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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.
21

Determinação experimental do equilibrio solido-liquido de sistemas binarios de acidos graxos saturados : estudo detalhado da fase solida / Experimental determination of solid-Liquid equilibrium of binary systems of saturated fatty acids : detailed study of the solid phase

Costa, Mariana Conceição da, 1977- 09 September 2008 (has links)
Orientadores: Maria Alvina Krahenbuhl, Antonio Jose de Almeida Meirelles / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-11T21:21:37Z (GMT). No. of bitstreams: 1 Costa_MarianaConceicaoda_D.pdf: 10674816 bytes, checksum: 76cfbb726dcbf23a7bdf88f2ccf727bd (MD5) Previous issue date: 2008 / Resumo: Os ácidos graxos são importantes não só por serem os principais constituintes dos óleos e gorduras de origem vegetal, mas também por terem grande importância no funcionamento de alguns sistemas lipídicos e porque podem ser usados como matéria prima na fabricação de emulsões, plásticos e produtos de limpeza entre outros. Além da grande influência que causam nas características finais de alguns produtos da indústria alimentícia, recentemente pesquisas também os apontam como bons materiais para o armazenamento de energia (phase change materials ¿ PCMs). Nesse trabalho são apresentados diagramas T-x do Equilíbrio Sólido-Líquido de sistemas binários de ácidos graxos saturados através de uma reinterpretação das curvas térmicas obtidas pela calorimetria exploratória diferencial. Esses diagramas de fase apresentam os pontos peritético e eutético além de transições na fase sólida. Esse trabalho investiga detalhadamente a fase sólida das misturas de ácidos graxos saturados, com a intenção de compreender a existência do ponto peritético e das transições na fase sólida que aparecem nos diagramas de equilíbrio. Para esse estudo foram usadas as técnicas de difração de Raios-X, de espalhamento Raman, a microscopia óptica convencional, a microscopia óptica a altas pressões e a calorimetria exploratória diferencial, através da qual foram determinados os diagramas de fase estudados. Através desse estudo foi possível apresentar um diagrama de fases muito mais complexo do que até agora foi encontrado na literatura. Essa complexidade se deve, além da reação peritética e da reação eutética, já conhecidas desses sistemas, a uma reação metatética que ocorre logo acima da temperatura peritética. Também há a formação de solução sólida nos extremos do diagrama de fases, comprovada através do diagrama de Tamman e a uma região de completa miscibilidade, devido à formação de um composto com ponto de fusão incongruente. / Abstract: Fatty acids are important not just to be the main constituent of oils and fats but also because of the important behavior of lipids systems and that can be used as row materials in the manufacture of emulsions, plastics and products for cleaning and others. Besides of the big influenced that causes in the final characteristics of some products for food industries recent research points that they are excellent phase change materials (PCMs). This work presents T-x diagrams of solid-liquid equilibrium of binary systems of saturated fatty acids through the reinterpretation of the differential thermal curves obtained by differential scanning calorimetry. These phase diagrams presents the peritectic and eutectic points besides the transitions on the solid phase. This work studies the solid phase of saturated fatty acids mixtures looking forward to verify the occurrence of the peritectic point and the transitions on the solid phase. For this study it was used the following techniques: X-ray diffratometry, FT-Raman spectroscopy, conventional optical microscopy, optical microscopy under high pressure and differential scanning calorimetry. The phase diagrams studied were determined by differential scanning calorimetry. The results obtained through these techniques shows a phase diagram more complex than previously reported in the literature. This complexity is due to a peritectic and eutectic, and to a metatectic reaction that occurs closer to the peritectic temperature. Besides these reactions there is formation of solid solution on the extremes of the phase diagram proven by the Tamman plot and the existence of a region with complete miscibility, close to the peritectic point, due the formation of a compound with incongruently melting point. / Doutorado / Desenvolvimento de Processos Químicos / Doutor em Engenharia Química
22

Qualidade nutricional da carne de tourinhos nelore e ½ angus-nelore terminados em confinamento ou em pastagem com suplementação / Nutritional quality of meat of nelore and ½ angus-nelore steers finished in feedlot or on pasture with supplementation

Reis, Renata Cunha dos 06 March 2017 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-04-19T15:32:03Z No. of bitstreams: 2 Tese - Renata Cunha dos Reis - 2017.pdf: 1668710 bytes, checksum: 8747c25747ed19ebf2fa1aba8886ebd8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-04-19T15:32:16Z (GMT) No. of bitstreams: 2 Tese - Renata Cunha dos Reis - 2017.pdf: 1668710 bytes, checksum: 8747c25747ed19ebf2fa1aba8886ebd8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-04-19T15:32:16Z (GMT). No. of bitstreams: 2 Tese - Renata Cunha dos Reis - 2017.pdf: 1668710 bytes, checksum: 8747c25747ed19ebf2fa1aba8886ebd8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-06 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / It was aimed to verify the influence of genetics between Nelore or ½ Angus-Nelore animals and the finishing phase systems, pasture with protein-energy supplementation or feedlot, on the contents of moisture, ashes, proteins, fat, iron, zinc, calcium, potassium, pH, color, fatty acids composition, vitamin E, lipid oxidation and cholesterol of the meat of these animals, after reaching 480 kg body weight. It was adopted the completely randomized design, in 2x2 factorial arrangement, with two breeds and two finishing systems. Meat from feedlot finished ½ Angus-Nelore animals obtained higher protein content (P <0.05) than feedlot Nelore animals. The ½ Angus-Nelore animals finished on pasture with supplementation obtained meat with higher content (P <0.05) of zinc and lower content of linoleic acid (C18:2 n-6) compared to meat of Nelore steers finished on pasture with supplementation and feedlot finished ½ Angus-Nelore. For myristic acid, one of the fatty acids considered to be hypocholesterolemic, the treatment with meat of feedlot finished Nelore showed a higher value (P <0.05) when compared to Nelore finished on pasture with supplementation and feedlot finished ½ Angus-Nelore. Meat of Nelore steers finished on pasture with supplementation obtained higher values (P<0.05) for stearic (C18:0), linolenic (C18:3n-3), DHA and total polyunsaturated fatty acids when compared to feedlot finished Nelore. Isolatedly, (P <0.05), the feedlot system generated higher contents of C18:1 trans-10 cis-12 fat. The pasture combined with supplementation system contributed to higher values of calcium, potassium, trans-vaccenic acid (C18:1 trans-11 cis-9) and vitamin E. For the Nelore breed, they were found higher contents of fat and vitamin E, while the ½ Angus-Nelore showed higher amount of potassium. The analysis of moisture, ash, iron, pH, color, cholesterol, palmitic acid (C16:0), total saturated fatty acids and oleic acid (C18:1n-9) were not significant. According to the obtained results, it was concluded that, under the conditions of the present study, Nelore animals finished on pasture with supplementation resulted in meat with a higher content of polyunsaturated, mainly omega-3, fatty acids, when compared to feedlot finished Nelore, while the ½-Angus-Nelore finished on pasteure with supplementation, lower omega-6 content, whose characteristic is very important with regard to n-6 / n-3 ratio; and the pasture finishing system contributed, isolatedly, to higher contents of calcium, potassium, vitamin E and trans-vaccenic acid, which is an intermediate of the ruminal biohydrogenation process, shown to be beneficial to health, while the feedlot system contributed to an increased deposition of intramuscular fat and higher content of the trans isomer, which is harmful to health. / O objetivo deste estudo foi verificar a influência da genética entre animais Nelore ou ½ Angus-Nelore e do tipo de terminação, a pasto com suplementação proteico-energética ou confinamento, sobre os conteúdos de umidade, cinzas, proteínas, gordura, ferro, zinco, cálcio, potássio, pH, cor, composição de ácidos graxos, vitamina E, oxidação lipídica e colesterol das carnes destes animais, após atingirem 480 kg. O delineamento experimental utilizado foi o inteiramente ao acaso com arranjo fatorial 2x2, sendo duas raças e dois tipos de terminação. A carne de animais ½ Angus-Nelore quando terminados em confinamento obtiveram maior teor de proteína (P<0,05) em relação a de Nelore quando receberam confinamento. Animais ½ Angus-Nelore a pasto com suplementação obtiveram carnes com maior teor (P<0,05) de zinco e menor teor de ácido linoleico (C18:2 n-6) em relação a carne de animais Nelore terminados a pasto com suplementação e aos ½ Angus-Nelore terminados em confinamento. Para o ácido mirístico, um dos ácidos graxos considerados hipocolesterolêmicos, o tratamento com carne de animais Nelore terminados em confinamento adquiriu maior valor (P<0,05) quando comparado com Nelore terminado a pasto com suplementação e também ao ½ Angus-Nelore em confinamento. A carne de animais Nelore terminados a pasto com suplementação obteve maiores valores (P<0,05) para os ácidos esteárico (C18:0), linolênico (C18:3n-3), DHA e para o total de ácidos graxos poli-insaturados em relação ao Nelore terminado em confinamento. De forma isolada (P<0,05), o sistema de confinamento gerou maiores teores de gordura e C18:1 trans-10 cis-12. O sistema à pasto com suplementação contribuiu para maiores valores de cálcio, potássio, ácido trans-vacênico (C18:1 trans11 cis-9) e vitamina E. Para a raça Nelore foram encontrados maiores teores de gordura e vitamina E enquanto para os ½ Angus-Nelore maior quantidade de potássio. As análises de umidade, cinzas, ferro, pH, cor, colesterol, ácido palmítico (C16:0), total de ácidos graxos saturados e ácido oleico (C18:1n-9) não foram significativas. Dos resultados obtidos conclui-se que, nas condições do presente trabalho, animais Nelore terminados a pasto com suplementação gerou carne com maior composição de ácidos graxos poliinsaturados, principalmente de ômega-3, enquanto os ½ Angus-Nelore terminados a pasto com suplementação menor teor de ômega-6, cuja característica é muito importante no que se refere a relação n-6/n-3 e a terminação a pasto de forma isolada contribuiu para maior teor de cálcio, potássio, vitamina E e ácido trans-vacênico, intermediário do processo de biohidrogenação ruminal apontado como benéfico à saúde, enquanto o sistema de confinamento contribuiu para uma maior deposição de gordura intramuscular e maior teor do isômero trans apontado como maléfico à saúde.
23

Suplementação com ácidos graxos de cadeia média na emissão de metano, produção e qualidade do leite em vacas lactantes / Suplement with medium chain fatty acids on methane emission, production and milk quality in cows lactating

Becker, Eduardo Garcia 26 February 2015 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Lipid additives used in the nutrition of dairy cows may affect both milk fat composition, as modifying the individual fatty acid profile, reducing methane emissions, becoming a sustainable practice for dairy cattle. To verify the effect of an additive based on medium chain fatty acids (MCFA) containing caproic acid, caprylic, capric, lauric and myristic, four treatments were tested: CTL (control without addition of MCFA), AGCM20 (5g MCFA), AGCM40 (10g MCFA) and AGCM80 (20g MCFA) on in vitro production gas (Experiment 1) and in the diet of lactating cows (Experiment 2). The bottles were distributed in a completely randomized design with repeated measurements over time and animals in triple latin square with four animals, four periods, four treatment, respectively. In Experiment 1 evaluated the production of gas, short chain fatty acids (SCFA) and methane (CH4); in Experiment 2 the productive parameters of milk and individual profile of fatty acids of milk fat. There was a significant decrease in gas production and methane (P<0.05), changing the profile of SCFA production in vitro treatment gas in AGCM40 and 80 compared with the control. No effects on productive parameters (P>0.05), however, were observed linear increase of C17:0 and C18: 3n6 (P<0.05) in the treatments AGCM20 and 80 respectively. It has been found that the use of MCFA 10 and 20g reduce the production of methane, without altering milk production and fatty acids of milk. / Aditivos lipídicos utilizados na nutrição de vacas leiteiras podem afetar tanto a composição da gordura do leite, quanto modificar o perfil de ácidos graxos individuais, reduzindo as emissões de metano, tornando-se uma prática sustentável para pecuária leiteira. Para verificar o efeito de um aditivo a base de ácidos graxos de cadeia média (AGCM), contendo ácido capróico, caprílico, cáprico, láurico e mirístico, foram testados quatro tratamentos: CTL (controle, sem suplementação), AGCM20 (5g AGCM), AGCM40 (10g AGCM) e AGCM80 (20g AGCM) na produção in vitro gás (Experimento 1) e na dieta de vacas em lactação (Experimento 2). Os frascos foram distribuídos em um delineamento inteiramente casualizado com medidas repetidas no tempo e os animais em um triplo quadrado latino, com quatro animais, quatro períodos, quatro tratamentos, respectivamente. No experimento 1 foram avaliados a produção de gás, ácidos graxos de cadeia curta (AGCC) e metano (CH4); no Experimento 2 os parâmetros produtivos de leite e perfil individual dos ácidos graxos da gordura do leite. Houve redução significativa na produção de gás e metano (P<0,05), alterando o perfil de AGCC na produção in vitro gás nos tratamento AGCM40 e 80 em comparação com o controle. Não foram observados efeitos nos parâmetros produtivos (P>0,05), entretanto, foram observados aumentos lineares de C17:0 e C18:3n6 (P<0,05), nos tratamentos AGCM20 e 80 respectivamente. Foi constatado que o uso de 10 e 20g de AGCM reduz a produção de metano, não alterando a produção de leite.
24

Uticaj sastava masne faze margarina na fizičke osobine i kvalitet peciva od laminiranog testa / INFLUENCE OF FAT PHASE COMPOSITION OF MARGARINE ON PHYSICAL CHARACTERISTICSAND QUALITY OF PUFF PASTRY

Šoronja-Simović Dragana 16 December 2009 (has links)
<p>U radu je ispitana mogućnost primene margarina za laminiranje smanjenog sadržaja trans masnih kiselina u izradi lisnatog peciva. U prvoj fazi eksperimentalnog rada ispitivanjem uticaja vrste (MZ1 i MZ2) i količine margarina za zames (1, 3 i 5% na masu bra&scaron;na) i količine emulgatora (0,1, 0,3, i 0,5% na masu bra&scaron;na), kao i njihove interakcije na fizičke osobine testa i kvalitet peciva, definisan je sirovinski sastav osnovnog testa, koji obezbeđuje optimalnu obradivost tokom laminiranja. Rezultati merenja empirijskih i fundamentalnih reolo&scaron;kih pokazatelja kvaliteta osnovnog testa i kvaliteta peciva jasno su pokazali da je optimalna količina dodataka 1% margarina MZ2 i 0,3% emulgatora.<br />Ispitivanjem uticaja sastava masne faze margarina za laminiranje na kvalitet peciva utvrđeno je da je količinu margarina, kao i vreme odmaranja između faza laminiranja neophodno prilagoditi fizičkohemijskim osobinama margarina. Zadovoljavajući kvalitet lisnatog peciva sa margarinom MLT1 najboljih fizičkih osobina, ali i najpoželjnijeg masnokiselinskog sastava, moguće je postići dodatkom samo 35% margarina, &scaron;to je najče&scaron;e donja granica u izradi lisnatog peciva. Za dobijanje prihvatljivih fizičkih i karakterističnih senzornih osobina peciva neophodan je dodatak 45% margarina MLT3, odnosno 55% margarina MLT2 i MLT4.<br />Primena margarina MLT1 i MLT4 koji imaju veći sadržaj čvrstih triglicerida zahteva vreme odmaranja od 30 minuta. Najbolji kvalitet peciva sa margarinom MLT2 ili MLT3 koje karakteri&scaron;e niži sadržaj SFC i manja tvrdoća dobija se kada je vreme relaksacije<br />između faza laminiranja 45 minuta.<br />Optimizacijom tehnolo&scaron;kog procesa proizvodnje peciva od laminiranog testa utvrđeno je da margarini niskog sadržaja trans masnih kiselina, kod kojih su očuvane optimalne fizičke osobine, mogu uspe&scaron;no da zamene margarine dobijene postupkom parcijalne hidrogenacije biljnog ulja. Primenom margarina modifikovanog sastava masne faze moguće je smanjiti energetsku vrednost peciva za 12%, odnosno smanjenjem udela masti za 30% i trans masnih kiselina za 100% pobolj&scaron;ati nutritivnu vrednost peciva.</p> / <p>The possibility of application of low-trans margarine in the puff pastry production was investigated in this work. The base dough formula, which ensures the optimal dough handling during the laminating, has been defined in the first phase of the experimental work. It has been achieved through the analysis of the influence of two dough margarines composition (MZ1 and MZ2) and quantity (1, 3 and 5 % based on flour) in combination with emulsifier quantity (0.1, 0.3 and 0.5% based on flour) on physical properties of dough and puff pastry quality. The results of the measurements of empirical and fundamental rheological parameters of the base dough quality as well as the quality of the puff pastry, have clearly indicated that the optimal quantity of margarine MZ2 and emulsifier are 1% and 0.3%, respectively.<br />By analyzing the impact of the fat phase composition of puff pastry margarine on pastry quality, it has been revealed that the quantity of the margarine and the relaxation time between laminating, need to be adjusted to the physicochemical characteristics of the margarine.<br />It is possible to achieve the satisfactory quality of the puff pastry with margarine MLT1 of the best physical, and of the most optimal fatty acid composition, by adding only 35% of margarine which is at most times, the lowest possible quantity in producing the puff pastry. For the achievement of the acceptable physical and typical sensory characteristics of the pastry it is needed to add 45 % of the margarine MLT3, or 55% of margarine MLT2 and MLT4.<br />The use of the margarines MLT1 and MLT4 which have high values of solid fat content, requires relaxation<br />time of 30 minutes. The best quality of the pastry with margarine MLT2 or MLT3 which is typical of lower solid fat content and lower firmness is achieved when the time of the relaxation between the laminating is 45 minutes.<br />By the optimization of the production of the puff pastry, it has been identified that the margarines of the low content of trans fatty acids can successfully replace the margarines produced by the partial hydrogenation of the vegetable oil. It is possible to reduce the energy value of the pastry by 12%, by using the margarine of the modified content of the fat phase. Namely by reducing the content of the fat by 30% and trans fatty acids by 100%, it is possible to improve the nutritive value of the pastry.</p>
25

Saturated Fatty Acid Blood Levels and Cardiometabolic Phenotype in Patients with HFpEF: A Secondary Analysis of the Aldo-DHF Trial

Lechner, Katharina, von Schacky, Clemens, Scherr, Johannes, Lorenz, Elke, Bock, Matthias, Lechner, Benjamin, Haller, Bernhard, Krannich, Alexander, Halle, Martin, Wachter, Rolf, Duvinage, André, Edelmann, Frank 29 February 2024 (has links)
Background: Circulating long-chain (LCSFAs) and very long-chain saturated fatty acids (VLSFAs) have been differentially linked to risk of incident heart failure (HF). In patients with heart failure with preserved ejection fraction (HFpEF), associations of blood SFA levels with patient characteristics are unknown. Methods: From the Aldo-DHF-RCT, whole blood SFAs were analyzed at baseline in n = 404 using the HS-Omega-3-Index methodology. Patient characteristics were 67 8 years, 53% female, NYHA II/III (87%/13%), ejection fraction 50%, E/e’ 7.1 1.5; and median NT-proBNP 158 ng/L (IQR 82–298). Spearman´s correlation coefficients and linear regression analyses, using sex and age as covariates, were used to describe associations of blood SFAs with metabolic phenotype, functional capacity, cardiac function, and neurohumoral activation at baseline and after 12-month follow-up (12 mFU). Results: In line with prior data supporting a potential role of de novo lipogenesis-related LCSFAs in the development of HF, we showed that baseline blood levels of C14:0 and C16:0 were associated with cardiovascular risk factors and/or lower exercise capacity in patients with HFpEF at baseline/12 mFU. Contrarily, the three major circulating VLSFAs, lignoceric acid (C24:0), behenic acid (C22:0), and arachidic acid (C20:0), as well as the LCSFA C18:0, were broadly associated with a lower risk phenotype, particularly a lower risk lipid profile. No associations were found between cardiac function and blood SFAs. Conclusions: Blood SFAs were differentially linked to biomarkers and anthropometric markers indicative of a higher- /lower-risk cardiometabolic phenotype in HFpEF patients. Blood SFA warrant further investigation as prognostic markers in HFpEF. One Sentence Summary: In patients with HFpEF, individual circulating blood SFAs were differentially associated with cardiometabolic phenotype and aerobic capacity.
26

Modificação de uma refeição brasileira com componentes mediterrâneos induz benefícios cardiometabólicos / Modification of a Brazilian meal including Mediterranean components induces cardiometabolic benefits

Pires, Milena Monfort 15 December 2015 (has links)
Introdução: Mudanças na alimentação e atividade física das populações elevaram a incidência de doenças crônicas não-transmissíveis associadas à adiposidade corporal. Este quadro contribui para mortalidade cardiovascular, motivando iniciativas em saúde pública visando à prevenção. Há evidências de que populações que consomem a dieta mediterrânea apresentam menor mortalidade por todas as causas, inclusive cardiovasculares. Os benefícios desta dieta, rica em fibras, gorduras insaturadas e polifenóis, parecem decorrer da atenuação da inflamação, envolvida na gênese de doenças cardiometabólicas. Objetivo: Este estudo investigou os efeitos da modificação de uma refeição diária, o desjejum, de forma a incluir alimentos mediterrâneos, sobre o metabolismo lipídico, glicídico, inflamação subclínica e expressão de genes inflamatórios. Métodos: Foi um ensaio clínico cruzado com duração total de 10 semanas, incluindo 80 adultos com excesso de peso, não-diabéticos. Os participantes passaram por 2 intervenções de 4 semanas no desjejum, com wash-out de 2 semanas entre elas. Os desjejuns, brasileiro e modificado, foram isocalóricos, diferindo quanto ao conteúdo de fibras e tipos de ácidos graxos. Antes e após cada intervenção foi realizado teste de sobrecarga de gorduras (FTT) com refeição rica em gorduras (saturadas e insaturadas MUFA e PUFA, dependendo da intervenção) e coletas sanguíneas seriadas até 240 minutos para determinação de glicose, insulina, lípides e marcadores inflamatórios. Foram também analisadas as expressões de genes inflamatórios, antes e após cada intervenção. Para comparar as respostas às intervenções foram usados teste t de Student ou os correspondentes não-paramétricos e ANOVA para medidas repetidas. Para as expressões dos genes foi utilizado o método delta ct e a expressão relativa calculada tendo como base valores de jejum e pré-intervenção. Valor de p <0,05 foi considerado significante. Resultados: No Artigo 1 (Modification in a single meal is sufficient to provoke benefits in inflammatory responses of individuals at low-tomoderate cardiometabolic risk), o FTT com desjejum brasileiro comparada ao modificado provocou maiores concentrações de IL-6 e IL-8, e esta resposta se acentuou após intervenção. As concentrações de selectina E, TNF-, IFN-, IL-10 e IL-17 se elevaram apenas após intervenção brasileira. No Artigo 2 (Inflammatory and metabolic response to dietary intervention differs among individuals at distinct cardiometabolic risk levels), a intervenção com desjejum modificado reduziu (p<0.05) a circunferência da cintura e pressão arterial e aumentou as concentrações de HDL. Indivíduos com síndrome metabólica melhoraram fatores clássicos (pressão arterial e glicemia, além de apolipoproteína B) após desjejum modificado, enquanto aqueles sem a síndrome melhoraram marcadores inflamatórios. O Artigo 3 (Comparison of inflammatory genes expression and their circulating products after short-term fatty acids interventions in humans) mostrou que o FTT com desjejum rico em gordura saturada induziu maior expressão pós-prandial de IL-1 quando comparado ao rico em insaturadas, antes e após as intervenções. Houve tendência à maior expressão de IFN- e IL-6 após intervenção com desjejum brasileiro. Na metanálise do Artigo 4 (Impact of the content of fatty acids of oral fat tolerance tests on postprandial triglyceridemia: systematic review and meta-analysis) foram incluídos 18 estudos buscando comparar as respostas dos triglicérides a ácidos graxos saturados e insaturados. Verificou-se que após 8 horas de refeição rica em MUFA há menor trigliceridemia. As menores concentrações observadas após ingestão de PUFA em relação à de saturados não atingiu significância. Conclusões: Pequenas modificações na dieta podem, em período relativamente curto, promover benefícios ao perfil de risco cardiometabólico. Tais benefícios foram evidentes em parâmetros clínicos habituais e reforçados pelos efeitos na expressão de genes inflamatórios e em marcadores circulantes. Vislumbra-se potencial de aceitação da introdução de componentes da dieta mediterrânea em população não-mediterrânea como a brasileira, o que poderia melhorar o perfil de risco cardiometabólico no longo prazo. / Introduction: Changes in dietary pattern and physical activity of populations have elevated the incidence of chronic non-communicable diseases associated with increased adiposity. Evidence has shown that populations consuming Mediterranean diets have lower mortality from all causes, including cardiovascular diseases. The benefits of this diet rich in fiber and unsaturated fats, derived in part on the effects of these nutrients on inflammatory condition that triggers cardiometabolic diseases. Objective: This study investigated the effects of changing a meal of Brazilian menu, the breakfast, in order to approximate it to the Mediterranean pattern on lipid and glucose metabolism, subclinical inflammation and also on the expression of inflammatory genes. Methods: This study was a crossover trial lasting a total of 10 weeks, including 80 overweight adults, nondiabetic without drug treatment for dyslipidemia. Participants who met the inclusion criteria underwent two 4-week interventions in breakfast, with wash-out of two weeks between them. The breakfasts (Brazilian and modified) were isocaloric, differing according to fiber and types of fatty acids contents. Before and after each intervention, fat tolerance tests with meals rich in fat (saturated and unsaturated depending on the intervention) were perfomed, with blood sample collections for glucose, insulin, lipids and inflammatory markers up to 240 minutes. Also, expression of inflammatory genes before and after each intervention was analyzed. To compare the acute and sub-acute responses to interventions were used Student t test or the corresponding nonparametric test and ANOVA for repeated measures. For expression of the genes, delta CT method was used and the relative expression calculated based on fasting and pre-intervention values. P value <0.05 was considered significant. Results: In Article 1 (Modification in a single meal is sufficient to provoke benefits in inflammatory responses of Individuals at low-to-moderate cardiometabolic risk), we observed higher IL-6 and IL- 8 concentrations after ingestion of the Brazilian FTT compared with the modified one, whose elevations were even more pronounced after the intervention period. Higher concentrations of E-selectin, TNF-, IFN-, IL-10 and IL-17 were found at fasting and in postprandial state only after the Brazilian intervention. In Article 2 (Inflammatory and metabolic response to dietary intervention Differs Among Individuals at distinct cardiometabolic risk levels), the intervention with the modified breakfast decreased waist circumference and blood pressure and increased the concentrations HDL (p <0.05). Participants with metabolic syndrome showed improvements in traditional risk factors (blood pressure and plasma glucose and apolipoprotein B) whit the modified breakfast, while those without the syndrome improved inflammatory markers. Article 3 (Comparison of inflammatory gene expression and their circulating products after short-term interventions fatty acids in humans) showed that the Brazilian FTT induced higher expression of IL-1 compared to the modified one, before and after the interventions. A tendency for higher postprandial expression of IFN- and increased IL-6 expression after intervention with Brazilian breakfast were also detected. In the meta-analysis of Article 4 (Impact of the content of fatty acids in oral fat tolerance tests on postprandial triglyceridemia: systematic review and metaanalysis) a total of 18 studies were included. When comparing the triglycerides responses to saturated and unsaturated fatty acids, lower areas under the curve with the meals rich in MUFA were observed. Postprandial triglyceridemia after PUFA was lower, but not significantly different from meals rich in saturated fat. Conclusions: Small changes in diet are able to induce benefits in cardiometabolic risk profile in a relatively short period. Such benefits are seen in routine clinical parameters, which are compatible with the favorable effects on the expression of inflammatory genes and circulating biomarkers. There is a potential acceptance of introducing components of the Mediterranean diet in non-Mediterranean populations like Brazil, which could improve the cardiometabolic risk profile in the long term.
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Efeitos dos diferentes ácidos graxos no metabolismo lipídico e estresse oxidativo em camundongos C57/BL alimentados com dieta hiperlipídica e rica em frutose / Effects of different fatty acids on lipid metabolism and oxidative stress in C57/BL mice fed a high fat diet and rich in fructose

Manca, Camila Sanches 30 June 2017 (has links)
A esteatose hepática não alcóolica está relacionada às causas crescentes de morbimortalidade de doenças hepáticas. Sua incidência está relacionada à obesidade e comorbidades vinculadas a esta, na qual tem despertado grande interesse na pesquisa. A modulação quantitativa da dieta pode promover ou retardar a patologia. Desta forma, terapias voltadas para retardar ou diminuir a esteatose hepática não alcóolica poderiam atenuar o dano hepático, melhorar a função hepática e reduzir sua progressão. Os objetivos do presente estudo foram: avaliar o consumo de óleos vegetais ricos em MUFAs e PUFAs usados comercialmente na prevenção ou redução da esteatose hepática analisando parâmetros do metabolismo lipídico hepático e sérico, estresse oxidativo e retardando a progressão de NAFLD. Material e Métodos: os animais foram divididos nos seguintes grupos: Controle (n=10) + HLF * (n=10); Grupo HLF * AZ (n=10); Grupo HLF* CN (n=10); Grupo HLF* S (n=10). Após 16 semanas de dieta e tratamento com os respectivos óleos, os animais foram anestesiados e o sangue retirado por punção cardíaca e os tecidos para as análises posteriores. Resultados: A oferta de uma dieta rica em gordura saturada (banha) + frutose ocasionou um aumento do peso no grupo HLF enquanto a administração dos respectivos óleos vegetais foi capaz de retardar o ganho de peso. O peso hepático e da soma dos tecidos adiposos epididimal e retroperitonial foi maior no HLF enquanto houve redução significativa no peso hepático HLF/S. O tecido retroperitonial foi menor no HLF/CN. De uma maneira geral o tratamento com os respectivos óleos vegetais diminui a esteatose em todos os grupos experimentais. A oferta de azeite extra virgem não refletiu no ganho de peso, porém o grupo teve um aumento significativo de TG e VLDL séricos, com diminuição do colesterol sérico. Avaliado histologicamente diminuiu o score de esteatose quando comparado ao HLF sendo classificado como esteatose macro e microvesicular de leve a moderada. O óleo de soja apresentou uma maior quantidade de PUFAs, sendo rico em n-6, refletiu na manutenção do peso dos animais, diminuiu a esteatose, sendo classificado como esteatatose leve, quando comparado ao HLF, porém aumentou o colesterol sérico. Apresentou um aumento de MDA e diminuição de GSH hepático. O óleo de canola devido a seu teor em ácidos graxos PUFAs (n-6 e n-3) teve maior incorporação do EPA e DHA que parecem ter evidenciado positivamente. Não apresentou alteração nos parâmetros bioquímicos e apresentou menor acúmulo de gordura hepática através da análise do percentual de gordura hepática e histopatologia, sendo caracterizado como esteatose leve. Pela peroxidação lipídica apresentou um maior acúmulo de MDA, porém um aumento de GSH. Contudo, a oferta dos respectivos óleos influenciou positivamente em diferentes mecanismos fisiológicos. / The Non-alcoholic fatty liver is related to the increasing causes of morbidity and mortality of liver diases. Its incidence is related to obesity and comorbidities linked to it, in which it has awaked great interest in the research. The disease is associated to genetic predisposition, lack of physical activity and high intake of saturated fats and fructose. Quantitative modulation of the diet may promote or retard the pathology. Thus, therapies aimed at delaying or decreasing non alcoholic hepatic steatosis could alleviate liver damage, improve liver function and reduce its progression. The objectives of the present study were: to evaluate the consumption of vegetable oils rich in commercially available MUFAs and PUFAs in the prevention or reduction of hepatic steatosis by analyzing parameters of hepatic and serum lipid metabolism, oxidative stress and delaying the progression of NAFLD. Material and Methods: animals were divided into the following groups: Control (n = 10) + HLF * (n = 10); Group HLF * AZ (n = 10); Group HLF * CN (n = 10); Group HLF * S (n = 10). After 16 weeks of diet and treatment with the respective oils, the animals were anesthetized and blood was withdrawn by cardiac puncture and tissues for further analysis. Results: The supply of a diet rich in saturated fat (lard) + fructose caused an increase in weight in the HLF group while the administration of the respective vegetable oils was able to delay the weight gain. Liver weight and sum of epididymal and retroperitoneal adipose tissues were higher in HLF while there was a significant reduction in HLF / S hepatic weight. Retroperitoneal tissue was lower in HLF / CN. In general, treatment with the respective vegetable oils decreases steatosis in all experimental groups. The supply of extra virgin olive oil did not reflect weight gain, but the group had a significant increase in serum TG and VLDL, with a decrease in serum cholesterol. Histologically it reduced the steatosis score when compared to the HLF being classified as mild to moderate macro and microvesicular steatosis. Soybean oil presented a higher amount of PUFAs, being rich in n-6, reflected in the maintenance of animal weight, decreased steatosis, being classified as mild steatosis when compared to HLF, but increased serum cholesterol. He presented an increase of MDA and decrease of hepatic GSH. Canola oil due to its content of PUFAs (n-6 and n-3) had greater incorporation of EPA and DHA than appear to have been positively evidenced. There was no alteration in the biochemical parameters and presented lower accumulation of liver fat through the analysis of the percentage of liver fat and histopathology, being characterized as mild steatosis. By the lipid peroxidation presented a greater accumulation of MDA, but an increase of GSH. However, the supply of the respective oils had a positive influence on different physiological mechanisms.
28

Efeitos dos diferentes ácidos graxos no metabolismo lipídico e estresse oxidativo em camundongos C57/BL alimentados com dieta hiperlipídica e rica em frutose / Effects of different fatty acids on lipid metabolism and oxidative stress in C57/BL mice fed a high fat diet and rich in fructose

Camila Sanches Manca 30 June 2017 (has links)
A esteatose hepática não alcóolica está relacionada às causas crescentes de morbimortalidade de doenças hepáticas. Sua incidência está relacionada à obesidade e comorbidades vinculadas a esta, na qual tem despertado grande interesse na pesquisa. A modulação quantitativa da dieta pode promover ou retardar a patologia. Desta forma, terapias voltadas para retardar ou diminuir a esteatose hepática não alcóolica poderiam atenuar o dano hepático, melhorar a função hepática e reduzir sua progressão. Os objetivos do presente estudo foram: avaliar o consumo de óleos vegetais ricos em MUFAs e PUFAs usados comercialmente na prevenção ou redução da esteatose hepática analisando parâmetros do metabolismo lipídico hepático e sérico, estresse oxidativo e retardando a progressão de NAFLD. Material e Métodos: os animais foram divididos nos seguintes grupos: Controle (n=10) + HLF * (n=10); Grupo HLF * AZ (n=10); Grupo HLF* CN (n=10); Grupo HLF* S (n=10). Após 16 semanas de dieta e tratamento com os respectivos óleos, os animais foram anestesiados e o sangue retirado por punção cardíaca e os tecidos para as análises posteriores. Resultados: A oferta de uma dieta rica em gordura saturada (banha) + frutose ocasionou um aumento do peso no grupo HLF enquanto a administração dos respectivos óleos vegetais foi capaz de retardar o ganho de peso. O peso hepático e da soma dos tecidos adiposos epididimal e retroperitonial foi maior no HLF enquanto houve redução significativa no peso hepático HLF/S. O tecido retroperitonial foi menor no HLF/CN. De uma maneira geral o tratamento com os respectivos óleos vegetais diminui a esteatose em todos os grupos experimentais. A oferta de azeite extra virgem não refletiu no ganho de peso, porém o grupo teve um aumento significativo de TG e VLDL séricos, com diminuição do colesterol sérico. Avaliado histologicamente diminuiu o score de esteatose quando comparado ao HLF sendo classificado como esteatose macro e microvesicular de leve a moderada. O óleo de soja apresentou uma maior quantidade de PUFAs, sendo rico em n-6, refletiu na manutenção do peso dos animais, diminuiu a esteatose, sendo classificado como esteatatose leve, quando comparado ao HLF, porém aumentou o colesterol sérico. Apresentou um aumento de MDA e diminuição de GSH hepático. O óleo de canola devido a seu teor em ácidos graxos PUFAs (n-6 e n-3) teve maior incorporação do EPA e DHA que parecem ter evidenciado positivamente. Não apresentou alteração nos parâmetros bioquímicos e apresentou menor acúmulo de gordura hepática através da análise do percentual de gordura hepática e histopatologia, sendo caracterizado como esteatose leve. Pela peroxidação lipídica apresentou um maior acúmulo de MDA, porém um aumento de GSH. Contudo, a oferta dos respectivos óleos influenciou positivamente em diferentes mecanismos fisiológicos. / The Non-alcoholic fatty liver is related to the increasing causes of morbidity and mortality of liver diases. Its incidence is related to obesity and comorbidities linked to it, in which it has awaked great interest in the research. The disease is associated to genetic predisposition, lack of physical activity and high intake of saturated fats and fructose. Quantitative modulation of the diet may promote or retard the pathology. Thus, therapies aimed at delaying or decreasing non alcoholic hepatic steatosis could alleviate liver damage, improve liver function and reduce its progression. The objectives of the present study were: to evaluate the consumption of vegetable oils rich in commercially available MUFAs and PUFAs in the prevention or reduction of hepatic steatosis by analyzing parameters of hepatic and serum lipid metabolism, oxidative stress and delaying the progression of NAFLD. Material and Methods: animals were divided into the following groups: Control (n = 10) + HLF * (n = 10); Group HLF * AZ (n = 10); Group HLF * CN (n = 10); Group HLF * S (n = 10). After 16 weeks of diet and treatment with the respective oils, the animals were anesthetized and blood was withdrawn by cardiac puncture and tissues for further analysis. Results: The supply of a diet rich in saturated fat (lard) + fructose caused an increase in weight in the HLF group while the administration of the respective vegetable oils was able to delay the weight gain. Liver weight and sum of epididymal and retroperitoneal adipose tissues were higher in HLF while there was a significant reduction in HLF / S hepatic weight. Retroperitoneal tissue was lower in HLF / CN. In general, treatment with the respective vegetable oils decreases steatosis in all experimental groups. The supply of extra virgin olive oil did not reflect weight gain, but the group had a significant increase in serum TG and VLDL, with a decrease in serum cholesterol. Histologically it reduced the steatosis score when compared to the HLF being classified as mild to moderate macro and microvesicular steatosis. Soybean oil presented a higher amount of PUFAs, being rich in n-6, reflected in the maintenance of animal weight, decreased steatosis, being classified as mild steatosis when compared to HLF, but increased serum cholesterol. He presented an increase of MDA and decrease of hepatic GSH. Canola oil due to its content of PUFAs (n-6 and n-3) had greater incorporation of EPA and DHA than appear to have been positively evidenced. There was no alteration in the biochemical parameters and presented lower accumulation of liver fat through the analysis of the percentage of liver fat and histopathology, being characterized as mild steatosis. By the lipid peroxidation presented a greater accumulation of MDA, but an increase of GSH. However, the supply of the respective oils had a positive influence on different physiological mechanisms.
29

Comportements anxiodépressifs et motivation alimentaire en contexte d'obésité : impacts des acides gras saturés sur le noyau accumbens

Décarie-Spain, Léa 12 1900 (has links)
L'obésité augmente la susceptibilité aux troubles anxieux et de l’humeur et, à son tour, un affect négatif influence les comportements alimentaires. Faisant partie du circuit de la récompense, le noyau accumbens intègre la signalisation dopaminergique avec des signaux corticaux et traduit ces informations en comportements motivés. Chez le rongeur, une alimentation riche en gras favorise des adaptations dopaminergiques au noyau accumbens et des études d'imagerie révèlent un recrutement amoindri de cette région du cerveau lors de la consommation d’aliments palatables en obésité humaine. Les altérations dopaminergiques au noyau accumbens perturbent les fonctions de récompense et contribuent fortement aux déficits motivationnels couramment observés en dépression. L'obésité induite par la diète résulte d'une surconsommation chronique d'aliments à forte densité énergétique, tels que ceux riches en gras, mais des acides gras alimentaires distincts influencent différemment la santé métabolique et l'humeur. Alors que les acides gras monoinsaturés, prédominants dans le régime méditerranéen, améliorent les paramètres du syndrome métabolique, les acides gras saturés, enrichis en produits d'origine animale et en aliments transformés, ont des actions pro-inflammatoires et leur consommation est corrélée aux symptômes dépressifs chez l’humain. Ainsi, nous avons émis l'hypothèse que l'obésité induite par une diète riche en gras saturés, et non monoinsaturés, favorise l’expression de comportements anxieux et dépressifs chez la souris via des adaptations moléculaires au noyau accumbens. Afin de tester cette hypothèse, nous avons exposé des souris mâles et femelles à une diète riche en gras saturés ou monoinsaturés ou à une diète faible en gras et avons évalué le rôle de l'inflammation au noyau accumbens dans l'expression d'un phénotype anxiodépressif. Dans notre première étude, impliquant uniquement des souris mâles, nous avons constaté que, malgré une prise de poids et une adiposité similaires, seules les souris nourries avec une diète riche en gras saturés présentaient des altérations métaboliques et des comportements anxiodépressifs. De plus, ces effets étaient accompagnés d'une augmentation des niveaux de marqueurs inflammatoires dans le noyau accumbens et, par approche virale, l’inhibition spécifique de la voie pro-inflammatoire du facteur nucléaire kappa-b dans cette région était suffisante pour empêcher l'expression de comportements anxiodépressifs ainsi que de recherche compulsive de sucrose. Dans notre deuxième étude, des souris femelles ont été placées sur les mêmes 3 régimes et nous avons également observé un phénotype anxiodépressif spécifique à la diète riche en gras saturés. Contrairement aux mâles, l'inflammation n'était pas associée à l’expression de comportements anxiodépressifs. À la place, des niveaux d'œstrogènes circulants élevés et une expression diminuée du récepteur à l’estrogène bêta dans le noyau accumbens ont distingué les souris sous diète riche en gras saturés des autres. Dans notre troisième étude, nous avons induit l'obésité et des comportements anxiodépressifs chez des souris mâles en les exposant à la diète riche en gras saturés. Par une approche chimiogénétique, nous avons renversé le phénotype dépressif induit par la diète riche en gras saturés en activant les neurones du noyau accumbens exprimant le récepteur dopaminergique de type 1. De plus, nous avons mis en évidence des effets différentiels de ces neurones, en condition de diète riche en gras saturés, avec une hausse des comportements anxieux par cette même manipulation. Dans notre quatrième étude, nous évaluons le potentiel d'un nouveau co-agoniste glucagon-like peptide-1/dexaméthasone à réduire la motivation pour les aliments riches en gras et en sucre chez les souris mâles. Nous avons constaté que ce co-agoniste pouvait inhiber, de manière aiguë, la motivation à obtenir des récompenses alimentaires à la fois sous diète contrôle et suite au sevrage d’une diète riche en gras et en sucre. Le traitement prolongé avec ce composé chez des souris obèses a permis de réduire le poids corporel et l'apport alimentaire, sans favoriser de comportements anxiodépressifs ou de déficit cognitif. Dans l'ensemble, notre travail supporte le rôle du noyau accumbens dans la susceptibilité accrue à l'anxiété et à la dépression chez les personnes obèses. Nous démontrons que la composition du régime alimentaire en différents acides gras, et non seulement la teneur, influence les altérations métaboliques et de l'humeur en obésité. Nos données suggèrent que cette relation est gouvernée par des mécanismes moléculaires distincts en fonction du sexe. Enfin, ces études pourraient orienter le développement de nouvelles approches thérapeutiques traitant à la fois les composantes métaboliques et motivationnelles de l'obésité. / Obesity increases the odds for mood disorders such as depression and anxiety and, in turn, negative affect influences feeding behaviours. Part of the reward circuitry, the nucleus accumbens integrates dopaminergic signaling with cortical inputs and translates this information into goal-oriented behaviours. In rodents, high-fat feeding promotes dopaminergic adaptations in the nucleus accumbens and imaging studies reveal blunted recruitment of this brain region during palatable food consumption in human obesity. Alterations in nucleus accumbens dopamine signaling disrupt reward function and heavily contribute to the motivational deficits commonly observed in depression. Diet-induced obesity results from chronic overconsumption of energy-dense foods, such as those with a high fat content, yet distinct dietary fatty acids influence metabolic health and mood differently. While monounsaturated fatty acids, predominant in the Mediterranean diet, have overall benefits for features of the metabolic syndrome, saturated fatty acids, enriched in animal-derived products and processed foods, have pro-inflammatory actions and their consumption correlates with depressive symptoms. Thus, we hypothesized that obesity induced by a saturated, but not monounsaturated, high-fat diet promotes anxiety and depressive behaviours in mice via molecular adaptations in the nucleus accumbens. In order to test this hypothesis, we placed male and female mice on either a saturated or monounsaturated high-fat diet or a control low-fat diet and assessed the role of nucleus accumbens inflammation in mediating the expression of an anxiodepressive phenotype. In our first study, only involving male mice, we found that, despite similar weight gain and overall adiposity, only mice fed the saturated high-fat diet displayed metabolic impairments and anxiodepressive behaviours. In addition, these impairments were accompanied by enhanced levels of inflammatory markers in the nucleus accumbens and region-specific viral mediated inhibition of the pro-inflammatory nuclear factor kappa-b pathway was sufficient to prevent the expression of anxiodepressive behaviours as well as compulsive sucrose-seeking. In our second study, female mice were placed on the same 3 diets and we also observed an anxiodepressive phenotype specific to the saturated high-fat diet. In contrast to the males, inflammation was not associated to the increase in anxiodepressive behaviours. Instead, elevated circulating levels of estrogen and diminished expression of estrogen receptor beta in the nucleus accumbens distinguished mice on the saturated high-fat diet from the others. In our third study, we induced obesity and anxiodepressive behaviours in male mice by exposing them to the saturated high-fat diet. Via a chemogenetic approach, we blocked the depressive phenotype induced by saturated high-fat feeding by activating neurons of the nucleus accumbens expressing the type 1 dopamine receptor. In addition, we evidenced differential effects of these neurons, under conditions of saturated high-fat feeding, as anxiety behaviours were enhanced by this same manipulation. In our fourth study, we assess the potential of a novel glucagon-like peptide-1/dexamethasone co-agonist to reduce motivation for high-fat/high-sugar rewards in male mice. We found that this co-agonist could acutely inhibit operant response for palatable foods under both chow and withdrawal from high-fat/high-sucrose diet conditions. Prolonged treatment with this compound in diet-induced obese mice successfully reduced body weight and food intake, without promoting anxiodepressive behaviours as well as cognitive impairment. Overall, our work supports a role for the nucleus accumbens in the greater susceptibility to anxiety and depression in obese individuals. We demonstrate that diet composition in fatty acids, and not just fat content, influences metabolic and mood impairments in obesity. Our data suggests this relationship to be mediating by distinct molecular mechanisms in a sex-specific manner. Finally, these studies may orient the development of novel therapeutic approaches addressing both the metabolic and motivational components of obesity.
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Analýza reologických vlastností rostlinných olejů a jejich složek / Analysis of the rheological properties of vegetable oils and their components

Divílek, Petr January 2014 (has links)
This Master’s thesis is dealing with theoretical analysis of vegetable, mineral oils and synthetic fluids, and with measuring of density and viscosity of selected samples of electric insulating fluids. The main part of the thesis is focused on vegetable oils and their elements called fatty acids. Those are more detail described in separate capitols. In those capitols is described their utilization in engineering practice with focus on energetics, where vegetable oils are used in larger scale. In experimental part of the work is measurement of density and dynamic viscosity. Viscosity was measured on two different machines, first the Hoppler viscometer and on vibrating viscometer. Results of these measurement are evaluated in tables and graphs.

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