IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 The 1-hydroxyoctan-3-one, a molecule potentially involved in the fresh mushroom off-flavor in wines

The 1-hydroxyoctan-3-one, a molecule potentially involved in the fresh mushroom off-flavor in wines

Abstract

An organoleptic defect, called fresh mushrooms off-flavor (FMOff), appeared in wines and spirits since the 2000’s. Numerous researches demonstrated that octen-3-one, 3-octanol and octen-3-ol (C8 compounds) were involved in the mushroom off-flavor in wines. Nevertheless, these molecules alone do not explain the entire defect in wines and some odorous zones still remain without chemical identification.  Recently, Crustomyces subabruptus has been shown to be a fungus capable of systematically producing FMOff under oenological conditions. The aim of this work was (a) to identify new markers of FMOff using Crustomyces subabruptus as a laboratory model, (b) to synthesize potential candidates and (c) to correlate the levels of these compounds determined by GC-MS with sensory characterization of healthy and affected wines. In practice, Pinot noir musts were artificially contaminated by Crustomyces subabruptus in the laboratory and then fermented. The musts and corresponding wines were analyzed in an untargeted way by GC-MS. By comparison with MS spectra libraries, the 1-hydroxy-3-octanone was formally and systematically identified in these matrices. This molecule, which has never been identified in grapes nor in wine, was only referenced in the fruit of the papaya mountain after enzymatic hydrolysis of the glycosidic fractions of the fruit pulp. In order to develop a targeted analysis by GC-MS, we synthesized the 1-hydroxy-3-octanone according to a previously published procedure. Briefly, 3-hydroxypropionitrile was first silylated to protect hydroxyl function and then reacted with pentylmagnesium bromide according to the Grignard reaction. The last step involved the deprotection of the resulting alcohol to obtain the expected product. Finally, 30 wines from different vintages (those of 2017, 2018, 2019, and 2021) on which were sensorially detected FMOff were spiked with deuterated internal standards (1-octen-3-one-d2, 1-octen-3-ol-d2, 3-octanol-d4), extracted with a pentane-dichloromethane mixture (2/1, v/v), rectified at 40°C, and then analyzed by GC-MS. The analysis of these wines showed the systematic presence of 1-hydroxy-3-octanone in the 2017 wines with levels that seemed to correlate significantly (test of spearman= 0,81) with the sensory analysis scores, r²=0.65. Wines with high sensory analysis scores for FMOff have a higher level of 1-hydroxyoctan-3-one than those with lower scores. On the other hand, the wines did not systematically contained octen-3-one, 3-octanol or octen-3-ol after 4 years of ageing, suggesting that 1-hydroxy-3-octanone could be a more stable chemical marker than the other compounds in the oenological matrix. In conclusion, 1-hydroxyoctan-3-one is a new molecular candidate for tracking the FMOff. Its formal identification completes the overview of the molecules involved in this defect and opens the way to a better understanding of the appearance and evolution of fresh mushrooms off flavors in wines.

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

Delcros Léa1, Costis Arnaud2, Collas Sylvie1, Herve Marion1, Blondin Bruno2 and Roland Aurélie2

1MHCS, Comité Champagne, Epernay, ZI Pierre et Marie Curie – 51530 OIRY, France
2SPO, Univ Montpellier INRAE, Institut agro, Montpellier, France

Contact the author

Keywords

1-hydroxyoctan-3-one, Fresh mushroom off-flavor, Wine, Must, Volatiles compounds

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Spatial determination of areas in the Western Balkans region favorable for organic production

In problematic conditions for production of grapes and wine caused by the COVID-19 pandemic and the resulting occurrence of wine surpluses, producers are increasingly turning to the innovative viticulture and winemaking of products that are more appealing to the market and the consumers. On the other hand, consumption of the food safety or organic products, and therefore of organic grapes and wine, is increasingly common in the world, in particular in Europe. The Regional Rural Development Standing Working Group (SWG RRD), as a regional intergovernmental organization gathers actors in the viticulture and winemaking sector from states and territories of the Western Balkans (South-East Europe) in the Expert Working Group for Wine, with the aim of improving viticulture and winemaking in this region through joint activities. In accordance with the aforementioned, the SWG RRD is working on advancing organic production of grapes and wine, and on recognition of specificities of the terroir of wine-growing areas in Western Balkans. In addition, as part of the project “Facilitation of Exchange and Advice on Wine Regulations in Western Balkan Countries” helmed by the German Federal Ministry of Food and Agriculture, in addition to harmonization of relevant legislation with EU regulations, efforts are being invested towards recognition of organic wines. Within activities and project implemented by this organization, expert analyses and scientific research of the terroir of Western Balkans were carried out, and some of the results are presented in this paper.

Revealing the Barossa zone sub-divisions through sensory and chemical analysis of Shiraz wine

The Barossa zone is arguably one of the most well-recognised wine producing regions in Australia and internationally; known mainly for the production of its distinct Shiraz wines. However, within the broad Barossa geographical delimitation, a variation in terroir can be perceived and is expressed as sensorial and chemical profile differences between wines. This study aimed to explore the sub-division classification across the Barossa region using chemical and sensory measurements. Shiraz grapes from 4 different vintages and different vineyards across the Barossa (2018, n = 69; 2019, n = 72; 2020, n = 79; 2021, n = 64) were harvested and made using a standardised small lot winemaking procedure. The analysis involved a sensory descriptive analysis with a highly trained panel and chemical measurement including basic chemistry (e.g. pH, TA, alcohol content, total SO2), phenolic composition, volatile compounds, metals, proline, and polysaccharides. The datasets were combined and analysed through an unsupervised, clustering analysis. Firstly, each vintage was considered separately to investigate any vintage to vintage variation. The datasets were then combined and analysed as a whole. The number of sub-divisions based on the measurements were identified and characterised with their sensory and chemical profile and some consistencies were seen between the vintages. Preliminary analysis of the sensory results showed that in most vintages, two major groups could be identified characterised with one group showing a fruit-forward profile and another displaying savoury and cooked vegetables characters. The exploration of distinct profiles arising from the Barossa wine producing region will provide producers with valuable information about the regional potential of their wine assisting with tools to increase their target market and reputation. This study will also provide a robust and comprehensive basis to determine the distinctive terroir characteristics which exist within the Barossa wine producing region.

Grapevine yield-gap: identification of environmental limitations by soil and climate zoning in Languedoc-Roussillon region (south of France)

Grapevine yield has been historically overlooked, assuming a strong trade-off between grape yield and wine quality. At present, menaced by climate change, many vineyards in Southern France are far from the quality label threshold, becoming grapevine yield-gaps a major subject of concern. Although yield-gaps are well studied in arable crops, we know very little about grapevine yield-gaps. In the present study, we analysed the environmental component of grapevine yield-gaps linked to climate and soil resources in the Languedoc Roussillon. We used SAFRAN data and IGP Pays d’Oc wine yields from 2010 to 2018. We selected climate and soil indicators proving to have a significant effect on average wine yield-gaps at the municipality scale. The most significant factors of grapevine yield were the Soil Available Water Capacity; followed by the Huglin Index and the Climatic Dryness Index. The Days of Frost; the Soil pH; and the Very Hot Days were also significant. Then, we clustered geographical zones presenting similar indicators, facilitating the identification of resources yield-gaps. We discussed the number of zones with the experts of IGP Pays d’Oc label, obtaining 7 zones with similar limitations for grapevine yield. Finally, we analysed the main resources causing yield-gaps and the grapevine varieties planted on each zone. Mapping grapevine resource yield-gaps are the first stage for understanding grapevine yield-gaps at the regional scale.

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.

Sustainable fertilisation of the vineyard in Galicia (Spain)

Excessive fertilization of the vineyard leads to low quality grapes, increased costs and a negative impact on the environment. In order to establish an integrated management system aimed at a sustainable fertilization of the vineyards, nutritional reference levels were established. For this purpose, 30 representative vineyards of the Albariño variety were studied, in which soil and petiole analyses were carried out for two years and grape yield and quality at harvest were measured. In both years of study, soil pH, calcium, sodium and cation exchange capacity were positively correlated with calcium content and negatively correlated with manganese in grapes. Irrigated vineyards had higher levels of aluminium in soil and lower levels of calcium in petiole. Climatic conditions were very different in the years of the study. The year 2019 was colder than usual, in 2020 there was a marked water stress with high summer temperatures. This resulted in medium-high acidity in grapes in 2019 and low acidity in 2020, with sugar levels being similar both years. A very marked decrease in must amino nitrogen was observed in 2020, with ammonia nitrogen remaining stable. The correlation of acidity and sugar values in grapes with soil and petiole analysis data made it possible to establish reference levels for the nutritional diagnosis of the Albariño variety in this region. Based on these results, an easy-to-use TIC application is currently being created for grapegrowers, aimed at improving the sustainability of the vineyard through reasoned fertilization. This study has now been extended to other Galician vine varieties.