16 research outputs found
Approches sensorielle et analytique de l'arÎme fruité des vins rouges : infuence relative des levures et des bactéries lactiques
Alcoholic (AF) and malolactic (MLF) fermentations are important steps in red winemaking for the revelation of wine fruity aroma. To investigate the relative importance of fermentative microorganisms, we studied the influence of six yeasts/lactic acid bacteria (LAB) combination - three yeast strains, two LAB - on Bordeaux red wines fruity notes modulation. A first analytical approach showed the predominant influence of yeast strain on the concentration of more than 70 potential fruity note markers. Special study of esters showed a yeast strain effect since the end of FA that persists over time, despite MLF and changes caused by wine aging. Sensory studies also highlighted the major influence of yeasts on red wines fruity aroma modulations at different aging steps. Nevertheless, results suggested the role of other aromatic compounds in fruity note modulation, not quantified in the first part of this study. The study of fractions made by HPLC with wine organic extracts enables the identification of an interested fraction involved in aromatic variations related to the yeast strain. Analysis of this fraction by gas chromatography has not allowed identifying compounds involved in these organoleptic variations. However, we highlighted a thiophenone that could act as a mask of fruity aroma and a hydroxylated ester that could be an interesting marker of bacterial activity. Its role as enhancer of fruity esters aroma is also considered.Les fermentations alcoolique (FA) et malolactique (FML) sont deux Ă©tapes importantes de la vinification en rouge dans lâĂ©tablissement de lâarĂŽme fruitĂ© des vins. Afin dâĂ©tudier lâimportance relative des microorganismes fermentaires, nous Ă©tudions lâinfluence de six couples levures/bactĂ©ries lactiques (BL) - trois souches de levures, deux de BL - sur la modulation des notes fruitĂ©es de diffĂ©rents vins rouges de Bordeaux. Une premiĂšre approche analytique montre lâinfluence prĂ©dominante de la souche de levures sur la concentration de plus de 70 marqueurs potentiels de la note fruitĂ©e. LâĂ©tude particuliĂšre des esters montre que lâeffet levures observĂ© dĂšs la fin de la FA persiste au cours du temps malgrĂ© la FML et les modifications engendrĂ©es par le vieillissement du vin. LâĂ©tude sensorielle conforte lâinfluence majeure des levures sur la modulation de lâarĂŽme fruitĂ© des vins rouges Ă diffĂ©rents temps dâĂ©levage. NĂ©anmoins, les rĂ©sultats obtenus suggĂšrent lâimplication dâautres composĂ©s aromatiques dans la modulation de la note fruitĂ©e des vins, non quantifiĂ©s dans la premiĂšre partie de cette Ă©tude. Un travail de fractionnement dâextraits de vin par HPLC permet par la suite lâidentification dâune fraction dâintĂ©rĂȘt impliquĂ©e dans des variations aromatiques liĂ©es Ă la souche de levures. Lâanalyse de cette fraction par chromatographie en phase gazeuse nâa pas permis dâidentifier le ou les composĂ©s impliquĂ©s. Nous avons nĂ©anmoins mis en Ă©vidence une thiophĂ©none qui pourrait agir en tant que masque de lâarĂŽme fruitĂ©, ainsi quâun ester hydroxylĂ© qui pourrait sâavĂ©rer ĂȘtre un marqueur intĂ©ressant de lâactivitĂ© bactĂ©rienne et dont lâeffet exhausteur de notes fruitĂ©es est Ă©galement envisagĂ© comme perspectives
Two different Oenococcus oeni lineages are associated to either red or white wines in Burgundy: genomics and metabolomics insights
Oenococcus oeni is the bacterium most often associated with spontaneous malolactic fermentation (MLF) of wine. During MLF, malic acid is transformed into lactic acid and several metabolites are modified, modulating wineâs total acidity and improving its sensory properties. Previous works have suggested that certain genetic groups of O. oeni strains are associated to different kinds of products. In the present study we have spotted two groups of strains isolated mainly from Burgundy wines, one associated to red wines and the other to white wines. Sequencing 14 genomes of red and white wine strains revealed that they share a common ancestor that probably colonised two different substrates âred and white wine-associated environmentsâ, diverging over time and disseminating to various regions. Their capacity to perform MLF and modify the volatile profile of wine was determined by fermenting a chardonnay wine and analysing its volatile fraction with a non-targeted metabolomics approach by GC-MS. The strains had a different impact on the volatile composition depending on their group of origin. These results show for the first time a correspondence between the product of origin of the strains and the volatile profile of the wines they produce. Furthermore, the genetic features that might be implied in these different phenotypes are examined
Analytical and sensorial approaches of red wines fruity aroma Influence of yeasts and lactic acid bacteria
Les fermentations alcoolique (FA) et malolactique (FML) sont deux Ă©tapes importantes de la vinification en rouge dans lâĂ©tablissement de lâarĂŽme fruitĂ© des vins. Afin dâĂ©tudier lâimportance relative des microorganismes fermentaires, nous Ă©tudions lâinfluence de six couples levures/bactĂ©ries lactiques (BL) - trois souches de levures, deux de BL - sur la modulation des notes fruitĂ©es de diffĂ©rents vins rouges de Bordeaux. Une premiĂšre approche analytique montre lâinfluence prĂ©dominante de la souche de levures sur la concentration de plus de 70 marqueurs potentiels de la note fruitĂ©e. LâĂ©tude particuliĂšre des esters montre que lâeffet levures observĂ© dĂšs la fin de la FA persiste au cours du temps malgrĂ© la FML et les modifications engendrĂ©es par le vieillissement du vin. LâĂ©tude sensorielle conforte lâinfluence majeure des levures sur la modulation de lâarĂŽme fruitĂ© des vins rouges Ă diffĂ©rents temps dâĂ©levage. NĂ©anmoins, les rĂ©sultats obtenus suggĂšrent lâimplication dâautres composĂ©s aromatiques dans la modulation de la note fruitĂ©e des vins, non quantifiĂ©s dans la premiĂšre partie de cette Ă©tude. Un travail de fractionnement dâextraits de vin par HPLC permet par la suite lâidentification dâune fraction dâintĂ©rĂȘt impliquĂ©e dans des variations aromatiques liĂ©es Ă la souche de levures. Lâanalyse de cette fraction par chromatographie en phase gazeuse nâa pas permis dâidentifier le ou les composĂ©s impliquĂ©s. Nous avons nĂ©anmoins mis en Ă©vidence une thiophĂ©none qui pourrait agir en tant que masque de lâarĂŽme fruitĂ©, ainsi quâun ester hydroxylĂ© qui pourrait sâavĂ©rer ĂȘtre un marqueur intĂ©ressant de lâactivitĂ© bactĂ©rienne et dont lâeffet exhausteur de notes fruitĂ©es est Ă©galement envisagĂ© comme perspectives.Alcoholic (AF) and malolactic (MLF) fermentations are important steps in red winemaking for the revelation of wine fruity aroma. To investigate the relative importance of fermentative microorganisms, we studied the influence of six yeasts/lactic acid bacteria (LAB) combination - three yeast strains, two LAB - on Bordeaux red wines fruity notes modulation. A first analytical approach showed the predominant influence of yeast strain on the concentration of more than 70 potential fruity note markers. Special study of esters showed a yeast strain effect since the end of FA that persists over time, despite MLF and changes caused by wine aging. Sensory studies also highlighted the major influence of yeasts on red wines fruity aroma modulations at different aging steps. Nevertheless, results suggested the role of other aromatic compounds in fruity note modulation, not quantified in the first part of this study. The study of fractions made by HPLC with wine organic extracts enables the identification of an interested fraction involved in aromatic variations related to the yeast strain. Analysis of this fraction by gas chromatography has not allowed identifying compounds involved in these organoleptic variations. However, we highlighted a thiophenone that could act as a mask of fruity aroma and a hydroxylated ester that could be an interesting marker of bacterial activity. Its role as enhancer of fruity esters aroma is also considered
Isolation of Taste-Active Triterpenoids from Quercus robur: Sensory Assessment and Identification in Wines and Spirit
Six new triterpenoids (1â6), two known genins (7 and 8), and five known functionalized triterpenoids (9â13) were isolated from a Quercus robur heartwood extract. The purification protocol was guided by LC-HRMS by searching for structural analogues of bartogenic acid on the basis of their putative empirical formula. The structures of the new compounds were unequivocally elucidated using HRESIMS and 1D/2D NMR experiments. Sensory analyses were performed in water and in a non-oaked white wine on the pure compounds 1â13 at 5 mg/L. All molecules were perceived as bitter in water and wine, but they were mostly reported as modifying the wine taste balance. Using LC-HRMS, compounds 1â13 were observed in oaked red wine and cognac and were semiquantified in oak wood extracts. The influence of two cooperage parameters, oak species and toasting process, on compounds 1â13 content was studied. All compounds were found in quantities significantly higher in pedunculate than in sessile oak wood. Toasting is a key step in barrel manufacture and modulates the concentration of the discussed compounds. Significantly higher quantities were observed in untoasted wood compared to medium or highly toasted wood. These findings provide new insights into the molecular origin of taste changes due to oak aging
Approches sensorielle et analytique de lâarĂŽme fruitĂ© des vins rouges. Influence majeure de la souche de levures.
Article dans une revue professionnelleLa typicitĂ© se dĂ©finit comme la propriĂ©tĂ© dâappartenance Ă un type distinguĂ© et identifiĂ© par un groupe humain de rĂ©fĂ©rence (Casabianca et al., 2005). Ainsi, il est depuis longtemps observĂ© de façon empirique lâexistence dâune expression fruitĂ©e des vins rouges, et, de façon plus spĂ©cifique aux vins de Bordeaux, de notes Ă©voquant les fruits rouges et noirs comme la framboise, la cerise ou encore le cassis. RĂ©cemment, lâexistence dâun espace sensoriel propre Ă ces vins a Ă©tĂ© dĂ©montrĂ©e (Pineau, 2007). Ces notes fruitĂ©es, non dĂ©tectĂ©es dans le moĂ»t, sont rĂ©vĂ©lĂ©es au cours des diffĂ©rentes Ă©tapes de vinification et dâĂ©laboration des vins. Les fermentations alcoolique et malolactique constituent des Ă©tapes clĂ©s dans la libĂ©ration ou la genĂšse des arĂŽmes du vin. Plusieurs travaux ont tentĂ© de dĂ©terminer lâinfluence des souches de levures ou de bactĂ©ries lactiques (BL) sur la modulation organoleptique du vin sans quâaucun consensus ne puisse encore ĂȘtre Ă©tabli (Ălvarez-PĂ©rez et al., 2012 ; McDaniel et al., 1987; Henick-Kling et al., 1994 ; Antalick et al., 2012). LâinterprĂ©tation molĂ©culaire de cette spĂ©cificitĂ© des vins rouges de Bordeaux est rendue difficile par le manque de connaissances sur les composĂ©s aromatiques responsables de ces nuances. Depuis plusieurs dĂ©cennies, de nombreux travaux se sont attachĂ©s Ă la caractĂ©risation molĂ©culaire des composĂ©s volatils du vin. Les premiĂšres Ă©tudes rĂ©alisĂ©es sur des vins blancs ont permis de faire lâassociation entre certains arĂŽmes caractĂ©ristiques et une ou plusieurs molĂ©cules dâintĂ©rĂȘt (Marais, 1983 ; Tominaga et al., 1998). De nombreux auteurs ont abordĂ© lâĂ©tude de lâarĂŽme fruitĂ© des vins rouges en tentant dâidentifier les composĂ©s aromatiques clĂ©s responsables de ces odeurs (Moio et Etievant, 1995 ; Kotseridis et Baumes, 2000 ; Campo et al., 2007 ; Siebert et al., 2008). Sâil nâa pas encore Ă©tĂ© possible dâidentifier des molĂ©cules spĂ©cifiques, expliquant Ă elles seules la typicitĂ© de lâarĂŽme fruitĂ©, lâexistence de tels composĂ©s ne peut pour autant ĂȘtre dĂ©finitivement exclue. NĂ©anmoins, plusieurs travaux rĂ©cents ont dĂ©montrĂ© lâimportance des interactions perceptives entre plusieurs familles dâodorants tels que des composĂ©s dâorigine variĂ©tale comme les norisoprĂ©noĂŻdes Ă 13 atomes de carbone (Pineau et al., 2007), les lactones (Loscos et al., 2007) ou les thiols (Tominaga et al., 1998), ou des composĂ©s fermentaires comme les esters (Lytra et al., 2012). Par ailleurs, plusieurs Ă©tudes ont visĂ© Ă dĂ©terminer lâimpact de micro-organismes fermentaires sur la modulation des teneurs en divers marqueurs potentiels de lâarĂŽme fruitĂ©. LĂ encore, aucun consensus nâa pu rĂ©ellement ĂȘtre mis en Ă©vidence. La variation de la note fruitĂ©e des vins rouges semble impliquer des phĂ©nomĂšnes plus complexes quâun simple effet souche et pourrait rĂ©sulter dâeffets liĂ©s aux propriĂ©tĂ©s de la matrice, combinĂ©s Ă lâinfluence de la souche de levures et/ou de la souche de BL. Au vu de ces derniĂšres acquisitions, nous avons choisi, dans le cadre de ce travail, dâĂ©tudier lâimpact organoleptique relatif des levures et des BL sur les nuances de lâarĂŽme fruitĂ© de plusieurs vins rouges bordelais. Une approche par lâanalyse chimique et sensorielle de vins produits dans des conditions de fermentation classique ou de microvinification a Ă©tĂ© effectuĂ©e pour trois sites en Bordelais sur deux millĂ©simes. Il a Ă©tĂ© choisi de travailler sur le Cabernet- Sauvignon. Plusieurs couples levures/BL ont Ă©tĂ© sĂ©lectionnĂ©s et implantĂ©s dans des cuves de quelques hectolitres Ă plusieurs dizaines dâhectolitres
Ethyl 2-hydroxy-3-methylbutanoate enantiomers: quantitation and sensory evaluation in wine
Aim: To investigate chemical and sensory characteristics of ethyl 2-hydroxy-3-methylbutanoate in wines.[br/] Methods and results: Ethyl 2-hydroxy-3-methylbutanoate has been recently identified as a potential marker of lactic acid bacteria esterase activity. Enantiomers of this fruity ester were quantitated in 99 wines from various vintages and French regions using chiral gas chromatography (γ-cyclodextrin phase). Analyses revealed the predominant presence of the R enantiomer in red and white wines, with a maximum R/S enantiomeric ratio of 94/6 in a 1993 red wine. Results also highlighted greater levels of the ester in red than white wines, depending on grape origin. The detection thresholds of the R- and S-form were estimated at 4 ”g/L and 1.5 ”g/L in water and 51 mg/L and 21 mg/L in red wine, respectively. Moreover, ranking tests made with levels found in wines did not show significant sensory differences.[br/] Conclusion: The concentrations found in wines were considerably below the detection threshold, indicating no direct effect of these compounds on fruity aroma modulation. The absence of significant difference in sensory tests demonstrates that ethyl 2-hydroxy-3-methylbutanoate does not contribute significantly to the fruity aroma of red wine.[br/] Significance and impact of the study: To our knowledge, no previous research had determined the enantiomeric distribution and the sensory characteristics of this compound in wine
J. Nat. Prod.
Quercoresinosides A and B (1 and 2), two new lignans, were isolated from a toasted Quercus petraea heartwood extract along with a known compound, 3-methoxy-4-hydroxyphenol 1-O-ÎČ-d-(6âČ-O-galloyl)glucopyranoside (3). The purification protocol was based on a taste-guided approach that sought to reveal new bitter compounds released from oak wood into wines and spirits. HRMS and NMR data were used to establish that compounds 1 and 2 are lignan derivatives bearing a glucosyl unit and a galloyl unit at the same positions. Hydrolysis of these compounds showed that they could be distinguished by the absolute configuration of their respective lyoniresinol genin as determined by chiral LC-HRMS in comparison with (+)- and (â)-lyoniresinol standards. Sensory analyses were performed in a non-oaked wine on the pure compounds 1â3. The three molecules exhibited a bitter taste at 2 mg/L that was particularly intense for compounds 2 and 3. Finally, LC-HRMS demonstrated the occurrence of compounds 1â3 in oaked wine and brandy, which supports the hypothesis of their contributions to the increase in bitterness during oak aging
Contribution of Grapes and Oak Wood Barrels to Pyrrole Contents in Chardonnay Wines: The Influence of Several Cooperage Parameters
The influence of some enological parameters on pyrrole concentrations in Chardonnay wines was studied. First, a quantitative method to assay five pyrroles was optimized and applied to determine their content in wines produced in different containers. All pyrroles were observed in wines aged in a stainless-steel tank, which indicated that they have a varietal or fermentative origin. However, their concentrations were significantly higher in wines made in new barrels than in older barrels or in a stainless-steel tank, so oak wood may largely contribute during the winemaking process. A quantitative method to assay pyrroles in oak wood extract was also developed to study the influence of several cooperage parameters such as different types of traditional toasting, as well as the temperature and the time of toasting. Significant differences were observed on pyrrole concentrations in oak wood extracts according to these different cooperage parameters. These findings bring new perspectives to the monitoring of winemaking and the aging of Chardonnay wines
Recherches sur la typicitĂ© des vins de Chardonnay de Bourgogne. Identification et quantification de nouveaux marqueurs de lâarĂŽme de noisette
Article dans une revue professionnelleLe Chardonnay est lâun des cĂ©pages blancs les plus cultivĂ©s au monde et Ă lâorigine des vins blancs secs les mieux valorisĂ©s. Des travaux antĂ©rieurs ont montrĂ© quâil existe un espace sensoriel propre aux vins qui en sont issus, câest-Ă -dire que les experts reconnaissent distinctement leur signature parmi des vins provenant dâautres cĂ©pages. Toutefois, selon le terroir et le mode de vinification, il donne des vins aux expressions contrastĂ©es, allant de notes simples (fruitĂ©, beurrĂ©, boisĂ©) jusquâĂ des nuances de fruits secs, de bergamote et de fleurs blanches. Ces arĂŽmes plus complexes sont notamment rencontrĂ©s dans les grands vins de Bourgogne mais demeurent largement inexpliquĂ©s au niveau molĂ©culaire. La mise en Ćuvre conjointe de mĂ©thodes dâanalyse chimique des composĂ©s volatils et dâanalyse sensorielle a permis dâĂ©tablir un lien entre la prĂ©sence de thiols polyfonctionnels connus et les notes dâagrumes et de pierre Ă fusil. En outre, cinq molĂ©cules appartenant Ă la famille des pyrroles et possĂ©dant un arĂŽme de noisette ont Ă©tĂ© identifiĂ©es. Leurs teneurs dans les vins de Chardonnay sont significativement plus Ă©levĂ©es que dans les vins blancs dâautres cĂ©pages. Cependant, elles demeurent nettement infĂ©rieures Ă leur seuil de dĂ©tection. Ces pyrroles nâont donc pas dâimpact direct sur lâarĂŽme des vins de Chardonnay. Toutefois, des dĂ©rivĂ©s thiol de deux molĂ©cules, le 1-mĂ©thylpyrrole-2-mĂ©thanethiol et le 1-Ă©thylpyrrole-2-mĂ©thanethiol, Ă lâodeur de noisette grillĂ©e, ont Ă©tĂ© mis en Ă©vidence pour la premiĂšre fois dans du vin. Les concentrations mesurĂ©es dans des vins de Chardonnay sont supĂ©rieures aux seuils de dĂ©tection de ces deux composĂ©s, ce qui confirme leur influence sur lâarĂŽme de noisette de ces vins
Food chem.
This research investigated the influence of lactic acid bacteria (LAB) strains on ester levels in Bordeaux red wines. These wines were made in five Bordeaux areas in two vintages, using three yeast strains. Malolactic fermentation (MLF) was carried out using industrial starters or indigenous strains, each in triplicate. Ester concentrations were determined by liquid-liquid-extraction- or HS-SPME-GC/MS at various stages in the winemaking process. The levels of most compounds were slightly impacted by LAB, depending on grape variety. Nevertheless, branched hydroxylated esters, such as ethyl 2-hydroxy-3-methylbutanoate and ethyl 2-hydroxy-4-methylpentanoate were the only compounds to be strongly influenced by the bacteria strain, regardless of matrix composition or the yeasts used for alcoholic fermentation. Moreover, the effect observed after MLF persisted over time, for at least 12 months. These esters are apparently important markers of LAB esterase activity. To our knowledge, this was the first time they had been identified in this role