Este trabalho tem como objetivo otimizar as etapas da rota de purificação da glicerina bruta proveniente da produção de biodiesel, sendo elas, hidrólise ácida e retirada de sais através dos processos utilizando o efeito salting-out e troca iônica até obter uma solução aquosa de glicerol e etanol. Foi feito um planejamento fatorial 22 com dois pontos centrais tendo como variáveis de processo temperatura e tempo de reação, e como respostas o valor de pH da solução e a massa de glicerina separada, para cada ácido testado (ácido sulfúrico e ácido clorídrico). Para a glicerina hidrolisada com ácido sulfúrico o valor de pH não sofreu influência das variáveis do modelo. Para a massa de glicerina separada, houve efeito significativo positivo da temperatura e negativo do tempo. Para a hidrólise com ácido clorídrico, na análise do valor de pH há uma leve suspeita da influência negativa para o tempo, sem influência da temperatura. Para a massa há uma suspeita da influência negativa da temperatura, sem influência do tempo. Assim, as condições estabelecidas são de temperatura de 70 °C e tempo de reação de 180 minutos para a hidrólise com ácido sulfúrico e 50 °C e 180 minutos pra a hidrólise com ácido clorídrico. Na segunda etapa, que é a retirada de sais por salting-out, foi feito um planejamento de mistura com inclusão de variáveis de processo. Foram planejados 45 experimentos em um planejamento de mistura em função da composição dos alcoóis - etanol (x1), isopropanol (x2), n-butanol (x3) e das variáveis de processo pH e temperatura, obtendo os seguintes modelos: Massa_ retida = 1,44x1 + 0,99x2 + 0,77x3 + 0,13x1pH + 1,90x2x3. Analisando a equação, tratando-se dos álcoois puros pode-se observar que o etanol é mais eficiente na retenção de massa, pois apresenta o maior coeficiênte (1,44). A melhor interação é entre isopropanol e butanol. Quanto as variáveis de processo, o valor de pH teve uma leve influência quando se tratava da solução de etanol. Na análise da condutividade da glicerina filtrada foi obtido o seguinte modelo: Condutividade = 159,14x1 + 255,74x2 + 588,64x3 - 668,14x1x3 + 44,90x1pH - 42,57x1T - 596,79x2x3. Analisando a equação para soluções de alcoóis puros pode-se verificar que o menor coeficiente é para solução de etanol (159,14). Para misturas, etanol e n-butanol apresentam o menor coeficiente que isopropanol e n-butanol. Para soluções de etanol o pH e a temperatura mostram uma leve influência. Para o efeito salting-out definiu-se que seria mais vantajosa a utilização do etanol, pois facilita as etapas posteriores pela facilidade de evaporação e recuperação e baixo custo. Com essas análises ficaram definidas as melhores condições da glicerina em pH 5 e temperatura de 25 ºC, na presença de etanol. A troca iônica foi efetuada obtendo resultados satisfatórios em que a glicerina após passar pela troca iônica estava com condutividade inferior a 10 S/cm. / This work aims to optimize the stages of raw glycerin purification route from biodiesel production, which are, acid hydrolysis and salts extraction through salting out and ion exchange process until to achieve aqueous solution of glycerol and ethanol. A 22 factorial planning with two central points was carried out. Temperature and time reaction were the process variables and pH of solution and glycerin separated mass the answers for each acid tested (sulfuric acid and hydrochloric acid). The pH was not influenced by process variables for glycerin hydrolyzed with sulfuric acid. For separated glycerin mass the effect was positive for temperature and negative for time. For hydrolysis with hydrochloric acid, the pH analyses shows that there might be negative influence of time, and no influence of temperature. For separated glycerin mass there might be negative influence of temperature, and no influence of time. According to the experiments, when the glycerin was hydrolyzed with sulfuric acid the better reaction conditions occur at 70 °C and time reaction equal to 180 minutes. In the hydrolization with hydrochloric acid the conditions were 50 °C and time reaction 180 minutes. In the second stage, salt removal by salting-out effect, a mixture planning with process variables inclusion was conducted. 45 experiments in function of alcohol composition - ethanol (x1), isoprophanol (x2), n-buthanol (x3) and process variables pH and temperature were planned, obtaining the following model: Retained_mass = 1,44x1 + 0,99x2 + 0,77x3 + 0,13x1pH + 1,90x2x3. Analyzing the equation, treating only pure alcohols, it is possible to observe that ethanol is the most efficient in retaining mass due to its biggest coefficient (1,44). The best interaction occurs between butanol and isopropanol. When ethanol solution was used the pH influence can not be neglected. The analysis of the conductivity results the model bellow: Conductivity = 159,14x1 + 255,74x2 + 588,64x3 - 668,14x1x3 + 44,90x1pH - 42,57x1T - 596,79x2x3. Observing the equation, for pure alcohols solutions, ethanol has the smallest coefficient (159,14). For mixtures, ethanol and buthanol have smaller coefficient than isoprophanol and buthanol. For ethanol solutions, pH and temperature have little influence. For the salting-out process it was defined that would be more gainful with ethanol utilization, because it favours the next steps by faciliting evaporation and recover and its low cost. After these analyses satisfactory results for raw glycerin purification were obtained at pH 5 and 25°C, using pure ethanol. The glycerin purification by ion exchange process was carried out obtaining good results. The glycerin conductivity was less than 10 S/cm.

Cette thèse est financée par Total et par l’agence nationale de la recherche (ANR), elle s’inscrit dans le cadre du projet SIGARRR (simulation de l’impact des gaz annexes injectés avec le CO2 pendant le stockage géologique sur la réactivité des roches réservoirs). L’objectif de la thèse est d’acquérir expérimentalement des points de solubilité du CO2 dans des solutions aqueuses salées de chlorure de sodium et de chlorure de calcium dans des conditions de hautes températures (323K < T < 423K) et hautes pressions (5 MPa < P < 20 MPa) à des salinités élevées (1 à 6 mol/kg).Suite à une synthèse bibliographique sur les techniques expérimentales utilisées pour la détermination de la solubilité du dioxyde de carbone dans les solutions aqueuses, trois méthodes de caractérisation ont été expérimentées :  Analyse de la phase aqueuse par chromatographie ionique (analyse en ligne) Estimation de la solubilité à l’aide des bilans matière, des quantités de corps pures injectés initialement dans l’autoclave et des paramètres expérimentaux (masse volumique de la phase liquide, volume molaire de la phase gaz à l’équilibre, volume total de l’autoclave…). Piégeage d’un échantillon liquide dans la soude puis dosage. Une étude de sensibilité a été réalisée sur la méthode d’estimation de solubilité par bilan matière. Cette étude a permis d’identifier le niveau de précision de la mesure du volume de l’autoclave afin d’obtenir des estimations de solubilité fiables et précises à haute pression. Pour la dernière méthode expérimentée (piégeage dans la soude puis dosage), un protocole d’échantillonnage, et deux protocoles d’analyses (titrations) ont été développés ; les échantillons des systèmes CO2-H2O et CO2-H2O-NaCl ont été analysés par dosage pH-métrique et les échantillons des systèmes CO2-H2O-CaCl2 ont été analysés par dosage conductimétrique. 84 points de solubilité ont été obtenus au cours de ce travail dont 45 points complétement originaux. Les données expérimentales obtenues ont été comparées avec les résultats de simulations réalisées par le logiciel PHREEQC avec une base de données Pitzer.dat. Le ‘’salting out effect’’ observé a été évalué pour chaque système dans toutes les conditions de températures et pressions étudiées. / This work was supported by Total and ‘’Agence National de la recherche’’ as a part of SIGARRR project (Simulation of the impact of annex gases co-injected with CO2 during its geological storage on the Reservoir-Rocks Reactivity. The aim of the thesis was to obtain experimental CO2 solubility data in salty aqueous solutions of sodium chloride and calcium chloride at different molalities (1, 3 and 6 mol/kg) under high temperature (323K < T < 423K) and high pressure (5 MPa < P < 20 MPa).Following a bibliographical study on experimental methods used for the carbon dioxide solubility determination, three characterization methods were tested: Aqueous phase analysis by ion chromatography Solubility estimation from mass balance, amounts of CO2 and liquid initially loaded into the cell and experimental parameters (density of liquid phase, molar volume of gas phase, and total volume of the equilibrium cell…). A liquid sample trapping in sodium hydroxide solution followed by a titrationA sensitivity study was carried out on the Solubility estimation method from mass balance. This study identified the level of accuracy of autoclave volume measurement to obtain reliable and accurate solubility data high-pressure.A sampling protocol was developed to withdraw aqueous samples and trap them into soda solution at high pressure. Two titration procedures were set up; liquid samples of CO2-H2O and CO2-H2O-NaCl systems were analyzed by potentiometric titration and samples of CO2-H2O-CaCl2 system were analyzed by conductimetric titration. 84 solubility data were obtained during this study, which include 45 new experimental data. Experimental measurement were compared to the results of simulation performed with PHREEQC software using a ‘’Pitzer.dat’’ database.The salting out effect observed was evaluated for each system under all temperature and pressure conditions.

Two experiments were conducted to determine the optimal brining levels and effective chlorinated antimicrobials in three selected commercial poultry abattoirs of south Africa.The objective of the study was two fold: Firstly, the primary objective of the study was to determine the optimal inclusion level of brine for application in chicken processing to elongate the shelf life by reducing spoilage bacteria under refrigeration stage while the secondary objective of the study was to determine the most effective chlorinated antimicrobial to be applied in poultry processing plants to reduce spoilage bacteria. For each experiment, a complete randomized design was used. The general linear model procedure was used to determine the effects of brining and chlorine antimicrobials on the Psychrotrophic bacterial load of individually quick frozen (IQF) chicken portions. Simultaneously, a quadratic type equation was used to determine the optimal inclusion level of brine in relation to the responses of Psychrotrophic bacterial loads. The results indicated that control samples (0% brine) had higher (P < 0.05) bacterial load than all samples injected with various injection levels. There were significant differences (P < 0.05) between samples injected with 15% and 20% for all major abattoirs combined. However, there were no differences (P > 0.05) between samples injected with 20% and 25% brine, respectively. In addition, there was a significant difference (P < 0.05) in Psychrotrophic bacterial load between the samples treated with 25% and 30% brine inclusion level as well as those treated with 30% and 35% brining levels in all abattoirs. Futhermore, the results of the study also showed that Acidified Sodium Chloride had significantly lower bacterial load than both aqueous chlorine and chlorine dioxide. However, the effect of percentage brining on average Psychotrophic bacterial count had minimum quadratic values of 24.45 – 0.517 brining + 0.805 brining2 with r = 0.995; r2= 0.989, with optimum percentage brining dose being 43.08%. By extension, the result implies that the lowest reduction in spoilage bacteria is attained at 43.08% of brine inclusion level. These findings have implications on the most effective and convenient antimicrobial to be used in chicken abatoirs as well as reduction of psychotrophic bacterial load on individually quick frozen (IQF) chicken portions / Agriculture, Animal Health and Human Ecology / M. Sc. (Agriculture)

Submitted by Rodrigues Geandra Rodrigues (geandrar@gmail.com) on 2017-12-15T17:50:06Z No. of bitstreams: 1 rayanecamposalves.pdf: 1193241 bytes, checksum: 30a2fd49938c67b79a7ae55e6306164e (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-12-21T11:14:51Z (GMT) No. of bitstreams: 1 rayanecamposalves.pdf: 1193241 bytes, checksum: 30a2fd49938c67b79a7ae55e6306164e (MD5) / Made available in DSpace on 2017-12-21T11:14:51Z (GMT). No. of bitstreams: 1 rayanecamposalves.pdf: 1193241 bytes, checksum: 30a2fd49938c67b79a7ae55e6306164e (MD5) Previous issue date: 2017-10-02 / O queijo de coalho é um alimento muito apreciado devido as suas características sensoriais. Apresenta alto teor de sódio para manutenção de suas propriedades funcionais, principalmente a resistência ao derretimento, porém, o consumo excessivo desse alimento tem sido associado à hipertensão arterial, e problemas cardíacos e renais. Portanto, o objetivo principal desse trabalho foi reduzir o teor de sódio por meio da substituição parcial do cloreto de sódio (NaCl) pelo cloreto de potássio (KCl) nas seguintes proporções: 0% KCl+100% NaCl (controle); 30% KCl+70% NaCl; 50% KCl+50% NaCl; 70% KCl+30% NaCl e avaliar os aspectos físico-químicos, sensoriais, capacidade de derretimento, proteólise, perfil de textura e microbiológico em quatro tempos de estocagem refrigerada (2, 15, 30 e 60 dias), em quatro repetições. A redução de sódio não influenciou na composição centesimal, no teor de cálcio, no pH e na atividade de água dos queijos quando comparados ao controle.Uma das características mais exigidas pelos consumidores do queijo de coalho é a resistência quando aquecido, ou seja, o derretimento. A análise de derretimento é importante, por ser um parâmetro de qualidade do queijo de coalho e a redução do sódio não influenciou no derretimento. Embora a proteólise apresentou um aumento ao longo do tempo, isso não impactou no derretimento dos queijos. O sódio e o potássio apresentaram alteração pela própria redução do cloreto de sódio e substituição pelo cloreto de potássio. Em relação à análise do perfil de textura, os parâmetros de dureza, coesividade e mastigabilidade se comportaram de forma semelhante em todos os tratamentos, porém houve alteração na adesividade e na elasticidade. Quanto às análises microbiológicas, houve alteração nos coliformes a 30ºC, coliformes a 45ºC, fungos filamentosos e leveduras e mesófilos aeróbios tanto em relação aos tratamentos, quanto ao tempo de armazenamento. No entanto, os Staphylococcus aureus não apresentaram alteração nos queijos. A aparência dos queijos, avaliada pela análise sensorial, não foi afetada pelo uso do cloreto de potássio, porém o aroma recebeu menor escore no tratamento 70% KCl+30% NaCl. O uso do cloreto de potássio interferiu no sabor e textura dos queijos. No entanto, a impressão global foi semelhante ao controle nos tratamentos com até 50% de substituição do NaCl. A redução de sódio no queijo de coalho com substituição parcial de até 50% NaCl por KCl é uma alternativa possível para esse produto. / The “coalho” type cheese is a much-appreciated food because of its sensory characteristics. This cheese has a high sodium content to maintain its functional properties and features high sodium content to maintain its functional properties, especially the melting resistance, also the overdone consumption has been associated with health problems such as hypertension, heart and kidney problems. Therefore, the main objective of this study was to reduce sodium content by partially replacing sodium chloride (NaCl) with potassium chloride (KCl) in the following proportions: 0% KCl + 100% NaCl (control); 30% KCl + 70% NaCl; 50% KCl + 50% NaCl; 70% KCl + 30% NaCl and analyze the physicochemical aspects, sensory, melting capacity, proteolysis, texture profile and microbiological in 4 refrigerated storage times (2, 15, 30 and 60 days), with four replications. There was no variation neither in the centesimal composition neither in the calcium content when compared with the control sample. One of the most demanded characteristics of coalho cheese is resistance when heated, in other words, the melting. The melting analysis is important and for being, a quality parameter of the coalho cheese, and reducing sodium did not affect the melt proprieties. Therefore, the proteolysis showed an increase over time, but it did not influence in the cheese melting. The sodium and the potassium presented an alteration caused by the reduction of the sodium and the potassium chloride. Regarding the texture profile analysis, the parameters of hardness, cohesiveness and chewing behaved in a similar way in all treatments, however there was an alteration in the adhesiveness and elasticity. As for microbiological analyzes, there was alteration in the coliforms at 30 ºC and 45 ºC, filamentous fungi, yeasts and aerobic mesophylls analysis, in relation of time and in relation of treatments, however, the Staphylococcus aureus showed no alterations in the cheese. The appearance of the cheeses measured by sensory analysis was not affected by the use of potassium chloride, but the aroma received an lower score in the 70% KCl + 30%NaCl treatment. The use of potassium chloride interfered with the taste and texture of the cheeses. However, the overall impression was similar to the control in the treatments up to 50% off Nacl. The partial reduction of sodium in the coalho cheese with 50% replacement NaCl by KCL is a possible alternative for this product.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-12-07T14:28:33Z No. of bitstreams: 1 rayanecamposalves.pdf: 1193241 bytes, checksum: 30a2fd49938c67b79a7ae55e6306164e (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-12-22T11:29:58Z (GMT) No. of bitstreams: 1 rayanecamposalves.pdf: 1193241 bytes, checksum: 30a2fd49938c67b79a7ae55e6306164e (MD5) / Made available in DSpace on 2017-12-22T11:29:58Z (GMT). No. of bitstreams: 1 rayanecamposalves.pdf: 1193241 bytes, checksum: 30a2fd49938c67b79a7ae55e6306164e (MD5) Previous issue date: 2017-10-02 / O queijo de coalho é um alimento muito apreciado devido as suas características sensoriais. Apresenta alto teor de sódio para manutenção de suas propriedades funcionais, principalmente a resistência ao derretimento, porém, o consumo excessivo desse alimento tem sido associado à hipertensão arterial, e problemas cardíacos e renais. Portanto, o objetivo principal desse trabalho foi reduzir o teor de sódio por meio da substituição parcial do cloreto de sódio (NaCl) pelo cloreto de potássio (KCl) nas seguintes proporções: 0% KCl+100% NaCl (controle); 30% KCl+70% NaCl; 50% KCl+50% NaCl; 70% KCl+30% NaCl e avaliar os aspectos físico-químicos, sensoriais, capacidade de derretimento, proteólise, perfil de textura e microbiológico em quatro tempos de estocagem refrigerada (2, 15, 30 e 60 dias), em quatro repetições. A redução de sódio não influenciou na composição centesimal, no teor de cálcio, no pH e na atividade de água dos queijos quando comparados ao controle.Uma das características mais exigidas pelos consumidores do queijo de coalho é a resistência quando aquecido, ou seja, o derretimento. A análise de derretimento é importante, por ser um parâmetro de qualidade do queijo de coalho e a redução do sódio não influenciou no derretimento. Embora a proteólise apresentou um aumento ao longo do tempo, isso não impactou no derretimento dos queijos. O sódio e o potássio apresentaram alteração pela própria redução do cloreto de sódio e substituição pelo cloreto de potássio. Em relação à análise do perfil de textura, os parâmetros de dureza, coesividade e mastigabilidade se comportaram de forma semelhante em todos os tratamentos, porém houve alteração na adesividade e na elasticidade. Quanto às análises microbiológicas, houve alteração nos coliformes a 30ºC, coliformes a 45ºC, fungos filamentosos e leveduras e mesófilos aeróbios tanto em relação aos tratamentos, quanto ao tempo de armazenamento. No entanto, os Staphylococcus aureus não apresentaram alteração nos queijos. A aparência dos queijos, avaliada pela análise sensorial, não foi afetada pelo uso do cloreto de potássio, porém o aroma recebeu menor escore no tratamento 70% KCl+30% NaCl. O uso do cloreto de potássio interferiu no sabor e textura dos queijos. No entanto, a impressão global foi semelhante ao controle nos tratamentos com até 50% de substituição do NaCl. A redução de sódio no queijo de coalho com substituição parcial de até 50% NaCl por KCl é uma alternativa possível para esse produto. / The “coalho” type cheese is a much-appreciated food because of its sensory characteristics. This cheese has a high sodium content to maintain its functional properties and features high sodium content to maintain its functional properties, especially the melting resistance, also the overdone consumption has been associated with health problems such as hypertension, heart and kidney problems. Therefore, the main objective of this study was to reduce sodium content by partially replacing sodium chloride (NaCl) with potassium chloride (KCl) in the following proportions: 0% KCl + 100% NaCl (control); 30% KCl + 70% NaCl; 50% KCl + 50% NaCl; 70% KCl + 30% NaCl and analyze the physicochemical aspects, sensory, melting capacity, proteolysis, texture profile and microbiological in 4 refrigerated storage times (2, 15, 30 and 60 days), with four replications. There was no variation neither in the centesimal composition neither in the calcium content when compared with the control sample. One of the most demanded characteristics of coalho cheese is resistance when heated, in other words, the melting. The melting analysis is important and for being, a quality parameter of the coalho cheese, and reducing sodium did not affect the melt proprieties. Therefore, the proteolysis showed an increase over time, but it did not influence in the cheese melting. The sodium and the potassium presented an alteration caused by the reduction of the sodium and the potassium chloride. Regarding the texture profile analysis, the parameters of hardness, cohesiveness and chewing behaved in a similar way in all treatments, however there was an alteration in the adhesiveness and elasticity. As for microbiological analyzes, there was alteration in the coliforms at 30 ºC and 45 ºC, filamentous fungi, yeasts and aerobic mesophylls analysis, in relation of time and in relation of treatments, however, the Staphylococcus aureus showed no alterations in the cheese. The appearance of the cheeses measured by sensory analysis was not affected by the use of potassium chloride, but the aroma received an lower score in the 70% KCl + 30%NaCl treatment. The use of potassium chloride interfered with the taste and texture of the cheeses. However, the overall impression was similar to the control in the treatments up to 50% off Nacl. The partial reduction of sodium in the coalho cheese with 50% replacement NaCl by KCL is a possible alternative for this product.

Denna studie undersöker effektiviteten hos Calamos nyligen utvecklade elektrolyt. Det är av stor betydelse att förstå hur denna nya elektrolyt, som är fosforfri och baserad på organiska syror, fungerar för att minska beroendet av ändliga resurser och därigenom främja en mer hållbar produktion. Projektets mål var att utveckla en enkel kvantitativ analysmetod för myrsyra, mjölksyra, glykolsyra och oxalsyra i den nya elektrolyten. Tekniken som användes för detektion och kvantifiering var gaskromatografi (GC) kopplad till en flamjoniseringsdetektor (FID). GC är begränsad till analyter som kan överföras till gasfasen utan att brytas ned termiskt. Ett sätt för att öka en förenings flyktighet, termiska stabilitet och kromatografiska beteende är genom en derivatiseringsreaktion. För bättre kromatografisk beteende derivatiserades karboxylsyror före GC-analys med N,O-bis-(trimetylsilyl)trifluoracetamid (BSTFA) som silyleringsreagens och dimetylformamid (DMF) som derivatiseringsmedium. Efter optimering validerades metoden och dess linjäriteten. Metoden har tillämpats för kvantitativ bestämning av karboxylsyror i elektrolyten, följt av lösningsmedelsextraktion med dietyleter. I detta arbete undersöktes även extraktionen av en karboxylsyra genom derivatisering med hjälp av dimetylkarbonat och natriummetoxid, vilket resulterade i bildandet av metylestrar som är relativt opolära och underlättar överföringen av karboxylsyror till den organiska fasen. Resultaten visade att båda teknikerna totalt sett inte verkar lämpliga för analys av karboxylsyror i elektrolyten. Dessutom utsaltningsextraktion av de karboxylsyrorna studerades också med användning av ett system bestående av butanon och ammoniumhydroxid. Resultaten indikerade att denna extraktionsmetod inte var effektiv för karboxylsyrorna. / This study examines the effectiveness of Calamo's newly developed electrolyte. It is of great importance to understand how this new electrolyte, which is phosphorus-free and based on organic acids, works to reduce dependence on finite resources and thereby promote more sustainable production. The project's goal was to develop a simple quantitative analysis method for formic acid, lactic acid, glycolic acid and oxalic acid in the new electrolyte. The technique used for detection and quantification was gas chromatography (GC) coupled to a flame ionization detector (FID). GC is limited to analytes that can be transferred to the gas phase without thermal degradation. One way to increase a compound's volatility, thermal stability and chromatographic behaviour is through a derivatization reaction. For better chromatographic behaviour, carboxylic acids were derivatized prior to GC analysis with N,O-bis-(trimethylsilyl) trifluoroacetamide (BSTFA) as the silylation reagent and dimethylformamide (DMF) as the derivatization medium. After optimization, the method and its linearity were validated. The method was applied for quantitative determination of carboxylic acids in the electrolyte, followed by solvent extraction with diethyl ether. In this work, the extraction of a carboxylic acid by derivatization with dimethyl carbonate and sodium methoxide was also investigated, which resulted in the formation of methyl esters that are relatively non-polar and facilitate the transfer of carboxylic acids to the organic phase. The results showed that both techniques overall did not seem suitable for the analysis of carboxylic acids in the electrolyte. In addition, salting-out extraction of the carboxylic acids was also studied using a system consisting of butanone and ammonium hydroxide. The results indicated that this extraction method was not effective for the carboxylic acids.

La Lyonnaise est la province gauloise la plus maritime, avec un trait de côte s’étendant sur plus de 3000 km de long. Ce travail de recherche concerne l’habitat dispersé (villae, fermes, ateliers) sur son littoral, du Ier au Vème siècle. Son objectif est de comprendre comment cette forme d’occupation et de gestion de l’espace rural a été adaptée au milieu géographique particulier qu’est le littoral. La question de la diffusion sur la façade Atlantique du phénomène des villae maritimes se pose également. Tout d’abord, les questions de typologie, de configuration et d’architecture des ensembles bâtis sont abordées. Ensuite, l’économie de ces établissements et en particulier l’exploitation des ressources maritimes est analysée. Bien que la documentation disponible soit ancienne et peu détaillée, des opérations archéologiques récentes ont contribué à renouveler les connaissances scientifiques sur le sujet, notamment sur les ateliers de salaisons et de sauces de poissons en Gaule et leurs productions. / With a coastline of at least 3000 kilometers, the Roman province of Lugdunensis is the most maritime area of the Gallic territories. This thesis deals with the occupation of the coastal countryside, dotted with villae, farms and craft workshops, between the 1st and 5th centuries AD. The main objective is to understand how the rural areas were managed and how roman society adapted to and transformed this landscape. This study also addresses the question of the dissemination of “villae maritimae” along the Atlantic coast. Themes covered included the organisation of Roman coastal settlements and their architectural influences, the role of farms in the management and exploitation of marine resources, and lastly, the types of products produced. The archaeological information available for use is extensive although dated, difficult to exploit, and as a such the analysis suffers. However, several recent surveys and excavations have allowed for the collection of new data about Roman salting and fish sauce workshops in western Gaul. Atlantic Coast and English Channel

Du fait de problèmes de santé publique, l’industrie agroalimentaire doit réduire la quantité de sel (chlorure de sodium) dans les aliments, et donc dans les charcuteries. Lors de la fabrication des jambons secs, une diminution du taux de sel pourrait se traduire par des problèmes de texture dus à une protéolyse excessive pouvant nuire à l’étape de tranchage industriel, et aussi par des problèmes de stabilité microbiologique. Dans ce contexte, les objectifs de cette thèse sont : (1) d’étudier le lien entre l’évolution de la protéolyse, de la texture et de la structure, tout au long des différentes étapes de fabrication de jambons secs et (2) de développer un modèle de « jambon numérique » afin de prédire spatialement les dynamiques d’évolution des teneurs en eau, en sel et celle de l’activité de l’eau (a w ), et de coupler ces évolutions à celle de la protéolyse. Ce travail combine études expérimentales et modélisation/simulation numérique. Tout d’abord, une méthode de quantification de la protéolyse utilisant la « Fluorescamine » a été développée et validée sur des échantillons de viande de porc et des échantillons extraits de jambons industriels ; un nouvel indice de protéolyse (IP) a été défini. Sur la base d’un plan d’expériences, l’évolution de la protéolyse au sein d’échantillons différemment salés et séchés et préparés à partir de 5 muscles différents d’un jambon de porc, a été quantifiée. Suite à l’application d’une régression linéaire multiple, des lois phénoménologiques ont été construites permettant de calculer la vitesse de protéolyse, pour un muscle donné, en fonction de la température et des teneurs en eau et en sel. Ensuite, au moyen du logiciel Comsol ® Multiphysics, ces lois ont été combinées avec des modèles de transferts de matière (eau, sel), de chaleur (température), et de calcul de l’a w , constituant ainsi un modèle de « jambon numérique ». Enfin, la dynamique d’évolution de l’IP, de 5 paramètres texturaux (dureté, fragilité, cohésion, élasticité et adhésion) et de 4 paramètres structuraux (nombre des fibres, espaces extracellulaires, taille des fibres et surface de tissu conjonctif) a été mesurée sur des échantillons prélevés dans deux muscles extraits de jambons industriels pris à cinq stades de fabrication différents. L’application d’une régression polynômiale multiple à ces données expérimentales a conduit à l’établissement de corrélations permettent de calculer certains paramètres texturaux et structuraux à partir de l’IP et des teneurs en eau et en sel. A court terme, ces lois seront incorporées dans le modèle numérique afin de constituer un vrai simulateur de procédé. A moyen terme, le modèle de « jambon numérique » devra être amélioré afin de tenir compte (1) de la diminution du volume du jambon, du fait du séchage et (2) de la diminution de la vitesse de protéolyse en fonction du temps, du fait de la réduction de la quantité de protéines hydrolysables dans le jambon. Une fois complété et amélioré, le simulateur de procédé pourra aider les professionnels à tester des scénarios visant à réduire la quantité de sodium dans les jambons secs, sans altérer leur qualité finale. / Because of public health problems, the food industry must lower sodium content in all food products, therefore in cured meat products. During the dry-cured ham elaboration process, decreasing salt content may induce microbial safety problems and texture defects due to an excessive proteolysis that could affect later the industrial stage of slicing. On account of that, this work of thesis aims at (1) studying the relationship between proteolysis, structure and texture during the various stages of dry-cured ham manufacture, and (2) building a “numerical ham” model to predict spatially the time course of water and salt content, and thus water activity (a w ), and to couple these variations with proteolysis. This work combines experimental studies and numerical modelling and simulation. Firstly, a new and powerful technique for quantifying proteolysis that uses “Fluorescamine” was developed and validated on pork meat samples and samples extracted from industrial dry-cured hams; a new proteolysis index (PI) was defined. Based on an experimental design, the time course of proteolysis was quantified in laboratory-salted and dried pork meat samples prepared from five different types of pork muscle. Applying multiple linear regression enabled us to build phenomenological models relating, for each pork muscle, PI velocity to temperature, and to water and salt content. Using Comsol ® Multiphysics software, these phenomenological models were then combined with heat and mass transfer models and associated with calculation of a w , thus constituting the “numerical ham” model. In addition, the time course of PI, five textural parameters (hardness, fragility, cohesiveness, springiness and adhesiveness), and four structural parameters (fiber number, extracellular spaces, cross section area, and connective tissue area) was quantified on samples extracted from two different muscles of industrial dry-cured hams removed from the process at five different processing times. Multiple polynomial regression was applied to build phenomenological models relating PI, salt and water content to some textural and structural parameters investigated. These last models could be rapidly incorporated in the “numerical ham” model to constitute a real process simulator. In the future, the “numerical ham” model should be improved in order to take into account (1) the strong decrease in ham volume due to drying and also (2) the decrease in proteolysis velocity with time as a result of the reduction in the amount of protein that can be hydrolysed in the ham. Once completed and improved, the process simulator will be available to professionals to test scenarios allowing sodium content to be reduced in dry-cured hams without altering their final quality.

Une caractéristique nutritionnelle peu connue des fromages est leur potentiel acidifiant, qui se révèle au cours du métabolisme et, à long terme, est susceptible d’induire des effets délétères sur la santé du consommateur. Malgré des conséquences physiopathologiques bien connues, très peu d’études se sont intéressées au potentiel acidifiant/alcalinisant des aliments et aucune à celui des fromages. L’objectif principal était d’évaluer d’une part le potentiel acidifiant des fromages et identifier ses déterminants au cours de la fabrication et d’autre part d’explorer des stratégies d’optimisation technologique permettant de réduire le potentiel acidifiant des fromages, tout en assurant leurs qualités gustatives. Le potentiel acidifiant a été évalué sur la base de l’indice PRAL (Potential Renal Acid Load, en tenant compte des teneurs en protéine, P, Cl, Na, K, Mg et Ca) et de la teneur en anions organiques (lactate et citrate). Dans un premier temps, l’étude du potentiel acidifiant de cinq types de fromages du commerce a permis d’établir un lien fort entre le type du fromage et son potentiel acidifiant. L’indice PRAL le plus faible est celui du fromage frais avec - 0,8 mEq/100 g, les indices les plus élevés atteignant 25,3 mEq/100 g pour le fromage à pâte pressée non-cuite (Cantal) et 28,0 mEq/100 g pour le fromage à pâte persillée (Fourme d’Ambert). Ce positionnement a ainsi permis de sélectionner un modèle fromage pour la suite des travaux : la Fourme d’Ambert. Dans une seconde phase, l’égouttage et le salage ont été identifiés comme les deux étapes technologiques déterminantes dans la génération du potentiel acidifiant du modèle fromage choisi, au cours de la transformation fromagère, suivie en milieu industriel. Ces études démontrent un déséquilibre important entre les éléments acidifiants (Cl, P, protéines) et les éléments alcalinisants majeurs (Na et Ca) du PRAL. En particulier, les Cl suivis par le P, ont exercé un très fort impact expliquant les indices élevés obtenus. Enfin, une substitution du NaCl par des sels organiques de calcium (lactate et citrate de Ca) a été testée en conditions industrielles pendant le salage à sec de la Fourme d’Ambert. Les deux sels ont montré un réel intérêt pour substituer partiellement le sel des fromages, sans affecter les propriétés sensorielles des produits finis et notamment les saveurs salée et amère. La substitution au lactate de Ca permettrait d’optimiser le potentiel acidifiant des fromages, en diminuant le PRAL et la teneur en Na et en augmentant la teneur en lactate. La substitution au citrate de Ca serait plutôt indiquée dans le cadre d’un enrichissement en Ca. En conclusion, ces études ont permis d’identifier les leviers à maîtriser pour réduire le potentiel acidifiant des fromages. L’approche adoptée a proposé la mise en application d’un concept connu principalement des nutritionnistes jusqu’ici dans les domaines de la biochimie et de la technologie alimentaires. Les perspectives d’innovation envisagées sont pertinentes avec les enjeux de santé publique actuels, en visant la réduction en Na dans les fromages et en participant à la limitation de l’acidose métabolique latente induite par les régimes occidentaux. Enfin, les retombées économiques de ces recherches sont prometteuses pour les filières fromagères. / A disregarded nutritional feature of cheeses is their acid-forming potential when ingested, associated with deleterious effects for consumers’ health. Despite the well-known pathophysiological consequences, very few studies investigated the acidifying/alkalizing potential of foods and especially, none targeted cheeses. The research project aimed on the one hand to evaluate the acid-forming potential of cheeses and identify the main key steps of the manufacture involved in this phenomenon and on the other hand to explore technological optimization strategies to reduce the acid-forming potential of cheeses, without altering their sensory properties. The acid-forming potential was evaluated on the basis of their Potential Renal Acid Load (PRAL) index (considering protein, P, Cl, Na, K, Mg and Ca contents) and organic anions contents (lactate and citrate). Firstly, the study of the acid-forming potential of five commercial cheeses from different cheese-making technologies established a strong link between the type of cheese and their acid-forming potential. PRAL index ranged from - 0.8 mEq/100 g for fresh cheese to 25.3 mEq/100 g for hard cheese (Cantal) and 28.0 mEq/100 g for the blue-veined cheese Fourme d’Ambert. This positioning allowed to select Fourme d'Ambert as model cheese for next steps. Secondly, draining and salting were identified as the main key steps responsible for the generation of the acid-forming potential of the model cheese, by following an industrial cheese-making process. These studies emphasized a great imbalance between acidifying elements of PRAL calculation (Cl, P and proteins elements) and alkalinizing ones (Na and Ca). Particularly, Cl followed by P elements had a strong impact on the PRAL value. Finally, the salt substitution with organic calcium salts (calcium lactate and calcium citrate) was tested under industrial conditions during the dry salting of Fourme d'Ambert cheese. Both salts showed a real nutritional interest to partially replace salt in cheese, without affecting their sensory properties and especially the salty and the bitter flavors. The salt substitution by calcium lactate could reduce the acid-forming potential of cheeses, by decreasing the PRAL and the sodium content and by increasing the lactate content. The calcium citrate substitution would rather be recommended for Ca enrichment of cheeses. As a conclusion, these studies allowed to identify technological solutions to reduce the acid-forming potential of cheeses. The adopted approach proposed the implementation of a concept, known mainly by nutritionists so far, to the biochemistry and the food technology fields. The considered prospects for innovation are relevant with the current public health issues, targeting the reduction of Na in cheeses and participating in the limitation of the Western diets induced metabolic acidosis. Finally, the economic benefits of this research are promising for cheese-making producers.