WAC 2022 banner
IVES 9 IVES Conference Series 9 WAC 9 WAC 2022 9 2 - WAC - Posters 9 Impact of toasting on oak wood aroma: creation of an oak wood aroma wheel

Impact of toasting on oak wood aroma: creation of an oak wood aroma wheel

Abstract

The impact of toasting process to produce aroma from oak wood intrinsic composition is well documented. It is admitted that such complexity contribute to the wine quality after barrel ageing. Despite our knowledge on the molecular identification of aroma impact compounds of oak wood, little research have been carried out, on a sensory level, on the aroma diversity of toasted oak wood. For this reason, this work aims at creating an aroma wheel to describe and categorize the complexity of aroma descriptors based on a lexical analysis. In a first experiment, a free association task was conducted to identify individual mental representations of oak wood samples. For that, a panel (13 persons from Seguin Moreau cooperage and wine makers) was selected to write down, via an online survey, the descriptors that come to mind to describe oak wood aroma according to a specific toasting intensity (non-toasted or toasted at 160 °C, 180 °C or 240 °C for 30 min). Data obtained were analyzed according to a semantic analysis to determine citation frequency of each descriptor. Synonyms or descriptors linked to the same lexical field were gathered, reducing the number of descriptors from 215 to 83. Citation frequencies were evaluated in order to identify the most relevant descriptors used by the panel (f>0.02). After that, a categorization of samples and descriptors was performed to highlight sensory boundaries among them. Samples categorization was performed by a correspondence analysis (AFC) applied to citation frequencies while words categorization was achieved by a sorting using a consensus approach. Finally, seven main descriptors were obtained, allowing distinguish oak wood samples depending on their toasting intensity: non-toasted oak wood was categorize with ‘fresh wood’ and ‘vegetable’ descriptors while highly toasted oak wood was categorize with ‘roasting’, ‘spices’ and ‘smoked’ descriptors, for example. Subsequently, a conventional profiling was performed by a trained panel (13 persons from the laboratory team) on oak wood samples (different toasting process). ANOVA analysis revealed the relevance of defined descriptors to describe oak wood aroma during its toasting. This work permits to purpose a visual tool to describe oak wood aroma. It provides specific terminology to describe the sensory changes during toasting process. This aroma wheel is intended to meet academic and professional needs for the quality assessment of oak wood aroma based on sensory analysis.

DOI:

Publication date: June 13, 2022

Issue: WAC 2022

Type: Article

Authors

Marie Courregelongue, Marie Courregelongue, Alexandre Pons

Presenting author

Marie Courregelongue – UMR ŒNOLOGIE (OENO), ISVV, UMR 1366, Université de Bordeaux, INRAE, Bordeaux INP, Villenave d’Ornon, France & Tonnellerie Seguin Moreau, Merpins, France

Tonnellerie Seguin Moreau, Merpins, France | UMR ŒNOLOGIE (OENO), ISVV, UMR 1366, Université de Bordeaux, INRAE, Bordeaux INP, Villenave d’Ornon, France & Tonnellerie Seguin Moreau, Merpins, France

Contact the author

Keywords

oak wood, toasting process, sensory approach, aroma wheel

Tags

IVES Conference Series | WAC 2022

Citation

Related articles…

First step in the preparation of a soil map of the Protected Designation of Origin Valdepeñas (Central, Spain)

This work is a first step to make a map of vineyard soils. The characterization of the soils of the Protected Designation of Origin (D.P.O.) Valdepeñas will allow to group the studied profiles according to their physico-chemical characteristics and the concentrations of most relevant chemical elements. 90 soil profiles were analysed throughout the territory and the soils were sampled and described according to FAO (2006) and classified according to and Soil Taxonomy (2014). All samples were air dried, sieved and some physico-chemical parameters were determined following standard protocols. Also, major and trace elements were analysed by X-ray fluorescence. The statistically study was made using the SPSS program. Trend maps were made using the ArcGIS program. The studied soils have the following average properties: pH, 8.3; electrical conductivity, 0,20 dS/m (low); clay, 18.8% (medium) and CaCO3, 17.1% (high). In the study for the major elements. The major elements of these soils are Si, followed by Ca and Al, with an average content of 203.7 g/kg, 105.5 g/kg and 74.0 g/kg respectively. On the other hand, 27 trace elements have been studied. Of all of them, it can be highlighted the average values of Ba (361.8 mg/kg), Sr (129.3 mg/kg), Rb (83.4 mg/kg), V (74.2 mg/kg) and Ce (70.6 mg/kg). Ba, V and Ce values are higher and the values of Sr and Rb are lower to those found in the literature. The discriminant analysis shows a percentage of grouping of 91%. The content of chemical elements together with the physico-chemical characteristics allows grouping the soils in 4 group according to their order in the classification to Soil Taxonomy; due to the importance of the Calcisols in Castilla-La Mancha, it has been decided to establish them as their own group even if they do not appear in Soil Taxonomy classification.

Photoselective shade films affect grapevine berry secondary metabolism and wine composition

Grapevine physiology and production are challenged by forecasted increases in temperature and water deficits. Within this scenario, photoselective overhead shade films are promising tools in warm viticulture areas to overcome climate change related factors. The aim of this study was to evaluate the vulnerability of ‘Cabernet Sauvignon’ grape berry to solar radiation overexposure and optimize shade film use for berry integrity. A randomized complete block design field study was conducted across two years (2020-2021) in Oakville, Napa Valley, CA, with four shade films (D1, D3, D4, D5) differing in the percent of radiation spectra transmitted and compared to an uncovered control (C0). Integrals for gas exchange parameters and mid-day stem water potential were unaffected by the shade films in 2020 and 2021. By harvest, berries from uncovered and shaded vines did not differ in their size or primary metabolism in either year. Despite precipitation exclusion during the dormant season in the shaded treatments, yield did not differ between them and the control in either season. In 2020, total skin anthocyanins (mg/g fresh mass) in the shaded treatments was greater than C0 during berry ripening and at harvest. Conversely, flavonol concentrations in 2020 were reduced in shaded vines compared to C0. The 2020 growing season highlighted the impact of heat degradation on flavonoids. Flavonoid concentrations in 2021 increased until harvest while flavonoid degradation was apparent from veraison to harvest in 2020 across shaded and control vines. Wine analyses highlighted the importance of light spectra to modify wine composition. Wine color intensity, tonality and anthocyanin values were enhanced in D4 whereas antioxidant properties were enhanced in C0 and D5 wines. Altogether, our results highlighted the need of new approaches in warm viticulture areas given the impact that composition of light has on berry and wine quality.

Bioclimatic shifts and land use options for Viticulture in Portugal

Land use, plays a relevant role in the climatic system. It endows means for agriculture practices thus contributing to the food supply. Since climate and land are closely intertwined through multiple interface processes, climate change may lead to significant impacts in land use. In this study, 1-km observational gridded datasets are used to assess changes in the Köppen–Geiger and Worldwide Bioclimatic (WBCS)

Impact of yeast derivatives to increase the phenolic maturity and aroma intensity of wine

Using viticultural and enological techniques to increase aromatics in white wine is a prized yet challenging technique for commercial wine producers. Equally difficult are challenges encountered in hastening phenolic maturity and thereby increasing color intensity in red wines. The ability to alter organoleptic and visual properties of wines plays a decisive role in vintages in which grapes are not able to reach full maturity, which is seen increasingly more often as a result of climate change. A new, yeast-based product on the viticultural market may give the opportunity to increase sensory properties of finished wines. Manufacturer packaging claims these yeast derivatives intensify wine aromas of white grape varieties, as well as improve phenolic ripeness of red varieties, but the effects of this application have been little researched until now. The current study applied the yeast derivative, according to the manufacture’s instructions, to the leaves of both neutral and aromatic white wine varieties, as well as on structured red wine varieties. Chemical parameters and volatile aromatics were analyzed in grape musts and finished wines, and all wines were subjected to sensory analysis by a tasting panel. Collective results of all analyses showed that the application of the yeast derivative in the vineyard showed no effect across all varieties examined, and did not intensify white wine aromatics, nor improve phenolic ripeness and color intensity in red wine.

How does aromatic composition of red wines, resulting from varieties adapted to climate change, modulate fruity aroma?

One of the major issues for the wine sector is the impact of climate change linked to the increasing temperatures which affects physicochemical parameters of the grape varieties planted in Bordeaux vineyard and consequently, the quality of wine. In some varietals, the attenuation of their fresh fruity character is accompanied by the accentuation of dried-fruit notes [1]. As a new adaptive strategy on climate change, some winegrowers have initiated changes in the Bordeaux blend of vine varieties [2]. This study intends to explore the fruitiness in wines produced from grape varieties adapted to the future climate of Bordeaux. 10 commercial single–varietal wines from 2018 vintage made from the main grape varieties in the Bordeaux region (Cabernet franc, Cabernet-Sauvignon and Merlot) as well as from indigenous grape varieties from the Mediterranean basin, such as Cyprus (Yiannoudin), France (Syrah), Greece (Agiorgitiko and Xinomavro), Portugal (Touriga Nacional) and Spain (Garnacha and Tempranillo), were selected among 19 samples using sensory descriptive analyses. Both sensory and instrumental analyses were coupled, to investigate their fruity aroma expression. For sensory analysis, samples were prepared from wine, using a semi preparative HPLC method which preserves wine aroma and isolates fruity characteristics in 25 specific fractions [3,4]. Fractions of interest with intense fruity aromas were sensorially selected for each wine by a trained panel and mixed with ethanol and microfiltered water to obtain fruity aromatic reconstitutions (FAR) [5]. A free sorting task was applied to categorize FAR according to their similarities or dissimilarities, and different clusters were highlighted. Instrumental analysis of the different FAR and wines demonstrated variations in their molecular composition. Results obtained from sensory and gas chromatography analysis enrich the knowledge of the fruity expression of red wines from “new” grape varieties opening up new perspectives in wine technology, including blending, thus providing new tools for producers.