Search

Cet article enquête sur le chocolat dans la société d’Ancien Régime à travers une sélection de traités, dictionnaires et romans de l’époque des Lumières. Ces textes fournissent des indications précieuses sur ses bienfaits, sa préparation et sa consommation – dévoilant de nouveaux rituels, tant alimentaires que sociaux, surtout liés à l’imaginaire libertin. Les romans témoignent par ailleurs de l’évolution des pratiques descriptives. Les analyses d’extraits permettent de proposer quelques topoï comme « prendre son chocolat », « inviter à prendre le chocolat », « éprouver plaisir lié au chocolat » ou encore « (tenter d’) administrer poison ou narcotique dans chocolat »., This article investigates chocolate in Ancien Régime society through a selection of treatises, dictionaries, and novels from the Enlightenment. These texts provide valuable information on its benefits, preparation, and consumption – revealing new dietary as well as social rituals, closely linked to the libertine imagination. In addition, the novels inform the evolution of descriptive practices. The analysis of short excerpts enables us to propose a few topoi, such as “to take one’s chocolate,” “to invite to take chocolate,” “to feel pleasure with chocolate” or “(to attempt) to administer poison or narcotic in chocolate.”

La Côte d’Ivoire est le premier pays producteur de cacao au monde. Plus de 65% de cette production est exportée sous la forme de fèves brutes. Cependant, depuis quelques années, des initiatives sont prises en campagne pour la transformation des fèves en divers produits. Cette innovante initiative des femmes analphabètes pour la plupart manque de soutiens. Comment malgré ces difficultés, cette innovation parvient-elle à autonomiser les femmes et réduire ainsi la pauvreté rurale ? Ce travail porte sur un total de 100 femmes regroupées en coopérative. Il montre la capacité des femmes rurales à transformer leur environnement. La méthode repose sur une étude bibliographique, des observations participantes et des entretiens individuels et de groupes. Les résultats montrent que ces unités de transformation sont certes artisanales mais elles donnent des produits variés (chocolat, savons au beurre de cacao, beignets de cacao...) capables d’apporter des revenus substantiels aux femmes. Cette activité a par ailleurs changé le statut des femmes en faisant d’elles des employés ayant des revenus constants. Elle a ouvert les campagnes sur le monde et intensifié les relations entre la ville et la campagne.

Cocoa pod-opening delay and bean fermentation promote the organoleptic quality of chocolate. The present research investigated the changes in the volatile fingerprint of cocoa harvested at a traditional plantation. Cocoa beans extracted from 2-days pod-opening delay were simultaneously fermented for 5 days using container and then sun-dried to 7-8% moisture content at five different locations: Akoupé, San Pedro, Soubré, Djekanou and Daloa. The aromatic analysis were done on cocoa using the HS-SPME-GC/MS technique. Professional panelists evaluated the sensory perceptions of the chocolate. The results shows that cocoa fermented in both Daloa and Soubré regions were differentiated by 2,3-butanediol while those processed in other regions presented highest acetoin content. However, fermented cocoa from Soubré region exhibited most amount of 2,3-butanediol, diacetate A whereas 2,3,5,6-tetramethylpyrazine differentiated those from Daloa region. Sensory properties of chocolate were not linked to the aromatic compound precursors profile of beans. The fermentation performed in San Pédro region promote both the generation of more desirable aromatic compounds of cocoa and sensory attributes of the finished chocolate. The fermentation location generates a greater differentiation of the volatile fingerprint of cocoa and the sensory perceptions of the finished chocolate.

Cocoa is produced in countries in the southern hemisphere and consumed in the countries of the northern hemisphere. This geographical dispersion has created a kind that isolated partitions tightly the world of cocoa than chocolate. The producers think they produce cocoa with the best attributes and chocolatiers who demand difficulty finding cocoa with the attributes they need. This finding is the basis of the research question and the purpose of this book. The use of quality attributes of cocoa / chocolate appreciated by European consumers as parameters to establish a marketing strategy for cocoa / chocolate Brazilian with quality and origin labels.; Véritables gages pour le consommateur, les labels alimentaires s’affichent partout et sont tellement nombreux qu’il devient de plus en plus difficile de s’y retrouver. Bio, Origine contrôlée, Commerce équitable, respect de l’environnement, etc. Cette profusion a entamé la confiance des consommateurs dans les labels en particulier à cause de leurs imprécisions sur la composition, l’origine et la faible traçabilité du produit. Les petits producteurs de cacao brésiliens s’interrogent sur les informations à fournir aux consommateurs pour leur garantir la qualité des tablettes de chocolat noir. Nous proposons, dans cette recherche, basée sur la théorie de l’action raisonnée et sur la psychologie cognitive, d’évaluer les effets des labels et des attributs intrinsèques des produits sur l’attitude et l’intention d’achat des produits alimentaires. A cette fin, deux modèles conceptuels qui intègrent les acquis de la littérature sur les labels et les marques, ceux de la littérature sur l’importance des avantages recherchés dans les produits sont proposés. Ils mettent en relation les effets comparés des labels Biologiques, Équitables et la marque artisan et des attributs intrinsèques, l’origine et le taux de cacao. Les résultats d’une expérimentation de 12 tablettes de chocolat noir auprès de 524 consommateurs ont permis d’une part de valider l’effet de halo des marques et des labels et le rôle des attributs intrinsèques dans l’évaluation des produits. Les informations apportées par les labels permettent une amélioration de l’attitude des consommateurs envers les produits dégustés en aveugle. Partant des bénéfices goût, santé et plaisir, nous montrons la contribution forte des labels au bénéfice plaisir et l’apport des bénéfices santé et gout par les attributs intrinsèques.

This research describes on-farm-inoculated cocoa bean fermentation with two selected strains of high aroma-producing Saccharomyces cerevisiae isolated from wine fermentation and their effects on volatile profile of resulted raw cocoa material and sensory characteristics of chocolates produced. Both strains produced suitably flavour-active esters, aldehydes, ketones and pyrazines in raw cocoa. Inoculation of S. cerevisiae at 0.5 g kg−1 significantly improved the volatile profile of raw cocoa beans and enabled production of chocolate with enhanced intense fresh fruits and floral notes. Chocolate produced thereof presented better overall quality attributed whatever the fermentation time in comparison to the chocolate issued from spontaneous fermentation. Our results suggested the ways of using selected enhanced yeasts as S. cerevisiae for on-farm implementation of bean fermentation as promising alternative possibilities to improve the cocoa fermentation process, desirable flavourful raw cocoa material and high-aroma-quality chocolates produced.

International audience

The aromatic quality of chocolate requires the use of cocoa with high aromatic potential, this being acquired during the fermentation of cocoa beans. Traditional fermentation is still often carried out on a small scale with wild strains of yeasts and acetic bacteria and under poorly controlled conditions leading to cocoa quality ranging from best to worst. This study is the first part of a project aiming to control quality of cocoa to produce high aromatic quality chocolate by using a mixed starter of selected strains of yeast and acetic bacteria and by controlling the conditions of fermentation. To achieve this objective, a mathematical model of the alcoholic fermentation of cocoa beans has been developed. The growth, glucose consumption and ethanol production of Saccharomyces cerevisiae LM strain in synthetic broth were modeled for the most important intrinsic (pH, glucose, ethanol, free nitrogen and oxygen levels) and extrinsic (temperature, oxygen level) fermentation parameters. The model was developed by combining the effects of individual conditions in a multiplicative way using the gamma concept. The model was validated in liquid synthetic medium at two different inoculation levels 104 and 106 CFU/mL with an increase in temperature that recorded during spontaneous fermentations. The model clearly shows that the level of inoculation and the speed of the increase in temperature clearly drive yeast growth, while other factors including pH and ethanol, free nitrogen and oxygen levels have no significant impact on yeast growth.

National audience; Le port de Saint-Tropez (3e port provençal à la fin du XVIIIe siècle) dont les marins ont pratiqué dès le XVIe siècle le commerce à la cueillette ou à l’aventure, particulièrement avec l’Empire Ottoman, apparaît comme un lieu d’observation privilégié pour appréhender l’émergence du café, du thé et du chocolat en Provence aux XVIIe et XVIIIe siècles. À partir de plusieurs centaines d’inventaires et de carnets de bord de la période, il s’agit de déterminer, les premières arrivées de ces boissons exotiques ; leur implantation dans les foyers provençaux, d’abord chez les nobles et les grands bourgeois puis dans les familles plus modestes, mais aussi sur les bateaux et dans les établissements dévolus à leur consommation ; les objets utilisés : matériaux, provenance, fréquence. Les archives de Fréjus et des communautés agricoles environnantes permettrons de mesurer l’expansion de ces boissons hors du milieu maritime.

The objective of this thesis is the formulation of fat-reduced chocolate and emulsifier free chocolate without affecting the viscosity and yield stress of the melt chocolate. To achieve these objectives, we control the rheological behavior of chocolate suspensions by optimizing the morphological properties (particle size distribution, particle shape and maximum packing fraction) of sugar and cocoa powders.First, we develop appropriate protocols for the characterization of the morphological and rheological properties of chocolate suspensions.Then, we study the effect of the production process on the rheological and morphological properties of chocolate and show that viscosity depends on the relative solid volume fraction (i.e., solid volume fraction to maximum packing fraction ratio) and that the yield stress depends on both the relative solid volume fraction and is inversely proportional to the particle mean size. Our experimental results show that the viscosity of chocolate suspension (i.e., sugar, cocoa, sugar and cocoa suspensions) can be related to the solid volume fraction and the maximum packing fraction by the phenomenological Krieger-Dougherty type equation.Moreover, we show that the maximum packing fraction of cocoa and sugar powders can be well predicted by the compressive packing model developed for the optimization mineral powders used in construction materials.Finally, we exploit these results and models to attain the objectives of this thesis. We show that, an accurate control of maximum packing fraction by adding “fine” cocoa particles, allows for the decrease of the amount of fat in chocolate without affecting viscosity and chocolate solid composition. We show that an accurate control of particle average size and maximum packing fraction by adding “coarse” sugar particles allows for the removal of the emulsifiers from chocolate without increasing the fat content of the suspension and affecting the viscosity and yield stress, L'objectif de cette thèse est la formulation de chocolat à faible taux de matière grasse et de chocolat sans émulsifiant tout en gardant les mêmes propriétés rhéologiques (viscosité et seuil) que ceux du chocolat conventionnel. Pour atteindre ces objectifs, nous contrôlons le comportement rhéologique des suspensions de chocolat en optimisant les propriétés morphologiques (taille et forme des particules et compacité maximale) des poudres de sucre et de cacao.Tout d'abord, nous développons des protocoles appropriés pour la caractérisation des propriétés morphologiques et rhéologiques des suspensions de chocolat.Ensuite, nous étudions l'effet du processus de production sur les propriétés rhéologiques et morphologiques du chocolat et montrons que la viscosité dépend de la fraction volumique solide relative (c'est-à-dire le rapport fraction volumique solide / compacité maximale) et que le seuil dépend de la fraction volumique solide relative et est inversement proportionnelle à la taille moyenne des particules. Nos résultats expérimentaux montrent que la viscosité de la suspension de chocolat (c'est-à-dire les suspensions de sucre, de cacao, de sucre et de cacao) peut être liée à la fraction volumique solide et à la compacité maximale par l'équation phénoménologique de type Krieger-Dougherty.De plus, nous montrons que la compacité maximale des poudres de cacao et de sucre peut être bien prédite par le modèle « Compressible Packing Model » développé pour l'optimisation des poudres minérales utilisées dans les matériaux de construction.Enfin, nous exploitons ces résultats et modèles pour atteindre les objectifs de cette thèse. Nous montrons qu'un contrôle précis de la compacité maximale en ajoutant des particules de cacao « fines » permet de diminuer la quantité de matière grasse dans le chocolat sans affecter la viscosité et la composition solide du chocolat. Nous montrons qu'un contrôle précis de la taille moyenne des particules et de la compacité maximale en ajoutant des particules de sucre « grossières » permet d'éliminer les émulsifiants du chocolat sans augmenter la teneur en matière grasse de la suspension et affecter la viscosité et le seuil

Les chocolatiers bean-to-bar redéfinissent le chocolat en mettant l’accent sur le processus de transformation et la biodiversité cacaoyère. Basée sur une ethnographie multisituée à Montréal et à Piura (nord péruvien), cette recherche retrace le trajet de la fève de cacao le long d’une filière de chocolat bean-to-bar pour analyser l’articulation entre les valeurs des économies morales des chocolatiers et des producteurs de cacao fin. Grâce à une incursion dans l’histoire du chocolat, l’économie morale des chocolatiers est définie comme un positionnement contre l’industrie du chocolat conventionnel et ses standards. Alors que les valeurs des chocolatiers gravitent autour d’une éthique gustative engendrant des préoccupations pour la biodiversité cacaoyère et les droits des cacaoculteurs, celles des producteurs visent plutôt à renforcer leurs rôles familiaux et communautaires et à mettre en place un projet de développement local collectif. Cette étude suggère qu’une analyse des économies morales peut rendre compte de l’articulation entre des économies capitalistes et précapitalistes et des phénomènes qui y sont créés, dans le cas présent, la production d’une localité cacaoyère., Bean-to-bar chocolate makers redefine chocolate by drawing attention to the transformation process and cacao biodiversity. Based on a multi-sited ethnography in Montreal and Piura (northern Peru), this research follows the cacao bean through a bean-to-bar chocolate filière to study how the values of chocolate makers and fine cacao producers' moral economies are embedded. Through an incursion into the history of chocolate, the moral economy of chocolate makers is defined as a posture against the conventional chocolate industry and its standards. While chocolate makers' values gravitate towards a taste ethic that generates preoccupations for cacao biodiversity and cacao farmers' rights, producers' values aim to reinforce their family and community roles and to implement a collective project of local development. This research puts forward moral economy as a conceptual tool for studying the embeddedness between capitalist and pre-capitalist economies and the phenomena that emerge from this nexus, in this case, the production of a cacao locality.

Despite the importance of fermentation for cocoa quality, process parameters are not controlled under spontaneous conditions at farms. This study evaluates the influence of spontaneous fermentation and processing under laboratory-controlled conditions using the acidic reagents acetic and lactic acids on the cocoa quality of two cultivars, FEAR 5 and CCN 51, at the sensory and metabolomic levels. Under spontaneous conditions, cocoa differs in flavour quality. While FEAR 5 produces chocolate with good global quality, chocolate made with CCN 51 does not have outstanding quality attributes. Transformation under controlled conditions with acidic reagents increases the perception of fine aromatic notes such as fruity, nutty and floral attributes in chocolates made from both cultivars of cocoa. Metabolomic profiles allowed grouping of cocoa samples as a function of postharvest treatment. Twenty-five differential metabolites were identified during the postharvest processes, and these metabolites may be related to the expression of fine sensory attributes; however, more research is needed.

National audience; Cette étude s’appuie sur les dépouillements de diverses sources écrites : sénéchaussée, justice et notaires principalement. Les inventaires d’intérieurs grassois témoignent de la consommation de nouveaux produits d’origine exotique à Grasse à partir du XVIIIe siècle : le café, le thé, le chocolat mais aussi le sucre qui les accompagne. Comme pour d’autres denrées, le notaire ou le greffier ne notent que rarement leur présence en considérant qu’il s’agit non seulement de denrées périssables mais, que trouvées en petites quantités, elles sont naturellement destinéesà être consommées à brève échéance. Par conséquent, ces nouvelles consommations sont davantage révélées par l’apparition et la diffusion d’une vaisselle spécifique ou parfois de quelques instruments spécialisés : cafetières, tasses à café, théières, chocolatières, sucriers... Si ces nouvelles consommations qui apparaissent d’abord dans les milieux aristocratiques deviennent plus courantes chez d’autres notables de Grasse, elles restent néanmoins limitéesaux catégories les plus élevées de la société.

Dark chocolate samples were previously classified into four sensory categories. The classification was modelled based on volatile compounds analyzed by direct introduction mass spectrometry of the chocolates&rsquo, headspace. The purpose of the study was to identify the most discriminant odor-active compounds that should characterize the four sensory categories. To address the problem, a gas chromatography-olfactometry (GC-O) study was conducted by 12 assessors using a comparative detection frequency analysis (cDFA) approach on 12 exemplary samples. A nasal impact frequency (NIF) difference threshold combined with a statistical approach (Khi&sup2, test on k proportions) revealed 38 discriminative key odorants able to differentiate the samples and to characterize the sensory categories. A heatmap emphasized the 19 most discriminant key odorants, among which heterocyclic molecules (furanones, pyranones, lactones, one pyrrole, and one pyrazine) played a prominent role with secondary alcohols, acids, and esters. The initial sensory classes were retrieved using the discriminant key volatiles in a correspondence analysis (CA) and a hierarchical cluster analysis (HCA). Among the 38 discriminant key odorants, although previously identified in cocoa products, 21 were formally described for the first time as key aroma compounds of dark chocolate. Moreover, 13 key odorants were described for the first time in a cocoa product.

International audience; The present study aims at developing an analytical methodology which allows correlating sensory poles of chocolate to their chemical characteristics and, eventually, to those of the cocoa beans used for its preparation. Trained panelists investigated several samples of chocolate, and they divided them into four sensorial poles (characterized by 36 different descriptors) attributable to chocolate flavor. The same samples were analyzed by six different techniques: Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS), Solid Phase Micro Extraction-Gas Chromatography-Mass Spectroscopy (SPME-GC-MS), High-Performance Liquid Chromatography (HPLC) (for the quantification of eight organic acids), Ultra High Performance Liquid Chromatography coupled to triple-quadrupole Mass Spectrometry (UHPLC-QqQ-MS) for polyphenol quantification, 3D front face fluorescence Spectroscopy and Near Infrared Spectroscopy (NIRS). A multi-block classification approach (Sequential and Orthogonalized-Partial Least Squares – SO-PLS) has been used, in order to exploit the chemical information to predict the sensorial poles of samples. Among thirty-one test samples, only two were misclassified.

Chocolate is a widely consumed product worldwide due to its exquisite flavor, which comes from the unique and fascinating cocoa flavor. This flavor depends on little controllable variables such as the genotype and the agroecological niche, and on the other side, on postharvest operations: (1) cocoa transformation from seeds to beans that comprises cocoa seeds preconditioning, fermentation, and drying, and (2) the production of chocolate from the bean in which roasting is highlighted. Postharvest transformation operations are critically important because during these, cocoa flavor is formed, allowing the differentiation of two categories: bulk and specialty cocoa. In this sense, this article presents an overview of cocoa postharvest operations, the variables and phenomena that influence and control the physical and biochemical transformation from seeds to cocoa beans, and their relation to the formation of chocolate flavor. Moreover, research perspectives in terms of control and management of postharvest practices in order to obtain cocoa with differentiated and specialty characteristics "from bean to bar" are discussed.

Approaches enabling prediction of chocolate quality from cocoa composition would avoid time- and money-consuming steps to chocolate makers. Average mass spectra of cocoa-polyphenol-extracts led to fingerprints used to select the molecules that discriminate chocolate sensory groups.16 worldwide cocoa samples were processed into chocolates which were characterized by sensory analysis, allowing sorting of the samples into four sensory groups.The cocoa polyphenol extracts were analyzed by liquid chromatography−low-resolution mass spectrometry. Averaging each mass spectrum provided polyphenolic fingerprints, which were combined into a matrix and processed with chemometrics (PCA, PLS-DA) to select the most meaningful molecules for discrimination of the chocolate sensory groups.A larger set of 44 cocoa samples was used to validate the previous results. 29 mass signals of known and unknown molecules, mainly flavan-3-ols, were finally targeted[1], including 2 newly described ethyl-bridged flavan-3-ols[2], enabling sensory-group discrimination. Average mass spectra fingerprints of cocoa-polyphenol-extracts proved to be quick and efficient to select the molecules that discriminate chocolate sensory groups.A targeted MRM (Multiple Reaction Monitoring) mass spectrometry method was then developed and validated to routinely analyse large series of cocoa samples.[1] Fayeulle et al., Fast Discrimination of Chocolate Quality Based On Average Mass Spectra Fingerprints of Cocoa Polyphenols, J Agric. Food Chem., 2019, 67, 2723-2731[2] Fayeulle et al., Characterization of new flavan-3-ol derivatives in fermented cocoa beans, Food Chem., 2018 (259), 207-212

International audience

This work aims to sort cocoa beans according to chocolate sensory quality and phenolic composition. Prior to the study, cocoa samples were processed into chocolate in a standard manner, and then the chocolate was characterized by sensory analysis, allowing sorting of the samples into four sensory groups. Two objectives were set: first to use average mass spectra as quick cocoa-polyphenol-extract fingerprints and second to use those fingerprints and chemometrics to select the molecules that discriminate chocolate sensory groups. Sixteen cocoa polyphenol extracts were analyzed by liquid chromatography-low-resolution mass spectrometry. Averaging each mass spectrum provided polyphenolic fingerprints, which were combined into a matrix and processed with chemometrics to select the most meaningful molecules for discrimination of the chocolate sensory groups. Forty-four additional cocoa samples were used to validate the previous results. The fingerprinting method proved to be quick and efficient, and the chemometrics highlighted 29 m/ z signals of known and unknown molecules, mainly flavan-3-ols, enabling sensory-group discrimination.

Sports performance depends on physical factors, but also on cognitive functioning. Nutritional supplements as potential ergogenic aids can impact muscle, but also the brain. Cocoa flavanols (CF) have antioxidant capacities, can stimulate vascular function, and potentially enhance cognitive function. CF intake might thus improve exercise performance and recovery by reducing oxidative stress, increasing NO availability and/or boosting cognitive function. It is the purpose of this PhD to identify the effects of CF on physical and cognitive performance in healthy athletes at sea level and altitude, as well as in patients with type 1 diabetes. Our systematic review showed that CF can reduce exercise-induced oxidative stress, but without improving exercise performance. Combining CF intake and exercise training improves cardiovascular risk factors and vascular function in healthy and overweight participants, but evidence on the synergistic effects of CF and exercise training on oxidative stress, inflammation and fat and glucose metabolism is lacking.In a randomized, placebo-controlled, double blind cross-over study, we showed that 900 mg CF intake increased prefrontal oxygenation in athletes, but without affecting executive function. BDNF was not affected by CF intake. The effects of high-intensity exercise largely overruled the effects of CF intake: large beneficial effects of exercise on prefrontal oxygenation and cognitive function were observed and CF supplementation did not enlarge these effects. In a 2nd study, the effect of acute CF intake (530 mg CF) on performance on a demanding cognitive test was assessed in normoxia and hypoxia (simulated altitude 4000 m). Electroencephalogram and fNIRS were used to analyse neuronal activity and hemodynamic changes. Acute CF intake improved the neurovascular response, but did not affect neuronal activity and cognitive performance in normoxia and hypoxia. Most cognitive functions, the cerebrovascular response and neuronal activity, were not altered in hypoxia in healthy subjects. In a 3rd study, we found that acute intake of 900 mg CF enhanced cognitive performance on the Flanker test in patients with type 1 diabetes, and their healthy matched controls. CF intake increased the BOLD response in brain areas activated during this specific task. While cognitive performance was not deteriorated in patients with type 1 diabetes, a different brain activation pattern during the cognitive task was observed, compared to healthy controls and this brain activation pattern was altered by CF intake. To conclude, acute CF intake improves prefrontal oxygenation and cerebrovascular responsiveness. This can be associated with better cognitive function in patients with type 1 diabetes, but does not result in improved executive function in healthy persons. Compared to exercise, the magnitude of the CF-induced neurovascular changes is small.Two studies were conducted examining the effects of CF on exercise-induced oxidative stress, NO availability and its implications for exercise performance, in well-trained cyclists. We found that acute CF (900 mg) improved the exercise-induced increase in total antioxidant capacity, but did not reduce the exercise-induced increase in lipid peroxidation. One week CF intake (530 mg CF) improved vascular function at rest, and prefrontal oxygenation at rest and during low-intensity exercise, but did not influence muscular oxygenation. One week CF intake partially restored the hypoxia-induced decline in prefrontal oxygenation during rest and low-intensity exercise, but not during high-intensity exercise. One week CF intake reduced exercise-induced lipid peroxidation, but did not alter total antioxidant capacity. Both acute and 1-week CF intake did not improve exercise performance and recovery and do not change NO production during exercise (in normoxia and hypoxia) in well-trained athletes.; Les athlètes utilisent les suppléments nutritionnels avec pour objectif d'améliorer leur performance sportive. La performance sportive dépend de facteurs physiques, mais également de facteurs cognitifs. Les suppléments nutritionnels riches en flavanols issu du cacao (CF) peuvent stimuler la fonction vasculaire, réduire le stress oxydant et améliorer la fonction cognitive. L'objectif de cette thèse est donc d’analyser les effets d'une consommation aigue, ou pendant une semaine, de CF, sur la performance physique et cognitive chez des athlètes, chez des sujets actifs et chez des personnes ayant un diabète de type 1 (DT1). De plus, l’objectif est d’investiguer les effets des CF en altitude simulé, où l’hypoxie limite la performance cognitive et physique.La consommation aigue de 900 mg CF (dont 196 mg d'épicatéchine) suscite une augmentation de l’oxygénation cérébrale, mais pas de la concentration de BDNF sérique et n'a pas d’effet sur la fonction cognitive chez des sportifs sains. L’effet bénéfique des CF sur l’oxygénation cérébrale au repos est dépassé par l’ampleur de l’augmentation de la perfusion et de l’oxygénation cérébrale à l’exercice physique et n'est donc plus visible en post-exercice.En hypoxie (altitude simulée de 4000 m), la consommation aigue de 530 mg CF (dont 100 mg d'épicatéchine) augmente la réponse hémodynamique du cortex préfrontal durant une tâche cognitive, mais n’affecte pas l’activité neuronale. Les CF améliorent la pensée abstraite en normoxie, mais n’améliorent aucun autre domaine des fonctions cognitives. Seule la précision lors du test de Stroop est diminuée par l’hypoxie. De plus, la réponse hémodynamique du cortex préfrontale et l’activité neuronale ne diffèrent pas en hypoxie vs. en normoxie.Le diabète de type 1 (DT1) est associé avec une dysfonction endothéliale, qui constitue un des facteurs de déclin cognitif lié au diabète. Dans une 3ième étude, la fonction cognitive n’est pas altérée chez les patients DT1, en comparaison des sujets sains, alors que l'activation cérébrale diffère entre ces 2 groupes. Cette différence d'activation cérébrale pourrait alors jouer un rôle compensatoire chez les patients DT1. La consommation aigue de CF peut améliorer les fonctions exécutives chez des patients DT1 et des sujets sains, et peut augmenter le signal BOLD dans les régions du cerveau activées par les tâches cognitives.Ainsi, la consommation aigue de CF augmente la vasoréactivité cérébrale. Ces changements sont associés avec une meilleure fonction cognitive chez des patients DT1, alors que ce n’est pas le cas chez des sujets entraînés, ni au niveau de la mer, ni en hypoxie. Malgré ces effets bénéfiques des CF, l’exercice physique semble rester un moyen beaucoup plus efficace pour stimuler la vasoreactivité cérébrale et les fonctions cognitives.Nous nous sommes aussi intéressés aux effets de CF sur la capacité antioxydante, le stress oxydant et la production de NO pendant l’exercice, ainsi que sur les implications pour la performance physique et la récupération, chez des athlètes. La consommation aigue de 903 mg CF augmente la capacité antioxydante au repos et pendant l’exercice, mais sans réduire le stress oxydant et la production de NO. La consommation pendant une semaine de 530 mg CF (dont 100 mg d'épicatéchine) atténue la peroxydation lipidique induite par l’exercice, mais n’influence pas la capacité antioxydante. Les CF ne modifient pas la production et la biodisponibilité du NO pendant un exercice en normoxie et en hypoxie (altitude simulée de 3000 m). La consommation de CF pendant une semaine peut augmenter la fonction endothéliale de repos, et peut réduire les effets nuisibles de l'hypoxie sur l’oxygénation préfrontale au repos et pendant l’exercice modéré. Par contre, cet effet disparait pendant l’exercice intense. La consommation aigue, et pendant une semaine, de CF n’augmente pas la performance physique, ni en normoxie, ni en hypoxie.

Sports performance depends on physical factors, but also on cognitive functioning. Nutritional supplements as potential ergogenic aids can impact muscle, but also the brain. Cocoa flavanols (CF) have antioxidant capacities, can stimulate vascular function, and potentially enhance cognitive function. CF intake might thus improve exercise performance and recovery by reducing oxidative stress, increasing NO availability and/or boosting cognitive function. It is the purpose of this PhD to identify the effects of CF on physical and cognitive performance in healthy athletes at sea level and altitude, as well as in patients with type 1 diabetes. Our systematic review showed that CF can reduce exercise-induced oxidative stress, but without improving exercise performance. Combining CF intake and exercise training improves cardiovascular risk factors and vascular function in healthy and overweight participants, but evidence on the synergistic effects of CF and exercise training on oxidative stress, inflammation and fat and glucose metabolism is lacking.In a randomized, placebo-controlled, double blind cross-over study, we showed that 900 mg CF intake increased prefrontal oxygenation in athletes, but without affecting executive function. BDNF was not affected by CF intake. The effects of high-intensity exercise largely overruled the effects of CF intake: large beneficial effects of exercise on prefrontal oxygenation and cognitive function were observed and CF supplementation did not enlarge these effects. In a 2nd study, the effect of acute CF intake (530 mg CF) on performance on a demanding cognitive test was assessed in normoxia and hypoxia (simulated altitude 4000 m). Electroencephalogram and fNIRS were used to analyse neuronal activity and hemodynamic changes. Acute CF intake improved the neurovascular response, but did not affect neuronal activity and cognitive performance in normoxia and hypoxia. Most cognitive functions, the cerebrovascular response and neuronal activity, were not altered in hypoxia in healthy subjects. In a 3rd study, we found that acute intake of 900 mg CF enhanced cognitive performance on the Flanker test in patients with type 1 diabetes, and their healthy matched controls. CF intake increased the BOLD response in brain areas activated during this specific task. While cognitive performance was not deteriorated in patients with type 1 diabetes, a different brain activation pattern during the cognitive task was observed, compared to healthy controls and this brain activation pattern was altered by CF intake. To conclude, acute CF intake improves prefrontal oxygenation and cerebrovascular responsiveness. This can be associated with better cognitive function in patients with type 1 diabetes, but does not result in improved executive function in healthy persons. Compared to exercise, the magnitude of the CF-induced neurovascular changes is small.Two studies were conducted examining the effects of CF on exercise-induced oxidative stress, NO availability and its implications for exercise performance, in well-trained cyclists. We found that acute CF (900 mg) improved the exercise-induced increase in total antioxidant capacity, but did not reduce the exercise-induced increase in lipid peroxidation. One week CF intake (530 mg CF) improved vascular function at rest, and prefrontal oxygenation at rest and during low-intensity exercise, but did not influence muscular oxygenation. One week CF intake partially restored the hypoxia-induced decline in prefrontal oxygenation during rest and low-intensity exercise, but not during high-intensity exercise. One week CF intake reduced exercise-induced lipid peroxidation, but did not alter total antioxidant capacity. Both acute and 1-week CF intake did not improve exercise performance and recovery and do not change NO production during exercise (in normoxia and hypoxia) in well-trained athletes.; Les athlètes utilisent les suppléments nutritionnels avec pour objectif d'améliorer leur performance sportive. La performance sportive dépend de facteurs physiques, mais également de facteurs cognitifs. Les suppléments nutritionnels riches en flavanols issu du cacao (CF) peuvent stimuler la fonction vasculaire, réduire le stress oxydant et améliorer la fonction cognitive. L'objectif de cette thèse est donc d’analyser les effets d'une consommation aigue, ou pendant une semaine, de CF, sur la performance physique et cognitive chez des athlètes, chez des sujets actifs et chez des personnes ayant un diabète de type 1 (DT1). De plus, l’objectif est d’investiguer les effets des CF en altitude simulé, où l’hypoxie limite la performance cognitive et physique.La consommation aigue de 900 mg CF (dont 196 mg d'épicatéchine) suscite une augmentation de l’oxygénation cérébrale, mais pas de la concentration de BDNF sérique et n'a pas d’effet sur la fonction cognitive chez des sportifs sains. L’effet bénéfique des CF sur l’oxygénation cérébrale au repos est dépassé par l’ampleur de l’augmentation de la perfusion et de l’oxygénation cérébrale à l’exercice physique et n'est donc plus visible en post-exercice.En hypoxie (altitude simulée de 4000 m), la consommation aigue de 530 mg CF (dont 100 mg d'épicatéchine) augmente la réponse hémodynamique du cortex préfrontal durant une tâche cognitive, mais n’affecte pas l’activité neuronale. Les CF améliorent la pensée abstraite en normoxie, mais n’améliorent aucun autre domaine des fonctions cognitives. Seule la précision lors du test de Stroop est diminuée par l’hypoxie. De plus, la réponse hémodynamique du cortex préfrontale et l’activité neuronale ne diffèrent pas en hypoxie vs. en normoxie.Le diabète de type 1 (DT1) est associé avec une dysfonction endothéliale, qui constitue un des facteurs de déclin cognitif lié au diabète. Dans une 3ième étude, la fonction cognitive n’est pas altérée chez les patients DT1, en comparaison des sujets sains, alors que l'activation cérébrale diffère entre ces 2 groupes. Cette différence d'activation cérébrale pourrait alors jouer un rôle compensatoire chez les patients DT1. La consommation aigue de CF peut améliorer les fonctions exécutives chez des patients DT1 et des sujets sains, et peut augmenter le signal BOLD dans les régions du cerveau activées par les tâches cognitives.Ainsi, la consommation aigue de CF augmente la vasoréactivité cérébrale. Ces changements sont associés avec une meilleure fonction cognitive chez des patients DT1, alors que ce n’est pas le cas chez des sujets entraînés, ni au niveau de la mer, ni en hypoxie. Malgré ces effets bénéfiques des CF, l’exercice physique semble rester un moyen beaucoup plus efficace pour stimuler la vasoreactivité cérébrale et les fonctions cognitives.Nous nous sommes aussi intéressés aux effets de CF sur la capacité antioxydante, le stress oxydant et la production de NO pendant l’exercice, ainsi que sur les implications pour la performance physique et la récupération, chez des athlètes. La consommation aigue de 903 mg CF augmente la capacité antioxydante au repos et pendant l’exercice, mais sans réduire le stress oxydant et la production de NO. La consommation pendant une semaine de 530 mg CF (dont 100 mg d'épicatéchine) atténue la peroxydation lipidique induite par l’exercice, mais n’influence pas la capacité antioxydante. Les CF ne modifient pas la production et la biodisponibilité du NO pendant un exercice en normoxie et en hypoxie (altitude simulée de 3000 m). La consommation de CF pendant une semaine peut augmenter la fonction endothéliale de repos, et peut réduire les effets nuisibles de l'hypoxie sur l’oxygénation préfrontale au repos et pendant l’exercice modéré. Par contre, cet effet disparait pendant l’exercice intense. La consommation aigue, et pendant une semaine, de CF n’augmente pas la performance physique, ni en normoxie, ni en hypoxie.

International audience; Direct-injection mass spectrometry (DIMS) techniques have evolved into powerful methods to analyse volatile organic compounds (VOCs) without the need of chromatographic separation. Combined to chemometrics, they have been used in many domains to solve sample categorization issues based on volatilome determination. In this paper, different DIMS methods that have largely outperformed conventional electronic noses (e-noses) in classification tasks are briefly reviewed, with an emphasis on food-related applications. A particular attention is paid to proton transfer reaction mass spectrometry (PTR-MS), and many results obtained using the powerful PTR-time of flight-MS (PTR-ToF-MS) instrument are reviewed. Data analysis and feature selection issues are also summarized and discussed. As a case study, a challenging problem of classification of dark chocolates that has been previously assessed by sensory evaluation in four distinct categories is presented. The VOC profiles of a set of 206 chocolate samples classified in the four sensory categories were analysed by PTR-ToF-MS. A supervised multivariate data analysis based on partial least squares regression-discriminant analysis allowed the construction of a classification model that showed excellent prediction capability: 97% of a test set of 62 samples were correctly predicted in the sensory categories. Tentative identification of ions aided characterisation of chocolate classes. Variable selection using dedicated methods pinpointed some volatile compounds important for the discrimination of the chocolates. Among them, the CovSel method was used for the first time on PTR-MS data resulting in a selection of 10 features that allowed a good prediction to be achieved. Finally, challenges and future needs in the field are discussed.

15. Weurman Flavour Research Symposium ; Graz (Autriche) - (2017-09-18 - 2017-09-22); International audience; A preliminary sensory study conducted on a set of 187 dark chocolates varying in terms of cocoa origin and variety allowed their classification into four distinct sensory categories. Fingerprints in volatile organic compounds (VOCs) of these chocolates wereobtained by a direct-injection mass spectrometry headspace method using Proton Transfer Reaction Mass Spectrometry (PTR-MS). This chemical analysis allowed discriminating the four sensory poles, so the sensory discrimination seemed to be mainly based on volatile compounds. Then, the key odorants responsible for chocolates differentiation were determined through identification of targeted aroma compounds by GC-MS after GC-O analyses of extracts representative of each subset of chocolates. Twelve dark chocolates were studied using the detection frequency method. The odour eventsgenerated by a panel of 12 assessors were grouped into 124 odorant areas (OAs).Correspondence analyses allowed distinguishing the samples while identifying 34 OAs that appear relevant to discriminate the chocolates sensory poles. Among these characteristic OAs, five were identified unambiguously with GC-MS and the remainingneed to be resolved from numerous coeluted peaks.

Con origen probable en la cuenca amazónica, el consumo del Theobroma cacao L. se difundió rápidamente al resto de América, de Europa y del mundo. A partir de estadísticas oficiales y otras fuentes bibliográficas y hemerográficas, el objetivo de este artículo es caracterizar el consumo de cacao y de sus productos derivados, tanto al nivel mundial (a partir de la década de 1960) como de Venezuela (a partir de 1949), desde una perspectiva sostenible. Es una investigación documental, descriptiva y explicativa. Los principales hallazgos dan cuenta que, exceptuando a Brasil, los mayores consumidores mundiales no son los países productores. Desde 1960 se ha registrado una tendencia creciente en el consumo mundial del cacao y derivados, así como una creciente inversión por parte de empresas trasnacionales. Con ello, la producción y molienda mundiales –salvo excepciones–, han crecido sostenidamente entre 1960 y 2014. Venezuela, con menos de 1/10 con respecto al primer consumidor mundial, apenas figura como país consumidor. No obstante, a partir de la década de 1980 se ha registrado una tendencia creciente en el consumo doméstico de cacao, productos y subproductos, con una mayor relevancia de los productos artesanales (de mayor calidad y valor agregado), en consonancia con lo observado en los consumidores de los países de mayor poder adquisitivo. Así, la ascendente demanda tanto mundial como doméstica de productos con sabor y aroma diferenciados y provenientes de cacaos aromáticos, aunada a la larga tradición de Venezuela como productora de estos tipos de cacao, constituyen una oportunidad a ser aprovechada para el desarrollo y consolidación de la cadena de valor del cacao. Por tanto, combinando sus excelentes condiciones edafoclimáticas, el material genético y unas buenas prácticas agrícolas, el diseño e implementación de planes de desarrollo podrían convertirse en un elemento dinamizador e impulsor del desarrollo territorial y del consumo sostenible. With probable origin in the Amazon basin, cocoa (Theobroma cacao L.) consumption spread rapidly to the rest of America, Europe and the entire world. Based on official statistics and also bibliographic and digital sources, the aim of this paper is to characterize the consumption of cocoa and its derivatives, both at the world level (from the 1960s until present) and the Venezuelan case (since 1949), by considering its sustainability over time. This is a documentary, descriptive and explanatory research. Main findings point out that, with the exception of Brazil, the world’s biggest consumers are not producer countries. Overall, since 1960 there has been a growing trend in world consumption of cocoa and derivatives, as well as a growing investment trend by major multinational companies upstream in the cocoa value chain. Thus, except a few years, world production and grinding have grown steadily between 1960 and 2013. Although Venezuela is a small consumer (compared to world leaders), since the 2000s there has been a growing trend in domestic consumption of cocoa and its derivatives products. Here, artisanal ones (i.e., those with high quality and added value products) have shown a growing importance. This finding is consistent with the observed trend in the international chocolate consumption, particularly in countries with higher purchasing power. Thus, under an increasing –both, world and domestic– demand for taste and differentiated cocoa aroma products scenario, together with the long tradition of Venezuela as a producer of these types of cocoa, there is a real and feasible opportunity for developing the cocoa value chain. In this way, combining their excellent soil and climatic conditions, quality genetic material and good agricultural practices, to designing and implementing development plans based on cocoa must be the key factor to reach territorial development and sustainable consumption in this country. L’origine du Theobroma cacao L. est probablement le bassin de l’Amazonie et à partir de là, sa consommation s’est diffusée rapidement au reste de l’Amérique, d’Europe et du monde. L’objectif de cet article est de caractériser la consommation de cacao et de produits dérivés à partir de références bibliographiques au niveau mondial (depuis 1960) et au Venezuela (depuis 1949). Il s’agit d’une recherche documentaire, descriptive et explicative. Les résultats montrent que, mis à part le Brésil, les principaux pays consommateurs ne sont pas forcément les principaux pays producteurs. Depuis 1960 il y a eu une croissance de la consommation mondiale de cacao et de produits dérivés ainsi que d’investissements de grands groupes agro-alimentaires dans le secteur chocolatier. C’est ainsi que la production et le broyage – sauf quelques exceptions- ont augmenté de manière soutenue entre 1960 et 2014. Le Venezuela, qui compte avec une consommation inférieure au 1/10 de la consommation mondiale, est à peine placée en tant que pays consommateur. Cependant à partir des années 1980 il a été registré une croissance dans la consommation interne du cacao et des produits dérivés, en particulier ceux d’origine artisanale, de majeure qualité et valeur ajoutée, ce qui correspond aux tendances des pays aisés. De cette manière l’augmentation de la demande mondiale et domestique de produits bien différenciés du point de vue organoleptique qui ont besoin pour leur fabrication de cacao d’arôme, dont le Venezuela possède une longue tradition productrice, représente une opportunité réelle pour le développement et renforcement de la filière de cacao dans ce pays. On remarque finalement que les excellentes conditions des sols, le climat et le matériel génétique liés aux bonnes pratiques agricoles rendent possible la mise en place de plans de production encadrés dans le développement et la consommation soutenables. De origem provavelmente amazônica, o consumo de Theobroma cacao L. se difundiu rapidamente por toda a América Latina, Europa e pelo mundo. Este estudo se baseia em estatísticas oficiais e em outras fontes bibliográficas e documentais, tendo por objetivo analisar, desde a perspectiva da sustentabilidade, a evolução do consumo de cacau e de produtos derivados, tanto em nível mundial (a partir da década de 1960) como na Venezuela (a partir de 1949). Trata-se de uma investigação de caráter documental, descritivo e explicativo. Entre os principais resultados consta que, à exceção do Brasil, os maiores consumidores mundiais não são os próprios países produtores. Desde 1960 se registra uma tendência crescente no consumo mundial de cacau e de seus derivados, assim como o nível de investimento por parte de empresas transnacionais. Com efeito, a produção e moagem mundiais - salvo algumas exceções – cresceram de forma sustentável entre 1960 e 2013. O caso da Venezuela, com menos de 10% em relação ao primeiro consumidor mundial, figura apenas como país consumidor. Não obstante, a partir dos anos 2000 temse uma tendência crescente no consumo doméstico do cacau e de seus subprodutos, crescendo em importância os produtos artesanais (de maior qualidade e valor agregado), em consonância com o observado no caso dos consumidores dos países de maior poder aquisitivo. Assim, a demanda crescente, tanto em nível mundial quanto doméstica de produtos com sabor e aroma diferenciados e provenientes de espécies diferenciadas, junto a uma larga tradição de Venezuela como país produtor destes tipos de cacau, representam, em boa medida, uma oportunidade real e tangível para o desenvolvimento e consolidação de uma cadeia de valor. A excelência das condições edafoclimáticas, bons recursos genéticos, práticas agrícolas e do desenho e implementação de adequados planos de desenvolvimento poderiam converter-se, conjuntamente, em elementos dinamizadores e impulsionadores do desenvolvimento territorial e de um consumo sustentável. 23-49 marliqr@ula.ve anidoriv@ula.ve antonioaz28061@gmail.com Semestral