• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 118
  • 115
  • 36
  • 25
  • 14
  • 14
  • 10
  • 8
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • Tagged with
  • 404
  • 404
  • 274
  • 238
  • 103
  • 89
  • 86
  • 70
  • 62
  • 49
  • 42
  • 40
  • 40
  • 35
  • 32
  • 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.
101

Etude de la cinétique de l’adaptation respiratoire à la naissance par la résonance magnétique : les effets des acides gras polyinsaturés oméga 3 sur la transition périnatale / Study of the kinetics of respiratory adaptation at birth by magnetic resonance : the effects of omega 3 polyunsaturated fatty acids on the perinatal transition

Houeijeh, Ali 20 March 2017 (has links)
L’adaptation à la vie extra-utérine requiert la résorption rapide du liquide pulmonaire, la création de la capacité fonctionnelle résiduelle (FRC), ainsi que l’augmentation du débit pulmonaire. Bien que ces mécanismes aient été largement étudiés, leurs cinétiques restent mal connues faute de méthode d’étude non invasive in vivo. L’échec de l’adaptation cardiorespiratoire à la naissance est la principale cause de mortalité et de morbidité de la période néonatale, malgré l’utilisation de stratégie préventive comme la corticothérapie anténatale, et l’amélioration des techniques de réanimation néonatale. Les acides gras polyinsaturés oméga 3 (AGPI n3) que l’on retrouve dans les huiles de poisson ont des effets cardiovasculaires et respiratoires qui pourraient améliorer la transition périnatale. Par ailleurs, leurs propriétés anti-inflammatoires peuvent réduire les conséquences des effets iatrogènes des techniques de réanimation dont la mise en oeuvre est nécessaire en cas de maladaptation cardiorespiratoire à la naissance. Les objectifs de ce travail ont été de : Mettre au point et valider une méthode d’exploration de la cinétique de réabsorption du liquide pulmonaire à la naissance par résonnance magnétique nucléaire Etudier les effets des AGPI n3 sur : l’adaptation ventilatoire à la naissance la circulation pulmonaire périnatale la prévention des lésions pulmonaires induites par une hyperoxie prolongée Les études ont été réalisées sur les modèles expérimentaux de foetus de brebis et de ratons nouveau-nés exposés à une hyperoxie prolongée. Nous montrons que la technique par IRM permet d’évaluer la cinétique de clairance du liquide pulmonaire in vivo en situations physiologique et pathologique. Alors que les AGPI n3 améliorent la circulation pulmonaire, ils n’ont pas d’effet sur la clairance du liquide pulmonaire. Par contre, ils réduisent les lésions pulmonaires induites par l’oxygène. Ces résultats expérimentaux suggèrent que les AGPI n3 pourraient prévenir les échecs d’adaptation cardiorespiratoire à la naissance et ses conséquences à long terme. / Perinatal transition requires clearance of pulmonary fluid, creation of functional respiratory capacity (FRC), and the multiplication of pulmonary blood flow by ten, to ensure gas exchange and blood oxygenation. Physiology of perinatal transition has been broadly studied but the kinetics of its evolution is less known. The aim of our study was to assess the kinetics of the respiratory transition. Besides, we supposed that polyunsaturated fatty-acids omega 3 (n3 PUFA) would improve this transition. To study the kinetic of respiratory transition, we used the MRI in 3 groups of lambs: premature group (Preterm) with a term of 122-124 days, two groups of late preterm lambs (134-136 days), including one group who received antenatal steroids (Late preterm + steroids), and a group without steroids (Late preterm). Surprisingly, we observed a rapid increase of lung fluid in preterm lambs reaching 30% at the end of the experimentation. Creation of FRC was also impaired in this group. In the Late preterm group, clearance of pulmonary fluid was slowed down with a moderate fall of 10%, whereas, in the Late preterm + steroids group, lung fluid dropped by 50% (p<0.05). Similarly, FRC in the Late preterm + steroids group was higher than the other 2 groups (p <0.05). Respiratory functions were closely related to lung fluid content and to FRC. We hypothesized that n3 PUFA would improve perinatal transition using two models: - An acute model: in a chronically instrumented model, catheters were introduced in the jugular and the carotid vessels of lamb fetuses at 122 days of gestation. Lamb fetuses received either Omegaven (n3 PUFA), or Intralipide (n6 PUFA), or isotonique physiological serum (SSI) for 4 days. Respiratory transition was explored by MRI. There was no significant difference between these three groups. Total lung fluid increased by about 20% in Omegaven group and 18% in SSI group (p> 0.05). - A model of Bronchopulmonary dysplasia: pups were exposed to hyperoxia for 10 days, and feeding rats received supplementation by either n3 PUFA (Omacor), n6 PUFA (sunflower oil), or SSI, with control groups that received the same feeding supply but which were exposed to air. Histological studies showed bronchopulmonary dysplasia lesions in the Hyperoxia groups, characterized by decrease of alveolar number, decrease in the number of secondary alveolar septa, and widening of the interstitial space. These lesions were similar in SSI and n6 PUFA groups, whereas n3 PUFA improved these lesions (p <0.05). To assess the effects of n3 PUFA in pulmonary vascular resistances (PVR), we studied their effects on fetal circulation characterized by elevated RVP using a chronically instrumented experimental model of lamb fetus. Lamb fetuses received either n3 PUFA (Omegaven), or n6 PUFA (Intralipid). We then explored the action mechanisms of n3 PUFA: 1) NO pathway using L-Nitro Argenine (LNA), 2) potassium channels pathway using Tetraethylamonium (TEA) and 3) epoxides produced by cytochrome P450 using MS-PPOH. Finally, we investigated the effect of Eicosapentaenoic Acid (EPA) perfusion, or Docosahexaenoic Acid (DHA) perfusion in pulmonary circulation. We showed that, unlike Intralipid, Omegaven induced pulmonary vasodilation, and an increase in pulmonary flow. An identical effect was reproduced by EPA infusion, while DHA did not modify PVR. This response was not modified by LNA. But it was reduced by MS-PPOH, and abolished by TEA. These results indicate that n3 PUFA induced pulmonary vasodilation, mediated by epoxides which act on potassium channels. To conclude, we demonstrated that respiratory transition in preterm lambs even in late preterm ones is altered with the presence of pulmonary edema. n3 PUFA did not improve lung fluid clearance but should be considered in the tretment of pulmonary hypertension, and in the prevention of brochopulmonary dysplasia of the newborns.
102

"Modulação da composição de ácidos graxos poliinsaturados ômega 3 de ovos e tecidos de galinhas poedeiras, através da dieta. I. Estabilidade oxidativa" / "Omega-3 polyunsaturated fatty acids modulated by the diet in laying hens eggs and tissues. I. Oxidation stability"

Maria Elena de Los Dolores Bernal Gómez 12 February 2003 (has links)
O objetivo deste estudo foi avaliar a influência de dietas suplementadas com semente de linhaça (ricas em ácido alfa-linolênico, LNA, ômega3) e antioxidantes naturais, provenientes do orégano e do alecrim, sobre o nível de incorporação dos ácidos graxos poliinsaturados ômega 3 (PUFA ômega3) em ovos e tecidos de aves. Para isto, 192 galinhas poedeiras da linhagem comercial Babcock de 22 semanas, foram alimentadas durante 30 dias com dietas constituídas de 0 (zero) e 5% de óleo de linhaça. Foram definidos 8 tratamentos: 4 grupos com 5% de óleo de linhaça (controle/sem antioxidante; BHA+BHT, 100+100 ppm; orégano, 200 ppm; alecrim, 200 ppm) e 4 grupos sem óleo de linhaça, mas utilizando os mesmos antioxidantes. A amostragem dos ovos foi realizada durante o experimento nos períodos 0, 10, 20 e 30 dias e dos tecidos das aves (sobrecoxa, coxa, asa, peito, coração, tecido adiposo e fígado) no tempo final do experimento. Os ácidos graxos foram determinados por cromatografia gasosa e o grau de oxidação lipídica através do teste do ácido tiobarbitúrico (TBA). De acordo aos resultados obtidos, verificou-se aumento significativo dos ácidos graxos alfa-linolênico (LNA) e docosahexaenóico (DHA) nas gemas de ovo das aves que receberam 5% de óleo de linhaça nos tratamentos controle, BHA+BHT, orégano e alecrim, nos diferentes tempos (10, 20 e 30 dias), quando comparados com a dieta 0% linhaça. Além disso, a incorporação máxima dos ácidos LNA e DHA nas gemas de ovo foi obtida aos 20 dias de alimentação das aves, com um índice de incorporação de 15 a 30 e de 2,5 a 4,5 vezes o grupo controle, respectivamente. Na avaliação do grau de oxidação lipídica nas gemas de ovo, foi verificada diferença significativa na redução dos valores de absorbância nas 2 dietas, em todos os tratamentos com antioxidantes, quando relacionados ao seu respectivo controle. Com relação aos tecidos das aves, também houve incorporação significativa dos ácidos LNA e DHA, quando comparadas as duas dietas, sendo o fígado o tecido que apresentou a maior concentração destes ácidos graxos. Também foi possível verificar a eficácia dos antioxidantes naturais na proteção contra a oxidação lipídica nos tecidos sobrecoxa, coxa, asa e peito. Portanto, os extratos das especiarias, alecrim e orégano, podem ser utilizados satisfatoriamente para se obter ovos e tecidos de aves enriquecidos com PUFA ômega-3, melhorando a estabilidade lipídica. Considerando que os PUFA ômega-3 têm um interesse considerável na saúde humana, o fornecimento de dietas ricas em ácido alfa-linolênico presente na linhaça, para galinhas poedeiras, permitiu a obtenção de ovos e tecidos enriquecidos, os quais tornam-se uma fonte alternativa de PUFA ômega-3. / The aim of this work was to evaluate the influence of diets containing flaxseed (rich in alpha-linolenic acid, LNA, omega-3) and natural antioxidants from oregano and rosemary on the level of incorporation of the polyunsaturated fatty acids omega 3 (PUFA omega-3) in eggs and tissues of poultry. For this purpose, 192 laying hens at 22 weeks of age, of commercial lineage Babcock, were fed for 30 days with diets containing 0 (zero) or 5% of flaxseed oil. The hens were divided in 8 groups: 4 groups received diets with 5% of flaxseed oil (control / no antioxidant; BHA+BHT, 100+100 ppm; oregano, 200 ppm; rosemary, 200 ppm) and 4 groups received no flaxseed oil, but the same antioxidants. The sampling of the eggs was accomplished in 4 periods (0, 10, 20 and 30 days) and of the tissues of poultry (upper thigh, thigh, wing, breast, heart, adipose tissue and liver) at the end of experiment. The fatty acids were analysed by gas chromatography and the lipid oxidation was determined by thiobarbituric acid test (TBA). The results showed that the levels of alpha-linolenic (LNA) and docosahexaenoic (DHA) acids increased in egg yolks from hens of the 4 groups fed diets with 5% flaxseed oil after 10, 20 and 30 days, when compared with diets 0% flaxseed oil. In addition, the maximum incorporation of LNA and DHA in egg yolks was obtained after 20 days, with an index of incorporation ranging from 15 to 30 and from 2.5 to 4.5, respectively. Also, a significant decrease of lipid oxidation in egg yolks for all groups receiving antioxidants was observed, when related with control. In the tissues of the hens, there was also significant incorporation of the LNA and DHA acids, when comparing the 2 diets, with the liver presenting the major concentration of these fatty acids. It was also possible to verify the effectiveness of the natural antioxidants in the protection against lipid oxidation in upper thigh, thigh, wing and breast tissues. Therefore, rosemary and oregano can be used satisfactorily to obtain eggs and tissues of poultry enriched with PUFA omega-3, improving the lipid stability. Considering that the PUFA omega-3 have considerable interest in the human health, the administration of diets rich in alpha-linolenic acid from flaxseed to laying hens allows the eggs and tissues enrichment as an alternative source of PUFA omega-3.
103

Características físico-químicas, nutricionais e sensoriais de pão de forma com adição de grãos de linhaça (Linum usitatissimum) / Physico-chemical, nutritional and sensory characteristics of flax seed wheat bread (Linum usitatissimum)

Neila Camargo de Moura 29 September 2008 (has links)
A indústria alimentícia tem oferecido ao consumidor muitas opções para aquisição de pães, dentre essas estão os pães enriquecidos e os integrais. A linhaça é um alimento com alegação funcional que vem se destacando pela presença do Omega-3, fibra solúvel e proteína, porém seu consumo é baixo devido à falta de hábito e também por escassez de informação dos consumidores. O objetivo do estudo foi formular pães com adição de grãos de linhaça nas concentrações de 3%, 6% e 9% e compará-los ao controle, sem adição de linhaça. Foram realizadas análises de determinação do perfil de ácidos graxos, composição centesimal, quantificação do teor de minerais, determinação de antinutricionais (ácido fítico, taninos, compostos fenólicos totais), digestibilidade de proteína in vitro, análise da qualidade dos pães através do peso da massa crua, peso da massa assada, perdas durante a cocção e índice de conversão. As propriedades físicas dos pães também foram avaliadas através da textura, volume e cor. As características sensoriais foram analisadas através de teste de aceitabilidade realizado em padaria com 116 provadores e também pela Análise Descritiva Quantitativa (ADQ) com 13 provadores treinados. Com os dados obtidos das análises químicas, elaborou-se um rótulo nutricional para cada formulação. Dentre os ácidos graxos quantificados, o palmítico, o oléico e o linoléico foram os maiores representantes nas 4 amostras de pães o que contribuiu para a frágil estabilidade dos produtos e para a formação de compostos indesejáveis, porém a presença de antioxidantes naturais nas sementes de linhaça controlou a oxidação lípidica. Nenhuma das amostras pode ser considerada fonte de fibra alimentar pelo fato de não conter 3g/100g de alimento pronto para consumo. O teor de fitatos presente nas amostras aumentou de acordo com a adição de sementes de linhaça. Nas 4 formulações de pães o teor de fitato diminuiu significativamente quando comparado ao da semente de linhaça. As amostras controle e com 6% de linhaça foram classificadas como volume específico Muito bom e as amostras com 3% e 9% de linhaça foram classificadas como volume específico Bom. Entre as amostras que receberam adição de linhaça, a amostra com 9% foi a melhor aceita pelos provadores e na ADQ, essa amostra apresentou médias superiores às demais em relação a maioria dos atributos levantados pelo provadores. Não foram identificados atributos indesejáveis para nenhuma das amostras através da ADQ. / Food industries offer to consumer several types of breads options which vary from whole wheat to enrich with multigrain such with flax seed. Flax seed is considered a functional food that has important content of omega 3 fat acids, soluble fiber and protein, however it intakes is very low in our diet. The aim of the research was to prepare a wheat bread enrich with flax seed at 3% or 6% or 9% concentration and to compare with a wheat bread control with no flax seed added. Analysis of fat acids composition, mineral composition, antinutritionals content (phytic acid, tannin, total phenolic compounds) and in vitro protein digestibility were carried out in the bread samples. Bread quality was evaluated analyzing the weight of the raw dough, the baked bread, and the lost during baking process and its conversion index. Physical properties of breads were evaluated for texture, volume and color. The sensory characteristics were evaluated using acceptability test with 116 panelists and by quantitative descriptive analysis (QDA) with 13 trained panelists. A nutritional label was formulated to each one of the bread preparations. The quantified fat acids profile showed that palmitic, oleic and linolenic acids were the most representative fat acids in the 4 bread sample analyzed. The presence of those fat acids possibly contributes to poor stability of product and for the development of undesirable compound. However, the presence of natural antioxidants in flax seed may help to control fat acid oxidation. None of the samples were considered source of dietary fiber because they have less then 3g/100 g of bread. The phytate content present in the samples increased according to the increase of flax seed concentration in the bread. Compared to raw flax seed, the phytate content in the bread samples were lower. The control and the sample with 6% of flax seed had the ranking for specific volume described as Very good and the samples with 3% and 9% of flax seed as Good. Between the bread samples, the best score in the acceptability test was obtained in the sample with 9% of flax seed. The same was observed for QDA which showed that the panel had high attributes for this sample compared to other ones. No undesirable attributes were identified in any other sample analyzed in QDA.
104

Stanovení mastných kyselin v lidských tkáních / Determination of fatty acids in human tissues

Turňová, Ivana January 2017 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Ivana Turňová Supervisor of Diploma Thesis: Mgr. Monika Kuchařová, Ph.D. Consultant: prof. MUDr. Zdeněk Zadák, CSc. Title of Diploma Thesis: Determination of fatty acids in human tissues The fatty acids are non-negligible component of lipids as one of the basic nutrients. This thesis in its theoretical part presents above all the group of polyunsaturated fatty acids (PUFA), which are important structural units of the cell membranes, they are also the precursors to several significant biologically active substances. In the human organism PUFA participate in many physiological and pathological processes this way, where they cause the large spectrum of actions. Onwards the thesis describes the gas chromatography method that is used in chemical analysis of lipids for the fatty acid determination as the gold standard. Experimentally, the fatty acid representation was determined in the blood, muscle, heart, liver and kidney among 26 cadavers divided into two groups according to the presence/absence of inflammatory process at the time of death. The data obtained were statistically analysed. The results were descriptively evaluated and there were indicated possible explanations of differences...
105

Stanovení spektra mastných kyselin u pacientů podstupujících léčbu taxany / Determination of the fatty acids spectrum in patients undergoing treatment with taxanes

Kuříková, Barbora January 2018 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Author of Diploma Thesis: Bc. Barbora Kuříková Supervisor of Diploma Thesis: Mgr. Monika Kuchařová, Ph.D. Consultant: prof. MUDr. Zdeněk Zadák, CSc. Title of Diploma Thesis: Determination of the fatty acids spectrum in patients undergoing treatment with taxanes The diploma thesis deals with the determination of fatty acids spectrum in erythrocytes in patients treated with taxanes. The theoretical part describes general features of fatty acids, their synthesis and degradation. Then it is focused on the topic of breast cancer, taxane treatment and negative side effects associated with taxane treatment, especially polyneuropathy. The gas chromatography, which is commonly used in practice, is also described in this part. The experimental part is divided into three parts. The first part describes working process, chromatographic analysis and evaluation of this analysis. In the second part there is comparing of spectrum of fatty acids of patients without and with polyneroupathy. And in the last part there is a comparing of spectrum of fatty acids of patients before taxane treatment, closely after treatment and about month after the treatment. Results of the experimental part are evaluated at the end...
106

Fluktuace hladin mastných kyselin v tkáních náhle zemřelých osob a srovnání s hodnotami u patologických stavů / The fluctuation of fatty acids levels in the tissues of suddenly deceased persons and comparison with values in pathological states

Čunátová, Alena January 2020 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Alena Čunátová Supervisor of Diploma Thesis: Mgr. Monika Kuchařová, Ph.D. Title of Diploma Thesis: The fluctuation of fatty acids levels in the tissues of suddenly deceased persons and comparison with values in pathological states Fatty acids and their metabolites are significantly involved in many physiological and pathological processes. This thesis monitors the levels of selected fatty acids in human tissues and the effect of long-term disease on their stores. In addition to the general characteristics, the theoretical part focuses on the intake of polyunsaturated fatty acids and their importance in the human body. It also deals with the effects of eicosanoids and other fatty acid metabolites. Methods used in fatty acid bioanalysis are also described. In the experimental part, the proportion of fatty acids in seven tissue types was compared between two groups of donors. One of them included 8 relatively young, healthy, suddenly deceased individuals. The second group included 12 elderly polymorbid patients. The obtained tissue samples were adjusted using extraction and derivatization techniques. Gas chromatography with flame ionization detection was used for analysis. The measured...
107

Fizičko-hemijska i reološka karakterizacija mikrokapsula ribljeg ulja inkorporiranih u čokoladni matriks / Physico-chemical and rheological characterization of fish oil microcapsules incorporated in a chocolate matrix

Kalić Marina 31 July 2020 (has links)
<p>Omega-3 masne kiseline su uslovne za zdravlje ljudi i imaju značajne fiziolo&scaron;ke uloge. Dijetetski proizvodi na bazi omega-3 masnih kiselina predstavljaju značajan izvor omega-3 masnih kiselina. Riblje ulje je dobar izvor polinezasićenih masnih kiselina (PUFA). Dnevni unos omega-3 polinezasićenih masnih kiselina je u većini delova sveta ispod preporučenog, uglavnom usled nedovoljne zastupljenosti ribe u ishrani. Zbog toga se danas riblje ulje nalazi u obliku različitih dijetetskih proizvoda i ponuda ovih preparata na trži&scaron;tu je veoma &scaron;iroka. Problem sa unosom ribljeg ulja kao dodatka ishrani je njegov intenzivan i neprijatan ukus i miris, &scaron;to može da dovede do neadekvatne suplementacije. Su&scaron;enje raspr&scaron;ivanjem (engl. spray drying) predstavlja tehniku koja omogućava trenutno su&scaron;enje rastvora, suspenzija ili emulzija. U pitanju je metoda koja ima &scaron;iroku primenu u farmaceutskoj industriji, a između ostalog se primenjuje i u cilju maskiranja neprijatnog ukusa lekova. Kao omotač mikrokapsula dobijenih su&scaron;enjem raspr&scaron;ivanjem je moguće koristiti proteine, ali je neophodno dobro ispitati i poznavati njihove fizičko-hemijske osobine i funkcionalnost. Inkorporiranjem mikrokapsula ribljeg ulja u čokoladu bi se dobila funkcionalna ili obogaćena hrana, &scaron;to predstavlja i finalnu formulaciju u ovom radu. Obogaćivanjem čokolade sa visokim sadržajem kakao delova mikrokapsulama ribljeg ulja kreirao bi se vi&scaron;estruko funkcionalan proizvod. Odabir čokolade kao matriksa za obogaćivanje uslovljen je činjenicom da je ona &scaron;iroko konzumiran proizvod. Ciljevi ovog rada bili su da se ispita uticaj metode su&scaron;enja raspr&scaron;ivanjem na stabilnost preformulacije ribljeg ulja, da se utvrde karakteristike mikrokapsula dobijenih su&scaron;enjem raspr&scaron;ivanjem (prinos i efikasnost mikrokapsulacije, oksidativnu stabilnost ulja, morfolo&scaron;ke osobine i veličinu mikrokapsula), zatim da se utvrdi uticaj veličine čestica na kristalizaciju u masnoj fazi suspenzije koja se koristi za izradu konditorskih proizvoda i da se utvrde fizičko-hemijske karakteristike (teksturu, boju, reolo&scaron;ke osobine) čokolade koja sadrži inkorporirane mikrokapsule ribljeg ulja u odnosu na čokoladu bez dodatka mikrokapsula. Metode su obuhvatale karakterizaciju proteina dobijenih iz soje, gra&scaron;ka, krompira, pirinča i surutke, njihovih rastvora, kao i emulzija ribljeg ulja u vodenim rastvorima tih proteina, određivanje prinosa i efikasnosti mikrokapsulacije i karakterizaciju dobijenih mikrokapsula. Prilikom ispitivanja uticaja veličine čestica na kristalizaciju u masnoj fazi suspenzije koja se koristi za izradu konditorskih proizvoda i fizičko-hemijskih osobina čokolade koja sadrži inkorporirane mikrokapsule ribljeg ulja primenjivane su metode za određivanje teksture, reolo&scaron;kih karakteristika, sadržaja čvrstih masti i boje dobijenih formulacija. Dobijeni rezultati su pokazali da se proteini pona&scaron;aju kao dobri emulgatori i da su&scaron;enje raspr&scaron;ivanjem predstavlja efikasan način za dobijanje mikrokapsula ribljeg ulja sa proteinima kao omotačima mikrokapsula. Kristalizacija masne faze u suspenziji koja predstavlja model čokolade zavisi od veličine čvrstih čestica. Kada je u pitanju proizvodnja čokolade sa inkorporiranim mikrokapsulama ribljeg ulja kod kojih su kao omotači kori&scaron;ćeni proteini soje, surutke i krompira, dodatak tih mikrokapsula ne utiče na karakteristike čokolade u meri dovoljnoj da bi se naru&scaron;io proizvodni proces izrade. Sve navedeno upućuje na zaključak da bi proizvodnja čokolade sa inkorporiranim mikrokapsulama ribljeg ulja, tehnolo&scaron;ki bila moguća.</p> / <p>Omega-3 fatty acids are essential for human health and have significant physiological roles. Dietary products based on omega-3 fatty acids are a significant source of omega-3 fatty acids. Fish oil is a good source of polyunsaturated fatty acids (PUFA). The daily intake of omega-3 polyunsaturated fatty acids is below the recommended level in most parts of the world, mainly due to the lack of fish in the diet. This is why fish oil is now found as various dietary products which are widely present in the world&rsquo;s market. The problem with fish oil intake as a dietary supplement is its intense and unpleasant taste and odor, which can lead to inadequate supplementation. Spray drying is a technique that allows instantaneous drying of solutions, suspensions or emulsions. It is a widely used method in the pharmaceutical industry and is used, among other things, to mask the unpleasant taste of medicines. It is possible to use proteins as a coating of spray-dried microcapsules, but it is necessary to test and know their physicochemical properties and functionality. Incorporating fish oil microcapsules into chocolate would make functional or enriched foods, which is consider as a final formulation in this work. Enriching the high cocoa content chocolate with fish oil microcapsules would create a multi-functional product. The choice of chocolate as a base is conditioned by the fact that it is a widely consumed product. The aim of this study was to investigate the effect of spray drying method on the stability of fish oil pre-formulation, to determine the characteristics of microcapsules obtained by spray drying (yield and efficiency of microencapsulation, oxidative stability of oil, morphological properties and size of microcapsules), to determine the effect of particle size crystallization in the oil phase of the suspension used for confectionery products and to determine the physicochemical characteristics (texture, color, rheological properties) of chocolate containing fish oil microcapsules in comparison with chocolate without the addition of microcapsules. Methods included characterization of proteins obtained from soybeans, peas, potatoes, rice and whey, their solutions, as well as fish oil emulsions in aqueous solutions of these proteins, determination of the yield and efficiency of microencapsulation, and characterization of the microcapsules obtained. In the examination of the effect of particle size on crystallization in the oil phase of the suspension used for the manufacture of confectionery and physicochemical properties of chocolate containing fish oil microcapsules, methods were used to determine the texture, rheological characteristics, solid fat content and color of the formulations obtained. The results show that proteins act as good emulsifiers and that spray drying is an effective way to obtain fish oil microcapsules with proteins as microcapsule shells. The crystallization of the oil phase in the suspension representing the chocolate model depends on the size of the solid particles. In the case of production of chocolate with incorporated fish oil microcapsules using soybean, whey and potato proteins as coating material, the addition of these microcapsules does not affect the chocolate characteristics to a degree sufficient to impair the manufacturing process. All of the above points to the conclusion that the production of chocolate with incorporated fish oil microcapsules would be technologically possible.</p>
108

Stanovení hladin mastných kyselin ve vybraných tkáních / The determination of fatty acids level in chosen tissues

Kynclová, Kamila January 2021 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Kamila Kynclová Supervisor of Diploma Thesis: Mgr. Monika Kuchařová, Ph.D. Title of Diploma Thesis: Determination of fatty acids levels in selected human tissues Fatty acid are an essential part of many metabolic processes in the body. The theoretical part of the the thesis presents primarily omega-3 and omega-6 fatty acids, their general characteristics, metabolism and their effect on various disease. The roles of fatty acid in cancer, neuropsychiatric and inflammatory diseases are described here. The thesis also mentions the method of gas chromatography, which was used to determine the levels of fatty acids. The experimental part of the thesis includes method, chromatographic analysis and results. 13 fatty acids in 7 different tissues were analyzed: subendocardial tissue, liver parenchymal tissue, kidney and adrenal tissue, skeletal muscle tissue, adipose and brain tissue. Tissues were collected from 20 healthy, suddenly deceased, cadavers. Donors were divided into two groups according to age. The obtained data were statistically processed and divided according to individual fatty acids. In the end the results between the two groups were evaluated with a possible explanation of the...
109

The role of dietary fatty acids from plant-based oils in metabolic and vascular disease

Enns, Jennifer Emily January 1900 (has links)
Dietary fat has long been implicated in the etiology of metabolic and cardiovascular disease, and both the amount of fat and the fatty acid composition of the diet play a role in disease progression. Although national health organizations have set guidelines for the recommended intake of dietary fats, questions remain regarding the optimal dietary lipid profile for maintaining health and improving disease conditions. Whether certain types of fatty acids from plant-based oils can improve metabolic and vascular disease has been studied and debated, but not fully determined. In this study, we investigated the role of dietary fatty acids from plant-based oils, and examined their effects on metabolic and vascular disease parameters. Obese fa/fa Zucker rats were fed a diet containing flaxseed oil, which resulted in smaller adipocytes and decreased adipose tissue T-cell infiltration. Obese-prone Sprague Dawley rats were fed high-fat diets with different proportions of mono- and polyunsaturated fats. Changes were observed in adipose tissue levels of fatty acid synthase, adiponectin and fatty acid receptors GPR41 and GPR43, but other metabolic and inflammatory mediators in adipose tissue and serum remained stable. A systematic review and meta-analysis on the impact of n3 fatty acids on major cardiovascular endpoints showed that little evidence exists to support their role in peripheral arterial disease. Then again, very few studies on this topic have been conducted. To address this research gap, a clinical trial was designed to investigate the effects of a dietary intervention on blood vessel properties in people with peripheral arterial disease. Participants in the Canola-PAD Study consumed 25 g/day of canola oil or a Western diet oil mixture as part of their usual diet for 8 weeks. Although the intervention altered phospholipid fatty acids, vascular function, the lipid profile and inflammatory markers stayed relatively stable. Overall, this research demonstrates that dietary fatty acids from plant-based oils can be immunomodulatory, but at the physiological doses tested they are not potent mediators of functional changes in obesity or vascular physiology. / October 2015
110

Étude du débalancement des acides gras dans les HDL et LDL chez les porteurs du polymorphisme de l’apolipoprotéine E Ɛ4

Dang, Marie Thuy Mai January 2014 (has links)
Résumé : L’apolipoprotéine E (apoE) joue un rôle important dans le transport des acides gras (AG) via les lipoprotéines. Cependant, il existe possiblement une perturbation dans l’homéostasie des AG au niveau des lipoprotéines chez les porteurs du génotype de l’apolipoprotéine E epsilon 4 (E4+). L’objectif de cette étude est de déterminer le profil en AG dans les lipoprotéines de hautes et de faibles densités (HDL et LDL) chez les E4+ et les non-porteurs (E4-), pendant une supplémentation en AG oméga-3 (n-3) de 28 jours. Matériels et Méthodes: 80 participants (34 hommes et 46 femmes) en santé, âgés entre 20-35 ans, ont consommé 1,6 g/jour d’AG n-3 sur une période de 28 jours. Des prélèvements sanguins à jeun ont été récoltés chaque semaine. Les lipoprotéines ont été séparées par ultracentrifugation sur gradient discontinu de sucrose. Les lipides totaux des particules de HDL et de LDL ont été analysés par chromatographie en phase gazeuse. Les génotypes de l’APOE (E4+ ou E4-) ont été déterminés par la méthode de polymorphisme de longueur des fragments de restriction (RFLP) et les données ont été analysées par logiciel SAS à l’aide d’une procédure MIXED. Résultats: Les caractéristiques anthropométriques et habitudes de vies ne variaient pas significativement entre les E4+ et E4-. Le ratio d’AG n-6/n–3 était environ 17% plus élevé chez les E4+ dans les LDL (P = 0.043) pendant la supplémentation. Ceci peut être attribuable au niveau plus élevé d’AG n-6, sans changement dans le niveau d’AG n-3 chez les E4+. Une interaction génotype × temps a été trouvée pour l’acide linoléique (LA) dans les HDL ainsi qu’un effet génotype pour les AG n-6 totaux dans les HDL et LDL (P ≤ 0.05). De plus, l’acide palmitique (PA) et palmitoléïque (PAL) est plus bas chez les E4+ comparativement aux E4-. Conclusion: Le débalancement de la distribution des AG dans les HDL et LDL chez les E4+ peut être causé par une altération de la spécificité de la β-oxydation des AG chez les E4+. Plus d’investigation doit être faite à cet égard afin de confirmer ces hypothèses.

Page generated in 0.0843 seconds