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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Couplage de procédés membranaires pour la production d’extraits anthocyaniques : application à Hibiscus sabdariffa / Coupling of membrane process for the production of extract anthocyanin : application to Hibiscus sabdariffa

Cissé, Mady 17 December 2010 (has links)
Hibiscus sabdariffa L. est une plante vivace herbacée localisée dans les zones tropicales et subtropicales des deux hémisphères. Au Sénégal, où elle a été introduite au 19ème siècle, H. sabdariffa, encore appelé bissap ou roselle, est cultivé sur l'ensemble du territoire et exploité principalement pour ses calices. Une boisson désaltérante est traditionnellement élaborée à partir des calices séchés par extraction à l'eau. La caractérisation physico-chimique et biochimique des calices nous a tout d'abord permis de mieux évaluer le potentiel de ce produit. Ainsi, les calices contiennent entre 767 et 1480 mg.100g -1 d'anthocyanes et entre 1347 et 3736 mg.100g-1 de polyphénols totaux. Ils présentent un pouvoir antioxydant voisin de 260 µmolTrolox.g-1. L'acide malique y est l'acide organique majoritaire avec une teneur pouvant atteindre 2,3 g.100g-1. De part ces caractéristiques, l'extrait aqueux de calices d'H. sabdariffa constitue une excellente source d'anthocyanes. Le travail s'est ensuite focalisé sur le procédé d'obtention de cet extrait. L'étude de l'extraction solide-liquide a été réalisée à partir de calices séchés et d'eau à des températures comprises entre 25 et 90 °C. Un rendement d'extraction en anthocyanes maximum de 88 % a été obtenu à 25 °C avec un ratio calice/eau de 1/25. La réduction de la taille des particules et l'augmentation de la température diminuent le temps d'extraction mais n'affectent pas le rendement d'extraction. Un modèle d'extraction solide-liquide incluant les cinétiques de dégradation thermique des anthocyanes a été proposé puis validé. La microfiltration tangentielle sur membrane céramique de diamètre moyen de pores 0,2 µm a permis de produire un extrait stérilisé à froid, stable pendant 90 j à 20 °C. Nous avons montré à ce niveau que la pression transmembranaire optimisée à un facteur de réduct ion volumique (FRV) égal à 1 n'est plus optimale lorsque le FRV augmente. Pour concentrer les anthocyanes présents dans l'extrait, l'ultrafiltration sur une membrane de seuil de coupure de 5 kDa peut être utilisée malgré une rétention incomplète (95-97 %). Par contre, la nanofiltration offre une rétention totale des anthocyanes. Le procédé, mis en uvre dans des conditions semi-industrielles, a permis d'augmenter la teneur en extrait sec soluble (ESS) de 40 à 250 g.kg-1 à 35 °C, à une pression transmembranaire comprise entre 20 et 30 bar avec un flux moyen de 15 kg.h-1.m-2. L'évaporation osmotique, testée sur un pilote équipé d'une membrane en polypropylène de 10 m2, a permis de concentrer l'extrait anthocyanique jusqu'à 620 g d'ESS.kg-1. Cet extrait concentré conserve toutes les qualités physico-chimiques, biochimiques, nutritionnelles et aromatiques de l'extrait initial. Le flux évaporatoire est directement corrélé à la teneur en extrait sec solub le du produit à concentrer. Enfin, divers couplages d'opérations unitaires ont été comparés pour obtenir un extrait concentré à partir de calices d'H. sabdariffa. Le procédé qui associe une extraction à froid, une pré-concentration par nanofiltration et une concentration par évaporation osmotique est la meilleure voie tant en terme de coûts d'investissement et de fonctionnement que de qualité de l'extrait. / Hibiscus sabdariffa L. is a herbaceous plant, cultivated largely in tropical and subtropical areas of both hemispheres. In Senegal, where it was introduced in the 19th century, H. sabdariffa L. also called bissap or roselle is grown throughout the territory and operated primarily for its calyx. A refreshing drink is traditionally made from dried calyx by water extraction. The physical-chemical and biochemical characterization of the calyx allowed us to assess better the potential of this product. Thus, the calyx contained between 767 and 1480 mg.100g-1 of anthocyanins and between 1347 and 3736 mg.100g-1 of total polyphenols. They have an antioxidant capacity closed to 260 μmolTrolox.g-1. Malic acid is the major organic acid with content up to 2.3 g.100g-1. Because of these characteristics, the aqueous extract of H. sabdariffa calyx is an excellent source of anthocyanins. The work was then focused on the process for obtaining this extract. The study of solid-liquid extraction was performed from dried calyx with water at temperature range from 25 and 90 ° C. A maximum extraction yield of anthocyanin of 88 % was obtained at 25 ° C with a solid-to-solvent ratio of 1/25. Reducing the particle size and increasing the temperature decreased the extraction time but do not affect the extraction efficiency. A model of solid-liquid extraction which included the thermal anthocyanins degradation kinetics has been proposed and validated. Crossflow microfiltration with tubular ceramic 0.2 pore size membrane has produced a cold sterilized extract, stable during 90 days at 20 °C. We have shown here that the transmembrane pressure optimized at a volume reduction ratio (VRR) equal to 1 is no longer optimum when the VRR is increasing. To concentrate the anthocyanins present in the extract, the ultrafiltration membrane with a cutoff of 5 kDa can be used despite incomplete retention (95-97%). By cons, nanofiltration offers a tot al retention of anthocyanins. The method, implemented in semi-industrial conditions, has increased the content of total soluble solids (TSS) from 40 to 250 g.kg-1 at 35 °C at a transmembrane pressure between 20 and 30 bar with an average flow of 15 kg.h-1.m-2. The osmotic evaporation, tested on a pilot equipped with a polypropylene membrane of 10 m2, has concentrated anthocyanin extract up to 620 g TSS. kg-1. This concentrated extract retains all the physical-chemical, biochemical, nutritional and aromatic quality of the original extract. The evaporation flux is directly correlated with the total soluble solids content of the product to concentrate. Finally, various couplings of unit operations were compared to obtain a concentrated extract from H. sabdariffa calyx. The process which combines a cold extraction, a pre-concentration by nanofiltration and concentration by osmotic evaporation is the best way both in terms of investment costs and operating and quality of the ext ract.
12

Extração alcoólica de óleos de gérmen de milho e de torta de macadâmia e aproveitamento do material desengordurado na produção de concentrado proteico / Alcoholic extraction of oils from corn germ and macadamia meal and use of the defatted material in the production of protein concentrate

Navarro, Sandra Lorena Blandon 19 December 2016 (has links)
No presente estudo objetivou-se avaliar o desempenho do etanol e isopropanol, absoluto e azeotrópico, na extração de óleo de macadâmia e milho. Nesse sentido, foram realizados experimentos de extração em batelada para determinar os efeitos do tipo de solvente e temperatura sobre o índice de retenção, rendimento de extração, qualidade do óleo e fração proteica. Assim, torta parcialmente desengordurada de macadâmia sem pré-tratamento prévio à etapa de extração (teor de lipídios 57,4 ± 0,7 % em base seca) foi submetida a extração, nas temperaturas de 60, 75 e 90 °C, enquanto as extrações de óleo do gérmen de milho em pellets (teor de lipídios 12,61 ± 0,05 % em base seca) foram realizadas a 50, 60, 70 e 80 °C. Os experimentos de extração em correntes cruzadas foram realizados a 70 e 75 °C para o gérmen de milho e a macadâmia, respectivamente. Os resultados mostraram que o rendimento de extração de óleo de macadâmia e milho é influenciado pelo tipo solvente, temperatura e pré-tratamento do material, sendo que com isopropanol absoluto, a 90 °C, foi possível extrair 66 % do óleo de macadâmia e a 80 °C, 87 % do óleo de milho. O índice de retenção de solução aderida as fibras (IR) foi impactado pelo tipo de solvente e características da matéria-prima, obtendo-se valores de IR maiores nas fases rafinado de macadâmia. A composição em ácidos graxos dos óleos de gérmen de milho extraídos com os solventes alcoólicos foi típica do óleo de milho, com predominância dos ácidos graxos oleico (34 %) e linoleico (48 %). As fases rafinado dos dois materiais apresentaram teor de proteínas maior que as matérias-primas iniciais, no entanto as condições do processo de extração impactaram negativamente no índice de solubilidade de nitrogênio, tornando inviável a produção de concentrado proteico de gérmen de milho. Para o óleo de milho a extração de tocoferóis e tocotrienóis foi maior com etanol, enquanto que com isopropanol conseguiu-se uma maior extração de carotenoides, o que pode ser decorrente da polaridade destes compostos bioativos. Os óleos de macadâmia extraídos com os solventes alcoólicos apresentaram maior estabilidade oxidativa (mais de 37 horas) quando comparados ao óleo bruto obtido por prensagem industrial (11,7 horas), sendo possível inferir que o uso dos solventes alcoólicos possibilita a extração de compostos que contribuem para o aumento da estabilidade do óleo. Nos experimentos em correntes cruzadas foi observado que para desengordurar a macadâmia com etanol e isopropanol absoluto são necessários mais de quatro estágios de contato, enquanto para o gérmen de milho dois estágios são suficientes. Em relação aos concentrados proteicos de macadâmia, o rendimento foi maior com os rafinados oriundos das extrações com isopropanol absoluto (13 %). Estes concentrados apresentaram boa capacidade de retenção de água e óleo (aproximadamente 2 g/g de concentrado) e estabilidade e atividade de emulsão na faixa de 56 a 59 %, desta forma pode-se sugerir que estes produtos apresentam potencial para seu aproveitamento na indústria de alimentos. A partir dos resultados pode-se inferir que a utilização dos solventes alcoólicos na extração de óleo de milho e macadâmia é tecnicamente viável, no entanto o desempenho dos solventes alcoólicos é influenciado pelas características da matéria-prima e pelo pré-tratamento do material sólido prévio à etapa de extração, obtendo-se maiores rendimentos de extração de óleo com o gérmen de milho em pellets. Também é possível inferir que os solventes em grau absoluto impactam menos na solubilidade das proteínas, permitindo a produção de concentrados proteicos de macadâmia com propriedades funcionais adequadas para seu uso na indústria de alimentos. / The objective of this study was to evaluate the performance of ethanol and isopropanol, absolute and azeotropic, in the extraction of macadamia and corn oil. Accordingly, extraction experiments were performed in batch to determine the effect of solvent type and temperature on retention index, extraction yield, quality indices of oil and protein fraction. Thus, partially defatted macadamia meal without pre-treatment prior to the extraction step (lipid content 57.4 ± 0.7 % on dry basis) was submitted to extraction at temperatures of 60, 75 and 90 °C, while oil extractions of corn germ in pellets (lipid content 12.61 ± 0.05 % on dry basis) were performed at 50, 60, 70 and 80 °C. The crosscurrent extraction experiments were performed at 70 and 75 °C for corn germ and macadamia, respectively. The results showed that the oil extraction yield of macadamia and corn is influenced by the solvent type, temperature and pre-treatment of the material, being that with absolute isopropanol at 90 °C, it was possible to extract 66 % of the macadamia oil and 87 % of the corn oil at 80 °C. The retention index of the solution adhered to the fibers (RI) was affected by the type of solvent and characteristics of the raw material, obtaining higher values of RI in the raffinate phases of macadamia. The fatty acid composition of corn germ oils extracted with alcoholic solvents was typical of corn oil, with predominance of oleic acid (34 %) and linoleic acid (48 %). The raffinate phases of the two materials showed higher protein content than the initial raw materials, however the conditions of the oil extraction process had a negative impact on the nitrogen solubility index, turning the production of protein concentrate from corn germ infeasible. For corn oil the extraction of tocopherols and tocotrienols was higher with ethanol, whereas with isopropanol a greater extraction of carotenoids was obtained, which can be due to the polarity of these bioactive compounds. Macadamia oils extracted with the alcoholic solvents showed higher oxidative stability (more than 37 hours) when compared to crude oil obtained by industrial cold pressing (11.7 hours). It is possible to infer that the use of alcoholic solvents enables to extract compounds that contribute to the increase of oil stability. In the crosscurrent extraction experiments it was observed that to produce defatted macadamia with absolute ethanol and isopropanol more than four stages of contact are required, whereas for the corn germ two stages are sufficient. Regarding protein concentrates of macadamia, the yield was higher with raffinate phases coming from the extractions with absolute isopropanol (13 %). These concentrates showed good water and oil retention capacity (approximately 2 g/g of concentrate) and emulsion stability and activity in the range of 56 to 59 %, therefore it can be suggested that these products have potential for their use in the food industry. From the results it can be inferred that the use of the alcoholic solvents in the extraction of corn and macadamia oil is technically feasible, however the performance of the alcoholic solvents is influenced by the characteristics of the raw material and by pre-treatment of the solid material prior to the extraction step, obtaining the highest oil extraction yields with the corn germ in pellets. Also, it is possible to infer that the solvents in absolute degree impact less on the solubility of the proteins, enabling the production of macadamia protein concentrates with functional properties suitable for use in the food industry.
13

Isolamento de polissacarí­deos não amiláceos da banana (musa cavendishii L. variedade Nanicão) e seu potencial uso como ingrediente funcional. / Isolation of non-starch polysaccharides from banana Cavendishii L. variety Nanicão) and its potential use as a functional ingredient.

Rayo Mendez, Lina Maria 19 July 2018 (has links)
Neste trabalho, polissacarídeos não amiláceos (PNAs) da banana madura com potencial de propriedades imunomoduladoras foram obtidos por meio da remoção dos açúcares solúveis (glicose, frutose e sacarose) do purê de banana submetido a duas técnicas de extração: sólido-líquido (ESL) com agitação mecânica e assistida por ultrassom (EAU) usando etanol a 99,5 g/100 g como solvente. Para o estudo em batelada, diferentes razões da matéria-prima/solvente (1:5, 1:7 e 1:10) g/mL, tempos de extração (30, 60 e 90) min e duas temperaturas de (25 e 65) °C foram estudados. No estudo cinético, o impacto da redução da razão matéria-prima/solvente de 1:5 para 1:3 g/mL foi estudado até 90 min, nas mesmas condições estudadas na extração em batelada. O teor de açúcares solúveis (AS) medido nos extratos foi superior na temperatura de 65°C, porém às razões de 1:7 e 1:10, não resultou em maior quantidade de AS nos extratos, portanto, menores quantidades de etanol podem ser usadas diminuindo custos. Com o emprego da técnica EAU à 25 °C e tempo de extração de 30 min, foi observado que uma redução da razão matéria-prima/solvente até 1:3 g/mL produz maior rendimento de processo. No entanto, foi observado que maiores tempos de extração promoveram degradação da parede celular da matéria-prima. Entre os modelos cinéticos testados, o ajuste do modelo de Patricelli aos dados experimentais indicou que a ESL é regida pela fase de lavagem em que ocorreu 85 % da extração dos AS. Frações molares de glicose, ácidos galacturônicos, manose, arabinose, xilose, galactose de conteúdo monossacarídeo foram observadas nos rafinados, indicando possivelmente serem parte de polissacarídeos do tipo ?-glicanos, xilomananos glucomananos, arabinogalactanos e arabinoxilanos. / In this work, non-starch polysaccharides (PNAs) of ripe bananas with potential for immunomodulatory properties were obtained by means removing the soluble sugars (glucose, fructose and sucrose) from banana puree submitted to two extraction techniques: solid-liquid (SLE) with mechanical stirring and ultrasonic assisted (UAE) using 99.5 g/ 100 g ethanol as solvent. For the batch study, different ratios of the raw material/ solvent (1:5, 1:7 and 1:10) g/ mL, extraction times of (30, 60 and 90) min and two temperatures of (25 and 65 ) °C were studied. In the kinetic study, the impact of reducing the raw material/ solvent ratio from 1:5 to 1:3 g/ mL was studied up to 90 min, under the same conditions studied in batch extraction. The soluble sugar content (AS) measured in the extracts was higher at temperature of 65 °C, however, at the ratios of 1:7 and 1:10, did not result in higher amount of AS in the extracts, therefore, smaller amounts of ethanol can be costs. With the use of the UAE technique at 25 °C and extraction time of 30 min, it was observed that a reduction of the raw material / solvent ratio up to 1:3 g / mL produces a higher process yield. However, it was observed that longer extraction times promoted degradation of the cell wall of the raw material. Among the kinetic models tested, the adjustment of Patricelli model to the experimental data indicated that the SLE the predominance is by the washing phase in which 85% of the AS extractions occurred. Glucose molar fractions, galacturonic acids, mannose, arabinose, xylose, galactose of monosaccharide content were observed in the raffinates, indicating possibly being part of polysaccharides as ?-glycan, xylomannans, glucomannans, arabinogalactans and arabinoxylans.
14

Extração alcoólica de óleos de gérmen de milho e de torta de macadâmia e aproveitamento do material desengordurado na produção de concentrado proteico / Alcoholic extraction of oils from corn germ and macadamia meal and use of the defatted material in the production of protein concentrate

Sandra Lorena Blandon Navarro 19 December 2016 (has links)
No presente estudo objetivou-se avaliar o desempenho do etanol e isopropanol, absoluto e azeotrópico, na extração de óleo de macadâmia e milho. Nesse sentido, foram realizados experimentos de extração em batelada para determinar os efeitos do tipo de solvente e temperatura sobre o índice de retenção, rendimento de extração, qualidade do óleo e fração proteica. Assim, torta parcialmente desengordurada de macadâmia sem pré-tratamento prévio à etapa de extração (teor de lipídios 57,4 ± 0,7 % em base seca) foi submetida a extração, nas temperaturas de 60, 75 e 90 °C, enquanto as extrações de óleo do gérmen de milho em pellets (teor de lipídios 12,61 ± 0,05 % em base seca) foram realizadas a 50, 60, 70 e 80 °C. Os experimentos de extração em correntes cruzadas foram realizados a 70 e 75 °C para o gérmen de milho e a macadâmia, respectivamente. Os resultados mostraram que o rendimento de extração de óleo de macadâmia e milho é influenciado pelo tipo solvente, temperatura e pré-tratamento do material, sendo que com isopropanol absoluto, a 90 °C, foi possível extrair 66 % do óleo de macadâmia e a 80 °C, 87 % do óleo de milho. O índice de retenção de solução aderida as fibras (IR) foi impactado pelo tipo de solvente e características da matéria-prima, obtendo-se valores de IR maiores nas fases rafinado de macadâmia. A composição em ácidos graxos dos óleos de gérmen de milho extraídos com os solventes alcoólicos foi típica do óleo de milho, com predominância dos ácidos graxos oleico (34 %) e linoleico (48 %). As fases rafinado dos dois materiais apresentaram teor de proteínas maior que as matérias-primas iniciais, no entanto as condições do processo de extração impactaram negativamente no índice de solubilidade de nitrogênio, tornando inviável a produção de concentrado proteico de gérmen de milho. Para o óleo de milho a extração de tocoferóis e tocotrienóis foi maior com etanol, enquanto que com isopropanol conseguiu-se uma maior extração de carotenoides, o que pode ser decorrente da polaridade destes compostos bioativos. Os óleos de macadâmia extraídos com os solventes alcoólicos apresentaram maior estabilidade oxidativa (mais de 37 horas) quando comparados ao óleo bruto obtido por prensagem industrial (11,7 horas), sendo possível inferir que o uso dos solventes alcoólicos possibilita a extração de compostos que contribuem para o aumento da estabilidade do óleo. Nos experimentos em correntes cruzadas foi observado que para desengordurar a macadâmia com etanol e isopropanol absoluto são necessários mais de quatro estágios de contato, enquanto para o gérmen de milho dois estágios são suficientes. Em relação aos concentrados proteicos de macadâmia, o rendimento foi maior com os rafinados oriundos das extrações com isopropanol absoluto (13 %). Estes concentrados apresentaram boa capacidade de retenção de água e óleo (aproximadamente 2 g/g de concentrado) e estabilidade e atividade de emulsão na faixa de 56 a 59 %, desta forma pode-se sugerir que estes produtos apresentam potencial para seu aproveitamento na indústria de alimentos. A partir dos resultados pode-se inferir que a utilização dos solventes alcoólicos na extração de óleo de milho e macadâmia é tecnicamente viável, no entanto o desempenho dos solventes alcoólicos é influenciado pelas características da matéria-prima e pelo pré-tratamento do material sólido prévio à etapa de extração, obtendo-se maiores rendimentos de extração de óleo com o gérmen de milho em pellets. Também é possível inferir que os solventes em grau absoluto impactam menos na solubilidade das proteínas, permitindo a produção de concentrados proteicos de macadâmia com propriedades funcionais adequadas para seu uso na indústria de alimentos. / The objective of this study was to evaluate the performance of ethanol and isopropanol, absolute and azeotropic, in the extraction of macadamia and corn oil. Accordingly, extraction experiments were performed in batch to determine the effect of solvent type and temperature on retention index, extraction yield, quality indices of oil and protein fraction. Thus, partially defatted macadamia meal without pre-treatment prior to the extraction step (lipid content 57.4 ± 0.7 % on dry basis) was submitted to extraction at temperatures of 60, 75 and 90 °C, while oil extractions of corn germ in pellets (lipid content 12.61 ± 0.05 % on dry basis) were performed at 50, 60, 70 and 80 °C. The crosscurrent extraction experiments were performed at 70 and 75 °C for corn germ and macadamia, respectively. The results showed that the oil extraction yield of macadamia and corn is influenced by the solvent type, temperature and pre-treatment of the material, being that with absolute isopropanol at 90 °C, it was possible to extract 66 % of the macadamia oil and 87 % of the corn oil at 80 °C. The retention index of the solution adhered to the fibers (RI) was affected by the type of solvent and characteristics of the raw material, obtaining higher values of RI in the raffinate phases of macadamia. The fatty acid composition of corn germ oils extracted with alcoholic solvents was typical of corn oil, with predominance of oleic acid (34 %) and linoleic acid (48 %). The raffinate phases of the two materials showed higher protein content than the initial raw materials, however the conditions of the oil extraction process had a negative impact on the nitrogen solubility index, turning the production of protein concentrate from corn germ infeasible. For corn oil the extraction of tocopherols and tocotrienols was higher with ethanol, whereas with isopropanol a greater extraction of carotenoids was obtained, which can be due to the polarity of these bioactive compounds. Macadamia oils extracted with the alcoholic solvents showed higher oxidative stability (more than 37 hours) when compared to crude oil obtained by industrial cold pressing (11.7 hours). It is possible to infer that the use of alcoholic solvents enables to extract compounds that contribute to the increase of oil stability. In the crosscurrent extraction experiments it was observed that to produce defatted macadamia with absolute ethanol and isopropanol more than four stages of contact are required, whereas for the corn germ two stages are sufficient. Regarding protein concentrates of macadamia, the yield was higher with raffinate phases coming from the extractions with absolute isopropanol (13 %). These concentrates showed good water and oil retention capacity (approximately 2 g/g of concentrate) and emulsion stability and activity in the range of 56 to 59 %, therefore it can be suggested that these products have potential for their use in the food industry. From the results it can be inferred that the use of the alcoholic solvents in the extraction of corn and macadamia oil is technically feasible, however the performance of the alcoholic solvents is influenced by the characteristics of the raw material and by pre-treatment of the solid material prior to the extraction step, obtaining the highest oil extraction yields with the corn germ in pellets. Also, it is possible to infer that the solvents in absolute degree impact less on the solubility of the proteins, enabling the production of macadamia protein concentrates with functional properties suitable for use in the food industry.
15

Extração de óleo de amêndoas de baru via solventes alcoólicos: avaliação da composição do óleo, das alterações proteicas e estudo da recuperação do solvente / Extraction of baru almond oil by alcoholic solvents: evaluation of oil composition, of proteic fraction and study of recovery of solvents

Aracava, Keila Kazue 12 February 2019 (has links)
Na presente Tese de Doutorado objetivou-se avaliar a viabilidade técnica da substituição do solvente hexana, de fonte não renovável e industrialmente utilizado na extração de óleos vegetais, por solventes geralmente reconhecidos como seguros (GRAS), tais como álcoois de cadeia curta, etanol ou isopropanol, com diferentes graus de hidratação. Em adição, uma propriedade específica dos álcoois de cadeia curta foi estudada, miscibilidade parcial entre álcoois e óleo, objetivando-se a recuperação do solvente, etapa posterior ao processo de extração de óleo, denominada de dessolventização. Nesse sentido, torta de amêndoas de baru proveniente da prensagem mecânica industrial foi submetida à extração, com etanol ou isopropanol, absoluto ou azeotrópico, nas temperaturas de 60 a 90 °C, em um único estágio de contato. Os resultados mostraram que a adição de água ao solvente alcoólico impactou negativamente na eficiência de extração de óleo, enquanto o aumento da temperatura favoreceu este processo, sendo que com solvente isopropanol absoluto, a 80 °C, foi possível extrair aproximadamente 91 % do óleo disponível. Em temperaturas acima de 80 °C, os solventes utilizados, com exceção do etanol azeotrópico, apresentaram rendimentos de extração de óleo estatisticamente iguais. A composição em ácidos graxos dos óleos obtidos da extração alcoólica sequencial foi característica de óleo de amêndoas de baru, com predominância dos ácidos graxos insaturados oleico e linoleico e do saturado palmítico (aproximadamente 51, 28 e 7 %, respectivamente), independentemente da condição de processo empregada. Ainda, a extração alcoólica sequencial não influenciou nos teores dos isômeros α- e γ- tocoferol e no teor total de tocoferóis. Em relação ao estudo da fração proteica, dos sólidos desengordurados provenientes da extração alcoólica sequencial em três e dois estágios, para as temperaturas 60 e 90 °C, respectivamente, tanto a solubilidade proteica como a estabilidade térmica dos sólidos foram afetadas, sendo o índice de solubilidade de nitrogênio afetado negativamente pela hidratação do solvente alcoólico, temperatura de processo e número de estágios de contato. De uma maneira geral, a extração de óleo com solventes alcoólicos proporcionou a obtenção de um material sólido desengordurado com melhorias na capacidade de absorção de água e de óleo. Adicionalmente, verificou-se que o processo de extração alcoólica exerceu influência negativa na atividade emulsificante e positiva na capacidade de formação e estabilidade de espuma. Ademais, no estudo da recuperação do solvente, dados de equilíbrio de fases determinados para sistemas lipídicos compostos por óleo de torta de amêndoas de baru, obtido da prensagem mecânica industrial, e solventes alcoólicos, na faixa de temperatura de 15 a 60 °C, mostraram que a temperatura exerceu maior influencia na solubilidade mútua dos componentes dos sistemas com solventes absolutos em comparação aos sistemas com solventes azeotrópicos, enquanto a hidratação do solvente levou a diminuição da solubilidade, com consequente redução do coeficiente de partição do óleo. Parâmetros do modelo NRTL ajustados aos dados experimentais apresentaram adequada descrição do comportamento dos sistemas lipídicos, com desvios nas frações mássicas variando de 0,0014 a 0,0086. / The aim of this Ph.D. Thesis was to evaluate the technical feasibility of replacing the solvent hexane, from a non-renewable source and industrially used in the extraction of vegetable oils, by solvents generally recognized as safe (GRAS), such as short chain alcohols, ethanol or isopropanol, with different levels of hydration. In addition, a specific property of the short-chain alcohols, the partial miscibility between alcohols and oil, has been studied aiming at recovering the solvent after the oil extraction process, called desolventization. In this sense, baru almond cake from industrial mechanical pressing was subjected to extraction with ethanol or isopropanol, absolute or azeotropic degress, at temperatures from 60 up to 90 °C, in a single contact stage. Results showed that the addition of water to the alcoholic solvent negatively affected the oil extraction efficiency, while the increase in temperature favored this process. It was possible to extract approximately 91 % of the oil with absolute isopropanol solvent at 80 °C. At temperatures above 80 °C, the solvents, with the exception of azeotropic ethanol, showed no statistical differences regarding extraction yields. The fatty acid composition of oils obtained from sequential alcoholic extraction was characteristic of baru almond oil, with predominance of oleic and linoleic unsaturated fatty acids and palmitic saturated fatty acid (approximately 51, 28 and 7%, respectively), regardless of the condition of used. Also, the sequential alcoholic extraction did not influence the contents of the α- and γ-tocopherol isomers and the total content of tocopherols. In relation to the protein fraction study, of the defatted solids from the sequential alcoholic extraction in three and two stages, for the temperatures of 60 and 90 °C, respectively, the protein solubility and the thermal stability of the solids were affected, being the nitrogen solubility index negatively affected by the hydration of the alcoholic solvent, by the process temperature and by the number of contact stages. In general, the extraction of oil with alcoholic solvents provided a defatted solid material with improvements in water and oil absorption capacities. Additionally, it was verified that the process of alcoholic extraction exerted a negative influence on the emulsifying activity and a positive on the capacity of foam formation and stability. Moreover, in the study of solvent recovery, phase equilibrium data determined for lipid systems composed of baru almond cake oil, obtained from industrial mechanical pressing, and alcoholic solvents, in the temperature range from 15 up to 60 °C, showed that the temperature exhibited the higher influence on the mutual solubility of the components of the system with absolute solvents compared to systems with azeotropic solvents, while the hydration of the solvent led to a decrease in solubility, with consequent reduction of the partition coefficient of the oil. NRTL model parameters adjusted to the experimental data presented an adequate description of the behavior of the lipid systems, with deviations in mass fractions varying from 0.0014 to 0.0086.
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Méthodologies de synthèse de résines formo-phénoliques chélatantes : vers une extraction solide-liquide optimisée des métaux stratégiques / Methods of synthesis of chelating formo-phenolic resins : toward an optimized solid-liquid extraction of strategic metals

Arrambide Cruz, Carlos 28 November 2017 (has links)
L’extraction d’éléments d’intérêt (terres rares, métaux lourds, métaux de transition, radionucléides) de de minerais conventionnels ou non conventionnels (mines urbaines) et d’effluents industriel ou nucléaire est un enjeu majeure dans les procédés d’extraction, de recyclage et/ou de décontamination.Un grand nombre de solides organiques et inorganiques, chélatants ou échangeurs d’ions, ont été développés pour un tri ionique sélectif par procédé solide/liquide.L’introduction covalente de ligands spécifiques dans le squelette de la résine permet d’augmenter la sélectivité vis-à-vis d’une cible métallique par la nature des agents de complexation, leurs sites de chélation et leur rigidité.L’objectif de cette thèse recouvre d’une part la synthèse de systèmes chélatant réactifs, leur polymérisation pour la préparation des résines « super »chélatantes et d’autre part, l’évaluation des polymères pour l’extraction/séparation d’ions, les terres rares étant plus particulièrement ciblées.A partir de résines formo-phénolique incorporant du catéchol et la 8-hydroxyquinoléine qui sont des précurseurs phénoliques, nous avons pu montrer que la récupération sélective du germanium été possible vis-à-vis du silicium ou du zinc en fonction de leur proportion dans la matrice polymérique.La synthèse des précurseurs phénoliques intégrant des ligands comme l’acide diglycolamique et les diglycolamides a permis la mise en œuvre de résine pour la récupération des terres rares. Une étude sur la compréhension de la synthèse des résines ainsi que leurs performances d’extraction a ainsi été réalisée et a pu mettre en évidence le potentiel de ces résines pour la récupération et valorisation des terres rares.Une ouverture vers d’autres possibilités de synthèses de ce type de résines (matériaux poreux, sous forme de mousse…) est également proposée pour permettre d’augmenter les surfaces de contacts lors des extractions solide-liquide et ainsi augmenter les performances de ces matériaux. / Extraction of specific targeted species (rare earth, heavy metals, transition metals, radionuclides) from industrial (mining deposit and urban mining) and nuclear effluents is an important issue in the recycling and / or decontamination processes. A large number of organic and inorganic solids, chelating or ion-exchanging materials, have been developed for selective ionic separation by solid / liquid process. Metal-specific ligands incorporate in the structure of the resin itself is an interesting way to perform ion separation taking the advantage of the selectivity of chelating agents. The aims of this project are firstly the synthesis of chelating original systems and then prepare specific ion exchange resins.From formo-phenolic resins incorporating catechol and 8-hydroxyquinoline, we have been able to show that the selective recovery of germanium from silicon or zinc was possible, , depending on their proportion of each phenolic precursors in the polymeric matrix.The synthesis of the phenolic precursors integrating ligands such as diglycolamic acid and diglycolamides allowed the use of resin for the recovery of rare earths elemnets. A study on the understanding of the synthesis of resins as well as their performance of extraction was thus realized and was able to highlight the potential of these resins for the recovery and valorization of the rare earths elements.An opening towards other possibilities of synthesis of this type of resins (porous materials, in the form of foam, etc.) is also proposed in order to increase the contact surfaces during solid-liquid extractions and thus increase the performance of these materials.
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Isolamento de polissacarí­deos não amiláceos da banana (musa cavendishii L. variedade Nanicão) e seu potencial uso como ingrediente funcional. / Isolation of non-starch polysaccharides from banana Cavendishii L. variety Nanicão) and its potential use as a functional ingredient.

Lina Maria Rayo Mendez 19 July 2018 (has links)
Neste trabalho, polissacarídeos não amiláceos (PNAs) da banana madura com potencial de propriedades imunomoduladoras foram obtidos por meio da remoção dos açúcares solúveis (glicose, frutose e sacarose) do purê de banana submetido a duas técnicas de extração: sólido-líquido (ESL) com agitação mecânica e assistida por ultrassom (EAU) usando etanol a 99,5 g/100 g como solvente. Para o estudo em batelada, diferentes razões da matéria-prima/solvente (1:5, 1:7 e 1:10) g/mL, tempos de extração (30, 60 e 90) min e duas temperaturas de (25 e 65) °C foram estudados. No estudo cinético, o impacto da redução da razão matéria-prima/solvente de 1:5 para 1:3 g/mL foi estudado até 90 min, nas mesmas condições estudadas na extração em batelada. O teor de açúcares solúveis (AS) medido nos extratos foi superior na temperatura de 65°C, porém às razões de 1:7 e 1:10, não resultou em maior quantidade de AS nos extratos, portanto, menores quantidades de etanol podem ser usadas diminuindo custos. Com o emprego da técnica EAU à 25 °C e tempo de extração de 30 min, foi observado que uma redução da razão matéria-prima/solvente até 1:3 g/mL produz maior rendimento de processo. No entanto, foi observado que maiores tempos de extração promoveram degradação da parede celular da matéria-prima. Entre os modelos cinéticos testados, o ajuste do modelo de Patricelli aos dados experimentais indicou que a ESL é regida pela fase de lavagem em que ocorreu 85 % da extração dos AS. Frações molares de glicose, ácidos galacturônicos, manose, arabinose, xilose, galactose de conteúdo monossacarídeo foram observadas nos rafinados, indicando possivelmente serem parte de polissacarídeos do tipo ?-glicanos, xilomananos glucomananos, arabinogalactanos e arabinoxilanos. / In this work, non-starch polysaccharides (PNAs) of ripe bananas with potential for immunomodulatory properties were obtained by means removing the soluble sugars (glucose, fructose and sucrose) from banana puree submitted to two extraction techniques: solid-liquid (SLE) with mechanical stirring and ultrasonic assisted (UAE) using 99.5 g/ 100 g ethanol as solvent. For the batch study, different ratios of the raw material/ solvent (1:5, 1:7 and 1:10) g/ mL, extraction times of (30, 60 and 90) min and two temperatures of (25 and 65 ) °C were studied. In the kinetic study, the impact of reducing the raw material/ solvent ratio from 1:5 to 1:3 g/ mL was studied up to 90 min, under the same conditions studied in batch extraction. The soluble sugar content (AS) measured in the extracts was higher at temperature of 65 °C, however, at the ratios of 1:7 and 1:10, did not result in higher amount of AS in the extracts, therefore, smaller amounts of ethanol can be costs. With the use of the UAE technique at 25 °C and extraction time of 30 min, it was observed that a reduction of the raw material / solvent ratio up to 1:3 g / mL produces a higher process yield. However, it was observed that longer extraction times promoted degradation of the cell wall of the raw material. Among the kinetic models tested, the adjustment of Patricelli model to the experimental data indicated that the SLE the predominance is by the washing phase in which 85% of the AS extractions occurred. Glucose molar fractions, galacturonic acids, mannose, arabinose, xylose, galactose of monosaccharide content were observed in the raffinates, indicating possibly being part of polysaccharides as ?-glycan, xylomannans, glucomannans, arabinogalactans and arabinoxylans.
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Vývoj HPLC-DAD-MS/MS metody pro stanovení vybraných toxinů v Muchomůrce zelené. / Development of HPLC-DAD-MS/MS method for determination of selected toxins in Amanita phalloides.

Musil, Karel January 2015 (has links)
(EN) This work has been focused on the development and optimization of analytical methodology, using high performance liquid chromatography with diode array detection (HPLC-DAD) and high performance liquid chromatography with diode array and tandem mass spectrometric detection (HPLC-DAD-MS/MS) for the determination of amatoxins (α- and β-amanitin) and phalotoxins (phallacidin and phalloidin) in the crude extract from cap of Amanita phalloides with the option to later use for clinical purposes. In order to guarantee the reliability of the analytical results the influence of various parameters on the quality of the separation and the determination of toxins was studied. The developed HPLC-DAD method achieves good linearity in the concentrations range 1 - 100 µg/ml, with correlation coefficients higher than 0,997. Limits of detection (LOD) and quantitation (LOQ) were calculated for all the studied toxins with following values: for α-amanitin 0,90 µg/ml (LOD); 2,99 µg/ml (LOQ), β-amanitin 1,07 µg/ml (LOD); 3,56 µg/ml (LOQ), phallacidin 2,17 µg/ml (LOD); 7,26 µg/ml (LOQ) and phalloidin 0,79 µg/ml (LOD); 2,64 µg/ml (LOQ). Key words: Amanita phalloides,-amanitin,-amanitin, phallacidin, phalloidin, solid-liquid extraction, HPLC-DAD, HPLC-DAD-MS/MS .
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Quantification of Progesterone and 17-β Estradiol in Mouse Serum by Liquid Chromatography-Tandem Mass Spectrometry

Kennard, Benjamin, Cobble, Allison, Gravitte, Amy, Galloway, Kaleigh, Kintner, Jen, Hall, Jennifer, Brown, Stacy C 05 May 2020 (has links)
Quantification of progesterone and 17-β estradiol in mouse serum by liquid chromatography-tandem mass spectrometry Authors: Benjamin Kennard, Allison Cobble, Amy Gravitte, Keleigh Galloway, Jen Kintner, Jennifer Hall, Stacy Brown Introduction: In the United States, Chlamydia trachomatis is a commonly appearing sexually transmitted infection1. It affects the U.S. healthcare system to a tune of about $500 million dollars annually2. In women, it generally appears asymptomatic and can lead to severe secondary complications such as pelvic inflammatory diseases or infertility1. Female sex hormones, estrogen and progesterone, are being identified to have a role in chlamydial infection. Specifically, this study aims to create quantification methods to detect levels of estrogen and progesterone in mice, infected with Chlamydia muridarum, plasma samples. Methods: Progesterone samples were prepared using solid-liquid extraction (SLE+) cartridges with ethyl acetate as the elution solvent. Estradiol samples were prepared using liquid-liquid extraction (LLE) with methyl tert-butyl ether and subsequent derivatization with DMIS. Following sample preparation, hormones were quantified in samples using LC-MS/MS with a gradient elution of 1 mM ammonium fluoride in water and acetonitrile. The separation was achieved using a UCT C18 column (100 x 21.mm, 1.8 μm particle size) maintained at 50oC. The mass spectrometer was set up to isolate molecular ions for progesterone (m/z 315.0910) and derivatized estradiol (m/z 431.1835). Quantification was facilitated by the use of deuterium-labeled internal standards and their corresponding molecular ions in the mass spectrometer (d9-progesterone; m/z 324.1230 and d5-estradiol; m/z 436.2922). Results: Several aspects of the assay presented have been optimized for maximum analyte recovery and analytical sensitivity, including column choice, mobile phase, derivatizing agents for estradiol, and extraction protocols for progesterone. The LC-MS/MS method was investigated for precision and accuracy over three separate days. The dynamic range of the progesterone assay was 5 – 100 ng/mL, with a limit of detection of 1 ng/mL. Likewise, the estradiol assay was linear in the range of 5 – 100 ng/mL, with a limit of detection of 0.5 ng/mL. The average precision, represented by % RSD was 0.74 – 8.5% and 6.3 – 13.4% for progesterone and estradiol, respectively. The accuracy of the method, represented by % error was 1.6 – 14.4% and 4.0 – 10.5% for progesterone and estradiol, respectively. Successful validation was defined as < 15% RSD and error (< 20% at the limit of quantification), per current FDA Guidelines. Conclusions: The developed LC-MS/MS method is specific for progesterone and estradiol, and the extraction is suitable for preparation of mouse serum samples. This assay could be successfully applied to hormone quantification in mouse samples to support the investigation of the link between chlamydia infection and hormone levels in female animals. References 1. Chlamydia - 2017 Sexually Transmitted Diseases Surveillance. https://www.cdc.gov/std/stats17/chlamydia.htm. Accessed October 23, 2018. 2. Owusu-Edusei K, Chesson HW, Gift TL, et al. The Estimated Direct Medical Cost of Selected Sexually Transmitted Infections in the United States, 2008. Sex Transm Dis. 2013;40(3):197-201. doi:10.1097/OLQ.0b013e318285c6d2
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Optimizing the Extraction of Phenolic Antioxidant Compounds from Peanut Skins

Ballard, Tameshia Shaunt'a 29 July 2008 (has links)
Peanut skins are a low-value byproduct of peanut blanching operations. They have been shown to contain significant levels of phenolic compounds with demonstrated antioxidant properties. The effects of two types of extraction methods: solid-liquid extraction (SLE) and microwave-assisted extraction (MAE) on the recovery of phenolic compounds from peanut skins were investigated. Response surface methodology was used to optimize extraction conditions based on total phenolic content (TPC), ORAC (oxygen radical absorbance capacity) activity and <i>trans</i>-resveratrol content. The protective effect of peanut skin extracts (PSE) against hydrogen peroxide (H₂O₂)-induced oxidative stress in human brain microvascular endothelial cells (HBMEC) and the effect of PSE on lipid oxidation in commercial peanut butter were also evaluated. In the SLE method, EtOH was found to be the most efficient extraction solvent followed by MeOH, water and EA. Despite EtOH extracts having a higher TPC, samples extracted with MeOH demonstrated slightly higher ORAC activity. Resveratrol was identified in MeOH extracts but was not found in EtOH, water or EA extracts. In the MAE procedure, the maximum predicted TPC under the optimized conditions was 144 mg phenols/g skins compared to 118 mg/g with SLE. The maximum predicted ORAC activity was 2789 μmol TE/g as opposed to 2149 μmol TE/g with the SLE method. MAE was able to extract more phenolic compounds (with higher antioxidant activity) in a faster time than the SLE procedure. In addition, resveratrol was identified in PSE derived from MAE although at relatively low levels. PSE were found to have some protective effects against oxidative stress in HBMEC. Higher doses of PSE appeared to have a slightly cytotoxic effect. However, the data were highly variable which made it difficult to arrive at any definitive conclusions regarding the potential benefits of PSE in preventing oxidative damage to cells. In the PB experiment, hexanal levels over the storage period were not high enough for the samples to be considered oxidized. However, hexanal values of PB samples treated with PSE were lower than the control throughout storage, which suggests that PSE may provide some protection against oxidation of PB. / Ph. D.

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