Macrowine 2021
IVES 9 IVES Conference Series 9 Effect of oenological tannins on wine aroma before and after oxidation: a real-time study by coupling sensory (TDS) and chemical (PTR-ToF-MS) analyses

Effect of oenological tannins on wine aroma before and after oxidation: a real-time study by coupling sensory (TDS) and chemical (PTR-ToF-MS) analyses

Abstract

AIM: Polyphenols are important compounds involved in many chemical and sensory wine features. In winemaking, adding oenological tannins claims to have positive impacts on wine stability, protection from oxidation and aroma persistence. Polyphenols are antioxidant compounds by either scavenging reactive oxygen and nitrogen species or chelating Fe2+ ions (1). However, as tannins oxidation leads to the formation of highly reactive species (i.e. ortho-quinones), it is still unclear if they have an effective role toward oxidation of wine aromas (2). In this work, we aim at studying the effect of two commercial tannins (proanthocyanidins, ellagitannins) on red wine flavour (mainly aroma) before and after air exposition.

METHOD: We coupled a dynamic sensory evaluation technique with a dynamic instrumental nosespace analysis, in order to decipher the impact of oenological tannins on in-vivo aroma release and perception. 17 trained subjects evaluated the temporal dominance of sensations (TDS) of 6 non-oaked Pinot Noir in duplicate, while their nasal cavity was connected to a Proton Transfer Reaction-Time of Flight-Mass Spectrometer (PTR-ToF-MS). Samples followed a Tannin by Oxidation factorial design including the base wine (BW), BW spiked with ellagitannins (BWE) or with proanthocyanidins (BWP), and the three wines after air exposition (OW, OWE, OWP). Each of these 6 samples was evaluated in 3 consecutive sips and this evaluation was duplicated.

RESULTS: TDS sensory results show that red wine oxidation decreases the fruity aroma dominance and increases the dominance of maderised and prune notes (3). The chemical analysis by PTR-MS revealed that the fruity decrease was correlated to the decrease of the fruity ethyl decanoate and the increase of Strecker aldehydes isobutyraldehyde and isovaleraldehyde. The addition of ellagitannins preserves the perception of fruity notes without the appearance of maderised ones after air exposition. This effect was not observed with proanthocyanidins: the TDS curves of OWP was similar to those recorded for OW, both showing dominant maderised and prune aromas, masking the fruity notes. Moreover, the monitoring of in vivo aroma release by PTR-ToF-MS suggests that ellagitannins increase aroma persistence in the non-oxidized wine.

CONCLUSIONS:

Results evidence that the presence of ellagitannins can have a positive impact on the aroma persistence of young red wine and on the preservation of its fruity aroma perception after oxidation. Being red wine oak-barrel ageing a storage in presence of ellagitannins and oxygen, these results could be helpful in managing the sensory shelf-life of fruity red wines with the preservation of these aromas. Indeed, these aromas are able to mask the appearance of oxidative notes, while balancing the sensory contribution of volatiles extracted from wood.

DOI:

Publication date: September 22, 2021

Issue: Macrowine 2021

Type: Article

Authors

Elisabetta Pittari, Isabelle, ANDRIOT (2,3) Luigi, MOIO (1) Jean-Luc, LE QUÉRÉ (2) Pascal, SCHLICH (2,3) Paola, PIOMBINO (1) Francis, CANON (2)

(1) Dept. of Agricultural Science, University of Naples Federico II, Italy (2) Université Bourgogne Franche-Comté, France (3) research infrastructure, ChemoSens facility, Dijon, France, CSGA, AgroSup Dijon, CNRS, INRAE, INRAE, PROBE

Contact the author

Keywords

PTR-ToF-MS – temporal dominance of sensations; proanthocyanidins; ellagitannins; red wine oxidation; oenological tannins

Citation

Related articles…

Mesoclimate impact on Tannat in the Atlantic terroir of Uruguay

The study of climate is relevant as an element conditioning the typicity of a product, its quality and sustainability over the years. The grapevine development and growth and the final grape and wine composition are closely related to temperature, while climate components vary at mesoscale according to topography and/or proximity to large bodies of water. The objective of this work is to assess the mesoclimate of the Atlantic region of Uruguay and to determine the effect of topography and the ocean on temperature and consequently on Tannat grapevine behavior.

Leaf vine content in nutrients and trace elements in La Mancha (Spain) soils: influence of the rootstock

The use of rootstock of American origin has been the classic method of fighting against Phylloxera for more than 100 years. For this reason, it is interesting to establish if different rootstock modifies nutrient composition as well as trace elements content that could be important for determining the traceability of the vine products. A survey of four classic rootstocks (110-Richter, SO4, FERCAL and 1103-Paulsen) and four new ones (M1, M2, M3 and M4) provided by Agromillora Iberia. S.L.U., all of them grafted with the Tempranillo variety, has been carried out during 2019. The eight rootstocks were planted in pots of 500 cc, on three soils with very different characteristics from Castilla-La Mancha (Spain). In the month of July, the leaves were collected and dried in a forced air oven for seven days at 40ºC. Then, the samples were prepared for the analysis determination, carried out by X-Ray fluorescence spectrometry. The results obtained showed that in the case of content in mineral elements in leaf, separated by soil type, we can report the importance of few elements such as Si, Fe, Pb and, especially, Sr. The rootstock does not influence the composition of the vine leaf for the studied elements that are the most important in determining the geochemical footprint of the soil. The influence of the soil can be discriminated according to some elements such as Fe, Pb, Si and, especially, Sr.

Mapping and tracking canopy size with VitiCanopy

Understanding vineyard variability to target management strategies, apply inputs efficiently and deliver consistent grape quality to the winery is essential. However, despite inherent vineyard variability, the majority are managed as if they are uniform. VitiCanopy is a simple, grower-friendly tool for precision/digital viticulture that allows users to collect and interpret objective spatial information about vineyard performance. After four years of field and market research, an upgraded VitiCanopy has been created to achieve a more streamlined, technology-assisted vine monitoring tool that provides users with a set of superior new features, which could significantly improve the way users monitor their grapevines. These new features include:
• New user interface
• User authentication
• Batch analysis of multiple images
• Ease the learning curve through enhanced help features
• Reporting via the creation of colour maps that will allow users to assess the spatial differences in canopies within a vineyard.
Use-case examples are presented to demonstrate the quantification and mapping of vineyard variability through objective canopy measurements, ground-truthing of remotely sensed measurements, monitoring of crop conditions, implementation of disease and water management decisions as well as creating a history of each site to forecast quality. This intelligent tool allows users to manage grapevines and make informed management choices to achieve the desired production targets and remain profitable.

Influence of climatic conditions on grape composition of Tempranillo in La Mancha DO (Spain)

The aim of this work was to analyze the variability in grape composition of the Tempranillo cultivar related to climatic conditions, in La Mancha Designation of Origin. Grape composition (sugar content, total acidity, pH, malic acid, and total and extractable anthocyanins) recorded during ripening, were analysed for the period 2000-2019. The weather conditions at daily time scale, recorded during the same period, were also evaluated. The relationships between grape parameters with climatic variables related to temperature and to water deficits, referring different periods between phenological events along the growing cycle, were evaluated using regression analysis. High variability in grape composition was observed in the period analysed. Total acidity varied between 3.7 and 7.3 gL-1 while malic acid varied between 1.2 and 4 gL-1. The extractable anthocyanins ranged between 526 and 972 mgL-1, and total anthocyanins ranged between 922 and 1388 mgL-1, being the lowest values recorded in the hottest year (2017). Total acidity decreased 0.77 gL-1 for an increase of 100 GDD, while malic acid decrease in 0.42 gL-1 for the same GDD increase, being the period between veraison and harvest the one that seemed to have higher influence on acidity. In addition, it was confirmed that increasing water deficits decreased acidity. Total and extractable anthocyanins increased in about 210 and 105 mgL-1, respectively, with an increase of 100 GDD from veraison to harvest, and the increase in water deficits favour the increase of anthocyanins, both total and extractable anthocyanins. Total and extractable anthocyanins concentration increased in 35 and 22 mgL-1 per an increase of 10 mm in the water deficit. These results can be of interest to understand the potential changes that grapes composition may suffer under future warmer climates.

Terroir analysis and its complexity

Terroir is not only a geographical site, but it is a more complex concept able to express the “collective knowledge of the interactions” between the environment and the vines mediated through human action and “providing distinctive characteristics” to the final product (OIV 2010). It is often treated and accepted as a “black box”, in which the relationships between wine and its origin have not been clearly explained. Nevertheless, it is well known that terroir expression is strongly dependent on the physical environment, and in particular on the interaction between soil-plant and atmosphere system, which influences the grapevine responses, grapes composition and wine quality. The Terroir studying and mapping are based on viticultural zoning procedures, obtained with different levels of know-how, at different spatial and temporal scales, empiricism and complexity in the description of involved bio-physical processes, and integrating or not the multidisciplinary nature of the terroir. The scientific understanding of the mechanisms ruling both the vineyard variability and the quality of grapes is one of the most important scientific focuses of terroir research. In fact, this know-how is crucial for supporting the analysis of climate change impacts on terroir resilience, identifying new promised lands for viticulture, and driving vineyard management toward a target oenological goal. In this contribution, an overview of the last findings in terroir studies and approaches will be shown with special attention to the terroir resilience analysis to climate change, facing the use and abuse of terroir concept and new technology able to support it and identifying the terroir zones.