Exploring the effect of ripening rates on the composition of aroma and phenolic compounds in Cabernet-Sauvignon wines

The balance between the different flavours of a wine largely determines its perception and appreciation by the consumers. In white wines, sweetness and sourness are usually the two poles balancing the taste properties. The bitter flavour, on the other hand, is frequently associated with a loss of equilibrium and all white wines (dry and sweet, young and aged) are affected.
Several bitter compounds are already well-described in wines.

In this video recording of the IVES science meeting 2024, German Puga (Wine Economics Research Centre, School of Economics and Public Policy, University of Adelaide, Adelaide, Australia) speaks about a climatic classification of the world’s wine regions and winegrape variety concentration. This presentation is based on an original article accessible for free on OENO One.

Analisi sulle zonizzazioni storiche, sulle produzioni tipiche ed originali e sulla “forestazione classica” per impostare innovative zonazioni vitivinicole e dei prodotti tipici, originali attraverso la “Nuova forestazione storica produttiva”. Le recenti ricerche ed attività svolte sulle zonizzazioni storiche, sulle produzioni tipiche ed originali e sulla “forestazione classica” dei Monti Iblei (Ragusa) (I) hanno permesso di rilanciare le produzioni tipiche ed originali vitivinicole in un innovativo programma integrato tra zonazione (“Grande Zonazione”) e “Nuova forestazione storica produttiva” (“Grande Forestazione Produttiva”) di questo importante territorio.

In response to changes in their environment, grapevines regulate transpiration using various physiological mechanisms that alter conductance of water through the soil-plant-atmosphere continuum. Expressed as bulk stomatal conductance at the canopy scale, it varies diurnally in response to changes in vapor pressure deficit and net radiation, and over the season to changes in soil water deficits and hydraulic conductivity of both soil and plant. It is necessary to characterize the response of conductance to these variables to better model how vine transpiration also responds to these variables. Furthermore, to be relevant for vineyard-scale modeling, conductance is best characterized using data collected in a vineyard setting. Applying a crop canopy energy flux model developed by Shuttleworth and Wallace, bulk stomatal conductance was estimated using measurements of individual vine sap flow, temperature and humidity within the vine canopy, and estimates of net radiation absorbed by the vine canopy. These measurements were taken on several vines in a non-irrigated vineyard in Bordeaux France, using equipment that did not interfere with ongoing vineyard operations. An inverted Penman-Monteith equation was then used to calculate bulk stomatal conductance on 15-minute intervals from July to mid-September 2020. Time-series plots show significant diurnal variation and seasonal decreases in conductance, with overall values similar to those in the literature. Global sensitivity analysis using non-parametric regression found transpiration flux and vapor pressure deficit to be the most important input variables to the calculation of bulk stomatal conductance, with absorbed net radiation and bulk boundary layer conductance being much less important. Conversely, bulk stomatal conductance was one of the most important inputs when calculating vine transpiration, further emphasizing the need for characterizing its response to environmental changes for use in vineyard water use modeling.

A wide range of olfactory descriptors ranging from fresh and jammy fruit notes to cooked and oxidized fruit notes could describe the fruity aroma of red wines [1]. The fruity character of a wine is mainly related to the grape variety selected, to the terroir and the vinification process applied for its conception. In white wines, some volatile compounds confer directly their aroma to the wine while the question of “key” compound is more complex in red wines. According to many studies performed over the past decades, some fruity ethyl esters are directly involved in the fruity perception of red wines while others, present at subthreshold concentrations, participate indirectly to the fruity expression via perceptive interactions [2].