 2-phenyl ethanol and a reduction of the ethanol yield, properties very interesting in the sector to deal with climate change effects. To understand the existing differences, we have used several omics techniques to analyze the dynamics of the (intra- and extracellular) metabolomes and/or transcriptomes of representative strains of S. cerevisiae, S. uvarum, S. kudriavzevii, and hybrids.

Does a white wine smell like red wine if you color it with red food coloring? A study by Morrot, Brochet, and Dubourdieu (2001, Brain and Language) suggests so. Subjects perceived red wine odors when tasting white wine that had been colored red. The perceived odor profile of the colored white wine became similar to that of a red wine. However, the forced-choice procedure used by Morrot et al. has some methodological shortcomings. Here, we used an alternative method (a rating procedure) to evaluate the presented wines.

Fumaric acid has been approved by the OIV in 2021 for its application on wine to control the growth and activity of lactic acid bacteria. Fumaric acid is currently being evaluated by the OIV as an acidifier of must and wine. Investigations during the 2023 vintage provided further information on its use on must or during AF, thus completing information provided during the previous vintage.

Catechins, a subclass of flavonoids widely found in plants and plant-based foods and beverages such as wine and tea, not only exhibit significant antioxidant properties [1], as extensively documented in the literature, but can also inhibit amyloid protein aggregation [2], a key process implicated in the onset of neurodegenerative diseases such as Parkinson’s, Alzheimer’s, and Huntington’s.

Increasingly warm and dry climate conditions are challenging the viticulture and winemaking sector. Digital technologies and crop modelling bear the promise to provide practical answers to those challenges. As viticultural activities strongly depend on harvest date, its early prediction is particularly important, since the success of winemaking practices largely depends upon this key event, which should be based on an accurate and advanced plan of the annual cycle. Herein, we demonstrate the creation of modelling tools to assess grape ripeness, through sugar concentration monitoring. The study area, the Portuguese Côa valley wine region, represents an important terroir in the “Douro Superior” subregion. Two varieties (cv. Touriga Nacional and Touriga Franca) grown in five locations across the Côa Region were considered. Sugar accumulation in grapes, with concentrations between 170 and 230 g l-1, was used from 2014 to 2020 as an indicator of technological maturity conditioned by meteorological factors. The climatic time series were retrieved from the EU Copernicus Service, while sugar data were collected by a non-profit organization, ADVID, and by Sogrape, a leading wine company. The software for calibrating and validating this model framework was the Phenology Modeling Platform (PMP), version 5.5, using Sigmoid and growing degree-day (GDD) models for predictions. The performance was assessed through two metrics: Roots Mean Square Error (RMSE) and efficiency coefficient (EFF), while validation was undertaken using leave-one-out cross-validation. Our findings demonstrate that sugar content is mainly dependent on temperature and air humidity. The models achieved a performance of 0.65