Macrowine 2021
IVES 9 IVES Conference Series 9 Screening of aroma metabolites within a set of 90 Saccharomyces strains

Screening of aroma metabolites within a set of 90 Saccharomyces strains

Abstract

Currently, the main demand in the global wine market relies on products with unique flavour profiles, character, and typicity, and the metabolism of yeasts greatly influences the organoleptic properties of wines. Therefore, the natural diversity of Saccharomyces strains rises in interest over the last decade, but a large part of this phenotypic diversity remains unexplored. Moreover, the genetic basis underlying the variation in the production of flavour-active metabolites within the Saccharomyces genus remains poorly understood. The main purpose of this project is to provide a better understanding of how the synthesis of these flavour-active compounds is modulated at genetic level, aiming to identify genes with specific functions in the metabolism of yeasts. This information will be obtained through the generation of novel hybrids between different Saccharomyces species and the use of quantitative genetics. In this context, the first step was to assess the phenotypic diversity at the scale of Saccharomyces genus, regarding traits of industrial interest. With this aim, 90 yeast strains of all the eight species which compose the Saccharomyces clade were screened for their fermentative capacities and the production of aromas and other compounds of interest (such as glycerol or succinate). Fermentations in oenological conditions were carried out at different temperatures, monitoring the kinetic profiles and analysing the production of the main fermentation metabolites (by HPLC) as well as the production of more than 40 aroma compounds (by GC-MS). The sporulation ability of the strains, necessary for the hybridization, was also assessed. Important differences were found in the kinetic and volatile profiles of the strains, and the whole dataset provides a comprehensive picture of the phenotypic diversity within the genus Saccharomyces. This information confirms the interest in further development of genetic approaches to identify the molecular basis underlying the studied traits and opens the door for their improvement.

DOI:

Publication date: September 3, 2021

Issue: Macrowine 2021

Type: Article

Authors

Rafael Álvarez-Rafael, Sylvie DEQUIN, Edward J. LOUIS, Carole CAMARASA

UMR 1083 Sciences Pour l’Oenologie, INRAE, Montpellier SupAgro, Montpellier, France, UMR 1083 Sciences Pour l’Oenologie, INRAE, Montpellier SupAgro, Montpellier, France ,Centre of Genetic Architecture of Complex Traits, University of Leicester, Leicester, UK, UMR 1083 Sciences Pour l’Oenologie, INRAE, Montpellier SupAgro, Montpellier, France

Contact the author

Keywords

Alcoholic fermentation; genus saccharomyces; phenotypic diversity; fermentative volatile compounds

Citation

Related articles…

Terroir effects on the response of Tempranillo grapevines to irrigation in four locations of Spain: grape and must composition

This work discusses the effects of soil and weather conditions on the grape composition of cv. Tempranillo in four different locations of Spain, during the 2008-2011 seasons.

Spectral discrimination between Vitis vinifera and labrusca by spectroradiometric techniques

Brazil is one of the few countries where vineyards of Vitis labrusca and Vitis vinifera coexist in the same geographical spaces, due to complex processes of territorial occupation by successive waves of European settlers.

Contribution of very high resolution satellite remote sensing to the mapping of harvest zones in the Maipo Valley (Chile)

Les images de très haute résolution spatiale sont utilisées depuis peu en viticulture comme une aide à la cartographie des zones de vendanges. A partir d’images multispectrales de très haute résolution spatiale IKONOS (résolution 4 m) et SPOT-5 en supermode (résolution 2.5 m), on propose ici une démarche de segmentation d’une région de vignoble en zones de vendanges.

An analytical framework to site-specifically study climate influence on grapevine involving the functional and Bayesian exploration of farm data time series synchronized using an eGDD thermal index

Climate influence on grapevine physiology is prevalent and this influence is only expected to increase with climate change. Although governed by a general determinism, climate influence on grapevine physiology may present variations according to the terroir. In addition, these site-specific differences are likely to be enhanced when climate influence is studied using farm data. Indeed, farm data integrate additional sources of variation such as a varying representativity of the conditions actually experienced in the field. Nevertheless, there is a real challenge in valuing farm data to enable grape growers to understand their own terroir and consequently adapt their practices to the local conditions. In such a context, this article proposes a framework to site-specifically study climate influence on grapevine physiology using farm data. It focuses on improving the analysis of time series of weather data. The analytical framework includes the synchronization of time series using site-specific thermal indices computed with an original method called Extended Growing Degree Days (eGDD). Synchronized time series are then analyzed using a Bayesian functional Linear regression with Sparse Steps functions (BLiSS) in order to detect site-specific periods of strong climate influence on yield development. The article focuses on temperature and rain influence on grape yield development as a case study. It uses data from three commercial vineyards respectively situated in the Bordeaux region (France), California (USA) and Israel. For all vineyards, common periods of climate influence on yield development were found. They corresponded to already known periods, for example around veraison of the year before harvest. However, the periods differed in their precise timing (e.g. before, around or after veraison), duration and correlation direction with yield. Other periods were found for only one or two vineyards and/or were not referred to in literature, for example during the winter before harvest.

Towards adaptation to climate change in Rioja: Quality evaluation of wines obtained from Grenache x Tempranillo selections

The wine sector is of great relevance and tradition in Mediterranean countries, however, it may be most susceptible to climate change. In recent years, wine production is facing changes worldwide, both at environmental as well as commercial levels, due to global warming and the shift in consumers’ preferences. Wine growers and wine makers are in search of solutions that allow to face these new challenges. One of the most promising initiatives in the long term is the introduction of new plant materials, specifically intraspecific hybridizations between premium varieties that may improve traditional germplasm in its adaptation to climate change. These inter-varietal crosses have the potential to generate quality wines, whilst maintaining the regional typicity, and constitute an attractive alternative for the consumer due to their sensory attributes. In this study, we have evaluated wines from 29 intraspecific Garnacha x Tempranillo hybrids in two different locations, with the aim to assess their oenological potential and sensory attributes. Thirteen of the selections were white and 16 were red. Microvinifications were conducted with two or three replications depending on grape availability. Conventional oenological parameters were determined for all wines. The sensory evaluation and hedonic scores were given by five experts. Red selections obtained higher quality scores than white ones. Among the white selections with higher quality scores, GT-41 Varea and GT-159 Varea outstand, due to their high total acidity and high malic acid content. Regarding red selections, GT-57 Varea and GT-57 UR were perceived as higher in quality, highlighted for their moderate alcoholic and high anthocyanin content. Our results indicate that intraspecific hybridization may be a powerful tool for adapting traditional cultivars to climate change in Rioja.