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Gerard Ligerbelair - One of the best experts on this subject based on the ideXlab platform.
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evaporation of droplets in a Champagne wine aerosol
Scientific Reports, 2016Co-Authors: Elisabeth Ghabache, Gerard Ligerbelair, Arnaud Antkowiak, Thomas SeonAbstract:In a single glass of Champagne about a million bubbles nucleate on the wall and rise towards the surface. When these bubbles reach the surface and rupture, they project a multitude of tiny droplets in the form of a particular aerosol holding a concentrate of wine aromas. Based on the model experiment of a single bubble bursting in idealized Champagnes, the key features of the Champagne aerosol are identified. In particular, we show that film drops, critical in sea spray for example, are here nonexistent. We then demonstrate that compared to a still wine, Champagne fizz drastically enhances the transfer of liquid into the atmosphere. There, conditions on bubble radius and wine viscosity that optimize aerosol evaporation are provided. These results pave the way towards the fine tuning of flavor release during sparkling wine tasting, a major issue for the sparkling wine industry.
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a synchronized particle image velocimetry and infrared thermography technique applied to convective mass transfer in Champagne glasses
Experiments in Fluids, 2016Co-Authors: Fabien Beaumont, Gerard Ligerbelair, Yannick Bailly, Guillaume PolidoriAbstract:In Champagne glasses, it was recently suggested that ascending bubble-driven flow patterns should be involved in the release of gaseous carbon dioxide (CO2) and volatile organic compounds. A key assumption was that the higher the velocity of the upward bubble-driven flow patterns in the liquid phase, the higher the volume fluxes of gaseous CO2 desorbing from the supersaturated liquid phase. In the present work, simultaneous monitoring of bubble-driven flow patterns within Champagne glasses and gaseous CO2 escaping above the Champagne surface was performed, through particle image velocimetry and infrared thermography techniques. Two quite emblematic types of Champagne drinking vessels were investigated, namely a long-stemmed flute and a wide coupe. The synchronized use of both techniques proved that the cloud of gaseous CO2 escaping above Champagne glasses strongly depends on the mixing flow patterns found in the liquid phase below.
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it s time to pop a cork on Champagne s proteome
Journal of Proteomics, 2014Co-Authors: Clara Cilindre, Gerard Ligerbelair, Alfonsina Damato, Elisa Fasoli, Pier Giorgio RighettiAbstract:Abstract Champagne is a world-renowned French sparkling wine, which undergoes many steps (fermentation, aging …) for its elaboration. Various compounds might evolve during this winemaking process and thus modify its final quality. Here, we report the first proteome analysis of two standard commercial Champagne wines, using the powerful Combinatorial Peptide Ligand Library (CPLL) technique. Indeed, wine proteins are present in small amounts but they are key compounds, likely to impact on both foam quality and aroma behavior. Forty-three unique gene products were retrieved in a single-varietal Champagne and a blended Champagne. Several proteins from Vitis vinifera together with seven yeast proteins were undoubtedly identified in these Champagne wines. Biological significance The main advantage of CPLLs was the detection of low abundance proteins despite the absence of purification or pre-concentration step. It is an important fact to take into account, since Champagne wines generally contain a low amount of proteins (5–10 mg/L) that implies to usually concentrate wine proteins before 1D or 2D electrophoresis. Most Champagne proteins are grape and yeast glycoproteins which are considered as good foam “promoters”. Some of these proteins might also interact with wine aromas, and thus contribute to the overall quality of Champagne wines. This article is part of a Special Issue entitled: Proteomics of non-model organisms.
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temperature dependence of ascending bubble driven flow patterns found in Champagne glasses as determined through numerical modeling
Advances in Mechanical Engineering, 2013Co-Authors: Fabien Beaumont, Gerard Ligerbelair, Catalin Popa, Guillaume PolidoriAbstract:A numerical modeling of bubble-driven flow patterns in a glass of Champagne has been carried out for three Champagne temperatures, by using the finite-volume method by CFD (computational fluid dynamics). In order to define source terms for flow regime and to reproduce accurately the bubble nucleation process responsible for Champagne effervescence, specific subroutines for the gaseous phase have been added to the main numerical model. These subroutines allow the modeling of bubbles behavior based on semiempirical formulas relating to bubble diameter, mass transfer, velocity, and drag force. Both ascending bubble dynamics and bubble-driven flow patterns dynamics were examined, respectively, 60 s, 180 s, and 300 s after pouring Champagne into the glass. Details and development of the various steps of modeling are presented in this paper, showing that the bubble-driven flow patterns velocities of the liquid phase significantly vary with the Champagne temperature.
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unraveling the evolving nature of gaseous and dissolved carbon dioxide in Champagne wines a state of the art review from the bottle to the tasting glass
Analytica Chimica Acta, 2012Co-Authors: Gerard Ligerbelair, Guillaume Polidori, Virginie ZeninariAbstract:Abstract In Champagne and sparkling wine tasting, the concentration of dissolved CO 2 is indeed an analytical parameter of high importance since it directly impacts the four following sensory properties: (i) the frequency of bubble formation in the glass, (ii) the growth rate of rising bubbles, (iii) the mouth feel, and (iv) the nose of Champagne, i.e., its so-called bouquet . In this state-of-the-art review, the evolving nature of the dissolved and gaseous CO 2 found in Champagne wines is evidenced, from the bottle to the glass, through various analytical techniques. Results obtained concerning various steps where the CO 2 molecule plays a role (from its ingestion in the liquid phase during the fermentation process to its progressive release in the headspace above the tasting glass) are gathered and synthesized to propose a self-consistent and global overview of how gaseous and dissolved CO 2 impact Champagne and sparkling wine science.
Philippe Jeandet - One of the best experts on this subject based on the ideXlab platform.
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evidence for ascending bubble driven flow patterns in Champagne glasses and their impact on gaseous co2 and ethanol release under standard tasting conditions
Bubble Science Engineering & Technology, 2012Co-Authors: Gerard Ligerbelair, Fabien Beaumont, Clara Cilindre, Philippe Jeandet, Guillaume PolidoriAbstract:A simple glass of Champagne or sparkling wine may seem like the acme of frivolity to most of people, but in fact it may rather be considered as a fantastic playground for any fluid physicist or physicochemist. In this tutorial review, some recent investigations on ascending bubble driven flow patterns found in various Champagne glasses, and their impact on gaseous carbon dioxide and ethanol release under standard tasting conditions, are reported. Ascending bubble driven flow patterns found in the bulk of various glasses were evidenced, through laser tomography techniques, which illustrate the fine interplay between ascending bubbles and the fluid around. Moreover, spontaneous and self-organised two-dimensional convective cells were also evidenced at the air/Champagne interface. In addition, the simultaneous monitoring of gaseous CO2 and ethanol in the headspace of both a flute and coupe filled with Champagne was reported, depending on whether or not the glass shows effervescence. Both gaseous CO2 and etha...
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On the Losses of Dissolved CO2 during Champagne Serving
Journal of Agricultural and Food Chemistry, 2010Co-Authors: Gérard Liger-belair, Sandra Villaume, M. Bourget, Herve Pron, Philippe Jeandet, Guillaume PolidoriAbstract:Pouring Champagne into a glass is far from being consequenceless with regard to its dissolved CO2 concentration. Measurements of losses of dissolved CO2 during Champagne serving were done from a bottled Champagne wine initially holding 11.4 ± 0.1 g L−1 of dissolved CO2. Measurements were done at three Champagne temperatures (i.e., 4, 12, and 18 °C) and for two different ways of serving (i.e., a Champagne-like and a beer-like way of serving). The beer-like way of serving Champagne was found to impact its concentration of dissolved CO2 significantly less. Moreover, the higher the Champagne temperature is, the higher its loss of dissolved CO2 during the pouring process, which finally constitutes the first analytical proof that low temperatures prolong the drink’s chill and helps it to retain its effervescence during the pouring process. The diffusion coefficient of CO2 molecules in Champagne and Champagne viscosity (both strongly temperature-dependent) are suspected to be the two main parameters responsible ...
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foaming properties of various Champagne wines depending on several parameters grape variety aging protein and co2 content
Analytica Chimica Acta, 2010Co-Authors: Clara Cilindre, Sandra Villaume, Gerard Ligerbelair, Philippe Jeandet, Richard MarchalAbstract:Abstract A comparison of the foaming parameters of various Champagne wines was undergone with two well distinct methods: (i) a classical gas-sparging method providing standardized but artificial effervescence conditions (the so-called Mosalux), and (ii) a computer assisted viewing equipment (CAVE), much closer to the real Champagne tasting conditions. The latter one is the only apparatus which enables a thorough descriptive analysis of foam behavior, during the pouring process of a sparkling wine, and from the end of its pouring. Various Champagne wines elaborated from two grape varieties (Chardonnay and Pinot Meunier) and having experienced different aging-periods (15 months and 5 years) were analyzed and compared to a model sparkling wine, elaborated from a model base wine (devoid of grape colloids). The CO 2 and protein content was also investigated to discuss the foaming behavior of these wines. A significant loss of the CO 2 content during aging was observed and might be the reason for the worse foaming properties of the old Champagnes, as determined with CAVE. It is worth noting that contradictory foaming parameters were obtained through the Mosalux method, which is indeed more intrusive than the CAVE, and finally far from the real Champagne tasting conditions, since it requires filtration and Champagne degassing prior experiment.
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co2 volume fluxes outgassing from Champagne glasses the impact of Champagne ageing
Analytica Chimica Acta, 2010Co-Authors: Gerard Ligerbelair, Clara Cilindre, Sandra Villaume, Philippe JeandetAbstract:Abstract It was demonstrated that CO 2 volume fluxes outgassing from a flute poured with a young Champagne (elaborated in 2007) are much higher than those outgassing from the same flute poured with an older Champagne (elaborated in the early 1990s). The difference in dissolved-CO 2 concentrations between the two types of Champagne samples was found to be a crucial parameter responsible for differences in CO 2 volume fluxes outgassing from one Champagne to another. Nevertheless, it was shown that, for a given identical dissolved-CO 2 concentration in both Champagne types, the CO 2 volume flux outgassing from the flute poured with the old Champagne is, in average, significantly lower than that outgassing from the flute poured with the young one. Therefore, CO 2 seems to “escape” more easily from the young Champagne than from the older one. The diffusion coefficient of CO 2 in both Champagne types was pointed as a key parameter to thoroughly determine in the future, in order to unravel our experimental observation.
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unraveling different chemical fingerprints between a Champagne wine and its aerosols
Proceedings of the National Academy of Sciences of the United States of America, 2009Co-Authors: Gerard Ligerbelair, Clara Cilindre, Marianna Lucio, Istvan Gebefugi, Regis D Gougeon, Philippe Jeandet, Philippe SchmittkopplinAbstract:As Champagne or sparkling wine is poured into a glass, the myriad of ascending bubbles collapse and radiate a multitude of tiny droplets above the free surface into the form of very characteristic and refreshing aerosols. Ultrahigh-resolution MS was used as a nontargeted approach to discriminate hundreds of surface active compounds that are preferentially partitioning in Champagne aerosols; thus, unraveling different chemical fingerprints between the Champagne bulk and its aerosols. Based on accurate exact mass analysis and database search, tens of these compounds overconcentrating in Champagne aerosols were unambiguously discriminated and assigned to compounds showing organoleptic interest or being aromas precursors. By drawing a parallel between the fizz of the ocean and the fizz in Champagne wines, our results closely link bursting bubbles and flavor release; thus, supporting the idea that rising and collapsing bubbles act as a continuous paternoster lift for aromas in every glass of Champagne.
Guillaume Polidori - One of the best experts on this subject based on the ideXlab platform.
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a synchronized particle image velocimetry and infrared thermography technique applied to convective mass transfer in Champagne glasses
Experiments in Fluids, 2016Co-Authors: Fabien Beaumont, Gerard Ligerbelair, Yannick Bailly, Guillaume PolidoriAbstract:In Champagne glasses, it was recently suggested that ascending bubble-driven flow patterns should be involved in the release of gaseous carbon dioxide (CO2) and volatile organic compounds. A key assumption was that the higher the velocity of the upward bubble-driven flow patterns in the liquid phase, the higher the volume fluxes of gaseous CO2 desorbing from the supersaturated liquid phase. In the present work, simultaneous monitoring of bubble-driven flow patterns within Champagne glasses and gaseous CO2 escaping above the Champagne surface was performed, through particle image velocimetry and infrared thermography techniques. Two quite emblematic types of Champagne drinking vessels were investigated, namely a long-stemmed flute and a wide coupe. The synchronized use of both techniques proved that the cloud of gaseous CO2 escaping above Champagne glasses strongly depends on the mixing flow patterns found in the liquid phase below.
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Unveiling self-organized two-dimensional (2D) convective cells in Champagne glasses
Journal of Food Engineering, 2016Co-Authors: Fabien Beaumont, Gérard Liger-belair, Guillaume PolidoriAbstract:Abstract Under standard tasting conditions, homogeneous stirring of Champagne under the action of rising bubbles confers an advantage compared with a situation where the liquid phase would be at rest. Convection helps renewal of the immediate subsurface layers with Champagne from the bulk, thus facilitating the evaporation of volatile organic compounds, and therefore better revealing the Champagne “bouquet”. Here, spontaneous and self-organized two-dimensional convective cells were evidenced (at the air/Champagne interface) in a laser-etched coupe poured with Champagne, through laser tomography. Various regimes were evidenced, from a highly unstable 8-cells regime, to a very stable 4-cells regime. Moreover, by blowing air bubbles through a nozzle positioned at the bottom of a goblet poured with water, and by using Particle Image Velocimetry, similar 2D convective cells were also evidenced at the air/water interface, thus pointing out the crucial role of ascending bubbles behind the formation of self-organized 2D convection cells.
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Convective Mass Transfer in a Champagne Glass
Mass Transfer - Advances in Sustainable Energy and Environment Oriented Numerical Modeling, 2013Co-Authors: Fabien Beaumont, Gérard Liger-belair, Guillaume PolidoriAbstract:Legend has it that the Benedictine monk Dom Pierre Perignon discovered the Champagne method for making sparkling wines more than 300 years ago. As it happens, a paper pre‐ sented to the Royal Society in London described the Champagne production method in 1662, six years before Perignon ever set foot in a monastery. In fact, Perignon was first tasked with keeping bubbles out of wine, as the effervescence was seen as vulgar at the time. But then tastes changed and fizz became fashionable, so Perignon’s mandate was reversed; he went on to develop many advances in Champagne production, including ways to in‐ crease carbonation. In any case, the process was not regularly used in the Champagne re‐ gion of France to produce sparkling wine until the 19th century. Since that time, Champagne has remained the wine of celebration, undoubtedly because of its bubbling behavior.
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temperature dependence of ascending bubble driven flow patterns found in Champagne glasses as determined through numerical modeling
Advances in Mechanical Engineering, 2013Co-Authors: Fabien Beaumont, Gerard Ligerbelair, Catalin Popa, Guillaume PolidoriAbstract:A numerical modeling of bubble-driven flow patterns in a glass of Champagne has been carried out for three Champagne temperatures, by using the finite-volume method by CFD (computational fluid dynamics). In order to define source terms for flow regime and to reproduce accurately the bubble nucleation process responsible for Champagne effervescence, specific subroutines for the gaseous phase have been added to the main numerical model. These subroutines allow the modeling of bubbles behavior based on semiempirical formulas relating to bubble diameter, mass transfer, velocity, and drag force. Both ascending bubble dynamics and bubble-driven flow patterns dynamics were examined, respectively, 60 s, 180 s, and 300 s after pouring Champagne into the glass. Details and development of the various steps of modeling are presented in this paper, showing that the bubble-driven flow patterns velocities of the liquid phase significantly vary with the Champagne temperature.
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Champagne cork popping revisited through high-speed infrared imaging: The role of temperature
Journal of Food Engineering, 2013Co-Authors: Gérard Liger-belair, Clara Cilindre, M. Bourget, Herve Pron, Guillaume PolidoriAbstract:Abstract Champagne cork popping out of standard 75 cL bottles was examined through high-speed infrared imaging for three various Champagne temperatures (namely, 4, 12, and 18 °C). The cloud of gaseous CO 2 gushing out of the bottleneck while cork popping (invisible in the visible light spectrum) was visualized. Both the volume of gaseous CO 2 gushing out of the bottleneck, and its overall dynamic behavior were found to depend on the Champagne temperature. The velocity of the cork popping out of the bottleneck was also measured, and found to logically increase with the Champagne temperature. By considering that gases under pressure in the bottleneck experience adiabatic expansion while cork popping, a thermodynamic model was built that accounts for the major physical parameters that influence the volume of gaseous CO 2 gushing out of the bottleneck, its drop of temperature, and its total energy released while cork popping. Only a small fraction of the total energy released while cork popping was found to be converted into the form of cork’s kinetic energy (only about 5%), whatever the Champagne temperature.
Clara Cilindre - One of the best experts on this subject based on the ideXlab platform.
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it s time to pop a cork on Champagne s proteome
Journal of Proteomics, 2014Co-Authors: Clara Cilindre, Gerard Ligerbelair, Alfonsina Damato, Elisa Fasoli, Pier Giorgio RighettiAbstract:Abstract Champagne is a world-renowned French sparkling wine, which undergoes many steps (fermentation, aging …) for its elaboration. Various compounds might evolve during this winemaking process and thus modify its final quality. Here, we report the first proteome analysis of two standard commercial Champagne wines, using the powerful Combinatorial Peptide Ligand Library (CPLL) technique. Indeed, wine proteins are present in small amounts but they are key compounds, likely to impact on both foam quality and aroma behavior. Forty-three unique gene products were retrieved in a single-varietal Champagne and a blended Champagne. Several proteins from Vitis vinifera together with seven yeast proteins were undoubtedly identified in these Champagne wines. Biological significance The main advantage of CPLLs was the detection of low abundance proteins despite the absence of purification or pre-concentration step. It is an important fact to take into account, since Champagne wines generally contain a low amount of proteins (5–10 mg/L) that implies to usually concentrate wine proteins before 1D or 2D electrophoresis. Most Champagne proteins are grape and yeast glycoproteins which are considered as good foam “promoters”. Some of these proteins might also interact with wine aromas, and thus contribute to the overall quality of Champagne wines. This article is part of a Special Issue entitled: Proteomics of non-model organisms.
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Champagne cork popping revisited through high-speed infrared imaging: The role of temperature
Journal of Food Engineering, 2013Co-Authors: Gérard Liger-belair, Clara Cilindre, M. Bourget, Herve Pron, Guillaume PolidoriAbstract:Abstract Champagne cork popping out of standard 75 cL bottles was examined through high-speed infrared imaging for three various Champagne temperatures (namely, 4, 12, and 18 °C). The cloud of gaseous CO 2 gushing out of the bottleneck while cork popping (invisible in the visible light spectrum) was visualized. Both the volume of gaseous CO 2 gushing out of the bottleneck, and its overall dynamic behavior were found to depend on the Champagne temperature. The velocity of the cork popping out of the bottleneck was also measured, and found to logically increase with the Champagne temperature. By considering that gases under pressure in the bottleneck experience adiabatic expansion while cork popping, a thermodynamic model was built that accounts for the major physical parameters that influence the volume of gaseous CO 2 gushing out of the bottleneck, its drop of temperature, and its total energy released while cork popping. Only a small fraction of the total energy released while cork popping was found to be converted into the form of cork’s kinetic energy (only about 5%), whatever the Champagne temperature.
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More on the Losses of Dissolved CO2 during Champagne Serving: Toward a Multiparameter Modeling
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Gérard Liger-belair, Maryline Parmentier, Clara CilindreAbstract:Pouring Champagne into a glass is far from being inconsequential with regard to the dissolved CO2 concentration found in Champagne. Three distinct bottle types, namely, a magnum bottle, a standard bottle, and a half bottle, were examined with regard to their loss of dissolved CO2 during the service of successively poured flutes. Whatever the bottle size, a decreasing trend is clearly observed with regard to the concentration of dissolved CO2 found within a flute (from the first to the last one of a whole service). Moreover, when it comes to Champagne serving, the bottle size definitely does matter. The higher the bottle volume, the better its buffering capacity with regard to dissolved CO2 found within Champagne during the pouring process. Actually, for a given flute number in a pouring data series, the concentration of dissolved CO2 found within the flute was found to decrease as the bottle size decreases. The impact of Champagne temperature (at 4, 12, and 20 °C) on the losses of dissolved CO2 found in s...
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evidence for ascending bubble driven flow patterns in Champagne glasses and their impact on gaseous co2 and ethanol release under standard tasting conditions
Bubble Science Engineering & Technology, 2012Co-Authors: Gerard Ligerbelair, Fabien Beaumont, Clara Cilindre, Philippe Jeandet, Guillaume PolidoriAbstract:A simple glass of Champagne or sparkling wine may seem like the acme of frivolity to most of people, but in fact it may rather be considered as a fantastic playground for any fluid physicist or physicochemist. In this tutorial review, some recent investigations on ascending bubble driven flow patterns found in various Champagne glasses, and their impact on gaseous carbon dioxide and ethanol release under standard tasting conditions, are reported. Ascending bubble driven flow patterns found in the bulk of various glasses were evidenced, through laser tomography techniques, which illustrate the fine interplay between ascending bubbles and the fluid around. Moreover, spontaneous and self-organised two-dimensional convective cells were also evidenced at the air/Champagne interface. In addition, the simultaneous monitoring of gaseous CO2 and ethanol in the headspace of both a flute and coupe filled with Champagne was reported, depending on whether or not the glass shows effervescence. Both gaseous CO2 and etha...
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foaming properties of various Champagne wines depending on several parameters grape variety aging protein and co2 content
Analytica Chimica Acta, 2010Co-Authors: Clara Cilindre, Sandra Villaume, Gerard Ligerbelair, Philippe Jeandet, Richard MarchalAbstract:Abstract A comparison of the foaming parameters of various Champagne wines was undergone with two well distinct methods: (i) a classical gas-sparging method providing standardized but artificial effervescence conditions (the so-called Mosalux), and (ii) a computer assisted viewing equipment (CAVE), much closer to the real Champagne tasting conditions. The latter one is the only apparatus which enables a thorough descriptive analysis of foam behavior, during the pouring process of a sparkling wine, and from the end of its pouring. Various Champagne wines elaborated from two grape varieties (Chardonnay and Pinot Meunier) and having experienced different aging-periods (15 months and 5 years) were analyzed and compared to a model sparkling wine, elaborated from a model base wine (devoid of grape colloids). The CO 2 and protein content was also investigated to discuss the foaming behavior of these wines. A significant loss of the CO 2 content during aging was observed and might be the reason for the worse foaming properties of the old Champagnes, as determined with CAVE. It is worth noting that contradictory foaming parameters were obtained through the Mosalux method, which is indeed more intrusive than the CAVE, and finally far from the real Champagne tasting conditions, since it requires filtration and Champagne degassing prior experiment.
Roger Douillard - One of the best experts on this subject based on the ideXlab platform.
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Relations between the air/wine adsorption layer and the bubble collar stability in experimental and commercial Champagnes
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2009Co-Authors: Khalil Abou Saleh, Laurence Foulon, Véronique Aguié-béghin, Michel Valade, Roger DouillardAbstract:A bubble collar is expected on a Champagne flute. The mechanisms of formation of that collar have been tackled. by an integrated approach including the analysis of the adsorption layer occurring at the air/Champagne interface, the measurement of the lifetime of isolated air bubbles blown in degassed Champagne and the kinetics of the area covered by the collar after pouring in a flute. In the case of experimental Champagnes where the surface concentration of the adsorption layer is varied, very good correlations were observed between the adsorption layer parameters, the lifetime of isolated bubbles and the kinetics of the collar area. These correlations were expected from the physics of bubbles and foams. The same parameters were determined on commercial samples bought in supermarkets. The adsorption layer concentrations were found to be in the same range as those of the experimental products, the lifetimes of isolated bubbles were often shorter and the area of the collar was much less stable than with the experimental samples. Moreover. with the commercial samples, no correlations were noticed between the measured parameters. It is hypothesised that the main differences between the experimental and the commercial samples come from the wine making technologies including the ageing on lees and in bottle.
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Characterization by optical measurements of the effects of some stages of Champagne technology on the adsorption layer formed at the gas/wine interface
Langmuir, 2007Co-Authors: K. Abou Saleh, Laurence Foulon, Véronique Aguié-béghin, Michel Valade, Roger DouillardAbstract:Abstract: This study analyzes the effects of some important factors of Champagne technology on the ellipticity and Brewster angle microscopy (BAM) of the air/Champagne interface in view of using the optical properties of the adsorption layer of base wine to forecast the stability of the Champagne bubble collar. Using standard, ultrafiltered, and ultraconcentrated wines it was observed that Champagne can lose amphiphilic macromolecules which adsorb on the inner glass wall of the bottle during storage, particles such as dead yeasts can adhere to the adsorption layer, a weak increase of the ethanol content during bottle fermentation can reduce significantly the ellipticity of the adsorption layer, and CO2 has no significant effect on the properties of that layer. Surprisingly, no visible differences of the adsorption layer were noticed between the experimental Champagnes of the 2004 vintage of three vine varieties (Chardonnay, Pinot noir, and Pinot meunier). From analysis of all samples it is proposed that the mean value and standard deviation of the ellipticity measured during 30 min after pouring the wine in a Petri dish are physical quantities which satisfactorily characterize the adsorption layer of Champagne. When needed, further characterization of the adsorption layer may be obtained by a detailed analysis of the kinetics of ellipticity during the same period and inspection of the BAM images of the interface.
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Champagne Bubbles : Isolation and Characterization of amphiphilic macromolecules responsible for the stability of the collar at the Champagne / air interface
arXiv: Chemical Physics, 2007Co-Authors: Véronique Aguié-béghin, Zouleika Abdallah, Véronique Aguié, Roger Douillard, Christophe BliardAbstract:The effervescence and the stability of the ring of fine bubbles crowning the surface of a Champagne glass, the “collar”, constitute one of the hallmarks of Champagne. Defects in the stability of this collar are not well understood and account for a significant proportion of bottle return. This study aims to better understand the surface properties of Champagne wine such that the foaming properties can be controlled more effectively. Early studies on Champagne foaming properties using the “Mosalux” measurement of the foam level formed by air flow in Champagne through fritted glass pointed to a link between protein concentration and foam level [5] but no satisfactory correlation between protein content and foam stability was established. Later measurements were conducted with either ultra-filtrates or ultra-concentrates [4]. The authors demonstrated that macromolecule concentration was an essential parameter in the foam stability. The stability of bubbles is usually ascribed to the presence of an adsorption layer formed at the gas/liquid interface and its properties [3]. Thus surface properties of Champagne were analysed by ellipsometry and tensiometry. Measurements conducted on base wine, on ultra-filtered base wines and degassed Champagne samples showed the presence of an adsorption layer formed at the air/Champagne wine interface [6] and that adsorption layer being composed of macromolecules in a 104 to 105 molecular range [7]. Previous studies on Champagne wine macromolecules had shown wine macromolecules to be mostly proteins and polysaccharides [8] with very little insight as to the chemical constitution. The present study describes the isolation and characterization of these macromolecules and their link with the adsorption layer.
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Phase separation in molecular layers of macromolecules at the Champagne-air interface
Journal of Microscopy, 2004Co-Authors: Nicolas Péron, Alain Cagna, Michel Valade, Jean Meunier, Roger DouillardAbstract:Bubble and foam stability, which are essential for the hallmark of Champagne, rely on the concentration of amphiphilic macromolecules originating from the grape, which form molecular layers at the interface between Champagne and gas. Ellipsometry and Brewster angle microscopy experiments were conducted at the air-Champagne interface to analyse the lateral organization of the layers of macromolecules. Several kinds of phase separations - leading in some cases to two-dimensional foams - were identified. At the beginning of layer formation, condensed domains develop at the expense of dilute domains. Thereafter, phase separations occur within the condensed domains. These findings may allow advances in the implementation of methods predicting bubble and foam stability of Champagnes.
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layers of macromolecules at the Champagne air interface and the stability of Champagne bubbles
Langmuir, 2001Co-Authors: Nicolas Péron, And Veronique Aguiebeghin, Alain Cagna, Michel Valade, Christophe Bliard, Roger DouillardAbstract:Adsorption layers formed at the air/degassed Champagne interface were characterized by ellipsometry and by surface tension measurements of the samples diluted four times with water. Ultrafiltration of the samples showed that the adsorption layer is mainly formed by macromolecules with molecular masses in the range 104 to 105. Nonsparkling base wine was ultrafiltrated with a molecular mass cutoff of 104, and the resulting ultraconcentrate and ultrafiltrate were combined to yield experimental base wines with adjusted macromolecular content. These samples were submitted to bottle fermentation. The resulting experimental Champagnes were tested for the extent of their bubble collar and for their surface properties. A good correlation was found between the two sets of data.