Dissertations / Theses: 'Flavour interaction'

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Bains, Gurjeet Singh. "Cocoa flavour : the interaction of pyrazines with carboxylic acids." Thesis, Queensland University of Technology, 1995. https://eprints.qut.edu.au/36919/1/36919_Bains_1995.pdf.

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The essential ingredient of chocolate is a product of the cocoa tree and is used world-wide in confectionary as a flavorant and as an ingredient of beverages. The flavour and odour of chocolate varies according to the source of the cocoa but must be free from objectionable or unpleasant characteristics. With the increasing demand for this product, chocolate producing companies have invested heavily in cocoa plantations in a number of areas in the world This has included South East Asia and Papua New Guinea. Cocoa from these sources suffers from high acidity and low chocolate flavour. It is felt that the presence of acids in excessive amounts can effect the flavour not only by imparting their own flavour but also by reacting with the basic flavour components which are formed during roasting. Such a group of compounds is pyrazines which make an essential contribution to chocolate flavour. The objective for the work in this thesis was to investigate the extent of reaction between the carboxylic acids and the methylpyrazines commonly found in different cocoas through the study of model systems in aqueous and non-aqueous environments. This involved the use of static gas chromatographic headspace analysis and 13C NMR :.pectroscopy. Data obtained from these techniques not only allowed observations on the reaction of pyrazines with carboxylic acids but also the calculation of the pKa of the pyrazines. It was shown that the acids which are commonly found in cocoa were present in sufficient concentration to reduce the concentration of free trimethylpyrazine and tetramethylpyrazine. The other methylpyrazines were not sufficiently basic to react with these acids to any extent and little or none of the pyrazine would be bound up in salt formation. The headspace analysis technique gave pKa values for the various methylsubstituted pyrazines which were consistently lower than those determined by other methods and reported in literature. However, when these values were normalised with respect to pyridine the pKa values agreed with the published values which had been determined by other techniques. The use of 13C NMR spectroscopy for the determination of the pKa value of pyrazine has been reported in literature. This technique was extended in this investigation to all other methylpyrazines. The results obtained were reproducible and compared favourably with the reported values. The analysis of Ghana and South East Asian cocoa liquors confirmed the unpublished results of Holm in which the concentration of alkylpyrazine in the latter were significantly higher than in the former. The application of the headspace analysis technique developed was used in a preliminary assessment of the alkylpyrazine concentrations in a number of chocolate tasters which had been prepared from cocoa liquors which originated from a number of South East Asian sources. Insufficient data was obtained to deduce any correlation with the taste panels scores of the samples. However, the method showed potential and warrants further investigation.

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Moon, Soo Yeun. "Elucidation of the interaction between soy protein isolate and simulated beef flavour." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/30959.

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The objective of this research was to explore interactions between aroma compounds in simulated beef flavour (SBF) and soy protein isolate (SPI) that may be involved in the suppression of beefy notes in SBF by SPI. A sensitive and reproducible headspace solid phase microextraction (HSSPME) was established to isolate volatile compounds in SBF for analysis by gas chromatography (GC). Volatile and odour-active compounds in SBF were qualitatively evaluated by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O) using detection frequency method, respectively. A total of 70 compounds were tentatively identified including three furans, six S-heterocyclic compounds, ten N-heterocyclic compounds, six aldehydes, three alcohols, and two esters. Of 49 volatile compounds detected in the sniffing port of GC-O, the most odour-active included 2-methyl-3-furanthiol, delta-3-carene, alphaterpinene, 2-ethyl-3,6-dimethylpyrazine, and several unidentified odourants. Descriptive analysis (DA) along with GC analysis was conducted to investigate changes in SBF aroma characteristics upon addition of SPI. Five attributes (beefy, roasted, yeasty, soymilk-like and cereal) were selected to assess various mixtures of SBF and SPI. The results from DA confirmed that "roasted", "beefy" and "yeasty" notes were highly positively correlated with SBF concentration, and the beefy related notes were substantially suppressed by increasing SPI content. Fifteen peaks from GC analysis were selected as indicator peaks to represent beef attribute in the mixtures of SPI and SBF. Changes in the release of beefy aroma components of SBF by addition of ingredients (glucosamine, sucrose, ascorbic acid, and/or polyethylene glycol) to SPI and the changes in SPI protein structure induced by the ingredients were investigated. The reduction of disulfide bonds, increased surface hydrophobicity and increased unordered structure in SPI containing ascorbic acid alone or with polyethylene glycol, along with increased GC peak areas of indicator peaks in those SPI-SBF mixtures, were found to be associated with an increase in the perceived beef characteristic attributes in descriptive analysis. These results provide the basis for further research to elucidate strategies maximizing perception of beefy aroma in soy based products.
Land and Food Systems, Faculty of
Graduate

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Maarman, Brenton Christopher. "Interaction between wine yeast and malolactic bacteria and the impact on wine aroma and flavour." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86703.

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Thesis (MScAgric)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Wine is a product of the fermentation of grape juice. Alcoholic fermentation is mainly conducted by the yeast Saccharomyces cerevisiae which metabolises grape sugars to mainly ethanol, CO2 and glycerol. Aside from these primary fermentation compounds, the yeast also produces many secondary metabolic by-products that are important to wine quality and style. Malolactic fermentation (MLF) is a secondary fermentation that normally occurs after alcoholic fermentation. Lactic acid bacteria (LAB) are responsible for the conversion of malic acid to lactic acid and CO2 during MLF, which is important for wine deacidification and also contributes to microbial stability. Malolactic fermentation and LAB strains can also influence the aroma profile of wines. The main genera associated with this process are Oenococcus, Lactobacillus, Pediococcus and Leuconostoc. Oenococcus oeni is the main species associated with MLF because it is able to survive the harsh physiochemical environment of winemaking. Recently L. plantarum has also been introduced as a commercial MLF starter culture. Research has started to focus on the potential of wine yeast and LAB interactions or combinations to alter the wine aroma profile via the production and/or degradation of aroma compounds. The overriding goal of this study is to unravel the interactions between wine yeast and different LAB strains and their impact on wine aroma and flavour. The first aim was to assess LAB growth during co- and sequential inoculation strategies, the ability to complete MLF and the impact on the production of aroma compounds in combination with two different yeast strains in a medium containing full complement of nitrogen supplementation. Malolactic fermentation was successful in the different inoculation strategies and the bacterial combination (L. plantarum and O. oeni) completed MLF in the shortest time. The impact of the bacterial strains on the modification of aroma compounds was bigger in co- than sequential inoculation. A general increase in total esters (contributing to the fruity character of wines) especially ethyl lactate and ethyl acetate was observed. The production of esters, volatile fatty acids and higher alcohols proved to be dependent on either the yeast strain used and/or the LAB strains used. The second aim of the research was to assess the effect of NH4Cl (ammonium) and amino acids supplementation on yeast and LAB strains (both in co- and sequential inoculation strategies) and the impact on the aroma profile of the fermented must. Fermentations supplemented with ammonia as sole nitrogen source showed the highest total bacterial growth in terms of cell numbers. Malolactic fermentation was completed in the shortest time with O. oeni and the bacterial combination inoculums. The co-inoculated strategies in combination with amino acids supplementation showed the biggest impact on the aroma compound profiles of the different fermentation strategies and bacterial treatments. A general increase in total esters was observed for NH4Cl additions with ethyl lactate and ethyl acetate showing the highest concentrations. The concentration of esters, volatile fatty acids and higher alcohols were strongly influenced by the yeast and the single LAB strains used. The results generated from this study showed that the chemical composition of the fermentation medium and the selection of yeast and LAB strains are important because these factors have an influence on the aroma and flavour profiles of wines.
AFRIKAANSE OPSOMMING: Wyn is die produk van gefermenteerde druiwe. Die gis, Saccharomyces cerevisiae is verantwoordelik vir alkoholiese fermentasies waar druiwe suikers na hoofsaaklik etanol, CO2 en gliserol gemetaboliseer word. Die gis produseer ook sekondêre metaboliete wat ‘n belangrike bydrae lewer tot wynstyl en kwaliteit. Appelmelksuurgisting (AMG) is ‘n sekondêre fermentasie wat gewoonlik na alkoholiese fermentasie plaasvind. Melksuurbakterieë (MSB) speel ‘n sleutel rol in die omskakeling van appelsuur na melksuur en CO2 gedurende AMG. Hierdie fermentasie lei tot ‘n afname in die suurheidsgraad en verbeter die mikrobiese stabiliteit van die wyn. Appelmelksuurgisting en MSB rasse kan die aroma- en geurprofiel van wyne beïnvloed. Die belangrikste genera wat met AMG geassosieer word is Oenococcus, Lactobacillus, Pediococcus en Leuconostoc. Oenococcus oeni is die mees algemene ras wat vir AMG gebruik word omdat dit in uiterste wyn toestande kan oorleef. Mees onlangs is Lactobacillus plantarum as kommersiële aanvangskultuur vir AMG geïdentifiseer. Navorsing het onlangs meer begin fokus op gis en MSB interaksie of kombinasies as ‘n strategie om die aroma profiele van wyne te verander. Die hoofdoel van die studie is om die interaksie tussen wyngiste en verskillende MSB rasse en die effek op die aroma profile van wyne te bestudeer. Die eerste doelwit was om die impak van die twee giste op die groei en AMG vermoeë van MSB gedurende ko- en sekwensiële inokulasie praktyke en die impak op die produksie van aroma komponente, in ‘n medium wat die volledige stikstof aanvullings bevat, te bestudeer. Appelmelksuurgisting was suksesvol in die verskillende inokulasie praktyke en die bakteriese kombinasie (L. plantarum en O. oeni) het AMG in die kortste tyd voltooi. Die impak van die bakteriese rasse op die modifikasie van die aroma komponente was groter met ko- as sekwensiële inokulasies. Daar was ‘n toename in die totale esterkonsentrasies veral in etiellaktaat en etielasetaat. Die produksie van esters, vlugtige vetsure en hoër alkohole word beïnvloed deur die gisras en MSB rasse wat gebruik word. Die tweede doelwit was om die impak van NH4Cl (ammonium) en aminosure aanvullings op die gis- en MSB rasse gedurende ko- en sekwensiële inokulasie strategieë te bepaal. Melksuurbakterieë se groei was beter met die ammonium aanvulling. Appelmelksuurgisting was in die kortste tyd voltooi met O. oeni en die bakteriese kombinasie. Die ko-inokulasie praktyke in kombinasie met die kompleks aminosure aanvulling het die grootste impak op die produksie van aroma komponente gehad. Daar was weereens ‘n toename in die totale esterkonsentrasies vir die NH4Cl aanvulling, veral in etiellaktaat en etielasetaat. Die gis en MSB rasse speel ‘n rol by die produksie en konsentrasies van esters, vlugtige vetsure en hoër alkohole. Die resultate van hierdie studie bewys dat die chemiese samestelling van die fermentasie medium, die seleksie van gis- en MSB rasse is belangrik omdat hierdie faktore die aroma en geur profiele van wyne beïnvloed.

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Thomsen, Maiken. "Perception de l'arôme du fromage à pâte pressée non cuite." Thesis, Dijon, 2012. http://www.theses.fr/2012DIJOS120.

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La perception de la flaveur des aliments dépend de la perception de plusieurs composés en mélange dans des proportions équilibrées. Interactions perceptives entre différents odorants ainsi que la libération dynamique des odorants par la matrice alimentaire sont les principaux facteurs qui influencent la perception globale. L’objectif de cette thèse de doctorat était d’étudier la perception du mélange d’odorants qui constituent l’arôme du fromage à pâte pressée, en prenant en compte les interactions perceptives et la dynamique de libération des composés par la matrice. Une stratégie, comprenant une caractérisation complète des odorants des fromages, suivie d’une recombinaison qualitative et d’une étude détaillée des rôles respectifs des composés clés, et finalement la prise en compte de la dynamique de libération par incorporation des composés dans une matrice fromagère, a été appliquée. Des caractérisations approfondies sensorielles et instrumentales nous ont permis de mettre en évidence des relations entre la perception sensorielle et la composition des composés volatils et proposer des hypothèses. La recombinaison des différents composés a été testée afin d’étudier le rôle de chacun en mélange. Aidés par des apprentis aromaticiens durant la phase des recombinaisons nous avons pu observer particulièrement que 12 composés étaient très importants pour l’odeur du fromage. Par la suite nous avons étudié des interactions entre odeurs en appliquant des techniques de stimulation odorante en phase gazeuse, puis la dynamique de libération des composés en incorporant l’arôme dans une matrice fromagère par des techniques permettant de mesurer la quantité libérée en fonction du temps
Perception of the aroma of food products depends both the chemical composition of food and human neurophysiology. The perception of food flavour, including cheese often relies on the perception of several aroma compounds in mixture in balanced proportions. Perceptual interactions among aroma compounds in mixtures and also the release of aroma compounds from the food product are the main factors that influence the global perceived aroma of food. Hence, the objective of this PhD study was to investigate the mixture of aroma compounds representing the aroma of semi-hard cheese by taking into account perceptual interactions among odorants and the dynamic release of the compounds by the cheese matrix. A strategy involving a complete characterisation of the cheeses followed by a recombination and investigation of the role of the key-aroma compounds and the dynamic release of the aroma compounds from the cheese matrix was taken into account. Comparison of the sensory and instrumental characteristics was made in order to highlight relationships between sensory perception of the aroma and the volatile composition of the cheeses and thus point out the molecular origins of the perceived cheese aroma. Recombination of selected aroma compounds was tested, in order to study the role of each aroma compound within the mixture. Especially 12 compounds seemed important for the semi-hard cheese aroma. To investigate the odour-odour interactions, different odour-stimulation tools were applied and dynamic release of aroma compounds was taken into account by incorporating the aroma compounds into a cheese matrix by different techniques allowing measuring the quantities released as function of time

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Tietz, Melanie. "Starch-flavour interactions : impact on flavour retention and release in model food systems /." Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17517.

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Symoneaux, Ronan. "Le "goût" du cidre : Exploration des interactions entre les composés chimiques et les caractéristiques organoleptiques des cidres." Thesis, Angers, 2015. http://www.theses.fr/2015ANGE0027/document.

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L’objectif de cette thèse est d’étudier l’influence des procyanidines, du sucre, de l’acide, de l’éthanol, des arômes et du CO2 sur le goût sucré, l’acidité, l’amertume et l’astringence du cidre. Des plans d’expériences ont été réalisés en solutions modèles et avec des cidres commerciaux afin d’étudier les effets directs des composés chimiques mais également les interactions entre eux sur la perception de ces quatre attributs sensoriels.Les résultats confirment le rôle déterminant des procyanidines,du sucre, de l’acide, de l’éthanol sur les quatre caractéristiques organoleptiques étudiées. Il faut souligner l’influence de la concentration et du degré de polymérisation des procyanidines qui modifient les perceptions sucrées et acides. Ces travaux montrent également une sur expression de l’amertume pour les procyanidines tétramères et pentamères mais seulement pour des concentrations de 750 mg/L, et une interaction entre la concentration et le degré de polymérisation pour l’astringence.Excepté pour l’amertume, la présence de gaz carbonique modifie la perception sensorielle des échantillons testés :l’astringence augmente, le goût sucré diminue pour les solutions les plus sucrées et finalement, il semble que les dégustateurs aient plus de mal percevoir les différences d’acidité entre les échantillons. Enfin, les arômes peuvent modifier la perception du goût sucré de certains cidres par un effet de congruence. En effet, la présence de notes aromatiques « fruitées » est accompagnée d’une surévaluation du goût sucré et des notes « terreux-foin »conduisent à une diminution du goût sucré perçu. Cependant,ce phénomène de congruence semble être concentration dépendante
The aim of this thesis is to study the influence of procyanidins, sugar, acid, ethanol, CO2 and aroma on the perception of sweetness, sourness, bitterness and astringency of cider. Experimental designs were carried out with model solutions or commercial ciders to study the direct effects and interactions of the chemical compounds on these four organoleptic characteristics.The results confirm the key role of procyanidins, sugar,acid, ethanol on the four organoleptic characteristics. We notably underline the influence of procyanidins concentration and polymerization degree on sweetness and sourness when literature only focused on bitterness and astringency. Our works also indicate an overexpression of bitterness for tetrameric and pentameric procyanidins but only for concentration of 750 mg/L, and an interaction between concentration and polymerization degree for astringency.Except for bitterness, adding CO2 modify sensorycharacteristics of the samples: astringency increases,sweetness decreases for the sweetest solutions and it seems that tasters have more difficulty perceive acidity differences between samples. Finally, the aromatic characteristics can modify sweetness perception of some ciders due to acongruency effect. Indeed, “fruity” notes generate an over evaluation of sweetness when “hay-earthy”aromas lead to a decrease of this taste. Nevertheless,this phenomenon appears to be concentration dependent

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Hollowood, Tracey Ann. "Taste-aroma-matrix interactions determine flavour perception." Thesis, University of Nottingham, 2002. http://eprints.nottingham.ac.uk/10262/.

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A newly recruited sensory panel was trained in magnitude estimation and time intensity sensory techniques. Sensory analysis was combined with instrumental analysis using MS Nose to investigate the relationship between stimulus and perception using simple model food systems. Volatile release data was collected after swallowing aqueous solutions containing a cocktail of aroma compounds. The compounds varied in their persistence during subsequent exhalations dependent on the degree of association with the mucous lining of the throat. The rate of breathing had no effect on the shape or intensity of the release profile. The data was successfully modelled using the basic principles of interfacial mass transfer. The mechanistic model included some estimated parameters for un-measurable anatomical and physiological variables, kinetic properties of the flavour compound and terms to represent the oscillatory breathing and airflow rate. Aside from the 1st exhalation, the model fitted the data very well. The panel rated the intensity of minty flavor in a 6% gelatine gel, containing varying concentrations of carvone. The flavor was assessed using Magnitude Estimation and Time Intensity Methods. In addition, the quantity of carvone released from the gel and reaching the assessors nose was measured, breath by breath during eating, using the MS Nose. The results showed that the quantity of volatile delivered to the nose was directly proportional to the concentration in the sample, however, the absolute quantity varied greatly between individuals. Further differences were observed in the temporal dimension of their release profiles, which related to differences in their anatomy, physiology and eating habits. In some cases, these differences were mirrored by the sensory data. The relationship between perceived intensity and sample concentration was linear for both types of sensory data. Neither the speed of eating nor the concentration of volatile reached in-nose, affected an individuals ability to judge intensity. There was evidence to suggest, however, that the speed of eating affected the level of adaptation to the carvone stimulus. The affinity of the aroma compound for water (hydrophobicity) was an important factor in influencing the temporal characteristics of the instrumental and sensory data. When aroma release was rapid (< Tmax) the sensory response occurred slightly later whereas when the aroma release was much slower (>Tmax), with intensity increasing more gradually, the sensory response preceded the instrumental data. These phenomena were explained in terms of a lag phase for neural processing when the stimulus was presented quickly and adaptation to the stimulus when it was delivered over a longer period of time. A trained sensory panel assessed flavour and sweetness intensity in solutions containing varying concentrations of Hydroxy Propyl Methylcellulose (HPMC), sugar and flavour volatile. The flavour and sweetness of the viscous solutions were rated using magnitude estimation with a controlled modulus. In addition, the concentration of volatile released on the breath was measured using MS Nose. For low concentrations of HPMC (<0.5g/100g), perceived flavour intensity remained the same, however, a steady decrease was noted at higher concentrations (>0.6g/100g). The change in perceived intensity occurred at the point of random coil overlap (c*) for this hydrocolloid. The perceived sweetness of the solution showed a similar pattern with increasing HPMC concentration, although the inflection at c* was not so obvious. Despite the change in perceived flavour intensity, the actual concentration of volatile measured on the breath was not affected by the change in HPMC concentration. Low order polynomial models were produced to describe perceived flavour intensity and sweetness in viscous solutions containing HPMC and potential explanations for the changes in perception were discussed.

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Davidson, James M. "Non-volatile flavour compounds in foods : their analysis and interactions." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324010.

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Walston, Sean Eric. "Heavy flavor decays of the Z⁰ and a search for flavor changing neutral currents /." wwwlib.umi.com/cr/uoregon/fullcit?p3136452 view abstract or download file of text, 2004.

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Thesis (Ph. D.)--University of Oregon, 2004.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 254-261). Also available for download via the World Wide Web; free to University of Oregon users.

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Labbe, David. "Mécanismes sous-jacents aux interactions perceptuelles et perceptions complexes." Paris, AgroParisTech, 2008. http://pastel.paristech.org/5001/01/Labbe_Thesis.pdf.

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Les interactions perceptuelles entre différentes modalités sensorielles affectent la perception des aliments. Si ce phénomène a été largement étudié entre des stimuli olfactifs et gustatifs en solution aqueuse, peu d'études ont été menées avec des produits existants dans le commerce. Similairement, peu de travaux sont dédiés à l'étude des interactions multi-sensorielles impliquant l'olfaction, le goût et la perception tactile en bouche et à l'étude des perceptions dites complexes, c'est-à-dire qui impliquent plusieurs modalités sensorielles. Le premier objectif de ma thèse était l'exploration des mécanismes sous-jacents aux interactions perceptuelles existant entre l'olfaction et la gustation durant la consommation de produits réels, et en solution avec des stimuli olfactifs à une concentration infraliminaire. Cette approche a ensuite été étendue aux perceptions olfactive, gustative et tactile (en bouche) et à la perception complexe "rafraîchissante". Il a été mis en évidence que la familiarité d'un produit et la stratégie d'attention durant l'exposition affectent de façon critique les interactions perceptuelles. Pour la première fois il a été démontré qu'une concentration infraliminaire d'odorant associé au goût sucré (fraise) augmente la perception sucrée d'une solution de sucrose. La multiplicité des interactions sensorielles présente dans un milieu alimentaire complexe a également été mis en évidence à un niveau bimodal (ex: entre la perception amer et le froid) et tri-modal (ex: entre la perception olfactive, sucrée et froide). Finalement il été démontré que la perception rafraîchissante est construite sur la base d'une combinaison de déterminants sensoriels, d'habitudes alimentaires ainsi que de facteurs hédoniques et psychophysiologiques tels que l'énergie mental. Pour conclure, les connaissances acquises par ce travail soulèvent d'autres interrogations notamment à propos des mécanismes neuronaux sous-tendant la mémorisation des associations perceptuelles et des conditions requises en termes de durée et de fréquence d'exposition pour la mise en place de ces interactions

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Rega, Barbara. "Texture-flavour interactions : how physicochemical data explain sensory perception in orange juice." Dijon, 2003. http://www.theses.fr/2003DIJOS053.

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Cette thèse a pour objectif d'étudier l'influence de la matrice alimentaire sur la libération et la perception des arômes. La première partie analyse le rôle de la pectine sur la diffusivité des arômes et sur les interactions moléculaires dans des systèmes modèles. La deuxième partie étudie le rôle des solides en suspension sur la répartition et la libération des arômes et sur la perception sensorielle dans le jus d'orange. La distribution des volatiles dans les différentes fractions du jus (pulpe, trouble et sérum) et le rôle des constituants non-volatils a premièrement été étudiée. En suite une méthodologie pour évaluer la qualité sensorielle des extraits en phase vapeur a été développée (Chromatographie gazeuse directe couplée à l'olfactométrie). Finalement, le rôle de la pulpe sur le profil sensoriel (texture, saveur, arôme odeur) du jus d'orange a été étudié. En parallèle, des analyses physico-chimiques, rhéologiques et la libération des arômes en phase vapeur ont été effectuées
The aim of this thesis was to investigate how the properties of the food matrix influence flavour release and perception in food. The thesis is organised in two parts. The first part focused on the role of pectins on aroma compound diffusivity and molecular interactions in a model system. The second part focused on the role of suspended solids on aroma compound distribution, flavour release and sensory perception in orange juice. Firstly we determined how aroma compounds are distributed within the macroscopic juice fractions (cloud, pulp and serum) and the role of non-volatile constituents. Secondly we developed a novel methodology (Direct Gas Chromatography Olfactometry) to evaluate the sensory quality of solventless extracts (e. G. SPME, static headspace). Finally, we investigated how pulp influence sensory profiles of texture, taste, odour and aroma in orange juice. At the same time rheological and physicochemical measurements as well as flavour release studies were performed

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Stassinakis, Argyrios. "A study of the atmospheric neutrino flavour content using the Soudan 2 detector." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388755.

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Brown, Zachary S. "Heavy flavor interactions and spectroscopy from lattice quantum chromodynamics." W&M ScholarWorks, 2015. https://scholarworks.wm.edu/etd/1539623998.

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In the present work, spectroscopy and interactions of hadrons containing heavy quarks is investigated. In particular, a focus is placed on properties of exotic heavy hadronic states, including doubly and triply heavy baryons and doubly heavy tetraquark states. The framework in which these calculations are carried out is provided by lattice quantum chromodynamics, a discrete formulation of the modern theory of the strong interaction. The main body of the thesis had two main project focuses. For the first project, an extensive calculation of the mass spectrum of doubly and triply heavy baryons including both charm and bottom quarks is carried out. The wide range of quark masses in these systems require that the various flavors of quarks be treated with different lattice actions. We use domain wall fermions for 2+1 flavors (up down and strange) of sea and valence quarks, a relativistic heavy quark action for the charm quarks, and non-relativistic QCD for the heavier bottom quarks. The calculation of the ground state spectrum is presented and compared to recent models. For the second project, the interaction potential of two heavy-light mesons in lattice QCD is used to study the existence of tetraquark bound states. The interaction potential of the tetraquark system is calculated on the lattice with 2+1 flavors of dynamical fermions with lattice interpolating fields constructed using colorwave propagators. These propagators provide a method for constructing all-to-all spatially smeared the interpolating fields, a technique which allows for a better overlap with the ground state wavefunction as well as reduced statistical noise. Potentials are extracted for 24 distinct channels, and are fit with a phenomenological non-relativistic quark model potential, from which a determination of the existence of bound states is made via numerical solution of the two body radial Schrodinger equation.

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Ployon, Sarah. "Interactions entre muqueuse orale, salive et molécules de la flaveur." Thesis, Dijon, 2016. http://www.theses.fr/2016DIJOS037/document.

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Le rôle de la salive dans la perception sensorielle est de plus en plus reconnu, notamment par le biais des interactions physico-chimiques pouvant s’établir entre protéines salivaires et constituants alimentaires. Ce travail s’intéresse à la pellicule salivaire, la couche de protéines salivaires ancrées aux cellules épithéliales, et vise à caractériser les interactions pouvant s’établir d’une part entre ces protéines et épithélium oral, et d‘autre part entre ces protéines et les molécules de la flaveur. Pour cela, un modèle in vitro de muqueuse orale a été développé. Une lignée cellulaire stable (TR146/MUC1) a été obtenue par transfection de la lignée cellulaire TR146 de manière à exprimer la mucine membranaire MUC1. Afin de former une pellicule salivaire, les cellules confluentes ont été incubées avec de la salive humaine. La rétention des mucines salivaires MUC5B par les cellules TR146/MUC1 est augmentée par rapport aux TR146, apportant ainsi un argument en faveur de l’implication de MUC1 dans l’ancrage des MUC5B aux cellules épithéliales. Le modèle développé a été appliqué à l’étude des interactions entre la muqueuse orale et les molécules d’arôme et les tanins. L’analyse des coefficients de partage par GC-FID a mis en évidence 1- l’importance de l’hydratation de la muqueuse sur la libération des composés les plus hydrophiles, 2- la capacité des cellules à métaboliser certaines molécules d’arôme, 3- l’absence d’effet de la pellicule sur la libération des molécules d’arôme à l’équilibre. En revanche, l’analyse par PTR-MS a révélé un effet de la muqueuse et de la pellicule sur la cinétique de libération des molécules d’arôme. Les interactions entre les protéines de la pellicule salivaire et les tanins modifient les caractéristiques structurales de la pellicule, en particulier le tapissage des cellules par les MUC5B. Les possibles implications sensorielles, respectivement dans les phénomènes de persistance aromatique et d’astringence, sont discutées
The role of saliva in food sensory perception is increasingly recognized, especially through physicochemical interactions occurring between salivary proteins and food components. This work focuses on the mucosal pellicle, a layer of salivary proteins anchored onto epithelial cells, and aims at characterizing interactions that may occur between the proteins of the mucosal pellicle and flavour compounds. For that purpose, an in vitro model of oral mucosa was developed. A stable cell line (TR146/MUC1) was obtaining by transfecting the TR146 cell line in order to express the membrane bound mucin MUC1. In order to form a salivary pellicle, confluent cells were incubated with human saliva. A higher retention of salivary MUC5B by TR146/MUC1 cells was observed compared to TR146 cells, emphasising the involvement of MUC1 in MUC5B anchoring to epithelial cells. The model was applied to the investigation of interactions between the oral mucosa and aroma molecules and tannins. Measurements of partition coefficients by GC-FID revealed 1- the role of hydration of the mucosa on the release of the most hydrophilic compounds, 2- the ability of cells to metabolize some aroma compounds, 3- the absence of effect of the mucosal pellicle itself on aroma release at the thermodynamic equilibrium. Oppositely, analyses by PTR-MS evidenced an effect of the mucosa and of the pellicle on aroma release kinetic. Interactions between proteins of the mucosal pellicle and tannins modified structural characteristics of the pellicle, especially the coating of cells by salivary MUC5B. Sensory relevance for the phenomena of aroma persistence and astringency, respectively, are discussed

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15

Ronniger, Michael [Verfasser]. "Spin and Flavour dependent Interactions within a Quark Model for Baryons / Michael Ronniger." Bonn : Universitäts- und Landesbibliothek Bonn, 2013. http://d-nb.info/104497110X/34.

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16

Gonzalez-Robles, Ivonne-Wendolyne. "Flavour interactions between the 'estery' and 'mature/woody' characters of whisky, bourbon & tequila." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/52370/.

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Estery and woody flavour notes are important characteristics of distilled spirit flavour. It has been reported for malt whisky that the estery character of mature whiskies typically declines relative to that of the new make spirit, even though the analytical concentrations of esters remain broadly constant. One potential explanation for this observation would be a sensory interaction between mature and estery characters. The work described in this thesis was designed to test this hypothesis and to further explore the nature of the congeners responsible for eliciting these characteristics across different spirit types, as influenced by their maturation conditions (time, temperature, cask provenance etc.). In the research described in Chapter 2, four pairs of non-mature and mature spirits (tequila, bourbon and 2 malt whiskies) were characterized by instrumental analysis with the aim of defining the key aroma compounds that determined the mature character in each spirit. According to PLS analysis of the full data set, concentrations of 17 congeners were positively correlated with ageing time and might thus influence the mature character of the aged spirits. In Chapter 3, the same eight spirit samples were analysed by GC-Olfactometry using the AEDA (aroma extraction dilution analysis) approach. Aged spirits presented a more complex aroma than new make spirits, and contained more compounds with the highest FD-factors. Whilst a full GC-O characterisation was completed, the main focus was on identifying compounds which contributed to the estery and woody/mature characters of each spirit. In Chapter 4 we attempted to reproduce these characters for each spirit through aroma recombination, based on blends of the odiferous compounds identified at high FD factors and their analytical concentrations in the actual samples as reported in Chapter 3. It soon became apparent that relatively simple mixtures of esters on the one hand and maturation-linked compounds on the other did not adequately reproduce the nature of these characteristics in the spirits themselves. This implied either that our analysis had missed some significant compounds contributing to these characteristics, or that the complexity of the full spirit matrix is required to give the groups of compounds the nuanced flavour that they lacked in isolation. The latter hypothesis was tested by adding in additional blends of compounds to increase the complexity of the recombinant aroma mixtures. It was concluded that the authenticity of the aroma blends overall was improved by both the addition of a cocktail of ‘low boiling compounds’ (those analysed by a separate direct injection GC technique) and the introduction of a ‘structuring’ compound (ethyl hexadecanoate) at a concentration that would cause agglomeration within the whisky (micellar structures) thus influencing aroma partitioning and release. It was concluded that these modifications produced recombinant aromas which were close enough to the authentic spirit characters to use them in sensory interaction studies (Chapter 5). As opposed to interaction effects there was simply a tendency for the woody/mature characters to suppress the corresponding estery character of mature spirits, particularly at the higher concentrations of added wood extractives. Because the woody/mature compounds which characterised maturation were broadly similar across the spirit types, but differed in concentration according to the maturation conditions, we decided finally to investigate the extraction kinetics of wood-derived compounds from oak sticks as a function of ageing time, temperature, spirit type and alcohol content (Chapter 6). Temperature and alcohol content were the most significant factors that determined the extraction rate and final concentrations of all 18 wood-extractive compounds (P < 0.05) analysed. Not surprisingly, extraction rates increased with increasing temperature, but the trend in terms of alcoholic strength depended on the particular compound. Overall this thesis has improved knoEstery and woody flavour notes are important characteristics of distilled spirit flavour. It has been reported for malt whisky that the estery character of mature whiskies typically declines relative to that of the new make spirit, even though the analytical concentrations of esters remain broadly constant. One potential explanation for this observation would be a sensory interaction between mature and estery characters. The work described in this thesis was designed to test this hypothesis and to further explore the nature of the congeners responsible for eliciting these characteristics across different spirit types, as influenced by their maturation conditions (time, temperature, cask provenance etc.). In the research described in Chapter 2, four pairs of non-mature and mature spirits (tequila, bourbon and 2 malt whiskies) were characterized by instrumental analysis with the aim of defining the key aroma compounds that determined the mature character in each spirit. According to PLS analysis of the full data set, concentrations of 17 congeners were positively correlated with ageing time and might thus influence the mature character of the aged spirits. In Chapter 3, the same eight spirit samples were analysed by GC-Olfactometry using the AEDA (aroma extraction dilution analysis) approach. Aged spirits presented a more complex aroma than new make spirits, and contained more compounds with the highest FD-factors. Whilst a full GC-O characterisation was completed, the main focus was on identifying compounds which contributed to the estery and woody/mature characters of each spirit. In Chapter 4 we attempted to reproduce these characters for each spirit through aroma recombination, based on blends of the odiferous compounds identified at high FD factors and their analytical concentrations in the actual samples as reported in Chapter 3. It soon became apparent that relatively simple mixtures of esters on the one hand and maturation-linked compounds on the other did not adequately reproduce the nature of these characteristics in the spirits themselves. This implied either that our analysis had missed some significant compounds contributing to these characteristics, or that the complexity of the full spirit matrix is required to give the groups of compounds the nuanced flavour that they lacked in isolation. The latter hypothesis was tested by adding in additional blends of compounds to increase the complexity of the recombinant aroma mixtures. It was concluded that the authenticity of the aroma blends overall was improved by both the addition of a cocktail of ‘low boiling compounds’ (those analysed by a separate direct injection GC technique) and the introduction of a ‘structuring’ compound (ethyl hexadecanoate) at a concentration that would cause agglomeration within the whisky (micellar structures) thus influencing aroma partitioning and release. It was concluded that these modifications produced recombinant aromas which were close enough to the authentic spirit characters to use them in sensory interaction studies (Chapter 5). As opposed to interaction effects there was simply a tendency for the woody/mature characters to suppress the corresponding estery character of mature spirits, particularly at the higher concentrations of added wood extractives. Because the woody/mature compounds which characterised maturation were broadly similar across the spirit types, but differed in concentration according to the maturation conditions, we decided finally to investigate the extraction kinetics of wood-derived compounds from oak sticks as a function of ageing time, temperature, spirit type and alcohol content (Chapter 6). Temperature and alcohol content were the most significant factors that determined the extraction rate and final concentrations of all 18 wood-extractive compounds (P < 0.05) analysed. Not surprisingly, extraction rates increased with increasing temperature, but the trend in terms of alcoholic strength depended on the particular compound. Overall this thesis has improved knowledge of the chemical and sensory changes that accompany spirit maturation and has highlighted some of the factors that cause differences in mature character across spirit types.
Moreover, it concludes that the sensory perception of woody/mature generally suppresses the fresh estery characteristic of new make spirits, even though analytically the esters are still there in similar concentrations. wledge of the chemical and sensory changes that accompany spirit maturation and has highlighted some of the factors that cause differences in mature character across spirit types. Moreover, it concludes that the sensory perception of woody/mature generally suppresses the fresh estery characteristic of new make spirits, even though analytically the esters are still there in similar concentrations.

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17

Wang, Qian (Qian Janice). "Music, mind, and mouth : exploring the interaction between music and flavor perception." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/91820.

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Thesis: S.M., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 119-126).
This thesis presents a study of how hearing and taste can influence each other, how this interaction can be measured, and how the results can be used to design new, powerful, immersive experiences. The goal of the thesis is to address two questions: does music significantly change flavor perception, and can music change the hedonic experience of a meal? Experimentally, I looked at ways to measure changes in sensory perception. Artistically, I explored how external factors can alter the eating experience. From a cultural perspective, I examined the history of multisensory experiences - in feasts, in everyday cooking, and in community rituals. I conducted a series of experiments to measure the effect of music on flavor perception, and designed a series of novel eating experiences that make use of congruencies between multiple senses, culminating in a multisensory feast for the Media Lab. From these studies, design patterns and challenges are extracted and analyzed, and new directions are discussed.
by Qian (Janice) Wang.
S.M.

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18

Wang, Aili. "The Interaction of Iron with Proteins and Sugars in Biological Fluids and Beverages." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/78796.

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Iron is one of the most common trace elements in natural water sources and an important component to living systems. The existence of iron may not only cause metallic flavor, it may also deeply impact health of human and animals by interacting with constituents in the related biological fluids such as saliva and milk. The overall goal of this study is to investigate the taste interaction between iron and sweeteners, and the interaction between iron and proteins in bovine milk and human saliva. Based on pairwise-ranking sensory test, we have found that sweetness of sweeteners was varied with different concentrations of minerals in water and with different types of sweeteners. Sweet-metallic taste interaction between sucrose and ferrous ions significantly (p<0.05) increased the acceptance of very hard water (3 mg Fe/L). The sweet-metallic interaction created a unique selection of the emotional term 'mild'. High iron concentration in bovine drinking water (2 mg Fe/L or higher), causing oxidative stress in dairy cattle, affected expression of both casein and whey proteins in the milk. Direct addition of iron above 5 mg Fe/L in processed whole commercial milk led to lipid oxidation during storage at 4°C. Oxidation level was positively associated with increasing concentration of added iron. Minerals (Mg, P, Na, K, Ca, Zn) in milk were not affected with the added iron in milk. Dietary supplementation with metal-binding protein significantly decreased (p<0.05) taste and smell abnormality score in cancer patients receiving chemotherapy, and this effect lasted at least 30 days after the treatment was ended. Although supplementation did not effectively reduce (p>0.05) the metallic taste intensity stimulated by ferrous sulfate solution (1 mg Fe/L), it significantly (p<0.05) decreased salivary Fe for both healthy subjects and cancer patients. The production of metallic taste perception both induced by chemotherapy and ferrous sulfate solution, might be associated with the decreased expression of low-abundance proteins (pH 5.5-8.5, MW 25-75kDa), which were mainly immune proteins in saliva. Supplementation may improve taste disorder by recovering low-abundance salivary proteins in cancer patients.
Ph. D.

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19

Kennedy, John James. "A search for single top-quark production and flavour-changing neutral-current interactions at H1." Thesis, University of Liverpool, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269575.

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20

Hamon, Julien. "Etude de la production des mésons charmés-étranges dans les collisions proton-proton et proton-plomb avec l'expérience ALICE au LHC." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAE012/document.

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L'étude de la production des quarks charmés dans les collisions de hautes énergies de noyaux atomiques offre une approche inédite pour l'étude du plasma de quarks et de gluons. La compréhension et la caractérisation de cet état de la matière déconfinée, de prime abord retrouvé dans les systèmes les plus lourds, nécessitent une connaissance fine des systèmes les plus légers, telles que les collisions proton-proton (pp) et proton-plomb (p-Pb). Dans ce manuscrit, nous présentons la mesure de la production des mésons charmés-étranges Ds+, à rapidité centrale, avec les données du run 2 du LHC, recueillies en 2016 par l'expérience ALICE. Deux systèmes sont étudiés : les collisions pp à √s=13 TeV et p-Pb à √sNN=5,02 TeV. La section efficace de production des Ds+, leur abondance relative et leur facteur de modification nucléaire sont mesurés puis comparés à d'autres mesures et à diverses prédictions théoriques. Le résultat p-Pb établit une nouvelle référence pour l'étude des collisions Pb-Pb
The study of the production of charm quarks in high-energy atomic-nucleus collisions offers an genuine approach for the study of the quark-gluon plasma. The understanding and characterisation of this state of deconfined-matter, at first sight created in heaviest systems, require a fine knowledge of lightest systems, such as proton-proton (pp) and proton-lead (p-Pb) collisions. In this manuscript, we present the measurement of the charm-strange mesons Ds+ production, at central rapidity, with the LHC run 2 data, collected in 2016 with the ALICE experiment. Two systems are studied: pp collisions at √s=13 TeV and p-Pb collisions at √sNN=5.02 TeV. The production cross-section of Ds+, their relative abundance and their nuclear modification factor are measured then compared to other measurements and to various theoretical predictions. The p-Pb result establishes a new reference for the study of Pb-Pb collisions

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21

Somov, Alexandre. "Hard proton nucleus interactions and production of heavy flavours at HERA-B." Doctoral thesis, [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=960834176.

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22

Amanik, Philip. "Effects of non-standard neutrino flavor changing interactions in core collapse supernovae." Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2006. http://wwwlib.umi.com/cr/ucsd/fullcit?p3216385.

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Thesis (Ph. D.)--University of California, San Diego, 2006.
Title from first page of PDF file (viewed September 5, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 87-89).

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23

Li, Zheng. "Interactions of flavor compounds with soy and dairy proteins in model systems /." free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9974652.

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24

Kikawa, Tatsuya. "Measurement of Neutrino Interactions and Three Flavor Neutrino Oscillations in the T2K Experiment." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/195958.

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25

Le, Thuaut Laurent. "Approche sensorielle et physico-chimique des interactions texture - flaveur dans une matrice alimentaire complexe." Nantes, 2004. http://www.theses.fr/2004NANT2011.

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Maîtriser les qualités sensorielles des aliments nécessite de comprendre les interactions entre perceptions lors de la dégustation. Pour analyser les interactions entre texture, saveur et arôme dans une matrice complexe, une stratégie d'étude combinant approches sensorielle et physicochimique a été appliquée à des desserts lactés variant par leur texture, leurs niveaux d'aromatisation et de sucre. La texture influence l'intensité de la saveur probablement en modifiant la cinétique de libération du sucre tandis que l'intensité de la saveur influence celle de l'arôme fruité par interaction entre sens. Ces deux effets, alliés à l'impact de l'agent de texture sur la libération en bouche des composée d'arôme expliqueraient l'effet de la texture sur la perception de l'arôme. L'impact du sucre sur la texture des desserts gélifiés s'explique par la modification du comportement mécanique. Ponctuellement, de faibles effets, de nature sensorielle, de l'arôme sur la texture sont observés
To control sensory properties of foods, interactions between sensory perceptions during eating should be better understood. To analyse texture-flavour interactions in complex food matrices, sensory and physicochemical approaches were applied to dairy custards varying in texture and in aroma and sucrose levels. Texture of the custards influences sweetness probably through changes in sugar release, whereas sweetness perception modifies aroma perception through sensorial interactions. These two mechanisms, together with changes in the in vivo release of aroma compounds with texture, explain the impact of texture on perceived aroma. Sucrose level influences texture perception through modification of the mechanical behaviour of gelled desserts. Some small sensory effects of aroma on specific texture attributes are found

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Galais, Sébastien. "Shock wave and neutrino self-interaction effects upon neutrino flavor conversion in the supernovae environment." Paris 7, 2012. http://www.theses.fr/2012PA077090.

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Les travaux présentés dans cette thèse portent sur la conversion de saveur des neutrinos de supernovae. Dans un premier travail, nous avons réalisé le premier calcul complet incluant l'onde de choc et l'auto-interaction pour l'estimation du flux du fond diffus de neutrinos de supernovae (DSNB) arrivant sur terre. Ce flux correspond à la combinaison des neutrinos provenant de toutes les supernovae ayant explose dans l'univers visible. En variant l'angle theta_13 de la matrice de mélange U_MNSP, nous avons montré que l'onde de choc a un impact significatif sur le flux du DSNB. Par la même occasion nous avons propose un modèle simplifié prenant en compte les effets de l'onde de choc et qui pourrait être utilisé pour de futurs calculs du DSNB. Les deux autres travaux se sont concentrés sur la première dérivation analytique exacte de la base de matière en présence de l'auto-interaction. Nous avons souligné, pour le cas à deux saveurs, le rôle important tenu par la phase de matière beta tilde et nous avons établi une condition sur les éléments de l' hamiltonien de saveur pour la fin de la phase de synchronisation et le début des oscillations bipolaires. Via cette base de matière, nous avons identifié en utilisant le formalisme des vecteurs polarisations une correspondance entre les phénomènes de « spectral split » et de résonance magnétique. Ceci nous a permis de confirmer des hypothèses telles que l'adiabaticité de la propagation, l'utilisation du champ magnétique moyen et du référentiel tournant qui avaient été postulé a l'aide d'un modèle simplifié. Une étude préliminaire du cas à trois saveurs nous indique la conservation de cette correspondance
The works presented in this thesis deal with the flavor conversion of the supernova neutrinos. In a first work, we performed the first complete calculation including the shock wave and the self-interaction for the estimate of the diffuse supernova neutrino background (dsnb) flux arriving on earth. This flux corresponds to the combination of the neutrinos coming from all the supernovae that exploded in the visible universe. By varying the angle theta_13 of the mixing matrix u_mnsp, we showed that the shock wave has a significant impact on the dsnb flux. At the same time we proposed a smplified model that accounts for the shock wave effects and that could be used for future calculations of the dsnb. The other two works are focused on the first exact analytical derivation of the matter basis in the presence of the self-interaction. We underlined, for the two flavors case, the important role of the matter phase beta tilde and we established a condition on the elements of the flavor hamiltonian for the end of the synchronization phase and the onset of the bipolar oscillations. Through the matter basis, we identified, by using the polarization vector formalism, a correspondence between the "spectral split" and the magnetic resonance phenomena. This has allowed us to confirm hypothesis such as the adiabaticity of the propagation, the use of the average magnetic field et the corotating frame that were postulated with the help of smplified models. A prelminary study of the three flavors case indicate us the conservation of this correspondence

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Tournier, Carole. "Interactions texture-flaveur : mécanismes physico-chimiques ou mécanismes cognitifs ? : application à un gel laitier onctueux." Dijon, 2006. http://www.theses.fr/2006DIJOS062.

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L’objectif de ce travail est d’étudier les interactions sensorielles entre texture, saveur et arôme, en relation avec la perception d’un critère de qualité : l’onctuosité. La première étape a consisté à définir le concept d’onctuosité. Trois groupes de consommateurs ont été mis en évidence en fonction des dimensions de texture, de saveur et de gras des produits laitiers. La seconde étape a consisté à étudier les interactions entre les dimensions de texture, de saveur et d’arôme, prises deux à deux et de façon réciproque, avec un panel de consommateurs et de comprendre l’origine des interactions en développant des mesures physico-chimiques. La texture modifie la perception de la saveur et de l’arôme par le biais de des mécanismes principalement physico-chimiques. En revanche la perception de la saveur et de l’arôme n’a pas eu d’impact sur la perception de la texture. Enfin, une interaction Saveur/Arôme réciproque, d’origine probablement cognitive a été mise en évidence
The present work aimed at studying sensory interactions between texture, taste and aroma, in relation with the perception of creaminess, an indicator of food quality. A first step consisted in defining the creaminess concept. This study highlighted three groups of consumers related to the texture, taste and fattiness of dairy products. The second step consisted in studying sensory interactions between texture, taste and aroma. Binary interactions were then studied in a reciprocal way using a consumers’panel. Physico-chemical complementary studies were finally developed in an attempt to better understand the origin of the observed interactions. Texture modified perceived taste and tended to modify aroma perception, via physico-chemical mechanisms principally. Conversely, taste and aroma perception did not affect texture perception. Finally, a reciprocal taste – aroma interaction, probably from cognitive origin, was observed

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Puget, Sabine. "Chlorine flavor perception and neutralization in drinking water." Phd thesis, Université de Bourgogne, 2010. http://tel.archives-ouvertes.fr/tel-00786522.

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For water suppliers, using chlorine is necessary to ensure water bacteriological quality from the treatment plant to the consumers' tap. However, chlorine flavour is one of the most common reasons advocated for choosing tap water alternatives as drinking water. As a consequence, the putative link between chlorine flavour perception and tap water consumption is an issue in drinking water habits studies. Since the sensory mechanisms involved in chlorine flavour perception remained largely unknown, the main objective of this thesis work was to first highlight those mechanisms and then to identify potential lever chlorine flavour sensory neutralisation.In a first step, we demonstrated that hypochlorous acid associated, which is likelyresponsible of chlorine flavour in tap water, could activate the olfactory system at low concentrations and the trigeminal system for concentrations up to 4 mg/L Cl2. Additionally, our results suggested that tap water consumption does not seem to be related to sensitivity to chlorine flavour but rather to consumers' tap water representation.In a second stage, we explored the impact of water mineral matrix on chlorine flavour perception. We demonstrated first that water molarity and cationic content variations modulate drinking water taste. We also evidenced that chlorine flavour intensity is modulated according to water composition. Nevertheless, our data suggest that physico-chemical, in- mouth physiological and sensory mechanisms are likely involved in such modulation.In the last part of the Thesis work, we investigate the putative influence of aroma perceptionon chlorine flavour. Our results showed that beyond chemical reactions between hypochlorous acid and odorants, aromas at peri-threshold concentration enhance chlorine flavour and decrease tap water acceptability

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29

Engel, Erwan. "Contribution des molécules hydrosolubles non volatiles à la flaveur des fromages : impact sur la saveur et interactions avec des composés odorants." Dijon, 2000. http://www.theses.fr/2000DIJOS093.

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30

Schmauch, Grégory. "Interactions tanins-protéines en oenologie." Thesis, Bordeaux 2, 2010. http://www.theses.fr/2010BOR21703/document.

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Depuis la mise en cuve du raisin jusqu'à la dégustation, les interactions entre tanins et protéines jouent un rôle prépondérant en Œnologie. Elles vont influencer de nombreuses caractéristiques du vin, notamment l'astringence. La cinétique et l'équilibre de l’interaction entre la BSA, une protéine modèle, et des tanins de raisin ont été étudiés. Différentes conditions de ratio initial, de pH et d'éthanol ont permis de mettre en évidence des propriétés essentielles du mécanisme. La non-stœchiométrie de la réaction et la dépendance linéaire du ratio initial tanin-protéine de la solution avec celui du précipité est un des points clefs. Les constantes cinétiques sont également dépendantes de ce ratio. La participation conjointe des forces hydrophobes et des liaisons hydrogènes a été montrée. En parallèle, le suivi des tanins et des protéines lors de la vinification et de la dégustation a été réalisé. La disparition des protéines dans le moût au début de vinification peut être corrélée au comportement des tanins. Une méthode HPLC permettant la titration de la salive par le vin montre un comportement classique des protéines salivaires dans l'interaction. La visualisation des protéines salivaires précipitant sous l'effet des tanins par gels 2D montre globalement une non-spécificité de l’interaction avec une précipitation non sélective des protéines salivaires par les tanins du vin
From wine making to wine tasting, interactions between tannin and protein detain a prominent role in Enology, influencing several wine characteristics like its astringency. Interaction kinetics and precipitation equilibrium between BSA, a model protein, and grape seed tannin have been studied. Variations of initial ratio, pH and ethanol conditions pointed out essential properties of the mechanism. Lack of stoichiometry of the interaction with a linear dependence between initial and final tannin/protein ratio are key points. Kinetic constants are also related to this ratio. Mutual participation of both hydrophobic forces and hydrogen bonds has been shown. Along with these investigations in model solution, tannin and proteins have been followed during wine making and tasting. Disappearance of protein in the must and tannin behaviour can be linked. An HPLC method allowing the titration of saliva with wine indicates a classical behaviour of salivary proteins. Observation of salivary proteins precipitating with tannin thanks to 2D gels shows a non selective precipitation of salivary proteins by wine

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31

Friedrich, Conrad. "Search for single top-quark production via flavour-changing neutral currents in strong interactions using s = 8 TeV ATLAS data." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2015. http://dx.doi.org/10.18452/17348.

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In dieser Dissertation werden Resultate einer Suche nach der Produktion von Einzel-Top-Quarks über flavour-verletzende neutrale Ströme (FCNCs) in starken Welchselwirkungen vorgestellt. Hierfür werden Daten aus Proton-Proton-Kollisionen am Large Hadron Collider bei einer Schwerpunktsenergie von 8TeV verwendet. Die Daten wurden mit dem ATLAS-Experiment im Jahr 2012 aufgenommen und entsprechen einer integrierten Luminosität von 14.1 fb−1. In der Analyse werden FCNC-Ereignisse selektiert, in denen ein leichtes Quark (u oder c) mit einem Gluon wechselwirkt, und ein einzelnes Top-Quark und potentiell ein weiterer einzelner Jet produziert wird. Mittels der Forderung nach genau einem Myon oder Elektron, großer fehlender Transversalenergie und exakt einem Bottom-Quark-Jet und eventuellem zusätzlichen Jet im Endzustand werden Kandidaten der gesuchten Ereignisse im leptonischen Zerfallskanal des Top-Quarks selektiert. Zur Unterscheidung zwischen Signal- und Untergrundereignissen werden multivariate Methoden herangezogen. Künstliche neuronale Netze werden verwendet, um diverse kinematische Variablen zu einem einzelnen Klassifikator zu kombinieren. Um die potentielle Produktion von Top-Quarks über FCNCs zu quantifizieren, werden die Ausgaben der neuronalen Netze einer Bayes''schen statistischen Analyse unterzogen. Da kein Überschuss an Signalereignissen festgestellt werden kann und die Ergebnisse den Erwartungen der theoretischen Vorhersagen entsprechen, werden neue obere Schranken auf den FCNC-Produktionswirkungsquerschnitt von Einzel-Top-Quarks ermittelt. Aus diesen werden unter Verwendung von modell-unabhängigen theoretischen Berechnungen neue obere Schranken auf die Kopplungskonstanten sowie auf die entsprechenden Verzweigungsverhältnisse ermittelt.
This thesis presents results of a search for single top-quark production via flavour-changing neutral currents (FCNCs) in strong interactions using data recorded with the ATLAS experiment at the Large Hadron Collider in 2012. A dataset from proton-proton collisions at a centre-of-mass energy of 8TeV and corresponding to an integrated luminosity of 14.1 fb−1 is used. It is searched for FCNC events in which a light quark (u or c) interacts with a gluon to produce a single top quark, either with or without the associated production of another light quark or gluon. Candidate events of leptonically decaying top-quarks are selected by requiring a single electron or muon, a substantial amount of missing transverse energy, and exactly one or two jets of which exactly one has to fulfil a b-tagging criterion. Multivariate techniques are employed in order to distinguish between signal- and background-like events by making use of artificial neural networks that combine multiple kinematic variables into a single classifier output. A Bayesian statistical analysis is performed on the classifier outputs in order to quantify potential signs of FCNC single top-quark production. No excess in signal events is observed and the results are in agreement with the theory predictions. Consequently a new upper limit is set on the FCNC single top-quark production cross-section multiplied by the t->Wb branching fraction. Using theory calculations within a model-independent effective theory framework, this limit is converted into upper limits on the coupling constants of the FCNC interactions as well as into respective upper limits on the branching fractions.

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Sharp, Michael D. "Analysis of Vanilla Compounds in Vanilla Extracts and Model Vanilla Ice Cream Mixes Using Novel Technology." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1258043461.

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Kora, fEnkelejda. "Interactions pysico-chimiques et sensorielles dans le yaourt brassé aromatisé : quels impacts respectifs sur la perception de la texture et de la flaveur ?" Paris, Institut national d'agronomie de Paris Grignon, 2004. http://www.theses.fr/2004INAP0005.

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Ramirez, Ramirez Gabriela. "Etude de la sorption des composés d'arôme du vin par le bois de chêne en système modèle d'élevage en fûts." Dijon, 2002. http://www.theses.fr/2002DIJOS062.

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Jung, Da-Mi. "Interactions between volatile flavor compounds and food matrix components studied using nuclear magnetic resonance spectroscopic and solid phase microextraction techniques /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.

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Calixto, Sanchez Alejandro Antonio. "Diversity, abundance, seasonality and interactions of ants (Hymenoptera: Formicidae) in pecans in Mumford, Robertson Co., Texas." Texas A&M University, 2004. http://hdl.handle.net/1969.1/1487.

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Alpha diversity, population dynamics and interactions of ant assemblages were studied in a pecan orchard located in Mumford, Texas. The assemblages included the invasive species Solenopsis invicta Buren, known as the red imported fire ant (RIFA). The study addressed the major question of what is the response of the ant assemblage to the reduction of RIFA following insecticide applications (bait and contact insecticide) and the impact of these on individual species. To address this question three treatments were established in a 16 hectare area in the orchard. The treatments were randomly assigned in 1.33 hectare blocks with four replications and periodically monitored. Treatments were: 1) insect growth regulator (IGR) bait treatment (ExtinguishTM, active compound is 0.5% s-methoprene) applied twice in 2000 and once in 2001; 2) the contact insecticide chlorpyrifos (LorsbanTM) applied on tree trunks four times in 2000 and once in 2001; and 3) untreated Control. Blocks were sampled using pitfall traps, baited vials, direct sampling, and colony counts. Data were analyzed by using ANOVA-GLM with the LSD multiple comparison test to compare the effect of treatment on the ant assemblage (using the Shannon index) and the effect on individual species. Additionally, data obtained from Control plots were used to compare sampling techniques and to determine what method is most efficient for collecting ants in this agroecosystem. Shannon indices were estimated for each method and compared. The ant assemblage consisted of 16 ant species. S. invicta was the most abundant followed by Paratrechina sp. and Monomorium minimum. The IGR treatment consistently reduced RIFA (77%). Native ants were found to coexist with RIFA in the Control and chlorpyrifos plots at lower densities and maintained higher densities in IGR plots. Chlorpyrifos trunk treatment did not have a significant impact on RIFA or native ant densities. The native ant, Dorymyrmex flavus, was greater in IGR plots following RIFA reduction and higher densities were found to persist for more than two years after the last IGR treatment. During this period, D. flavus was observed carrying large numbers of dead RIFA, some taken inside the nest, and some disarticulated RIFA taken out of the nest. RIFA remains were accumulated in D. flavus middens, further indication of an important interaction between these two species. These results indicate D. flavus resisted reinvasion by RIFA.

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Mollet, Simon. "Exploration of 6-dimensional models with non trivial topology and their predictions for fermions masses and mixings, neutrino physics, flavour changing interactions and CP violation." Doctoral thesis, Universite Libre de Bruxelles, 2016. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/230863.

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In this thesis, we study several scenarios which go beyond the Standard Model of particle physics with the aim of gaining a better understanding for the multiplication of fermion families, their masses and mixings pattern and its relation to CP violation. The common feature of the models we envisaged (and the guiding principle of the thesis) is the introduction of extra space dimensions. In a first attempt to explain the fermion mass structure, we elaborate on a model with two extra-dimensions and a Nielsen- Olesen vortex background established on it. In this framework, three families in 4D can be seen as different modes of a single generation in 6D, while their extra-dimensional wavefunctions turn out highly constrained by the dynamics, which allows to determined the mass matrices with few parameters. Moreover, with a few additional hypotheses only, it is possible to simultaneously account for the striking differences between neutrinos and charged fermions. After a summary of the model, we illustrate this with the explicit formulation of a benchmark model which reproduces convincingly all the mass and mixing parameters of the Standard Model, taking advantage of new, more precise numerical solutions of the field equations, and including the recent measurements of the Standard Model scalar boson mass and of the neutrino heta_13 mixing angle (the latter has however been correctly predicted by the model before its first measurement). We then turn to the predictions which mainly concern the neutrino and gauge sectors. In the former, we remind the Majorana nature, and the natural tendency for inverted hierarchy pattern with an almost maximally suppressed neutrinoless double beta decay. On the other hand, we predict new (neutral) gauge bosons whose couplings to fermions are not flavour-diagonal but are however constrained (in their strength and their flavour structure) by the 6D anatomy of the theory. We compare their detectability in precision low energy processes and at colliders (especially at the LHC), and show that in the simplest geometries at least, the bounds from the former exclude interesting phenomenology for the latter. Nevertheless, we turn to more phenomenological effective Lagrangians with the same overall structure and in which we are able to lower the mass scale of the new bosons to a reachable energy, and thus analyse the possible signatures for LHC.In the last part of this work, we turn to the issue of CP violation and show how in certain 6D models with non simply connected topologies, it is possible to generate a non negligible CP violation at the 4D level in a pure gauge approach. We carefully study how the 4D CP symmetry is related to particular transformations of the original 6D theory and subsequently show how an incompatibility of such transformations with the compactification scheme can lead to an effective CP breaking. As a proof of concept, we build a toy model with two extra-dimensions compactified on a flat torus and end in 4D with a light neutral fermion with a non zero electric dipole moment.Dans cette thèse, nous étudions plusieurs scénarios au-delà du Modèle Standard de la physique des particules à la recherche d'une meilleure compréhension de la multiplication des familles de fermions, de leurs masses et de leurs mélanges, ainsi que la relation à laviolation de CP.La caractéristique commune à tous les modèles envisagés (et le concept sous-jacent à toute la thèse) est l'introduction de nouvelles dimensions spatiales. Dans une première tentative pour expliquer le spectre des fermions, nous développons un modèle où une structure de vortex à la Nielsen-Olesen est établie sur deux dimensions supplémentaires. Dans ce cadre, les trois familles à 4D peuvent être vues comme différents modes d'une unique génération à 6D, tandis que leur fonctions d'onde extra-dimensionnelles s'avèrent fortement contraintes par la dynamique ;ceci permet d'établir les matrices de masses en terme d'un petit nombre de paramètres. De plus, grâce à quelques hypothèses additionnelles seulement, il est possible de justifier simultanément les différences marquées entre neutrinos et fermions chargés. Nous synthétisons le modèle et l'illustrons en en formulant une réalisation particulière qui parvient à reproduire de manière convaincante tous les paramètres de masse et de mélange du Modèle Standard. Pour l'occasion, nous exploitons de nouvelles solutions aux équations des champs, numériquement plus précises, et prenons en compte les mesures récentes de la masse du boson scalaire et de l'angle de mélange heta_13 pour les neutrinos (le modèle avait cependant prédit ce dernier avant qu'il ne soit mesuré pour la première fois). Nous nous tournons ensuite vers les prédictions du modèle et qui concernent principalement le secteur des neutrinos et celui des bosons de jauge. Pour le premier, nous rappelons la nature "Majorana" des neutrinos, ainsi que la tendance naturelle à une hiérarchie inverse avec une suppression quasi maximale de la double désintégration bêta sans neutrino. D'autre part, nous prédisons de nouveaux bosons de jauge (neutres) dont les couplages aux fermions ne sont pas diagonaux dans l'espace des saveurs mais sont contraints (autant en terme de valeurs qu'en termes de structure) par l'anatomie de la théorie à 6D. Nous comparons leurs détections potentielles dans les processus de précision à basse énergie et auprès des collisionneurs (en particulier au LHC). Nous montrons que, dans les géométries les plus simples du moins, les limites imposées par les premiers excluent toute phénoménologie intéressante du côté des seconds. Toutefois, en nous tournantvers des Lagrangiens effectifs qui conservent la même structure d'ensemble mais ouvrent à une étude plus phénoménologique, nous sommes capables de réduire l'échelle de masse de ces nouveaux bosons jusqu'à une énergie accessible, et donc d'en analyser de potentielles signatures au LHC.Dans la dernière partie de ce travail, nous nous intéressons à la question de la violation de CP et montrons comment dans certains modèles à 6D avec une topologie non-simplement connexe, il est possible de générer une violation de CP non négligeable à 4D dans une approche de "pure jauge". Nous étudions attentivement comment la symétrie CP à 4D est reliée à des transformations particulières de la théorie originale à 6D, suite à quoi nous montrons comment l'incompatibilité de ces transformations avec la façon dont sont "compactifiées" les dimensions supplémentaires peut conduire à une brisure effective de CP. Pour illustrer la faisabilité de notre approche, nous élaborons un "modèle jouet" où deux dimensions supplémentaires sont compactifiées sur un tore plat, et obtenons à 4D un fermion neutre léger et qui possède un moment électrique dipolaire non nul.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

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38

Natarajan, Aparna. "Identification of disease resistance networks in Maize involved in resistance to Aspergillus flavus and to aflatoxin accumulation." OpenSIUC, 2010. https://opensiuc.lib.siu.edu/theses/259.

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Aspergillus flavusis a filamentous fungusthat causes an ear and kernel rot in maize (Zea mays L.). It produces a toxic secondary metabolite, aflatoxin, on the colonized maize kernels. Aflatoxin is a carcinogen to humans and animals. The toxin is also an immunosuppressant and causes aspergillosis in immune compromised individuals. Therefore, the presence of aflatoxin in food is strictly regulated by governmental agencies. Contaminated food leads to severe loss in profit and in marketable yield. There has been extensive research to investigate resistance of maize toA. flavus. Certain lines of maize exhibit increased resistance to A. flavus and aflatoxin accumulation compared to others and correlated with that are proteins and metabolites that differ in abundance in those lines. Among them are members of the cupin superfamily of proteins and products of special nitrogen metabolism (derived from glutamate). The goal here was to identify networks underlying disease resistance indifferent maize genotypes through the identification of protein-protein interactions and the analysis of transcript abundance profiles realting to cupins and glutamate. The outcome will be an understanding of host resistance to A. flavussufficient to develop methods to prevent pre-harvest contamination by aflatoxin. A protein abundant in resistant maize was identified as a cupin and named ZmCUP1. The cDNA isolation, expression in E. coliand characterization of the protein encoded by the mRNA, Zmcup1, lead to the discovery that the ZmCUP1 protein had anti fungal properties and oxalate decarboxylase activity (EC 4.1.1.2). Another part of the project aimed at understanding the involvement of a transgene that encoded bacterial NADPH-glutamate dehydrogenase (GDHA; EC 4.2.3.1) that reduced aflatoxin accumulation by half. A maize partial predicted protein to protein interactome was built and used to identify potential interactions between proteins expressed differentially in lines of maize resistant to A. flavus. These interactions were characterized in-silico and one specific interaction, between Zmcup1 and a maize zinc finger protein was characterized in vitro.

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PACI, KORA Enkelejda. "Interactions physico-chimiques et sensorielles dans le yaourt brassé aromatisé: quels impacts respectifs sur la perception de la texture et de la flaveur?" Phd thesis, INAPG (AgroParisTech), 2004. http://tel.archives-ouvertes.fr/tel-00005733.

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Une approche intégrée physico-chimique et sensorielle a ete mise en oeuvre pour étudier la nature des interactions texture-flaveur dans un produit laitier fermenté aromatisé sans matière grasse de type yaourt brassé.

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Paravisini, Laurianne. "Flaveur du caramel : impacts de la fraction volatile odorante et de la fraction non volatile sur la perception." Thesis, Dijon, 2013. http://www.theses.fr/2013DIJOS055.

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L’objectif de cette étude est d’étudier l’impact de la fraction volatile odorante et de la fraction non-volatile sur la perception de la flaveur du caramel. Dans la première étape, la fraction volatile du caramel a été analysée par Chromatographie en Phase Gazeuse couplée à l’Olfactométrie (GC/O), par GC couplée à la Spectrométrie de Masse (GC/MS) et par heart-cutting MDGC. Les résultats mettent en évidence une centaine de composés volatils et démontrent la richesse aromatique du caramel. L’objectif de la deuxième étape était d’évaluer la contribution de ces composes volatils à la typicité odorante du caramel. Des études ont montré que l’intensité odorante n’était pas suffisante pour évaluer l’impact des composés. Ce travail de thèse propose une approche originale de recombinaison d’odeur à partir de composés triés selon leur qualité odorante. Les résultats montrent que la typicité odorante caramel est le fruit d’un équilibre entre les notes caramel, fruité, fruits secs, végétal, animal, grillé, floral et piquant. Des tests d’addition, d’omission et d’un plan d’expérience factoriel complet ont démontré l’existence d’interactions perceptives. L’objectif de la dernière étape était d’étudier l’impact de la fraction non volatile sur la perception de la flaveur du caramel. L’étude de la libération de composés d’arôme in vitro par analyses SPME/GC/MS dans différentes matrices non volatiles démontre l’existence d’interactions physico-chimiques entre les composés d’arôme et les macromolécules non volatiles. Ces premiers résultats laissent supposer que la fraction non volatile est susceptible de moduler la perception de la flaveur
The aim of this study was to investigate the impact of the volatile odorant fraction and the non-volatile matrix on the perception of the caramel flavour. The first step focused on the analytical characterization of the volatile odorant fraction of aromatic caramel thanks to Gas Chromatography coupled to Olfactometry (GC/O), GC/Mass Spectrometry (GC/MS) and heart-cutting MDGC/MS/O. Results highlighted the presence of more than one hundred compounds and demonstrated the complexity of the caramel volatile fraction. The objective of the second step was to understand the contribution of odorant compounds identified to the caramel aroma typicality. Literature shows that odour intensity is not sufficient to evaluate the impact of compounds on the aroma. This thesis proposed an original approach to carry out the aroma recombination by taking into account odour qualities. Results showed that the caramel typicality results from a complex balance between caramel, fruity, vegetal, sharp, nutty, floral, roasted and animal odours. Omission, addition tests and a 24 factorial design showed the existence of perceptive interactions. The third step focused on studying the impact the macromolecules that constitute the non-volatile fraction on the perception of caramel flavour. In vitro aroma release was followed by SPME/GC/MS in different matrices varying in non-volatile composition. Results evidence physico-chemical interactions between aroma and macromolecule of the non-volatile fraction. Those preliminary results suggest that the non-volatile matrix is able to impact the flavour perception

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RAMIHONE, RANDRIAMANARIVO MONIQUE. "Contribution a l'etude des causes de la flaveur acide excessive du saucisson sec." Clermont-Ferrand 2, 1988. http://www.theses.fr/1988CLF21085.

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Une collecte d'echantillons a ete effectuee aupres des salaisonniers francais. L'influence de la taille des saucissons, ainsi que celle des parametres de fermentation et de sechage, sur l'apparition de la flaveur acide, ont ete etudiees. Les resultats montrent que les grosses pieces sont en moyenne plus acides que les petites, et que les echantillons acides ont une teneur en d-lactate plus elevee que les echantillons "doux". Les autres parametres mesures ne semblent pas intervenir dans cet accident de fabrication. La quantite importante de d-lactate dans les saucissons acides peut etre expliquee par la forte presence de leuconostoc dans les melees en fin d'etuvage. Le role de leuconostoc mesenteroides dans l'apparition de la saveur acide a ete verifie par son ensemencement dans les melees experimentales. L'effet de cette bacterie est accentue lorsque celle-ci est inoculee en meme temps que pediococcus pentosaceus, et supprime lorsqu'elle est associee a debaryomyces hansenii. Si le taux d'apport de glucose passe de 0,3 a 1%, la saveur acide du saucisson est plus prononcee. Compare au glucose, l'utilisation d'un sucre complexe (sirop de glucose) induit une vitesse initiale de fermentation plus lente, mais une production prolongee de lactate

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Friedrich, Conrad [Verfasser], Ulrich [Akademischer Betreuer] Husemann, Heiko [Akademischer Betreuer] Lacker, and Arno [Akademischer Betreuer] Straessner. "Search for single top-quark production via flavour-changing neutral currents in strong interactions using s = 8 TeV ATLAS data / Conrad Friedrich. Gutachter: Ulrich Husemann ; Heiko Lacker ; Arno Straessner." Berlin : Humboldt Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2015. http://d-nb.info/1078666466/34.

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Wilson, Aaron Benjamin. "Using the NCAR CAM 4 to Confirm SAM’s Modulation of the ENSO Teleconnection to Antarctica and Assess Changes to this Interaction during Various ENSO Flavor Events." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1376919626.

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44

Decourcelle, Nicolas. "Interactions composition-structure-texture-flaveur dans le yaourt brassé sans matière grasse aromatisé "à la fraise" : rôles des agents de texture, des édulcorants, et du temps." Dijon, 2004. http://www.theses.fr/2004DIJOS074.

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Des substituants de la matière grasse (agents de texture et édulcorants) sont incorporés dans les yaourts aromatisés « 0% » pour rétablir les changements liés à l’absence des globules gras. Ce procédé doit être étudié car il modifie les propriétés physico-chimiques et organoleptiques du yaourt. Nous montrons que seuls la pectine, l’amidon et le caroube en mélange dans le yaourt ont un effet sur la rhéologie (↓n et ↑K) et la libération des composés d’arôme (pectine↓ ; amidon↓ ; caroube↑). Les édulcorants n’ont pas d’effet sur les propriétés physico-chimiques des yaourts en présence d’agents de texture en mélange. La pectine agirait par le biais d’un réseau tri-dimensionnel et d’interactions avec les caséines. L’analyse prospective des résultats montre d’ailleurs la nécessité d’approfondir le rôle très particulier de la pectine que nous avons observé. Des interactions hydrophobes entre l’amidon et les composés d’arôme sont fortement suspectées. Le caroube exercerait un effet « salting-out » en diminuant la disponibilité de l’eau libre. Tous ces effets s’articulent autour des comportements linéaires et quadratiques des agents de texture, mais aussi de leurs interactions (synergies et antagonismes), et du temps. La méthodologie des plans d’expériences couplée à l’analyse des résultats par des régressions PLS nos a permis de décrire dans cet environnement complexe les interactions composition-structure-texture-flaveur dont l’approche est multidimensionnelle. Nous montrons ainsi qu’il existe une nette implication de la composition en agents de texture et des paramètres de structure et de déstructuration du yaourt (G’ et λe) dans les mécanismes de la perception de la flaveur (R2Ycum>0,8 et Q2cum>0,6). Nous montrons aussi qu’une composition similaire en composés d’arôme de la phase vapeur a une influence inverse sur la perception des descripteurs « fraise » et « floral ».

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Borsato, Martino. "Study of the BO to Kstar0 electron positron decay with the LHCb detector and development of a novel concept of PID detector : the Focusing DIRC." Sorbonne Paris Cité, 2015. https://theses.hal.science/tel-01456521.

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Les courants neutres changeant le saveur de type b —>sy sont interdites au niveau de l'arbre dans le Modèle Standard (MS) et ils se produisent au premier ordre à travers des diagrammes radiatives à boucle. Par conséquent, ils sont sensibles à la Nouvelle Physique (NP), qui peut contribuer soit au niveau de l'arbre ou de la boucle. En outre, la chiralité de l'interaction faible dans le MS implique que le photon émis a une polarisation gauche. Cependant, toute une classe de théories de NP ne partagent pas cette caractéristique du MS et pourraient se manifester sans ambiguïtés comme une contribution droite à la polarisation. Cette thèse présente la première étude de la polarisation du photon provenant du processus b —>sy à travers une analyse angulaire du canal BO —>K* 0 e+e-. Même si BO —> *K* 0 e+e- n'est pas une transition b—>s de type radiative, la contribution avec un photon virtuel qui se couple à la paire de leptons domine dans la région de bas q carré. De plus, le canal avec des électrons plutôt que des muons permet de mieux isoler cette contribution à l'extrémité inférieure du spectre de q carré. La luminosité intégrée de 3 fb-1 recueillie par LHCb au cours du Run 1 du LHC a permis pour la première fois de sélectionner un échantillon d'évènements B0—>K* 0 e+e¬ assez grands pour mesurer les asymétries transverses AT(2)=-0. 23±0. 23±0. 05 et ATIm=0. 14±0. 22±0. 05 dans la région de bas q carré entre 0. 002 GeV2/c4 et 1 GeV2/c4. Ces mesures sont consistent avec les prédictions du MS et ils fournissent de nouvelles contraintes sur les contributions droitiers à la polarisation avec le même niveau de précision que ceux venant des mesures faites avec des désintégrations radiatives. Les expériences de physique du saveur nécessitent de détecteurs avancés dédiés à l'identification des différentes saveurs des hadrons chargés. Ces détecteurs sont pour la plupart basés sur la détection de la lumière Cherenkov émise par ces particules lorsqu'elles traversent un milieu diélectrique. Cette thèse présente également l'activité de R&D sur un nouveau concept de détecteur basé sur le détecteur DIRC de l'expérience BABAR : le FDIRC. Son design est destiné à l'utilisation dans un environnement avec un bruit de fond deux ordres de grandeurs plus grand que dans BABAR grâce à une caméra d'imagerie plus rapide, de dimension réduite et composée de silice fondue résistant à l'irradiation. Le premier prototype à grande échelle a été testé au télescope à rayons cosmiques de SLAC et a démontré la faisabilité du concept de détecteur
Flavour-changing neutral current processes of the type b --+ sy are forbidden at the tree level in the Standard Model (SM) and occur at leading order through radiative loop diagrams. Therefore, they are sensitive to new physics (NP), which may contrebute either at the tree or loop level. Furthermore, the chirality of the weak interaction in the SM implies that the photon emitted has left-handed polarisation. However, a whole class of NP theories do not share this SM feature and may manifest unambiguously as a right-handed contribution to the polarisation. This thesis presents the first study of the b-* sy photon polarisation through an angular analysis of the B0-*K* 0 e+e- channel. Even though BO-*K* 0 e+e- is not a radiative b s transition, the contribution from a virtual photon coupling to the lepton pair dominates in the low-q2 region. Furthermore, the channel with electrons rather than muons allows to better isolate the virtual photon contribution at the low end of the q 2 spectrum. The integrated luminosity of 3 fb-1 collected by LHCb during LHC Run 1 allowed for the first time to select a sample of B0-›K* 0 e+e- events large enough to measure the transverse asymmetries AT(2)=-0. 23±0. 23±0. 05 and ATIm=0. 14±0. 22±0. 05 in the low q2 region between 0. 002 GeV2/c4 and 1 GeV2/c4. These measurements are found to be consistent with SM predictions and provide new constraints on right handed contributions to the photon polarisation at the same level of precision as the ones from measurements involving radiative decays. Flavour physics experiments require advanced detectors dedicated to the identification of the different flavours of charged hadrons. Most of them are based on the detection of the Cherenkov light emitted by these particles as they traverse a dielectric medium. This thesis presents also the R&D activity on a new detector concept based on the BABAR DIRC, the FDIRC. Its design is intended to operate the detector in an environment with background two orders of magnitude larger than BABAR thanks to a faster and smaller imaging camera made of radiation-hard fused silica. The first full-scale prototype of the FDIRC was tested at the SLAC Cosmic Ray Telescope and demonstrated the feasibility of the detector concept

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Li, Shuang. "Muon production from heavy-flavour hadron decays in p-Pb and pp collisions with ALICE at the CERN-LHC." Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22602/document.

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Les collisions d’ions lourds au LHC permettent l’étude des propriétés de la matière nucléaire soumise à des conditions extrêmes de température et densité d’énergie où on assisterait à la formation du Plasma de Quarks et Gluons (QGP). La mesure des saveurs lourdes ouvertes (charme et beauté) est particulièrement intéressante pour l’étude des propriétés du QGP. L’étude des collisions d’ions lourds au LHC nécessite aussi la mesure des collisions pp et p–Pb. Les collisions p-Pb permettent en particulier d’étudier les effets nucléaire froids et d’interpréter les effets nucléaires chauds observés dans les collisions Pb–Pb. Cette thèse est dédiée à l’étude de la production des saveurs lourdes ouvertes via les muons simples dans les collisions p–Pb à √8NN = 5.02 TeV aux rapidités avant et arrière avec le détecteur ALICE au LHC. La référence pp est estimée à partir des mesures pp à √8 = 2.76 TeV et 7 TeV et utilisant des calculs pQCD pour l’extrapolation à √8 = 5.02 TeV. Les mesures du facteur de modification nucléaire (RpPb) et du rapport des sections efficaces aux rapidités avant et arrière indiquent que les effets nucléaires froids sont faibles sur tout le domaine en impulsion transverse (pT) aux rapidités avant (RpPb ≈ 1). Aux rapidités arrière, le facteur de modification nucléaire est sensiblement plus grand que un dans la région 2 < pT < 4 GeV/c. Les résultats confirment que la forte suppression des taux de production des muons issus du charme et de la beauté mesurée dans les collisions centrales Pb–Pb est due au milieu dense et chaud. Le facteur de modification nucléaire et le rapport des sections efficaces aux rapidités avant et arrière sont aussi mesurés en fonction de la centralité dans les collisions p-Pb. Le facteur de modification nucléaire reste compatible avec l’unité à grand pT dans les collisions centrales
The LHC heavy-ion physics program aims at investigating the properties of strongly-interacting matter in extreme conditions of temperature and energy density where the Quark-Gluon Plasma (QGP) is formed. In high-energy heavy-ion collisions, heavy quarks (charm and beauty) are regarded as efficient probes of the properties of the QGP. The heavy-ion physics program requires also the study of proton-proton (pp) and proton-nucleus (p–Pb) collisions. The study of p–Pb collisions is used to investigate cold nuclear matter effects and to validate and quantify hot nuclear matter effects which are observed in nucleus-nucleus (Pb–Pb) collisions. This thesis work is devoted to the study of open heavy-flavour production at forward and backward rapidity via single muons in p–Pb collisions at √8NN = 5.02 TeV with the ALICE experiment at the LHC. The pp reference using available measurements at 2.76 and 7 TeV and a pQCD-driven method for the scaling to 5.02 TeV is estimated. The measurements of the nuclear modification factor (RpPb) at forward and backward rapidity and forward-to-backward ratio in p–Pb collisions, indicate that cold nuclear matter effects are small over the whole transverse momentum (pT) region at forward rapidity (RpPb compatible with unity within uncertainties). In the backward rapidity, the nuclear modification factor deviates from unity in the intermediate pT region (2 < pT < 4 GeV/c). These results confirm that the strong suppression measured at high pT in central Pb–Pb collisions is due to final-state effects induced by the hot and dense nuclear medium. The results of the nuclear modification factor and forward-to-backward ratio as a function of centrality in p–Pb collisions are discussed. Even in central collisions, the nuclear modification factor is compatible with unity at high pT

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Afzal, Muhammad Inam. "Physiologie et aspects technologiques de Carnobacterium maltaromaticum LMA 28 en biopréservation alimentaire." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0174/document.

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Carnobacterium maltaromaticum est une bactérie lactique atypique isolée de fromages à pâte molle. Les caractéristiques majeures de cette bactérie sont i) sa capacité à produire un arôme de type malté ou chocolaté, le 3-méthylbutanal à partir du catabolisme de la leucine ii) sa capacité à produire des bactériocines, peptides à activité antibactérienne vis-à-vis de flores pathogènes et/ou d'altération fréquemment rencontrées en industries alimentaire, telle que Listeria monocytogenes. Une caractérisation phénotypique et génotypique réalisée sur six souches de C. maltaromaticum isolées du même biotope a montré que celles-ci ne sont pas phylogénétiquement identiques. Même si ces souches n'ont pas la capacité à coaguler rapidement le lait, elles sont acidotolérantes. Elles n'influent pas sur la capacité ni la rapidité de coagulation des starters, Lactococcus lactis et Streptococcus thermophilus utilisés en industrie laitière. L'étude de l'impact de C. maltaromaticum sur la flore bactérienne du fromage a révélé que sa présence provoque la diminution de la concentration de Psychrobacter, germe pouvant être responsable d'une accélération du phénomène de vieillissement du fromage. Un plan d'expérience a été réalisé pour mettre en évidence ces inhibitions et les éventuelles interactions entre différents facteurs (concentration cellulaire initiale, concentration en NaCl, pH, durée d'incubation). Deux modèles ont été choisis i) Psychrobacter sp. et ii) L. monocytogenes. La concentration cellulaire de C. maltaromatiucm est le facteur le plus important pour inhiber les bactéries testées. Cette espèce opportuniste pourrait être considérée comme un auxilliaire de fabrication intéressant et pourrait être retenue comme flore bactérienne d'affinage. Toutes les souches de C. maltaromaticum testées sont capables de produire du 3-méthylbutanal pouvant conférer une flaveur maltée au fromage. Les études menées sur la biosynthèse du 3-méthylbutanal ont montré la présence et la fonctionnalité de deux voies métaboliques; la voie directe impliquant l'alpha-cétoacide décarboxylase et la voie indirecte passant par l'alpha-cétoacide déshydrogénase. L'oxygénation du milieu de culture a un impact positif sur la formation du 3-méthylbutanal et du 3-méthylbutanol avec la stimulation des voies directes et indirectes
Carnobacterium maltaromaticum is a lactic acid bacterium isolated from atypical soft cheeses. The major characterstics of this bacterium are i) its ability to produce a malty or chocolate-like flavor 3-methylbutanal from leucine catabolism ii) its ability to produce bacteriocins against pathogenic and spoilage bacteria for instance, Listeria monocytogenes. Phenotypic and genotypic characterization of six strains of C. maltaromaticum isolated from the same habitat showed that they were not phylogenetically identical. Although these strains lacked the ability to coagulate the milk quickly, they were acid tolerant. They did not affect the milk coagulation capacity of startes, Lactococcus lactis and Streptococcus thermophilus used in dairy industry. The study on the impact of C. maltaromaticum on the bacterial flora of cheese showed that its presence resulted in the decrease of the concentration of Psychrobacter, which might be responsible for accelerating the aging phenomenon of cheese. An experimental plan was realized to highlight these inhibitions and possible interactions between factors (cell concentration, NaCl, pH, incubation time) by choosing two models i) Psychrobacter sp. and ii) L. monocytogenes. The cell concentration of C. maltaromatiucm was the factor more significant for the inhibitions of the tested bacteria. Being psychrotrophic, alkalinophilic, malty or chocolate flavor producing and biopreservative agent, this species could play a role as a ripening flora of cheese. All strains of C. maltaromaticum tested were able to produce 3-methylbutanal conferring any malt flavor to cheese. The results on the physiology involved in the biosynthesis of 3-methylbutanal showed the presence and functionality of both metabolic pathways; the direct by alpha-ketoacid dacarboxylase enzyme and indirect comprising alpha-keto acid dehydrogenase enzyme. The oxygenation of culture medium had a positif impact on the formation of 3-methylbutanal and 3-methylbutanol with the stimulation of both direct and indirect metabolic routes

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Zhang, Zuman. "Open heavy-flavour measurements via muons in proton-proton and nucleus-nucleus collisions with the ALICE detector at the CERN-LHC." Thesis, Université Clermont Auvergne‎ (2017-2020), 2018. http://www.theses.fr/2018CLFAC077/document.

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Les collisions d'ions lourds ultra-relativistes ont pour objectif l'étude d'un état de matière en interaction forte dans des conditions extrêmes de densité d'énergie et température, le plasma de quarks et gluons (QGP). Les saveurs lourdes (charme et beauté) sont produites principalement lors de processus durs aux premiers instants de la collision et participent aux différentes étapes de la collision. Par conséquent, la mesure des saveurs lourdes ouvertes devrait permettre d'extraire des informations importantes concernant le système créé aux premiers instants de la collision. L'étude des collisions proton-proton (pp) fournit la référence indispensable pour la mesure des saveurs lourdes dans les systèmes lourds. Cette thèse est dédiée à l'étude de la production des muons de décroissance des hadrons charmés et beaux aux rapidités avant (2.5 < y < 4) dans les collisions pp sqrt (s) = 5.02 TeV, Pb-Pb à sqrt (sNN) = 2.76 et 5.02 TeV et Xe-Xe à sqrt (sNN) = 5.44 TeV enregistrées avec le détecteur ALICE au CERN-LHC. La mesure des sections efficaces différentielles de production des muons de décroissance des hadrons charmés et beaux dans les collisions pp à sqrt (s) = 5.02 TeV couvre un grand domaine en impulsion transverse de 2 à 20 GeV/c et ont une meilleure précision par rapport aux résultats publiés à sqrt (s) = 2.76 et 7 TeV. Les résultats sont en bon accord avec les calculs perturbatifs de QCD. Une importante suppression de la production des muons de décroissance des hadrons charmés et beaux est observée dans les collisions centrales (0-10%) Pb-Pb à sqrt (sNN) = 2.76 et 5.02 TeV. Cette suppression est attribuée au milieu dense et chaud formé dans ces collisions. L'influence de la taille du système est étudiée avec le système Xe-Xe à sqrt (sNN) = 5.44 TeV. La suppression est similaire à celle mesurée dans les collisions Pb-Pb. Les résultats obtenus dans les collisions Pb-Pb et Xe-Xe apportent des contraintes fortes aux paramètres des modèles
The study of ultra-relativistic heavy-ion collisions aims at investigating a state of strongly-interacting matter at high energy density and temperature, the Quark-Gluon Plasma (QGP). Heavy quarks (charm and beauty) are predominantly produced in initial hard scattering processes during the early stage of the collisions and experience the full evolution of the medium. Therefore, the measurement of open heavy flavours should provide essential information on the QGP properties. Similar measurements in small systems are also essential for a comprehensible understanding of the QGP properties. The study of open heavy flavours in proton-proton (pp) collisions provides the mandatory reference for measurements in heavy-ion collisions. This thesis presents measurements of the production of muons from heavy-flavour hadron decays at forward rapidity (2.5 < y < 4) in pp collisions at sqrt (s) = 5.02 TeV, Pb-Pb collisions at sqrt (sNN) = 2.76 and 5.02 TeV and Xe-Xe collisions at sqrt (sNN) = 5.44 TeV collected with the ALICE detector at the CERN-LHC. The differential production cross sections of muons from heavy-flavour hadron decays in pp collisions at sqrt (s) = 5.02 TeV are obtained in a wide transverse momentum interval, 2 < pT < 20 GeV/c, and with an improved precision compared to the previously published measurements at sqrt (s) = 2.76 and 7 TeV. The measurements are described within uncertainties by predictions based on perturbative QCD. A strong suppression of the yield of muons from heavy-flavour decays is observed in the 10% most central Pb-Pb collisions at both sqrt (sNN) = 2.76 and 5.02 TeV. This suppression is due to final-state effects induced by the hot and dense medium. The suppression in Xe-Xe collisions is similar to that observed with Pb-Pb collisions. The comparison in the two colliding systems provides insight in the path-length dependence of medium-induced parton energy loss. The results constrain model calculations

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Ticse, Torres Royer Edson. "Search for the Higgs boson in the ttH(H -> bb) channel and the identification of jets containing two B hadrons with the ATLAS experiment." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4052/document.

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En juillet 2012, le CERN a annoncé la découverte du boson de Higgs qui est la dernière particule manquante du Modèle Standard (MS). Le boson de Higgs a été observé dans différents canaux. La mesure précise de ses propriétés est maintenant très importante pour rechercher des déviations par rapport au SM. Cette thèse présente une recherche du boson de Higgs produit en association avec une paire de quarks top et se désintégrant en une paire de b quark, le canal ttH(H → bb) , en utilisant les données de collisions proton-proton à √s = 13 TeV, collectées avec le détecteur ATLAS en 2015 et 2016. Ce document détaille en particulier la reconstruction du systéme ttH et la séparation du signal du bruit de fond principal tt + jets. Des études récentes montrent qu'il existe une fraction importante du bruit de fond ttbb avec des jets contenant deux hadrons b. Un nouvel algorithme a été développé pour séparer ces jets des jets contenant un seul b-hadron. La description de cet outil est présenté dans cette thèse
In July 2012, CERN announced the discovery of the Higgs boson, the last missing piece of the Standard Model (SM). The Higgs boson was observed in different channels. Precise measurement of its properties is now very important to investigate for possible deviations from the SM. This thesis presents a search for the Higgs boson produced in association with top quarks and decaying to a b quark pair, the ttH(H→bb) channel, using proton-proton collisions at √s = 13 TeV, collected with the ATLAS detector in 2015 and 2016. This document details in particular the full reconstruction of the ttH(H→bb) system and the discrimination between signal and the main background, tt+jets. The ttbb is a subset of the tt+jets backgrounds recent studies show that there is a large fraction of ttbb events with jets containing two b-hadrons. A new algorithm has been developed to discriminate such jets from single b-hadrons jets. The description of this tool is presented in this thesis

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Lytra, Georgia. "Importance des interactions perceptives dans l’expression de l’arôme fruité typique des vins rouges." Thesis, Bordeaux 2, 2012. http://www.theses.fr/2012BOR21986/document.

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La plupart des composés volatils connus et impliqués dans les mécanismes de l’expression fruitée des vins rouges sont présents à des teneurs inférieures ou proches de leurs seuils de perception individuels. Compte tenu de phénomènes d’interactions perceptives entre eux, il est très complexe de déterminer leur impact réel sur l’arôme du vin. Au vu des difficultés rencontrées pour reconstituer fidèlement l’arôme des vins à partir uniquement de composés purs, nous avons développé une méthodologie permettant d’aborder cette reconstitution aromatique à partir de fractions issues du vin lui-même, afin de pouvoir évaluer l’importance relative de ces différentes fractions aromatiques vis-à-vis de l’arôme global du vin. Grâce à l’analyse sensorielle, et en s’attachant à quelques descripteurs particuliers, nous avons pu mettre en évidence, quelques interactions perceptives particulières comme des effets de contributions marquées ou de masquage. La caractérisation des composés présents dans les fractions concernées et à l’origine de ces effets notables a été mise en œuvre. Nos résultats soulignent le rôle indirect du 2-hydroxy-4-méthylpentanoate d’éthyle, un ester éthylique élué dans la fraction à l’origine d’une contribution marquée aux notes de fruits noirs frais qui, en provoquant la diminution du "seuil de perception" du pool fruité des vins rouges et l’augmentation de l’intensité de leurs notes de fruits noirs et de fruits frais, agit comme un exhausteur naturel de ces notes fruitées. Nous sommes aussi parvenus à mettre en évidence, le rôle direct du diacétyle, mais aussi le rôle indirect de l’acétoïne, de l’acide acétique et de la γ-butyrolactone, malgré leurs concentrations infraliminaires, sur la diminution de l’intensité globale et l’intensité du caractère de fruits frais. Ces résultats soulignent leur fort caractère, seuls ou en mélanges, de "réducteurs" de l’intensité de ces notes, et ce, même à des concentrations infraliminaires. Enfin, le comportement particulier, au sein d’un mélange fruité, du 3-hydroxybutanoate d’éthyle, de l’acétate de 2-méthylpropyle, du propanoate d’éthyle et de l’acétate de butyle, présents à des concentrations infraliminaires a été mis en évidence. La présence en mélange des deux premiers provoque la baisse notable du "seuil de perception" du pool fruité et celle des trois derniers augmente l’intensité des notes de fruits frais et fruits noirs traduisant l’effet exhausteur d’arômes dû à ces composés, effet comparable de celui du 2-hydroxy-4-méthylpentanoate d’éthyle qui présente quelques analogies structurales avec ces composés
Most of volatiles involved in red wines’ fruity expression are present at levels below or close to their individual perception thresholds. Given the existence of perceptive interactions between them, it is very difficult to determine their real impact on wine aroma. Rather than assessing the olfactive behavior of mixtures prepared from pure products, the main goal of this work was to highlight and study the impact of perceptive interactions on wine fruity aroma expression using various aromatic reconstitutions prepared from wine fractions. Sensory profile analyses identified significant differences among aromatic reconstitutions for the intensity of some descriptors, as particular "additive" or "masking" effects. The composition of the involved fractions was then studied by instrumental methods. The final target was to investigate the impact of fraction components on fruity aroma by preparing aromatic reconstitutions and using sensory reconstitution tests, to assess the role of these compounds on the perceptive interactions previously observed. Further analysis revealed that ethyl 2-hydroxy-4-methylpentanoate, eluted in fraction which had an "additive" effect on the black-berry and fresh fruity aroma, does not play a direct role as a key compound in red wine aroma. In contrast, our findings highlighted its indirect contribution to wine aroma, showing that this ester contributed to a synergistic effect, enhancing the perception of fruity character. Finally, it was clearly demonstrated that this compound acts as a natural enhancer for black-berry and fresh fruit notes in red wine. It was also established that diacetyl, acetoin, acetic acid and γ-butyrolactone together played the same hypo-additive role as fractions of which they were eluted, presenting a "masking" effect on fresh fruity aroma. The impact of the last three compounds was demonstrated conclusively, even at subthreshold concentrations. These findings highlighted the existence of new remarkable perceptual interactions impacting overall and fresh-fruit aroma perception. The particular behavior, in a fruity mixture, of ethyl-propanoate, ethyl-3-hydroxybutanoate, butyl acetate and 2-methylpropyl acetate, present at subthreshold concentrations, was demonstrated. The presence of ethyl-3-hydroxybutanoate and 2-methylpropyl acetate in mixture led to a significant decrease of the olfactory threshold of fruity pool confirming their synergistic effect in the overall increase intensity. These compounds with close chemical structures, participate, both quantitatively and qualitatively, in the modulation of red wines’ fruity aromas acting as natural enhancers of black-berry and fresh-fruit aromas

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Dissertations / Theses on the topic 'Flavour interaction'

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