Submitted by Maike Costa (maiksebas@gmail.com) on 2016-05-23T12:12:31Z No. of bitstreams: 1 arquivo total.pdf: 1933896 bytes, checksum: b0b1871a7575744c7578f10900648224 (MD5) / Made available in DSpace on 2016-05-23T12:12:31Z (GMT). No. of bitstreams: 1 arquivo total.pdf: 1933896 bytes, checksum: b0b1871a7575744c7578f10900648224 (MD5) Previous issue date: 2015-05-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Life support in various ecosystems is made possible by a group of organisms, called primary producers. Because they are mostly photoautotrophic, these individuals secure the middle nutrients (in higher carbon part) through the process of photosynthesis. In aquatic ecosystems phytoplankton (microalgae) is responsible for most of the primary production. As a link between individuals of the first trophic level and individuals of higher trophic levels are the organisms belonging to the zooplankton. Thus, the study of the biochemical composition of the zooplankton community can be used as an indicator of nutritional status in aquatic ecosystems. Thus, this study aimed to build PLS multivariate calibration models for the simultaneous spectrofluorimetric determination of neutral and polar lipid classes. In order to simplify the procedures involved in the construction of models, commercial standards were used to perform the calibration mixtures. These solutions were previously defined by conducting a Brereton mixture design of three levels and two factors. In a preliminary step, the models built were used to predict the concentrations of the two commercial lipids, triolein (TO) and phosphatidylcholine (PC), a set of external standards. In evaluating the performance parameters related to this step, it was observed that the models were in an acceptable condition for application to real samples. However, when evaluating the synchronous fluorescence spectra of the samples (macro and mesozooplankton), it was observed that máx the band corresponding to the neutral lipids varies between samples, so that the proposed method can not be applied to real system. / A sustentação da vida nos mais diversos ecossistemas é possibilitada por um grupo de organismos, denominados produtores primários. Por serem em sua maioria fotoautotróficos, esses indivíduos fixam os nutrientes do meio (em maior parte carbono) através do processo de fotossíntese. Nos ecossistemas aquáticos o fitoplâncton (microalgas) é responsável pela maior parcela da produção primária. Como elo entre os indivíduos do primeiro nível trófico e os indivíduos dos níveis tróficos superiores estão os organismos pertencentes ao zooplâncton. Dessa forma, o estudo da composição bioquímica da comunidade zooplanctônica pode ser usado como um indicador da condição nutricional nos ecossistemas aquáticos. Diante disso, este trabalho teve como objetivo a construção de modelos de calibração multivariada PLS para a determinação espectrofluorimétrica simultânea das classes de lipídios neutros e polares. A fim de simplificar o procedimento envolvido na construção dos modelos, foram utilizados padrões comerciais para a realização das misturas de calibração. Estas soluções foram previamente definidas mediante a realização de um planejamento de misturas Brereton de três níveis e dois fatores. Em uma etapa preliminar, os modelos construídos foram usados para prever as concentrações dos dois lipídios comerciais, trioleína (TO) e fosfatidilcolina (PC), em um conjunto de padrões externo. Ao avaliar os parâmetros de desempenho relacionados a esta etapa, observou-se que os modelos estavam em condições aceitáveis para aplicação em amostras reais. Entretanto, ao avaliar os espectros de fluorescência sincrônica das amostras analisadas (macro e mesozooplâncton), foi observado que máx da banda correspondente aos lipídios neutros varia entre as amostras, de modo que o método proposto não pode ser aplicado em sistema real.

Polycyclic aromatic hydrocarbons (PAH) are a class of environmental pollutants consisting of a minimum of two fused aromatics rings originating from the incomplete combustion of organic matter and/or anthropogenic sources. Numerous possible anthropogenic and natural sources make the presence of PAH ubiquitous in the environment. The carcinogenic nature of some PAH and their ubiquitous presence makes their chemical analysis a topic of environmental and toxicological importance. Although environmental monitoring of PAH is an important step to prevent exposure to contaminated sites, it provides little information on the actual uptake and subsequent risks. Parent PAH are relatively inert and need metabolic activation to express their carcinogenicity. Covalent binding to DNA appears to be the first critical step in the initiation of the tumor formation process. To this end, the determination of short term biomarkers – such as monohydroxy-PAH metabolites (OH-PAH) - fills an important niche to interpret actual PAH exposure levels, prevent extreme body burdens and minimize cancer risk. One would certainly prefer an early warning parameter over a toxicological endpoint – such as DNA-adducts – indicating that extensive damage has already been done. Several methods have been developed to determine OH-PAH in specific tissue or excreta and food samples. The general trend for the analysis of OH-PAH follows the pattern of sample collection, sample clean-up and pre-concentration, chromatographic separation and quantification. Popular approaches for sample clean-up and preconcentration include liquid-liquid extraction (LLE) and solid-phase extraction (SPE). Chromatographic separation and quantification has been based on high-performance liquid iv chromatography-room temperature fluorescence detection (HPLC) and gas chromatographymass spectrometry (GC-MS). Although chromatographic techniques provide reliable results in the analysis of OHPAH, their experimental procedures are time consuming and expensive. Elution times of 30-60 minutes are typical and standards must be run periodically to verify retention times. If the concentrations of target species are found to lie outside the detector’s response range, the sample must be diluted and the process repeated. On the other end of the concentration range, many samples are “zeroes,” i.e. the concentrations are below detection limits. Additional problems arise when laboratory procedures are scaled up to handle thousands of samples under mass screening conditions. Under the prospective of a sustainable environment, the large usage of organic solvents is one of the main limitations of the current chromatographic methodology. This dissertation focuses on the development of a screening methodology for the analysis of OH-PAH in urine and milk samples. Screening techniques capable of providing a “yes or no” answer to OH-PAH contamination prevent unnecessary scrutiny of un-contaminated samples via conventional methods, reduce analysis cost and expedite the turnaround time for decision making purposes. The proposed methodology is based on capillary zone electrophoresis (CZE) and synchronous fluorescence spectroscopy (SFS). Metabolites extraction and pre-concentration is achieved with optimized SPE, LLE and/or QuEChERS (quick, easy, cheap, effective, rugged and safe) procedures. The small sample and extracting solvent volumes facilitate the simultaneous extraction of numerous samples via an environmentally friendly procedure, which is well-suited for routine monitoring of numerous samples. Sample stacking is successfully implemented to improve CZE limits of detection by two orders of magnitude. The unique electrophoretic pattern of positional isomers of OH-PAH demonstrates the potential of CZE for v the unambiguous determination of metabolites with similar chromatographic behaviors and virtually similar fragmentation patterns. The direct determination of OH-PAH without chromatographic separation is demonstrated via SFS. The non-destructive nature of SFS provides ample opportunity for further metabolite confirmation via chromatographic techniques

Human activities over the years, especially the unconventional exploitation of oil sands deposits, downstream on the Athabasca River (AR), might have affected the water quality and ecological integrity of the river basin, thereby presenting a threat to the environment and human health. There have been concerns that the oil sands process-affected waters stored in tailing ponds may be percolating to surface waters as well as underground waters, contaminating neighboring watersheds with a cocktail of chemicals including Polycyclic aromatic hydrocarbons (PAHs). PAHs are present both naturally and from human activities as pollutants in the environment. Forest fires, geologic activities, and oil seeps are examples of natural sources of PAHs in the environment. The major sources of PAHs in the Athabasca region are leaching of oil sands deposits and contamination from oil sands production. On occasions, forest fires contribute PAHs in the area. There has been no comparative data on the exposure of PAHs to fish along the AR and Slave River. I used an integrative monitoring of selected fishes as an indicator to achieve four objectives: i) describe the spatial and seasonal distribution of measurable concentrations of products of biotransformation of polycyclic aromatic hydrocarbons (PBPAH) in bile of fish; ii) determine the levels of parent PAHs in the muscle of fish, and extrapolate the data to estimate potential risk to human consumers, and to identify which species and geographic regions, if any, pose the greatest risk to humans; iii) use patterns of contamination to provide a scientific basis for elucidating the source of contamination; and iv) perform fish health investigation by collecting morphometric health measures and perform a systematic assessment of the occurrence of lesions in the fishes. I sampled whitefish (Coregonus clupeaformis), jackfish/northern pike (Esox luscius), walleye (Sander vitreus), goldeye (Hiodon alosoides) and burbot (Lota lota) from Fort McMurray, Fort McKay, and Fort Chipewyan in Alberta, and from Fort Smith and Fort Resolution on the Slave River in the Northwest Territories. The rationale for selecting fishes included: their abundance along the basin (some have short ranges, e.g., northern pike); their dietary/nutritional and cultural significance to communities in the area; their feeding strategy, such as benthic, supra-benthic, or pelagic, trophic status, and patterns of migration and habits of spawning. I addressed the first objective in Chapter 2, where the total PBPAHs were determined. Concentrations of products of biotransformation of 2 and 3-ringed, 4-ringed, and 5-ringed PAHs were measured using synchronous fluorescence spectroscopy. Spatial and seasonal differences were observed with greater concentrations of PBPAHs in samples of bile of fish collected from Fort McKay as well as greater concentrations of PBPAHs in bile of fish collected during summer compared to those collected in other seasons. Overall, PBPAHs were greater in fishes of lower trophic levels and fishes more closely associated with sediments. In particular, goldeye (Hiodon alosoides), consistently contained greater concentrations of all the PBPAHs studied. In Chapter 3, I achieved the second objective by measuring levels of parent PAHs in muscle of selected fishes and extrapolated the results to determine potential human health risks due to fish consumption. Dorsal muscle of fishes from upstream reaches of the AR close to oil sands extraction and upgrading activities, contained greater concentrations of individual PAHs than concentrations in muscle of fishes from further downstream in the Slave River. Risks posed by PAHs to humans were assessed using a B[a]P equivalents approach. According to the risk assessment results, the average lifetime risk of additional cancers for humans who consumed fish was less than 10-6. In Chapter 4, alkylated PAHs were also measured in fish muscle to achieve the third objective. The general presence of naphthalenes and phenanthrenes and the evaluation of molecular ratios (i.e., LMW/HMW alkyl-PAHs) allowed me to conclude that the major source of pollution is petrogenic, probably due to increases in oil sand activities around Fort McMurray and Fort McKay. I achieved the fourth objective in Chapter 5 by studying the health status and potential effects of industrial development on individuals of economically and culturally significant fishes. A resurgence in condition factor of all species after a low in 2011 was observed. Annual variation was also observed in condition factor and the incidence of anomalies or lesions. Morphometric data demonstrated relatively consistent health among fishes in both the Athabasca and Slave rivers. Analysis of condition factor and somatic indices did not demonstrate consistent differences along the river system. Overall, the health of fish as determined by the metrics employed in this study, does not appear to be adversely affected by the current level of development in the Alberta oil sands region. The data presented in this dissertation make invaluable contribution to the much needed monitoring program in the Athabasca and Slave Rivers. Overall, my findings provide baseline data on fish health, concentrations of parent and alkylated PAHs, and products of biotransformation of PAH in five species of large-bodied fishes consumed by humans in communities in the Lower Athabasca and Slave River basin. These results will be useful for establishing the status and trends and spatial distribution of PAHs during monitoring of the lower Athabasca basin and most importantly, as a valuable reference point before any potential permitted discharges of wastewaters from processing of oil sands to the AR.

Bisfenol A (BFA) é usado em uma variedade de produtos de consumo, incluindo alguns tipos de papéis, principalmente os papéis termossensíveis, no qual é utilizado como revelador. Mesmo assim, pouco é conhecido sobre a magnitude da contaminação ou exposição humana ao BFA, como resultado do contato com papéis. Neste estudo, foi desenvolvido e validado uma metodologia para determinação de BFA por espectroscopia de fluorescência sincronizada. O método desenvolvido e validado é rápido, simples e de baixo custo e apresenta boa sensibilidade, sendo apropriado para aplicação em amostras de papéis. O método apresentou linearidade no intervalo de concentração entre 25 e 450 ?g.L-1 (r = 0,9993). Os limites de detecção e quantificação foram de 1,20 e 3,99 ?g.L-1, respectivamente. Valores de precisão inter e intra ensaio foram de 3,21 a 8,54% e de 0,29 a 3,92%, respectivamente. A exatidão variou de 87,4 a 111% (para as concentrações de 25, 250 e 450 ?g.L-1). Os valores de recuperação estiveram entre 100 e 102% (amostra extraída). A metodologia validada foi aplicada na determinação de BFA em 13 tipos de produtos de papel (n=444), incluindo papel termossensível (n=341), bilhete de loteria (n=7), bilhete de ônibus (n=5), cartão de visita (n=12), envelope (n=11), flyer (n=10), guardanapo (n=8), papel de impressão sulfite A4 (n=3), embalagem de alimento (n=20), papel higiênico (n=8), papel toalha (n=4) e revista (n=9), jornal (n=6). BFA foi encontrado em 98% das amostras de papel termossensível (n =341) com concentrações variando desde menores que o LQ até 27,7 mg.g-1 e média geométrica e mediana de 14,6 mg.g-1 e 17,7 mg.g-1, respectivamente. Já a maioria (96%) dos outros tipos de papéis analisados (n = 103) apresentou concentrações de BFA variando desde menores que oLQ até 379 ?g.g-1 e média geométrica e mediana de 14,7 ?g.g-1 e 17,3 ?g.g-1,respectivamente. Os papéis termossensíveis apresentaram mais altas concentraçõesde BFA (ordem de mg.g-1) comparado aos outros tipos de papéis analisados,principalmente os produzidos a partir de papel reciclado com concentrações na ordemde ?g.g-1. A estimativa da exposição humana ao BFA através da manipulação de ii diferentes tipos de papéis foi estimada baseado na concentração de BFA e frequência de manipulação. A ingestão diária aceitável de BFA, ajustada pelo peso corporal (calculado para a mediana das concentrações), através da absorção dérmica, via manipulação de papéis pela população em geral e por indivíduos expostos ocupacionalmente foi de 14,5 e 1070 (ng/Kg peso corporal/dia), respectivamente / Bisphenol A (BPA) is used in a variety of consumer products, including some paper products, particularly thermal receipt papers, for which it is used as a color developer. Nevertheless, little is known about the magnitude of BPA contamination or human exposure to BPA as a result of contact with papers. In this study, was develop and validate an methodology for determination of BPA by synchronous fluorescence spectroscopy. The developed and validated method was fast, easy, low cost, with a good sensibility and appropriate for application in paper samples. The method was linear on the range of to 25 a 450 ?g.L-1(r = 0,9993). The detection and quantification limits were 1,20 and 3,99 ?g.L-1 respectively. Inter and intraday precision were between 3,21 to 8,54% and 0,29 to 3,92%, respectively. Accuracy was between 87,4 to 111%. The recovery was between 100 to 102 % (extracted samples). The validated methodology was applied in the BPA determination in 13 types pf paper products (n=444), including thermal receipt papers (n=341), lottery tickets (n=7), bus tickets (n=5), business cards (n=12), mailing envelopes (n=11), flyers (n=10), napkins (n=8), printing paper (n=3), food contact paper (n=20), kitchen rolls (n=4), toilet paper (n=8), newspaper (n=6), and magazines (n=9). BPA was found in 98% of thermal receipt papers (n = 341) at concentrations ranging from below the limit of quantitation (LOQ) to 27,7 mg.g-1 with a geometric mean of 14,6 mg.g-1 and a median of 17,7 mg.g-1. The majority (96%) of other paper products (n = 103) contained BPA at concentrations ranging from below the LOQ to 379 ?g.g-1 with a geometric mean of 14,7 ?g.g-1 and a median of 17,3 ?g.g-1. Whereas thermal receipt papers contained the highest concentrations of BPA (milligram-per-gram), the others types of papers, especially those produced from recycled paper contain lower concentrations of BPA (microgram-per-gram). Estimation of human exposure to BFA through manipulation of different paper types was calculated based on the measure of concentration and frequency of manipulation. The estimated daily intake for BFA adjusted body weight (calculated at median concentrations) through dermal absorption from handling of papers was 14.5 and 1070 ng/day for the general population and occupationally exposed individuals, respectively.

In this work, the water obtained from six watersheds in Sergipe State from Brazil was analyzed using fluorescence spectroscopy, dissolved organic carbon(DOC) and UVVis absorbance, to characterize the dissolved organic matter (DOM). The water sample were collected in the period from may 2009to january 2010. Twenty-three sampling sites distributed in different rivers from watersheds were used for collection. As results, DOC concentrations showed the following variation: from 0.35 to 34.7mg.L-1 in Sergipe river basin; 0.50 to 18.95mg.L-1 in Piauí river basin;0.93 to 56mg.L-1 in São Francisco river basin; 1.1 to 14.85mg.L-1 in Vaza Barris river basin; 1.7 to 11.85mg.L-1 in Japaratuba river Basin and 20.3 to 27.2mg.L-1 in Real River basin. The synchronous fluorescence spectra presented four peaks (I, II, III and IV) with varying intensities, depending on the localization and period sampling. The highest fluorescence intensity occurred in peaks II and III, showing that the origin of DOM is predominantly terrestrial from a lixiviated soil due to superficial runoff in raining period that occurs from may/09 to september/09. From December/09 to January/10, the peaks I and II were predominant due to autochthonous organic matter produced by algal activity and anthropogenic sources, respectively. In Japaratuba, São Francisco, Piauí and Real basins, was observed a linear regression between DOC and absorbance at 254nm, suggesting that the DOM, in these rivers, are predominantly from land source, consisting of humic substances. Though, in Sergipe and Vaza Barris Basins the nonlinearity of the DOC according to the absorbance at 254nm highlights a significative contribution from anthropogenic sources in the DOM of these rivers. The principal component analysis was applied to data from May(rainy season) and December(dry season) of 2009 and separated the samples from the rainy season into three groups while a single cluster was obtained for the dry season. The most important factor to separate the samples was the qualitative characteristics of DOM in the water. The input of organic matter from terrestrial and anthropogenic origin, transported to rivers by rain water was essential for the separation process. / Nesse trabalho foram utilizadas a espectroscopia de fluorescência e as medidas do carbono orgânico dissolvido (COD) e absorvância no UV Vis, para caracterização da matéria orgânica dissolvida (MOD) nas águas das seis bacias hidrográficas do Estado de Sergipe. Foram realizadas quatro campanhas de amostragem no período de maio de 2009 a janeiro de 2010, e em cada campanha foram coletadas amostras em vinte e três sítios de amostragem distribuídos nos diferentes rios das bacias. As concentrações do COD apresentaram a seguinte variação: bacia do rio São Francisco entre 0,93 e 56,00 mg L-1; bacia do rio Sergipe entre 0,35 e 34,70 mg L-1; bacia do rio Japaratuba entre 1,70 e 11,85 mg L-1; bacia do rio Vaza Barris entre 1,10 e 14,85 mg L-1; bacia do rio Piauí entre 0,50 e 18,95 mg L-1e bacia do rio Real entre 20,30 e 27,20 mg L-1. Os espectros de fluorescência sincronizada mostraram a presença de quatro picos (I, II, III e IV), com intensidades variáveis em função da localização e do período de amostragem. Em maio/09 e setembro/09 as maiores intensidade de fluorescência ocorreram nos picos II e III, evidenciando a predominância da MOD de origem terrestre, lixiviada pelo maior escoamento superficial no período chuvoso. Em dezembro/09 e janeiro/10 verificou-se a presença predominante dos picos I e II, associados à matéria orgânica autóctone, produzida pela atividade algal e pelo aporte de fontes antropogênicas, respectivamente. As bacias dos rios Japaratuba, São Francisco, Piauí e Real, apresentaram uma regressão linear entre o COD e a medida da absorvância em 254 nm, sugerindo que nesses rios predominou a MOD de origem terrestre, constituída pelas substâncias húmicas. A não linearidade do COD em função à medida da absorvância em 254 nm, registrada para as bacias do Rio Sergipe e Vaza Barris, evidencia a contribuições significativas de aportes antropogênicos para a MOD nesses rios. A análise de componentes principais aplicada aos dados de maio (período chuvoso) e dezembro (período seco) de 2009, separou as amostras em três grupos no período chuvoso e mostrou um único agrupamento no período seco. As características qualitativas da matéria orgânica dissolvida na água foram as mais importantes na separação das amostras e o aporte de matéria orgânica de origem terrestre e antropogênica, transportada para os rios pelas águas da chuva, foi o fator determinante do processo de separação.

The purpose the diploma thesis was to determine main fluorophores of soil and lignite humic substances using methods of 2D synchronous fluorescence spectroscopy (SFS) and 3D SFS. These fluorescence methods are frequently used for characterization multifluorophore systems. Measured synchronous spectra were compared with standards IHSS. Next to that the aim was to find differences between chosen samples of humic and fulvic acids.

The Master Thesis focuses on monitoring of intracellular ion concentrations in bacteria Escherichia coli and yeast Saccharomyces cerevisiae using genetically encoded fluorescent probes with green fluorescent protein (GFP). Aquired knowledge about this protein and its spectral characteristics is summarized in the introduction. For experimental study a pH-sensitive sensor which displays a ratio change of two excitation fluorescence peaks - pHluorin - was chosen. This probe was tested in bacteria and yeast cells. The experiments concentrated on the ability of the cell to maintain a constant cytosolic pH under various conditions like different pH values of the suspension, addition of glucose or KCl to the suspension. Another topic discussed in the thesis is the elimination of the cell autofluorescence from the GFP signal. For this purpose the synchronous fluorescence scan technique was succesfully used. I have found out that by using this method the measurements of cytosolic pH values are even more accurate thanks to the improved signal to noise ratio.

La Directive Cadre sur l'Eau exige le retour au bon état des cours d'eau en Europe. Ces cours d'eau reçoivent en effet différentes pollutions liées aux différentes activités économiques des populations installées le long de leurs rives. On s'intéresse souvent de façon isolée à des types particuliers de pollution: pollution agricole dues aux pesticides, engrais et résidus d'élevage en milieu rural, pollution spécifique d'une industrie (sidérurgie, papeterie, etc.), pollution domestique plus ou moins bien traitée, etc. Or dans de nombreux cas, on a affaire à un mélange de polluants. Dans le cas de la Moselle, la pollution générée par les activités humaines dans la partie française du bassin versant de la Moselle impacte la qualité des eaux de surface en aval, et donc celle du Rhin. Notre but est de contribuer à caractériser l’état de certains affluents de la Moselle (Madon, Meurthe, Vologne et Fensch) en fonction de leurs pressions anthropiques et de proposer une stratégie pour calculer les flux des polluants le long de ces cours d’eau. Dans ce contexte des compagnes de prélèvement avec un pas spatial fin. Outre les paramètres habituels de caractérisation de l’état des masses d’eau (conductivité, pH, carbone organique dissous, azote ammoniacal, nitrates, etc.) une attention particulière a été portée aux propriétés optiques (absorbance UV-visible, fluorescence synchrone) de la matière organique dissoute afin de mieux comprendre son origine. Les spectres de fluorescence synchrone ont été étudiés par déconvolution ou par analyse en composantes principales. En outre une méthode a été développée, basée sur la spectroscopie de fluorescence synchrone, pour détecter la présence des azurants optiques. Enfin une méthodologie a été mise au point appliquée au Madon pour calculer les flux journaliers moyens de pollution à chaque station d'échantillonnage pour chaque période d'échantillonnage à partir de données géographiques. Cette méthode permet ensuite d’évaluer les flux de pollution / The Water Framework Directive demands a return to good condition for rivers in Europe. These rivers receive different types of pollution related to various economic activities of populations installed along their banks. We are often interested in an isolated manner to particular types of pollution: pollution due to agricultural pesticides, fertilizers and livestock waste in rural areas, pollution due to a specific industry (steel, paper mill, etc.), more or less well treated domestic pollution, etc. But in many cases, we are dealing with a mixture of pollutants. In the case of the Moselle, the pollution generated by human activities in the French part of the Moselle watershed impacts surface water quality downstream and therefore the Rhine. Our goal is to characterize the state of some tributaries of the Moselle (Madon, Meurthe, Vologne and Fensch) versus anthropogenic pressures and propose a strategy to calculate the flow of pollutants along these rivers. In this context, sampling campaigns with a dense spatial stations have been organized. In addition to the usual parameters characterizing water quality (conductivity, pH, dissolved organic carbon, ammonia nitrogen, nitrate, etc.) a particular attention has been given to optical properties (UV-visible absorbance, synchronous fluorescence) of dissolved organic matter in order to understand its origin. Synchronous fluorescence spectra were studied by deconvolution or by principal components analysis. A method has been developed, based on the synchronous fluorescence spectroscopy, to detect the presence of optical brighteners. Finally, a methodology has been developed in Madon watershed in order to calculate the mean daily pollution flux at each sampling station for each sampling period from geographic data

Les ventes des fromages AOP subissent un affaiblissement. L’utilisation de ces fromages sous forme d’ingrédient représente une alternative intéressante à la dégustation et permettrait de maintenir une activité durable aux producteurs de ces fromages. L’objectif de ce travail est d’explorer les potentialités de 4 catégories de fromages à pâte persillée AOP du Massif-Central à être utilisés comme ingrédient à chaud pour répondre à des propriétés telles que « fondant, nappant, filant, gratinant». Les fonctionnalités recherchées pour ce type d’usage ont été prospectées à l’aide de méthodes physico-chimiques et instrumentales classiques mais également à l’aide de méthodes spectrales et sensorielles afin d’enrichir les observations de la macro et microstructure fromagère et de la perception du consommateur. Dans un premier temps, les caractéristiques physicochimiques, rhéologiques et sensorielles à froid et certaines propriétés à chaud ont été décrites pour les 4 catégories de fromages. Ces premiers résultats ont permis de cataloguer les fromages selon des caractéristiques essentiellement liées à l’organisation matricielle des composants tels que les protéines, les matières grasses, les minéraux. L’analyse sensorielle a permis de décrire précisément certaines propriétés à froid qui ne sont pas mises en évidence par d’autres analyses. Les pâtes persillées ont une grande hétérogénéité de pâte due à la présence de« veines » de moisissures. La seconde partie est une étude sur la capacité de la SFS en tant que méthode d’étude de la micro structure, à prédire la diversité de composition de ces fromages. Malgré la forte hétérogénéité des fromages, la SFS permet une « empreinte » identifiable des fromages et prédit certains mais pas la totalité des paramètres physicochimiques. L’évolution de la macro et microstructure de ces fromages au cours du chauffage et du refroidissement a ensuite été étudiée par SFS et par test de compression dynamique. Ces méthodes décrivent bien la fonte de la matière grasse et de la matrice fromagère. Elles sont corrélées entre elles et démontrent une relation entre la structure moléculaire et les propriétés rhéologiques de ces fromages. Une étude comparative des propriétés sensorielles des fromages a été menée à froid et après chauffage. Les attributs décrivent des caractéristiques de texture différentes entre les 2 conditions. Cette démarche a permis de bien différencier les 4 catégories de fromages et de mettre en évidence certains attributs de qualité ou de défaut pour une utilisation à chaud. En conclusion, ces 4 catégories de fromages à pâte persillée ont des potentialités à être utilisées comme ingrédient pour usage à chaud. L’analyse sensorielle a caractérisé les perceptions des consommateurs vis à vis de ces fromages chauffés et ainsi aider à préciser leurs fonctionnalités. Les analyses rhéologiques et spectrales ont apporté des explications liées à ce traitement au niveau de la macro et microstructure de la matrice fromagère. / Sales of PDO cheeses undergo a decline. The use of these cheeses in the form of ingredient represents an interesting alternative to the tasting and would allow to maintain a sustainable business activity to the producers of these cheeses. The objective of this work is to investigate the potentialities of four categories of Blue cheese PDO of the Massif Central as an ingredient to meet their properties during heating such as "melting, stretchability, browning". The functional properties desired for this type of cheese have been investigated by physico-chemical methods and instrumental classics and also by spectral method and sensory evaluations to enrich the observations of the macro and microstructure of the cheese and the consumer perception. First, the physicochemical, rheological, sensory characteristics and certain properties during heating have been reported for four categories of Blue cheese. These initial results allowed us to characterize the cheese studied according to their characteristics essentially which were related to the organization matrix constitutes such as proteins, fats, minerals. The sensory analysis allowed to describe exactly certain properties which are not revealed by theother analyses. Blue-veined cheeses have a great heterogeneity due to the presence of "veins" of mold. The second part is a study on the ability of the SFS method to study the micro structure and to predict the diversity of composition of these cheeses. Despite the high heterogeneity of cheeses, SFS allows an identifiable 'fingerprint' of cheese and predicts some but not the totality of the physicochemical parameters. The evolution of the macro-and microstructure of these cheeses during heating and cooling was then studied by SFS and dynamic shear test. These methods describe well the melting temperature of the fat and the cheese matrix. They are correlated between them and demonstrate a relationship between the molecular structure and the rheological properties of these cheeses. A comparative study of the sensory textural properties of cheeses was carried out in the non- and heated forms. The attributes describe different characteristics of texture between the two conditions. This approach allowed to differentiate well the four categories of cheeses and to highlight on certain attributes of quality or defects to be used in cooking application. In conclusion, these four categories of Blue-veined cheeses have the potential to be used as an ingredient in cooking application. The sensory analysis characterized the perceptions of the consumers in both non- and heated forms and thus helps to specify their features. The rheological and spectral analyses have provided explanations related to this treatment at the level of the macro and microstructure of the cheese matrix.

This dissertation presents experimental and instrumentation developments that take full advantage of the multidimensional nature of line narrowing spectroscopy at liquid nitrogen (77 K) and liquid helium (4.2 K) temperatures. The inconvenience of sample freezing procedures is eliminated with the aid of cryogenic fiber optic probes. Rapid collection of multidimensional data formats such as wavelength time matrices, excitation emission matrices, time-resolved excitation emission matrices and time resolved excitation emission cubes is made possible with the combination of a pulsed tunable dye laser, a spectrograph and an intensifier-charged coupled device. These data formats provide unique opportunities for processing vibrational luminescence data with second order multivariate calibration algorithms. The use of cryogenic fiber optic probes is extended to commercial instrumentation. An attractive feature of spectrofluorimeters with excitation and emission monochromators is the possibility to record synchronous spectra. The advantages of this approach, which include narrowing of spectral bandwidth and simplification of emission spectra, were demonstrated with the direct analysis of highly toxic dibenzopyrene isomers. The same is true for the collection of steady-state fluorescence excitation-emission matrices. These approaches provide a general solution to unpredictable spectral interference, a ubiquitous problem for the analysis of organic pollutants in environmental samples of unknown composition. Since commercial spectrofluorimeters are readily available in most academic institutions, industrial settings and research institutes, the developments presented here should facilitate the widespread application of line-narrowing spectroscopic techniques to the direct determination, no chromatographic separation, of highly toxic compounds in complex environmental matrixes of unknown composition.