terclim by ICS banner
IVES 9 IVES Conference Series 9 International Congress on Grapevine and Wine Sciences 9 2ICGWS-2023 9 Wine odors: chemicals, physicochemical and perceptive processes involved in their perception

Wine odors: chemicals, physicochemical and perceptive processes involved in their perception

Abstract

The odors of wines are diverse, complex and dynamic and much research has been devoted to the understanding of their chemical bases. However, while the “basic” chemical part of the problem, namely the identity of the chemicals responsible for the different odor nuances, was satisfactorily solved years ago, there are some relevant questions precluding a clear understanding. These questions are related to the physicochemical interactions determining the effective volatilities of the odorants and, particularly, to the perceptual interactions between different odor molecules affecting in different ways to the final sensory outputs.

The understanding of perceptual interactions has been delayed to a large extent by the common misunderstanding that odorants and odors are the same thing. Odorants are, however, chemical entities -volatile molecules- able to impact the olfactory receptors, while odors are the sensory experiences encoded by odorants. A significant part of the code is nowadays known, and can be explained in terms of odor x odor interactions. These interactions can be competitive, cooperative, destructive and creative. Cooperative interactions are relevant because give rise to the concept of odor vector, establishing a key link between the chemical and sensory spaces. Different studies have shown that the nearly 80 main wine odorants form 35 different wine aroma vectors, classified into 10-different aroma categories. Yet, aroma vectors can further interact by creative interactions to form new aroma nuances. Some of these interactions have been identified and will be shown. Furthermore, destructive interactions can also take a major role in wine, since ethanol and the higher alcohols are strong aroma suppressors. These suppression effects are of the highest interest in wine dealcoholization.

Finally, it will be shown that physicochemical interactions with different matrix components are enough to change the volatilities of some odorants by factors between 2 and 4, more than enough to have sensory relevance.

Acknowledgement. Most of this research has been funded by the Spanish government (projects MYCIN PID2021-126031OB; MINECO AGL2017-87373)

DOI:

Publication date: October 20, 2023

Issue: ICGWS 2023

Type: Article

Authors

Vicente Ferreira

Laboratory for Aroma Analysis and Enology (LAAE), University of Zaragoza, Spain

Tags

2ICGWS | ICGWS | ICGWS 2023 | IVES Conference Series

Citation

Related articles…

Biotype diversity within the autochthonous ‘Bobal’ grapevine variety

Bobal is the second most widely grown Spanish red grape variety (54,165 has), mainly cultivated in the Valencian Community and especially, in Utiel-Requena region (about 67% of 34,000 has). In this study, agronomic and enological parameters were determined in 98 biotypes selected during 2018 and 2019 in more than 50 vineyards over 50 years-old in the Utiel-Requena region. Moreover, a multi-criteria approach considering temperature and rainfall (Fig. 1A), among other parameters, was made to establish three different zones within the region (Fig. 1B), where in the future the selected biotypes will evaluated. In fact, in 2020, 4 replicates and 12 vines per biotype were planted in an experimental vineyard to preserve this important intra-cultivar diversity.

Physicochemical behaviour of wine spirit and wine distillate aged in Sherry Casks® and Brandy casks

Brandy is a spirit drink made from “wine spirit” (<86% Alcohol by Volume – ABV; high levels of congeners and they are mainly less volatile than ethanol), it may be blended with a “wine distillate” (<94.8%ABV; low levels of congeners and these are mainly more volatile than ethanol), as long as that distillate does not exceed a maximum of 50% of the alcoholic content of the finished product[1]. Brandy must be aged for at least 6 months in oak casks with <1000L of capacity. During ageing, changes occur in colour, flavour, and aroma that improve the quality of the original distillate.

Drought responses of grapevine cultivars under different environments

Using grapevine genetic diversity is one of the strategies to adapt viticulture to climate change. In this sense, assessing the plasticity of cultivars in their responses to environmental conditions is essential. For this purpose, the drought tolerance of Grenache, Tempranillo and Semillon cultivars grafted onto SO4 was evaluated at two experimental vineyards, one located in Valencia (Spain) and the other in Bordeaux (France). This was done by assessing gas exchange parameters, water relations and leaf hydraulic traits at the end of the season.

Implications of the nature of organic mulches used in vineyards on grapevine water status, yield, berry quality and biological soil health  

Climate emergency is going to affect the agricultural suistainability, wine grapes being probably one of the crops more sensitive to environmental constraints. In this context, mitigation strategies such as the revalorization of agricultural wastes are paramount to cope with the current challenges. The use of organic mulches has been reported to reduce soil water evaporation and improve vine water status, reduce soil erosion, and increase soil organic matter with little impact on berry quality. However, less is known about their effects on the microbiote of vineyards.

Optimization of the acquisition of NIR spectrum in grape must and wine 

The characterization of chemical compounds related with quality of grape must and wine is relevant for the viticulture and enology fields. Analytical methods used for these analyses require expensive instrumentation as well as a long sample preparation processes and the use of chemical solvents. On the other hand, near-infrared (NIR) spectroscopy technique is a simple, fast and non-destructive method for the detection of chemical composition showing a fingerprint of the sample. It has been reported the potential of NIR spectroscopy to measure some enological parameters such as alcohol content, pH, organic acids, glycerol, reducing sugars and phenolic compounds.