Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2014-09-05T15:25:03Z No. of bitstreams: 1 Dissertação LeandrodMF.pdf: 1496532 bytes, checksum: a3f1f8effe11a679e223ba5bdceeeb54 (MD5) / Approved for entry into archive by Fatima Cleômenis Botelho Maria (botelho@ufba.br) on 2014-09-05T15:56:02Z (GMT) No. of bitstreams: 1 Dissertação LeandrodMF.pdf: 1496532 bytes, checksum: a3f1f8effe11a679e223ba5bdceeeb54 (MD5) / Made available in DSpace on 2014-09-05T15:56:02Z (GMT). No. of bitstreams: 1 Dissertação LeandrodMF.pdf: 1496532 bytes, checksum: a3f1f8effe11a679e223ba5bdceeeb54 (MD5) / CNPq / Neste trabalho foi proposto um sistema de análises por injeção sequencial (SIA) para determinação espectrofotométrica da capacidade antioxidante em amostras de bebidas, a partir da geração “in situ” do radical derivado do reagente N-fenil-1,4-fenilenodiamino (NFFD•+). O radical NFFD•+ foi produzido em linha pela oxidação do NFFD empregando o Fe3+ como oxidante. Na otimização do sistema SIA foram avaliados os seguintes parâmetros: ordem de aspiração dos reagentes e amostra, estabilidade da solução de NFFD, pH da amostra, proporção NFFD/Fe3+, volumes das soluções dos reagentes e amostra e tempo de interrupção do fluxo. O ácido gálico foi empregado como padrão de calibração para os ensaios. Após as etapas de otimização univariada do método proposto obteve-se faixa linear de 10 a 40 mg L-1, com limites de detecção (3σ) de 1,0 mg L-1 e quantificação (10σ) de 3,3 mg L-1, respectivamente. Para avaliar o método proposto, foram realizados testes de reatividade do radical NFFD•+ frente a compostos fenólicos, tiólicos e de outra natureza. A redução do sinal analítico frente a inibição do radical derivado do NFFD foi mais pronunciada para ácido ascórbico, ácido tânico e cisteína, nesta ordem. A capacidade antioxidante com o radical derivado do NFFD foi avaliada em amostras de vinhos e chás, e os resultados foram concordantes com os métodos de referência (Folin-Denis, ABTS e DPPH), de acordo com o coeficiente de correlação, além do ensaio com radical DMPD•+, baseado no teste t. Assim a amina NFFD por ser utilizada para avaliação da atividade antioxidante em amostras de bebidas. Adicionalmente, as amostras de vinhos foram submetidas a testes de estabilidade temporal e avaliação do efeito do processo de ozonização em relação à variação da capacidade antioxidante / In this work was proposed a sequential injection system for spectrophotometric determination of antioxidant capacity in beverage samples with “in situ” radical generation from N-phenyl-1,4-phenylenediamine (NFFD•+). The radical NFFD•+ was produced by on line oxidation of NFFD employing Fe3+ as oxidant. The optimization of SIA system evaluated: aspiration order of reagents and sample, stability of the NFFD solution, sample pH, NFFD/Fe3+ proportion, reagents and sample volumes and stopped flow time. The gallic acid was used as standard of antioxidant compound for proposed sequential injection method. After chemical and physical univarieted optimization the linear range obtained in gallic acid concentration was from 10 to 40 mg L-1, with detection (3σ) and quantification (10σ) limits of 1.0 and 3.3 mg L-1, respectively. To evaluate selective of radical, studies of reactivity were performed with NFFD•+ and phenolic and thiol molecules and others compounds. The reducing capacity of NFFD•+ radical was observed preferentially for ascorbic acid, tannic acid and cysteine in this order. The antioxidant capacity with NFFD•+ radical was measured in samples of wines, infusions and teas. The results were agreement with the references methods (Folin-Denis, ABTS and DPPH), in accord with correlation coefficient, and additionally with the radical DMPD•+, based on t test. This way, the SIA spectrophotometric method exploring the radical NFFD•+ can be employed for the antioxidant capacity measured. Additionally, temporal stability and the ozonization effect in wine samples were evaluated using antioxidant capacity as parameter .

Un grand vin de garde se distingue par sa capacité à se bonifier avec le temps, exprimant alors une complexité aromatique particulièrement attendue par les dégustateurs. L’apparition du bouquet de vieillissement, signature de la qualité organoleptique des grands vins vieillis en bouteille, est un des phénomènes les plus impressionnants de l’œnologie mais également l’un des plus mal connus. En effet, ses déterminants sensoriels et moléculaires ont jusqu’à présent été peu étudiés. Grâce à une approche holistique séquencée en trois étapes, nous avons pu décrypter sensoriellement le concept du bouquet de vieillissement des vins rouges de Bordeaux. Une définition sensorielle partagée par des professionnels du vin a pu émerger, s’articulant autour de huit notes aromatiques principales : « sous-bois », « truffe », « fruits frais rouges et noirs », « épicé », « réglisse », « menthe », « grillé » et « empyreumatique ». D’autre part, nous avons pu souligner l’importance de l’expertise dans la définition d’un tel concept olfactif, nécessitant à la fois des connaissances œnologiques, des compétences sensorielles et des ressources lexicales. Par une étude moléculaire ciblée sur certaines classes de molécules aromatiques se formant et/ou conservées au cours du vieillissement en bouteille, nous avons pu identifier que plusieurs composés soufrés volatils tels le sulfure de diméthyle, le 2-furaneméthanethiol et le 3-sulfanylhexanol contribuaient activement à la typicité du bouquet de vieillissement. Présents à des teneurs significativement plus élevées dans les vins rouges exprimant un bouquet de vieillissement, nous avons montré que ces composés volatils participaient plus particulièrement aux notes aromatiques caractéristiques de sous-bois, truffe et empyreumatique. La mise en œuvre de fractionnements d’extraits de vins et de reconstitutions aromatiques, puis l’application de la GC-O et de la GC-MS sur les fractions d’intérêt ont permis par la suite d’identifier la D,L-pipéritone, un monoterpène associé pour la première fois aux nuances de menthe typiques du bouquet de vieillissement des vins rouges de Bordeaux. Enfin, nous avons montré que certains paramètres du terroir pouvaient influencer l’expression aromatique du bouquet de vieillissement. La mesure du rapport isotopique (δC13) de l’éthanol a permis de retracer l’état hydrique des vignes ayant produit les vins étudiés et a montré qu’une contrainte hydrique modérée ou forte de la vigne était favorable à cette typicité. De plus, la différence sensorielle de la note menthe observée entre les vins rouges de Bordeaux semble trouver son origine dans la nature du cépage, avec des teneurs en D,L-pipéritone significativement plus importantes dans les vins pour lesquels le Cabernet Sauvignon est le cépage prédominant. / A wine with ageing potential is noticeable by its ability to improve over time, expressing the aromatic complexity particularly expected by wine tasters. The development of wine ageing bouquet, the "signature" of the organoleptic quality of fine wines aged in bottle, is one of the most fascinating but least known phenomena in oenology. Indeed, both its sensory and molecular markers are poorly documented.A three-step holistic approach made it possible to decipher the sensory characteristics of the ageing bouquet of red Bordeaux wines. More precisely, a shared sensory definition emerged among wine professionals, structured around eight main aromatic notes: "undergrowth", "truffle", "fresh red- and black berry fruits", "spicy», "liquorice", "mint», "toasted" and "empyreumatic". Furthermore, the importance of expertise based on oenological knowledge, sensory skills, and lexical capabilities in defining olfactory concepts was highlighted. A molecular study, targeting specific classes of aromatic compounds formed and/or preserved during bottle ageing, identified dimethyl sulphide, 2-furanmethanethiol and 3-sulfanylhexanol as key contributors to the typicality of wine ageing bouquet. These volatile compounds were present in the highest concentrations in all wines with an ageing bouquet and participated more specifically in their undergrowth, truffle, and empyreumatic aromas. Subsequently, wine fractionations and aromatic reconstitutions, analyzed by both GC-O and GC-MS, were used to identify D,L-piperitone, a monoterpene which was shown for the first time to be involved in the typical mint nuances in the ageing bouquet of red Bordeaux wines. Finally, influence of some parameters of “terroir” was highlighted. Isotope ratio measurement (δC13) in ethanol of studied wines was used as an indicator of vine water status and revealed that a moderate to severe water deficit was in favor to the genesis of a wine ageing bouquet. Interestingly, the sensory difference in minty character observed in red Bordeaux wines apparently originated from grapes, as D,L-piperitone levels were significantly higher in wines where Cabernet Sauvignon was dominant

Tandis que la Drôle de Guerre est l’occasion d’une première confrontation avec la réglementation et la réquisition, la signature de l’armistice marque pour les entreprises de la Gironde occupée le début d’un dialogue complexe et fécond avec le gouvernement de Vichy et les autorités allemandes. Celles-ci font face à une polycratie franco-allemande, imposant des nouveaux cadres, administratifs et territoriaux, à leur activité. L’entreprise devient un enjeu réel de pouvoir. Apparaissent à la fois des réels points de convergence (aryanisation des « entreprises juives », rémunérations du travail) et d’importantes surfaces de tension (contrôle du port, concentration de la production, départ d’ouvriers pour l’Allemagne). Par ailleurs, le régime de Vichy ne lésine pas sur les moyens, en vue de faire de l’entreprise une vitrine idéologique (Révolution nationale) : cérémonies collectives, structures d’entraide, corporatismes, associations politiques, mouvements collaborationnistes. Armé d’un redoutable arsenal législatif et répressif, il parvient – avec le soutien des Allemands – à en faire un lieu d’exclusion, d’où sont violemment extraits les éléments jugés indésirables, que ce soit pour leurs activités politiques (les communistes) ou pour leur appartenance religieuse abusivement qualifiée de « raciale » (les juifs). À l’inverse, la stratégie consistant à faire de chaque établissement un lieu d’intégration à ses idéaux, ne rencontre qu’un succès mitigé. L’attachement des acteurs de l’entreprise à la personne même du maréchal Pétain, réel au début de la période, s’estompe sous l’effet des épreuves et des sujétions dont sont victimes les Girondins. De ce point de vue, la politique sociale de l’État français (Charte du travail et comités sociaux) ne lui permet pas – sauf exception – de « ramener » patrons et ouvriers dans le giron vichyste. Dans un contexte de graves pénuries (matières premières, main-d’œuvre, moyens de transport), les entreprises girondines cherchent bien des alternatives à ce qu’on appelle communément la « collaboration économique » : utilisation de produits de remplacement, reconversion des activités, réadaptation de l’appareil productif, essor des pratiques illicites (marché noir). Mais rares sont les patrons à ne pas devoir se poser la question de l’opportunité de proposer une offre de services à l’occupant. Cette offre est largement répandue, mais variable selon les métiers, les branches et les temps de l’Occupation. Les occupants tirent ainsi profit des atouts du tissu économique local, puisqu’ils parviennent à intégrer à leur économie de guerre les industries anciennement mobilisées pour la Défense nationale et plus encore les richesses tirées du sol girondin : le bois, la résine, le vin. / While the Phoney War occasioned a first confrontation with regulations and requisition, the signing of the Armistice marked the start of a complex period for the enterprises in occupied Gironde, in that it prompted a fruitful dialogue with the Vichy government and the German authorities. These enterprises faced a French German polycracy, which imposed new administrative and territorial executives on their activities. Enterprise became a real power issue. There were points of convergence (the aryanisation of “Jewish enterprises”, the remuneration of work) as there were of conflict (the control of the port, the concentration of production, the workers' departure for Germany). Moreover, the Vichy regime did all it could to make enterprise an ideological showcase (“Révolution Nationale”): ceremonies, support groups, corporatism, political associations, collaborationist movements. Armed with a formidable legislative and repressive arsenal, it managed – with the support of the Germans – to create a place of exclusion, from which were violently removed, any elements that were judged undesirable either for their political activities (communists) or for their religious affiliation, abusively qualified as “racial” (Jews). On the contrary, the strategy which consisted in making each establishment a place of integration of its ideals, was not met with much success. The attachment that the actors of the enterprises had for Maréchal Pétain himself, which was very real in the beginning, soon faded with the trials and constraints that the people of Gironde had to suffer. From this point of view, the social policy of the French State (“Charte du Travail”) did not allow it – with some exceptions – to “bring” employers and workers back to the Vichy realm. In a context of severe shortage (primary goods, labour and means of transport), enterprises in Gironde looked for alternatives to what we commonly call the “economic collaboration”: use of products of replacement, reconversion of activities, readjustment of the productive machine, development of illicit practices (black market). Few entrepreneurs, however, missed the business opportunity that lay in offering their services to the occupying forces. These services were widespread, but varied according to jobs, fields of activity and times of the Occupation. In this way, the occupying forces benefited, from the strengths of the local economic fabric, since they managed to integrate into their war economy not only the industries that had earlier been mobilized for the “Défense Nationale” but also the natural resources of the land: wood, resin, wine.