Different Wines from Different Yeasts? 'Saccharomyces cerevisiae Intraspecies Differentiation by Metabolomic Signature and Sensory Patterns in Wine'

Alcoholic fermentation is known to be a key stage in the winemaking process that directly impacts the composition and quality of the final product. Twelve wines were obtained from fermentations of Chardonnay must made with twelve different commercial wine yeast strains of Saccharomyces cerevisiae. In our study, FT-ICR-MS, GC-MS, and sensory analysis were combined with multivariate analysis. Ultra-high-resolution mass spectrometry (uHRMS) was able to highlight hundreds of metabolites specific to each strain from the same species, although they are characterized by the same technological performances. Furthermore, the significant involvement of nitrogen metabolism in this differentiation was considered. The modulation of primary metabolism was also noted at the volatilome and sensory levels. Sensory analysis allowed us to classify wines into three groups based on descriptors associated with white wine. Thirty-five of the volatile compounds analyzed, including esters, medium-chain fatty acids, superior alcohols, and terpenes discriminate and give details about differences between wines. Therefore, phenotypic differences within the same species revealed metabolic differences that resulted in the diversity of the volatile fraction that participates in the palette of the sensory pattern. This original combination of metabolomics with the volatilome and sensory approaches provides an integrative vision of the characteristics of a given strain. Metabolomics shine the new light on intraspecific discrimination in the Saccharomyces cerevisiae species Keywords: yeast; Saccharomyces cerevisiae; Chardonnay wine; metabolomic; volatile compounds; sensory analysi

Impact of Glutathione on Wines Oxidative Stability: A Combined Sensory and Metabolomic Study

This paper is a comprehensive study regarding the role of glutathione as a natural antioxidant on white wines aging potential. It includes sensory and ultrahigh resolution mass spectrometry (FTICR-MS) metabolomics of aged chardonnay wines from 2008 to 2009 vintages, made after glutathione spiking at alcoholic fermentation or bottling. The closure effect was also considered. The sensory analysis revealed a clear vintage, closure and glutathione effect on wines oxidative character after several years of bottle aging. Spearman rank correlation was applied to link the sensory analysis and the exact mass information from FT-ICR-MS. FTICR–MS along with multivariate statistical analyses put in evidence that glutathione efficiency against wines sensory oxidative stability is related to wines antioxidant metabolome consisting of N- and S- containing compounds like amino acids, aromatic compounds and peptides. The chemical composition and origin of wines antioxidant metabolome suggests that its management since the very beginning of the vinification process is a key factor to estimate wines aging potential

Heat transfer inside wood treated by infrared radiation (IR): application to the process of barrel making. Experimental result

International audienc

White Wine Antioxidant Metabolome: Definition and Dynamic Behavior during Aging on Lees in Oak Barrels

White wines’ oxidative stability is related to a flow of chemical reactions involving a number of native wine compounds comprising their antioxidant metabolome. By applying the combination of powerful and modern analytical approaches (EPR, DPPH, and UPLC-qToF-MS-based metabolomics), we could define wine antioxidant metabolome as the sum of molecular antioxidant markers (AM) characterized by their radical scavenging (AM-RS) and nucleophilic (AM-Nu) properties. The impact of on-lees barrel aging of chardonnay wines on the antioxidant metabolome was studied for two consecutive vintages. The identification of wines’ antioxidant metabolome allows for a detailed understanding of the transient chemical interplays involved in the antioxidant chemistry associated with well-known antioxidants and opens an avenue towards personalized winemaking. The present study gathers for the first time the dynamics of wines’ antioxidant metabolome during on-lees aging. Monitoring the variations of the wine antioxidant metabolome can provide an avenue to better control the winemaking process using the knowledge of how to optimize the wine aging potential

Capillary Electrophoresis in Wine Science

International audienceCapillary electrophoresis appeared to be a powerful and reliable technique to analyze the diversity of wine compounds. Wine presents a great variety of natural chemicals coming from the grape berry extraction and the fermentation processes. The first and more abundant after water, ethanol has been quantified in wines via capillary electrophoresis. Other families like organic acids, neutral and acid sugars, polyphenols, amines, thiols, vitamins, and soluble proteins are electrophoretically separated from the complex matrix.Here, we will focus on the different methodologies that have been employed to conduct properly capillary electrophoresis in wine analysis.Two examples informing on wine chemistry obtained by capillary electrophoresis will be detailed. They concern polyphenol analysis and protein profiling. The first category is a well-developed quantitative approach important for the quality and the antioxidant properties conferred to wine. The second aspect involves more research aspects dealing with microbiota infections in the vineyard or in the grape as well as enological practices

A key to wine conservation lies in the glass–cork interface

International audienceThis study investigates the evolution of the oxygen barrier properties of the bottleneck–stopper system under conditions simulating the conservation of wine in the bottle (presence of model wine, storage position, and temperature) over a long aging period of 24 months. The results highlighted that the oxygen diffusion coefficient of the stopper alone is not modified regardless of the storage conditions. At 20°C, the presence of model wine favors oxygen transfer at the glass–cork interface, accounting for nearly 75% of total oxygen transfer in comparison to cork studied without model wine. Yet, the position of the bottle during storage, vertical (i.e. cork in contact with the vapor phase of the model wine) or horizontal (i.e. cork in contact with the liquid phase), does not influence the oxygen transfer. At higher storage temperatures (35 and 50°C), the barrier properties of the bottleneck–cork system remain stable up to 9 and 3 months, respectively. After this period, an alteration of the barrier properties is observed with an increase of the transfer at the glass–cork interface

L’interface bouchon/goulot : Un élément clé de la conservation du vin en bouteille

National audienceLe liège est un matériau versatile utilisé depuis plusieurs siècles pour ses propriétés remarquables telles que son élasticité, sa faible perméabilité aux liquides et aux gaz ou encore son imputrescibilité. À ce jour, la majeure partie de la production mondiale du liège (environ 73 %) est destinée à l’industrie vitivinicole pour la fabrication de bouchons à base de liège. Si le marché des obturateurs œnologiques a longtemps été dominé par les bouchons en liège naturel, différentes technologies de bouchage se sont progressivement développées, comme les capsules à vis, les bouchons synthétiques ou encore les bouchons agglomérés

The bottleneck/cork interface: a key parameter in bottle-aging of wine

International audienceA study of changes in oxygen transfer through micro-agglomerated corks was carried out over 24 months under controlled storage conditions (Chanut et al., 2023a). This work demonstrated that the glass/cork interface can represent a major entry route for oxygen into wine bottles. It also showed that there is no difference in oxygen transfer at 20°C between bottles stored horizontally and vertically. However, high storage temperature greatly increases oxygen transfer at the interface between the cork and the bottleneck

Caractérisation de la structure poreuse du liège par imagerie. Voyage au cœur du bouchon

National audienceLe liège est un matériau provenant de la partie externe de l’écorce du chêne liège. Ce matériau est le plus utilisé pour le bouchage de plus de deux tiers des bouteilles de vins, en particulier ceux de longue garde. Les bouchons en liège sont classés visuellement en différentes catégories en fonction de leurs défauts apparents. Moins il y a de lenticelles en surface, plus le liège est considéré de qualité élevée.L’objectif de cette étude était d’identifier et de quantifier les défauts de deux catégories de bouchons de liège selon deux approches : en analysant sa surface par photographie optique ou bien en volume par imagerie de neutrons ou de rayons X.Les photographies ont permis de quantifier les défauts présents à la surface des bouchons. Le grade 0 (la meilleure qualité de liège) a présenté 4,1 % de défauts alors que le grade 4 en a compté 6,7 %. L’imagerie neutrons (ou rayons X) a permis de quantifier non seulement les défauts présents à la surface mais aussi ceux à l’intérieur du matériau, invisibles à l’œil nu. Cette technique a permis de comptabiliser 5,4 % de défauts en volume pour le grade 0 et 6,5 % pour le grade 4