Questa tesi è dedicata alla qualità dell'alimento ittico in tre delle sue possibili accezioni. Dopo aver spiegato il complicato rapporto del consumatore con gli alimenti ittici e come l'Unione Europea abbia cercato di fare chiarezza al riguardo, gli argomenti di discussione saranno: Autenticazione d'origine La polpa di 160 esemplari di spigola (Dicentrachus labrax), suddivisi tra selvatici, allevati intensivamente e allevati estensivamente, provenienti dall'Italia e dall'estero per un totale di 18 fonti indagate, è stati analizzata individualmente per caratterizzarne la componente lipidica, isotopica e minerale e verificare le potenzialità di queste informazioni ai fini della autenticazione di origine in senso lato. Stima della Freshness Quality Numerosi lotti di seppia (Sepia officinalis), nasello (Merluccius merluccius) e triglia di fango (Mullus barbatus) sono stati sottoposti a due possibili modalità di stoccaggio sotto ghiaccio fondente, per indagare come, nell’arco della loro vita commerciale, ne evolvessero importanti connotati chimici (cataboliti dell’ATP e loro rapporti), fisici (proprietà dielettriche dei tessuti) e sensoriali (Quality Index Methods specie-specifici. Studio del profilo nutrizionale La componente lipidica di numerosi lotti di mazzancolla (Penaeus kerathurus), canocchia (Squilla mantis) e seppia (Sepia officinalis) è stata caratterizzata allo stato crudo e dopo cottura secondo tecniche “dedicate” per stabilire il contributo di queste matrici come fonte di acidi grassi polinsaturi della serie omega 3 e per pervenire alla determinazione dei loro coefficienti di ritenzione vera. / This dissertation revolves around finfish and shellfish quality according to three quite different approaches, preceded by an in-depth study of the complicated relationship between Seafood and the Consumer. Origin authentication The flesh from 160 specimens of seabass (Dicentrarchus labrax), either caught in the wild or reared at different density and coming from 18 possible sources, was individually analyzed as to lipid content and composition, macro- and micro-elemental concentrations, as well as nitrogen and carbon stable isotopic abundances. The aim was to verify if and to what extent each homogeneous set of variables was able to discriminate among seabass origin, latu sensu. Freshness quality evaluation Three complete storage experiments were conducted using several batches of European common cuttlefish (Sepia officinalis), European hake (Merluccius merluccius) and red mullet (Mullus barbatus). Specimens were stored under melting ice according to two different theses until the end of their shelf life, during which chemical determinations (i.e. ATP and related compounds, as well as pertinent ratios), physical measurements (i.e. dielectric properties) and sensory assessments (species-specific Quality Index Methods) were made, in order to ascertain which trait evolved much in the way the sensory traits did, as the leading parameters Nutritional profiling Several batches of caramote prawns (Penaeus kerathurus), mantis shrimps (Squilla mantis) and European common cuttlefish (Sepia officinalis) were analyzed as to their lipid content and composition both at the raw state and upon cooking following a specific method (steam cooking, pan frying in a non-stick pan and pressure cooking, in the very same order), the aim of this research being twofold: to determine the fatty acid content and composition of these low-fat species and to gain knowledge of the true retention coefficients of these nutrients.

Salmonella and Campylobacter are common causes of human gastroenteritis. Their epidemiology is complex and a multi-tiered approach to control is needed, taking into account the different reservoirs, pathways and risk factors. In this thesis, trends in human gastroenteritis and food-borne outbreak notifications in Italy were explored. Moreover, the improved sensitivity of two recently-implemented regional surveillance systems in Lombardy and Piedmont was evidenced, providing a basis for improving notification at the national level. Trends in human Salmonella serovars were explored: serovars Enteritidis and Infantis decreased, Typhimurium remained stable and 4,[5],12:i:-, Derby and Napoli increased, suggesting that sources of infection have changed over time. Attribution analysis identified pigs as the main source of human salmonellosis in Italy, accounting for 43–60% of infections, followed by Gallus gallus (18–34%). Attributions to pigs and Gallus gallus showed increasing and decreasing trends, respectively. Potential bias and sampling issues related to the use of non-local/non-recent multilocus sequence typing (MLST) data in Campylobacter jejuni/coli source attribution using the Asymmetric Island (AI) model were investigated. As MLST data become increasingly dissimilar with increasing geographical/temporal distance, attributions to sources not sampled close to human cases can be underestimated. A combined case-control and source attribution analysis was developed to investigate risk factors for human Campylobacter jejuni/coli infection of chicken, ruminant, environmental, pet and exotic origin in The Netherlands. Most infections (~87%) were attributed to chicken and cattle. Individuals infected from different reservoirs had different associated risk factors: chicken consumption increased the risk for chicken-attributed infections; animal contact, barbecuing, tripe consumption, and never/seldom chicken consumption increased that for ruminant-attributed infections; game consumption and attending swimming pools increased that for environment-attributed infections; and dog ownership increased that for environment- and pet-attributed infections. Person-to-person contacts around holiday periods were risk factors for infections with exotic strains, putatively introduced by returning travellers.

La presenza di Escherichia coli produttori di verocitotossine (VTEC o STEC) rappresenta una tra le più importanti cause di malattia alimentare attualmente presenti in Europa. La sua presenza negli allevamenti di animali destinati alla produzione di alimenti rappresenta un importante rischio per la salute del consumatore. In conseguenza di comuni contaminazioni che si realizzano nel corso della macellazione, della mungitura i VTEC possono essere presenti nelle carni e nel latte e rappresentano un grave rischio se la preparazione per il consumo o i processi di lavorazione non comportano trattamenti in grado d’inattivarli (es. carni crude o poco cotte, latte non pastorizzato, formaggi freschi a latte crudo). La contaminazione dei campi coltivati conseguente alla dispersione di letame o attraverso acque contaminate può veicolare questi stipiti che sono normalmente albergati nell’intestino di ruminanti (domestici e selvatici) e anche prodotti vegetali consumati crudi, succhi e perfino sementi sono stati implicati in gravi episodi di malattia con gravi manifestazioni enteriche e complicazioni in grado di causare quadri patologici gravi e anche la morte. Stipiti di VTEC patogeni ingeriti con gli alimenti possono causare sintomi gastroenterici, con diarrea acquosa o emorragica (nel 50% dei casi), crampi addominali, febbre lieve e in una percentuale più bassa nausea e vomito. In alcuni casi (circa 5-10%) l’infezione gastroenterica si complica con manifestazioni tossiemiche caratterizzate da Sindrome Emolitico Uremica (SEU o HUS) con anemia emolitica, insufficienza renale grave e coinvolgimento neurologico o con una porpora trombotica trombocitopenica. Il tasso di mortalità dei pazienti che presentano l’infezione da E. coli è inferiore all’1%. I dati forniti dall’ECDC sulle infezioni alimentari nel periodo 2006-2010 hanno evidenziato un trend in leggero aumento del numero di infezioni a partire dal 2007. L’obiettivo degli studi condotti è quello di valutare la prevalenza ed il comportamento dei VTEC per una analisi del rischio più approfondita. / The presence of verotoxigenic Escherichia coli (VTEC or STEC) is one of the most important causes of disease food currently present in Europe. Its presence in the breeding of animals for food production is a major risk to the health of the consumer. As a result of common influences that occur during slaughter and milking VTEC can be found in meat and milk and pose a serious risk if the preparation for consumption or processing do not involve treatments in the degree of inactivation (eg. raw meat or undercooked, unpasteurized milk, soft cheeses made from raw milk). The contamination of fields resulting from the dispersion of manure or through contaminated water can carry these strains that are normally present in intestine of ruminants (domestic and wild) and also vegetables eaten raw, juices and even seeds have been implicated in serious cases of enteric disease with severe manifestations and complications can cause serious pathological and even death. VTEC strains ingested with food can cause gastrointestinal symptoms as watery or hemorrhagic diarrhea, abdominal cramps, mild fever and a lower percentage nausea and vomiting. In some cases (about 5-10%) infection is complicated by gastrointestinal manifestations characterized by Hemolytic Uremic Syndrome (HUS or HUS) with hemolytic anemia, severe renal and neurological involvement or with thrombotic thrombocytopenic purpura. The mortality rate of patients with infection with E. coli is less than 1%. The data provided by the ECDC on food-borne infections in the period 2006-2010 showed a trend of slight increase in the number of infections from 2007. The aim of these studies was to evaluate the prevalence and behavior of VTEC for a more in-depth risk analysis.

Perfluoroalkylated substances are a group of chemicals that have been largely employed during the last 60 years in several applications, widely spreading and accumulating in the environment due to their extreme resistance to degradation. As a consequence, they have been found also in various types of food as well as in drinking water, proving that they can easily reach humans through the diet. The available information concerning their adverse effects on health has recently increased the interest towards these contaminants and highlighted the importance of investigating all the potential sources of human exposure, among which diet was proved to be the most relevant. This need has been underlined by the European Union through Recommendation 2010/161/EU: in this document, Member States were called to monitor their presence of in food, producing accurate estimations of human exposure. The purpose of the research presented in this thesis, which is the result of a partnership between an Italian and a French laboratory, was to develop reliable tools for the analysis of these pollutants in food, to be used for generating data on potentially contaminated matrices. An efficient method based on liquid chromatography-mass spectrometry for the detection of 16 different perfluorinated compounds in milk has been validated in accordance with current European regulation guidelines (2002/657/EC) and is currently under evaluation for ISO 17025 accreditation. The proposed technique was applied to cow, powder and human breast milk samples from Italy and France to produce a preliminary monitoring on the presence of these contaminants. In accordance with the above mentioned European Recommendation, this project led also to the development of a promising technique for the quantification of some precursors of these substances in fish. This method showed extremely satisfying performances in terms of linearity and limits of detection, and will be useful for future surveys.

Le sostanze perfluoralchiliche (PFAS), composti fluorurati ampiamente utilizzati negli ultimi anni in diverse applicazioni industriali e commerciali, sono ritrovati diffusamente nell’ambiente e in diverse specie animali. Recentemente i PFAS hanno destato preoccupazione anche per la salute umana. Il rischio di esposizione è principalmente legato alla dieta (i prodotti ittici sembrano essere gli alimenti più contaminati). Lo scopo di questo lavoro è stato quello di valutare la presenza del perfluorottanosulfonato (PFOS) e dell’acido perfluorottanoico (PFOA), in diverse matrici alimentari: latte vaccino commercialmente disponibile in Italia, latte materno italiano, diverse specie di pesce commercialmente disponibili in Italia e 140 branzini di diverse aree (principalmente Mediterraneo). I campioni di latte sono stati trattati con estrazione liquido-liquido seguita da due fasi di purificazione mediante cartucce SPE prima dell’iniezione nell’UPLC-MS/MS. L’analisi del latte vaccino ha evidenziato una contaminazione diffusa di PFOS, ma a basse concentrazioni (fino a 97 ng/L), mentre il PFOA è stato ritrovato raramente. In questo studio, in grado di individuare anche i livelli delle ultra-tracce, sono state osservate nel latte materno concentrazioni di 15-288 ng/L per il PFOS e di 24-241 ng/LPFOA. Le concentrazioni e le frequenze più alte, per entrambi i PFAS, sono stati ritrovate in campioni di latte forniti da donne primipare, suggerendo un rischio di esposizione per i primogeniti. Il metodo utilizzato per i campioni di pesce era basato su un’estrazione con solvente organico seguita da due fasi di purificazione: una con i sali e una con fase solida dispersiva. L’estratto, analizzato in UPLC-MS/MS, ha confermato la contaminazione di questa matrice a livelli significativi, ma anche l’alta variabilità delle concentrazioni misurate. Il monitoraggio monospecie ha mostrato una contaminazione rilevante (PFOS 11,1- > 10000 ng/L; PFOA < 9-487 ng/L), soprattutto nei branzini pescati, rispetto a quelli allevati. / Perfluoroalkyl substances (PFASs) are fully-fluorinated compounds widely employed for the production of different industrial and consumer applications. They have been frequently found in the environment and several animal species. These emerging contaminants have recently become of relevant concern for human health. The risk of exposure to PFASs is mainly related to diet; fish and other seafood seem to be the most contaminated foods. The aim of this work was to monitor the presence of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), the two most important and investigated PFASs, in various food matrices: cow milk commercially available in Italy, Italian breast milk, different species of fish commercially available in Italy and 140 sea basses collected from different areas (mainly Mediterranean Sea). Milk samples were treated with liquid-liquid extraction followed by two purification steps through SPE cartridges before UPLC-MS/MS analysis. The analysis of cow milk demonstrated that a contamination by PFOS was often present, but at low concentrations (up to 97 ng/L), and PFOA was rarely found. This study, capable to detect these contaminants at ultra-trace levels, has found concentrations for human milk in the range 15-288 ng/L for PFOS and 24-241 ng/L for PFOA. The highest concentrations and frequencies of both PFAS were found in milk samples provided by primiparous women, suggesting the higher risk of exposure for first-borns. The method used for fish samples was based on extraction with organic solvent followed by two purification steps: one with salts and one with dispersive solid phase. The extract analyzed by UPLC-MS/MS confirmed the contamination of this matrix at significant levels, but also the high variability of measured concentrations. The single species monitoring showed a relevant contamination (PFOS 11,1- > 10000 ng/L and PFOA < 9- 487 ng/L) in particular in fished basses compared to the reared ones.

La presenza di micotossine nelle materie prime desta grande preoccupazione a causa delle importanti implicazioni nella sicurezza di alimenti e mangimi. Lo scopo di questo lavoro è stato quello di mettere a punto e validare una metodica analitica rapida e semplice, in cromatografia liquida ad ultra prestazione accoppiata a spettrometria di massa-tandem (UPLC-MS/MS), per la determinazione simultanea di differenti micotossine: aflatossine (B1, B2, G1, G2), ocratossina A, fumonisine (B1, B2), deossinivalenolo e zearalenone in matrici biologiche. Il metodo sviluppato per l’analisi di campioni di mangime secco per cani ha mostrato prestazioni adeguate ed è stato applicato a 49 campioni reperibili in commercio, al fine di valutare la sua efficacia e di ottenere alcuni dati preliminari sulla contaminazione da micotossine in alimenti per cani disponibili sul mercato italiano. Lo studio ha evidenziato una percentuale alta di campioni positivi, contenenti principalmente fumonisine, deossinivalenolo e ocratossina A; tutti i tenori si sono dimostrati inferiori al limite di legge previsto (Racc. CE 576/2006). Una seconda metodica è stata messa a punto e validata per l’identificazione e la quantificazione micotossine in campioni di formaggio; per questa matrice è stata inserita anche l’aflatossina M1, specifica dei prodotti lattiero - caseari. Le differenti proprietà chimico-fisiche degli analiti e la complessità della matrice hanno implicato alcune difficoltà nello sviluppo della metodica. Tuttavia, il metodo validato si è mostrato rapido, semplice ed affidabile ed è stato applicato a diversi tipi di formaggi per verificarne la versatilità. I risultati preliminari hanno mostrato l’assenza di contaminazione da parte delle micotossine in oggetto. Entrambi i metodi si sono dimostrati utili per il monitoraggio di contaminanti in matrici complesse ad oggi ancora poco studiate. / The occurrence of mycotoxins contamination in various crops is of major concern as it has major implications for food and feed safety. The aim of the study was the set up and the validation of fast and simple methods by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UPLC–MS/MS) for the simultaneous determination of different mycotoxins: aflatoxins (B1, B2, G1, G2), ochratoxin A, fumonisins (FB1, FB2), deoxynivalenol and zearalenone in biological matrices. A method was developed for the analysis of samples of dried pet-food; the method showed appropriate performances and was applied to 49 commercial samples in order to test its efficacy and gain some preliminary data about mycotoxins contamination in dog food available in the Italian market. The results have shown a quite high percentage of positive samples, mainly contaminated by fumonisin, deoxynivalenol and ochratoxin A. All the observed values were below the limits specified by regulations (Rec. CE 2006/576). A second method was set up and validated for the identification and quantification of mycotoxins in cheese samples; for this matrix it was included also the aflatoxin M1, which is specific of dairy products. Different chemical-physical properties of the analytes and the complex composition of the matrix led to some difficulties to the development of the method. Finally, the method validated has proved to be rapid, simple and reliable and was applied to different types of cheeses to prove its versatility. Preliminary results have shown the absence of all mycotoxins detected. Both methods are useful tools for the monitoring of mycotoxins contamination in unconventional matrices, not subjected to wide studies until now.

Foodborne diseases impact human health and economies worldwide in terms of health care and productivity loss. Prevention is necessary and methods to detect, isolate and quantify foodborne pathogens play a fundamental role, changing continuously to face microorganisms and food production evolution. Official methods are mainly based on microorganisms growth in different media and their isolation on selective agars followed by confirmation of presumptive colonies through biochemical and serological test. A complete identification requires form 7 to 10 days. Over the last decades, new molecular techniques based on antibodies and nucleic acids allow a more accurate typing and a faster detection and quantification. The present thesis aims to apply molecular techniques to improve official methods performances regarding two pathogens: Shiga-like Toxin-producing Escherichia coli (STEC) and Listeria monocytogenes. In 2011, a new strain of STEC belonging to the serogroup O104 provoked a large outbreak. Therefore, the development of a method to detect and isolate STEC O104 is demanded. The first objective of this work is the detection, isolation and identification of STEC O104 in sprouts artificially contaminated. Multiplex PCR assays and antibodies anti-O104 incorporated in reagents for immunomagnetic separation and latex agglutination were employed. Contamination levels of less than 1 CFU/g were detected. Multiplex PCR assays permitted a rapid screening of enriched food samples and identification of isolated colonies. Immunomagnetic separation and latex agglutination allowed a high sensitivity and rapid identification of O104 antigen, respectively. The development of a rapid method to detect and quantify Listeria monocytogenes, a high-risk pathogen, is the second objective. Detection of 1 CFU/ml and quantification of 10–1,000 CFU/ml in raw milk were achieved by a sample pretreatment step and quantitative PCR in about 3h. L. monocytogenes growth in raw milk was also evaluated.

Pascal Quignard se fait l’écho dans sa littérature : « Va à la source de la langue et non pas à la langue ». La source, l’origine quignardienne, est l’ab-origine qui n’a ni forme, ni modèle. C’est un monde inconnu, inconnaissable. En ce sens, Pascal Quignard recherche la langue naturelle et non pas la langue maternelle. Cette thèse intitulée « Sources et Ressources de la langue d’écriture de Pascal Quignard :essais de lectures coréennes » s’intéresse donc à la langue qui n’appartient qu’à la nature. La notion de nature pourrait être formulée comme suit : « Natura, mère, et notre ultime idem ». L’homme fatigué par la langue et par la civilisation veut s’en retourner à la nature, à la nudité, et à la source, où il s’abreuve. La source de la langue qui se rattache à la langue naturelle est un monde plus singulier, plus originel, et plus universel, puisqu’il est inhumain, non-verbal et non-linguistique. C’est ainsi que son intérêt se porte davantage vers l’art des images que vers l’art des discours. Quignard n’explique pas mais illumine. Il s’intéresse plutôt à la Physis, à la Natura qu’au Mundus. Il aime quand la « langue touche directement au corps ». Quignard préfère, à travers elle, atteindre à la sensation plutôt qu’à l’émotion. C’est en cela que résident la force et la merveille de la littérature de Quignard, qui ne poursuit pas la belle langue, mais qui conserve une vitalité dans la pauvreté et dans la nudité mêmes de sa langue. Cette étude sur la littérature de Pascal Quignard devra sans cesse évoquer la vitalité. On sait que l’art n’est guidé que par la passion : c’est le premier éclat du bouton, le premier débordement. C’est la joie originelle, l’essence de la vie et de l’art. / Pascal Quignard echoes in his literature:« Go to the source of language and not to the language ». The source, the quignardian’s origin, does not have neither shape nor model. This world is unknown and unknowable. This way, Quignard is seeking for the natural tongue and not for the mother tongue. This thesis entitled « Sources and Resources of writing language of Pascal Quignard: Attempt of Korean readings » is then focused on the language that only belongs to nature. The notion of nature could be expressed as followed: «Natura, mother, and our last idem». The man frazzled by language and civilization wants to go back to nature, to nudity, to the source where he can quench his thrist. This source of language, linked to the natural language, is a more singular, more original and universal world since it is unhuman, nonverbal and non-linguistic. Therefore, this is how Quignard shows more interest in the art of images than in the art of speeches. He does not explain but enlightens. He’s rather interested in Physis, in Natura than in Mundus. He loves when «language directly reaches the body». Quignard favours, through language, to affect to the sensation even more than to the emotion. This is where lies the strength and the wonder of Quignard’s literature that does not pursue fine language, but instead wants to preserve a certain vitality in the core of the poverty and the nudity of his own language. Our study about Quignard’s literature ought to constantly call to mind vitality. We understand that way why Quignard’s writing is so astonishing. It is known that Art is only guided by passion: it is the first blooming of the bud, the first overflowing. It’s the original, the essence of life and art.

Cette thèse s’intéresse aux enjeux d’une origine éprouvée comme problématique par un sujet féminin. Et nous ne parlerons plus d’hier, le roman qui en compose le volet créatif se déploie sous la forme d’un double récit de voyage qui met en scène deux protagonistes, une fille et son père. La première séjourne au Mexique, dans un village côtier où sa famille et elle ont vécu plusieurs mois lorsqu’elle était enfant. Elle effectue ce périple dans l’espoir de parvenir à raviver sa mémoire d’une époque où son père, qu’elle a perdu de vue vers l’âge de neuf ans, à la suite de la séparation de ses parents, faisait encore partie de sa vie. C’est en explorant les lieux – les rues rocailleuses de La Peñita, son camping, ses plages – et par l’écriture qu’elle tente de remédier à l’oubli, mais les souvenirs restent évanescents et les mots se dérobent, lui donnant le sentiment d’échouer à saisir tant la matière brute de son enfance que le sens de son histoire. Ce premier récit, relaté au je, alterne avec un autre mettant en scène le père de la narratrice lorsqu’il avait quinze ou seize ans. Afin d’échapper au milieu étriqué et malsain dont il est issu, ce dernier quitte à pied, au milieu de la nuit, la ferme de ses parents. Il compte rejoindre en autostop les champs de tabac de l’Ontario, puis poursuivre sa route vers l’Ouest canadien. Il attend de cette expérience qu’elle transforme le garçon frêle et meurtri, pétri de crainte, qu’il est en un jeune homme riche, séduisant et rusé. C’est aussi la fille qui assure la narration de ce second récit, mais elle le fait en recourant à la deuxième personne du singulier, comme si elle s’adressait à l’adolescent que fut son père. Par le biais d’une telle narration, l’héroïne reste fidèle au désir qui l’anime, au moment où elle décide de se rendre au Mexique, de se rapprocher, en renouant avec son passé, de l’absent qui la hante. Le volet réflexif de la thèse se penche quant à lui sur Œuvre poétique d’Alejandra Pizarnik, Le rapt de Kathryn Harrison et les « Aurélia Steiner » de Marguerite Duras de manière à montrer que les femmes auxquelles ces auteures prêtent la parole vivent, comme la narratrice de mon roman, le rapport à l’origine sur le mode de la privation et de la hantise. Mon étude se divise en trois chapitres, Hantise et mélancolie de l’origine dans Œuvre poétique d’Alejandra Pizarnik, Angles morts de l’origine dans Le rapt de Kathryn Harrison, L’entretien avec les fantômes de l’« Aurélia Steiner » de Marguerite Duras, et tend également à illustrer que le défaut d’origine dont souffrent les consciences féminines de ces textes les exile d’elles-mêmes, les rendant impuissantes à éprouver leur présence au monde. Ma réflexion critique s’articule, en résumé, autour de trois axes : 1) la souffrance et l’aliénation découlant d’une origine vécue comme trouble – ou spectrale – chez un sujet féminin; 2) l’appel au témoin que suppose, dans un tel contexte, le recours à l’adresse et, enfin, 3) la possibilité de réparation qu’implique, aussi malaisée et angoissée puisse-t-elle dans certains cas s’avérer, la mise en récit ou en poème (parole) de l’expérience ayant provoqué ou aggravé la hantise.

L’origine des éléments volatils, éléments avec des températures de condensation très basses comme l’eau, l’azote, le carbone et les gaz rares, sur Terre et sur les autres planètes telluriques reste mal comprise. Comprendre comment ces éléments sont arrivés sur Terre permettra de mieux appréhender les mécanismes de formation du système solaire. De par leur caractère inerte, les gaz rares (He, Ne, Ar, Kr, Xe) constituent des traceurs uniques des sources d’éléments volatils. L’étude de la composition en gaz rares du manteau terrestre s’avère donc essentielle afin de déterminer l’origine de ces éléments. L’objectif de ces travaux était de mesurer précisément la composition des isotopes stables et non-radiogéniques des gaz rares dans le manteau à partir de verres basaltiques. Ces derniers étant très souvent contaminés par l’air, des techniques d’analyse des gaz rares ont été mises en place pour s’affranchir de cette contamination. Des échantillons du volcan Fernandina du point chaud des Galápagos ont été étudiés par ablation laser. Les résultats montrent que le rapport 20Ne/22Ne des bulles est en moyenne de 12,65 ± 0,04 (1σ), ce qui est proche de la valeur estimée pour le pôle d’implantation du vent solaire (~ 12,7). Cette étude suggère donc que l’implantation du vent solaire sur les grains précurseurs de la Terre serait à l’origine des éléments volatils légers du manteau.Des données d’échantillons de popping rocks, aussi analysés par cette technique, indiquent que le manteau supérieur est hétérogène à petite échelle et pourraient impliquer le recyclage de gaz rares dans le manteau, y compris He, Ne, lors de la subduction. Un nouveau protocole d’analyse du Kr et Xe a été développé. Les résultats montrent les plus forts excès en 124Xe, 126Xe et 128Xe mesurés pour le manteau et suggèrent une source chondritique. Les isotopes fissiogéniques du xénon ont permis de dater le début du recyclage des éléments volatils dans le manteau aux alentours de 3 Ga. / The origin of volatiles, elements with low condensation temperatures such as water, nitrogen, carbon and noble gases, on Earth and other terrestrial planets is still misunderstood. Determining how these elements were delivered to the Earth will allow a better understanding of the processes of solar system formation. Due to their inertness, noble gases (He, Ne, Ar, Kr, Xe) constitute unique tracers of volatiles sources. Studying the noble gas composition of the Earth’s mantle is hence critical to unravel volatile origin. The aim of this PhD was to measure precisely the composition of non-radiogenic, stable noble gas isotopes in the mantle from basaltic glasses. The latter being very often contaminated by air, analytical techniques were thus set up to overcome this contamination.Samples from Fernandina volcano from the Galápagos hotspot were studied with laser ablation. The results show that the mean 20Ne/22Ne ratio in the vesicles is 12.65 ± 0.04 (1σ), close to the estimated value of the solar wind implanted end-member (~ 12,7). This study suggests that light volatiles in the mantle would originate from implantation of solar wind on the Earth’s precursors grains. Data from popping rock samples, also analyzed with this technique, indicate that the upper mantle is heterogeneous at small scale and that noble gases, included He, Ne, could be recycled into the mantle in subduction zones. A new protocol to analyse Kr and Xe was set up. The results show the highest measured excess in 124Xe, 126Xe and 128Xe for the mantle and suggest a chondritic source. The xenon fissiogenic isotopes allowed us to constrain the onset of volatile recycling in the mantle to around 3 Ga.