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…

Early defoliation positively enhances bioactive composition of berries with no effect on cuticle characteristics

Leaf removal in the fruit-zone has been employed to improve cluster light exposure and ventilation and therefore increase metabolite accumulation and reduce botrytis incidence in berries. When applied before flowering (early defoliation – ED), it can also decrease cluster compactness and regulate yield in high-yielding varieties. This study aimed to evaluate the impact of ED on the physiology and metabolism of Aragonez (syn. Tempranillo) berries along the ripening period. The experiment was set up in 2013 at a commercial vineyard located in the Lisbon winegrowing region.

Detoxification capacities of heavy metals and pesticides by yeasts 

Winegrowing is still characterized by the extensive use of chemical fertilizers and plant protection products, despite strong recommendations to limit these practices. A part of these xenobiotics and metals are then found in grape juice and wine, causing a major health concern, as well as negatively affecting the fermentation process. In recent years, there has been renewed interest in non-Saccharomyces yeasts. These species have a wide phenotypic diversity, which would be exploited to broaden the aromatic palette of wines.

Grapevine cane pruning extract enhances plant physiological capacities and decreases phenolic accumulation in canes and leaves 

Vine cane extracts are a valuable byproduct due to their rich content of polyphenols, vitamins, and other beneficial compounds, which can affect and benefit the vine and the grapes. This study aims to evaluate the response of grapevine plants to irrigation with water supplemented with a vine cane extract, both at physiology response and phenolic composition in different parts of the plant (root, trunk, shoot, leaf, and berry).
Cane extract was obtained by macerating crushed pruning residues with warm water (5:1) and pectolytic enzymes. Two-year-old potted plants were irrigated with water (Control) while others were irrigated with cane extracts, either at 1:4 (w/v, cane extract/water; T 1:4) or at 1:8 (w/v, cane extract/water; T 1:8).

Time vs drought: leaf age rather than drought drives osmotic adjustment in V. vinifera cv. Pinot Noir

Global warming and increased frequency and/or severity of drought events are among the most threatening consequences of climate change for agricultural crops. In response to drought, grapevine (as many other plants) exhibits osmotic adjustment through active accumulation of osmolytes which in turn shift the leaf turgor loss point (TLP) to more negative values, allowing to maintain stomata opened at lower water potentials1. We investigated the capacity of Pinot noir leaves to modulate their osmotic potential as a function of: (i) time (seasonal osmoregulation), (ii) growing temperatures, and (iii) drought events, to enhance comprehension of the resilience of grapevines in drought conditions. We performed trails under semi-controlled field conditions, and in two different greenhouse chambers (20/15 °C vs 25/20 °C day/night). For two consecutive vegetative seasons, grafted potted grapevines (Pinot noir/SO4) were subjected to two different water regimes for at least 30 days: well-watered (WW) and water deficit (WD).

Climate change and viticulture in Nordic Countries and the Helsinki area

The first vineyards in Northern Europe were in Denmark in the 15th century, in the southern parts of Sweden and Finland in the 18th century at 55–60 degrees latitude. The grapes grown there have not been made into wine, but the grapes have been eaten at festive tables. The resurgence of viticulture has started with global warming, and currently the total area of viticulture in the Nordic countries, including Norway, is estimated to be 400–500 hectares, most of which is in Denmark. Southern Finland, like all southern parts of Northern Europe, belongs to the cool-cold winegrowing area.