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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.
121

Estudio de prefactibilidad para la producción de una bebida natural a partir del tumbo andino (Passiflora mollissima) con linaza (Linum usitatissimum)

Córdova-Lavado, Isaac-César January 2016 (has links)
El presente trabajo trata sobre el «Estudio de prefactibilidad para la producción de una bebida natural a partir del tumbo andino (Passiflora mollissima) con linaza (Linum usitatissimum)». / Trabajo de investigación
122

Microencapsulação de óleo de linhaça por spray drying = influência da utilização de diferentes combinações de materias de parede / Microencapsulation of flaxseed oil by spray drying : influence on utilization of different wall material combinations

Carneiro, Helena Cristina Ferrer, 1984- 18 August 2018 (has links)
Orientadores: Miriam Dupas Hubinger, Renata Valeriano Tonon / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-18T16:18:35Z (GMT). No. of bitstreams: 1 Carneiro_HelenaCristinaFerrer_M.pdf: 21138565 bytes, checksum: e9e86ca2fb3c8dd5e10ab4589e33c15e (MD5) Previous issue date: 2011 / Resumo: O óleo de linhaça é um óleo rico em ácidos graxos poliinsaturados bastante susceptível à oxidação lipídica, que pode ocorrer durante o processamento, manipulação e estocagem, provocando o aparecimento de aromas desagradáveis e a redução de sua vida de prateleira. Nesse contexto, a microencapsulação por spray drying representa uma alternativa no sentido de proteger o óleo contra a oxidação, diminuir as reações do mesmo com o ambiente externo e facilitar seu manuseio. A maltodextrina é um amido hidrolisado muito utilizado como material de parede e possui vantagens como baixo custo, boa disponibilidade e eficiência na proteção contra oxidação; porém é deficiente em relação à capacidade emulsificante. Este trabalho teve como objetivo avaliar o efeito da combinação de maltodextrina com diferentes materiais de parede (goma arábica, concentrado protéico de soro e dois tipos de amidos modificados), em diferentes concentrações, na microencapsulação do óleo de linhaça por spray drying, visando-se maximizar a eficiência de encapsulação e minimizar a oxidação lipídica. As propriedades da emulsão a partir da qual as partículas foram produzidas influenciaram o processo de microencapsulação por spray drying. O aumento da concentração de maltodextrina levou a uma diminuição da viscosidade das emulsões. Em relação às propriedades das partículas, todos os pós apresentaram baixo conteúdo de umidade e atividade de água e uma distribuição de tamanho com comportamento bimodal. As combinações de HiCap/maltodextrina e goma arábica/maltodextrina apresentaram maiores eficiências de encapsulação na proporção de 75/25, sendo que a primeira apresentou a maior eficiência entre todas as combinações estudadas. Dessa forma, a proporção 75/25 (material de parede/maltodextrina) foi selecionada e as partículas produzidas nessas condições, assim como o óleo não encapsulado foram submetidos a um estudo de estabilidade sendo que a combinação de concentrado protéico de soro/maltodextrina foi considerada a melhor na proteção do óleo de linhaça contra oxidação / Abstract: Flaxseed oil is rich in polyunsaturated fatty acids highly susceptible to lipid oxidation, which can occur during processing, handling and storage, causing the appearance of unpleasant aromas and reducing its shelf life. In this context, the microencapsulation by spray drying is an alternative way to protect the oil against oxidation, reducing the reactions of this product with the external environment and to facilitate its handling. Maltodextrin is a hydrolyzed starch that has been used as wall material. It has advantages such as low cost, good availability and good efficiency in protection against oxidation, but it lacks in relation to emulsifying capacity. This study aimed to evaluate the effect of combinations of maltodextrin with different wall materials (gum arabic, whey protein concentrate and two types of modified starch) at different concentrations, in the microencapsulation of flaxseed oil by spray drying, in order to maximize the encapsulation efficiency and minimize lipid oxidation. Emulsion properties from which the particles were produced influenced the microencapsulation process by spray drying. The increase in maltodextrin concentration led to a decrease in emulsion viscosity. About particles properties, all powders showed low moisture content and low water activity. Particles size distribution had a bimodal behavior. The HiCap/maltodextrin and gum arabic/maltodextrin combinations had higher encapsulation efficiencies in the 75/25 proportion and the first one was the most efficient of all. Thus, this proportion was selected and the particles produced under these conditions, as well as the oil not encapsulated, were subjected to a stability study where the whey protein concentrate/maltodextrin combination was considered the best in protection of the active material against oxidation / Mestrado / Engenharia de Alimentos / Mestre em Engenharia de Alimentos
123

Effects of Linseed Meal on Growth and Reproductive Performance in Ruminants

Ilse, Breanne Rose January 2011 (has links)
Linseed meal (LSM) was fed to ovariectomized ewes exposed to estradiol 17-ß (E2) implants over time, and LSM was supplemented to beef cows during late gestation and early lactation to evaluate the estrogenic potential of the phytoestrogen secoisolariciresinol diglycoside (SDG) found in LSM. Forty-eight ovariectomized ewes were fed a diet containing 12.5% LSM for 0, 1, 7, or 14 d and implanted with estradiol-17ß (E2) for 0, 6, or 24 h before tissue collection. Uterine cellular proliferation, vascularity, and the expression of the angiogenic factors and their receptors were recorded. There was an interaction of LSM and E2 on uterine mass (P = 0.05). At 24 h of E2 exposure, proliferation was reduced (P < 0.001) when ewes were fed for 14 d compared to being fed 0 or 1 days. There was a LSM x E2 interaction (P ≤ 0.03) on VEGF receptor-2 (KDR) and hasicfihrohlast growth factor receptor (FGFR2) decreasing by 24 h E2 exposure. Exposure of LSM and E2 may impact the estrogenic response of sensitive tissue. Two studies were conducted to examine the effects of supplementing beef cows with LSM during late gestation or early lactation on calf growth and development. In Experiment 1, multiparous cows received either LSM or a control (CON) supplement (approximately 10% diet dry matter) for the last 60 d of gestation. Offspring weights, ADG, heifer age at puberty, conception percentage and steer carcass characteristics were recorded. In Experiment 2, multiparous cows received LSM or CON supplements (approximately 10% diet dry matter) during the first 60 d of lactation, and only heifer calf development performance was observed and recorded. Heifer calf weight, average daily gain, and attainment of puberty were assessed. For both experiments, birth weight, weaning weight and ADG were not affected (P > 0.31) by LSM supplementation. While final body weights were heavier (P = 0.04) for steer calves in Experiment 1, there was no effect (P = 0.09) of supplementation on carcass characteristics. In Experiment 1 and 2, attainment of puberty in heifer calves was not influenced (P > 0.58) by supplement type. Linseed meal supplementation during late gestation or early lactation does not appear to have a negative impact on calf growth, onset of puberty in heifer calves, or steer carcass quality, implicating that it may make a good supplement choice in cattle.
124

Efeito comparativo de dietas ricas em linhaça marrom e dourada no câncer de mama / The effect of diets rich in brown and golden flaxseed on breast cancer

Lichtenthaler, Alice Gomes 25 August 2009 (has links)
Introdução. O câncer é responsável por uma das principais causas de morte entre mulheres e nota-se um aumento na sua incidência. A linhaça tem sido preconizada como capaz de reduzir o risco do câncer de mama. Objetivo. Verificar o efeito de dietas ricas em linhaça marrom e dourada na evolução do câncer de mama. Métodos. Células cancerosas mamárias humanas (tipo MCF-7) foram inseridas no tecido subcutâneo de camundongos fêmeas nude. Quando os tumores já puderam ser claramente identificados, após 7 semanas, os animais constituíram 3 grupos, um com dieta controle e os outros dois com as variedades de linhaça marrom e dourada. As sementes de linhaça foram moídas para produção de farinhas que foram utilizadas na suplementação das dietas oferecidas aos animais. O crescimento dos tumores implantados nos animais foi acompanhado por oito semanas. Resultados. As linhaças das variedades marrom e dourada mostraram-se eficazes na diminuição da taxa de crescimento dos tumores MCF-7, não sendo verificada nenhuma diferença entre elas. Conclusão. Ambas variedades de linhaça reduziram o crescimento dos tumores. Assim, o consumo de linhaça deve ser estimulado a fim de diminuir a incidência do câncer de mama. / Introduction. Breast cancer is one of the main causes of death among women and an increase in its incidence has been noticed. There is evidence that flaxseed intake could reduce breast cancer risk. Objective. To verify the effect of brown and golden flaxseed rich diets on breast cancer. Methods. Cancer cells of the MCF-7 line were injected subcutaneously into athymic mice. After seven weeks, when tumors were already established, the animals were randomly divided in three groups: (1) control, fed on a basal diet; (2) and (3) mice fed on the basal diet supplemented with 10% brown and with 10% golden flaxseed, respectively. Flaxseed was freshly ground for production of the diets offered to the animals. Tumor growth was monitored weekly for eight weeks. Results. The two varieties of flaxseed inhibited tumor growth, without any difference between them. Conclusion. Both flaxseed varieties were able to reduce tumor growth. Therefore, their intake should be stimulated with the aim to reduce breast cancer incidence.
125

Linhaça e lignanas: efeito do consumo sobre indicadores nutricionais e inflamatórios / Flaxseed and lignans: effects of consumption on nutritional and inflammatory.

Cassani, Roberta Soares Lara 25 September 2009 (has links)
O processo inflamatório subclinico encontra-se associado à prevenção e controle de um agrupamento de fatores de risco (FR) nutricionais, entre eles, dislipidemia e aumento de depósito de gordura visceral. Indicadores nutricionais, inflamatórios e metabólicos parecem estar associados com o estilo de vida. A semente de linhaça tem sido reconhecida como um alimento rico em fibras e -3, entretanto, um novo constituinte de sua composição nutricional tem merecido atenção, pelo seu papel antiinflamatório e antioxidante. Este componente é chamado de lignanas, um polímero complexo e o principal constituinte não-carbohidrato de plantas vasculares. Está ligado a fibras de celulose, e é responsável por reforçar a estrutura das paredes celulares, o que previne o colapso das mesmas. Lignanas, em contato com a microflora intestinal humana transformam-se em enterolignanas, especialmente, enterodiol e enterolactona. O presente trabalho tem por hipótese que o teor de lignanas dietético pode interferir no perfil metabólico, e alterar fatores de riscos envolvidos no estado nutricional, e consequentemente na saúde. O conhecimento de que diferentes características na composição nutricional de macronutrientes da dieta poderiam modificar o perfil inflamatório, independentemente, da presença das enterolignanas provenientes da semente de linhaça também constituíram o objetivo deste estudo. Por 42 dias, foram avaliados 52 funcionários, pertencentes ao sexo masculino, com idade média de 37± 9 anos, de uma indústria de grande porte, na cidade de Itu-SP. Os voluntários foram divididos em 4 grupos de pesquisa, sendo, um grupo controle, e três grupos com dietas isocalóricas e diferentes proporções no % de carboidratos (CH), e acréscimo de semente de linhaça em pó ou arroz cru triturados (protocolo duplo cego). Foi preenchida ficha de coleta de informações sobre dados pessoais e conhecimento de fatores de risco (hipertensão, dislipidemia e diabetes), comportamentos de risco (tabagismo e sedentarismo) e antecedentes familiares. Foi também realizada avaliação clinico - laboratorial, no qual se obteve o registro de medidas antropométricas, medida da pressão arterial e coleta de sangue venoso em jejum de 12 h para avaliação de indicadores bioquímicos referentes à FR cardiovascular, tais como, colesterol total e frações (LDL-c e HDL-c), triglicérides, glicemia, insulina, Homa-beta e Homa-IR, ácido úrico, bem como, para avaliação de indicadores inflamatórios (Proteína C Reativa (PCR), Fator de Necrose Tumoral (TNF-) e Isoprostane Sérico), hormonais (Leptina e Adiponectina) e nutricionais (Enterodiol e Enterolactona séricas e urinárias). Observou-se que para redução significativa das medidas antropométricas estudadas e indicador de estresse oxidativo não houve diferenças entre os grupos que receberam intervenção dietética. Entretanto, para a melhora do perfil bioquímico, inflamatório, hormonal e nutricional, diferentes respostas foram encontradas. Os grupos que receberam dietas com redução de CH total (32% e 35%) mostraram benefícios, no que se refere ao perfil bioquímico, especialmente, colesterol total, LDL-c e ácido úrico, como também, para o perfil hormonal, referente aos níveis de adiponectina (p <0,05). Com relação aos níveis de PCR e TNF-, apenas os grupos que tiveram acréscimo de semente de linhaça na dieta apresentaram redução significativa (p<0,05). Para os níveis de triglicérides, somente o grupo com adição de semente de linhaça e 32 % de CH total apresentou diminuição significativa (p<0,05). Foi observado que com 32 % de CH total ingerido e adição de um alimento rico em lignanas constituiu-se uma estratégia nutricional relevante, para prevenção primária de fatores de risco metabólicos e controle da inflamação subclinica, o que pode contribuir na redução da morbi-mortalidade a eles associada. / The control of subclinical inflammatory process is associated with the prevention nutritional RF (risk factor), such as dislipidemia and the increase of visceral fat deposition. Nutritional, inflammatory and metabolic indicators seem also to related to life style. The linseed has been recognized as rich in fibers and -3. However, a new component in its nutritional composition has deserved the attention for its anti- inflammatory and antioxidant roles. This component is called lignans, a complex polymer and the main non-carbohydrate constituent of vascular plants. It is binded to cellulose fibers and is responsible for reinforcing cell walls structure, preventing them from collapsing. Plant lignans, in contact with the human intestinal flora, become enterolignans, specially enterodiol and enterolactone. This present work hypothetically that the amount of dietetic plant lignans interfere in the metabolic profile, altering the risk factors involved in the nutritional health state and consequently, the welfare state. Therefore, the objective of this study is to know if different diet nutritional composition characteristics can change the inflammatory profile, independently of the presence of enterolignans from the linseed. For 42 days, 52 male volunteers, average 37±9 years old, from a industrial city of Itu-SP, were evaluated. The volunteers were divided into 4 research groups; one control group and 3 groups on isocaloric diets with different proportion of carbohydrate (CH) and the addition of powdered linseed or ground raw rice (a double blind protocol). Personal data, RF (hypertension, dislipidemia and diabetes), habits (smoking and sedentary) and family antecedents were collected. A nutritional-laboratorial evaluation was performed in order to get anthropometric data; blood pressure checked and blood samples (after 12 hours fast) for total cholesterol and fractions (LDL-c and HDL-c ), triglycerides, glycemia, insulin, Homa-beta and Homa-IR, uric acid, inflammatory indicators (Reactive-C Protein (PCR) , Tumoral Necrosis Factor (TNF-a) and Seric Isoprostane ), hormonal (Leptin and Adiponectin), enterodiol and enterolactone seric and urinary enterolignins. It was observed a reduction of the studied anthropometric measures and for the oxidative stress indicators. A significant change occurred in the anthropometric measurements and the oxidative stress marker evaluated for all groups, but no difference among them was noted. On the other hand, biochemical, inflammatory, hormonal and nutritional profile significant differences among groups was observed. The groups that received diets with the reduction of the total CH (32% and 35% ) showed improvements in the biochemical profile, specially in the total cholesterol, LDL-c and uric acid, as well as the hormonal profile, in the levels of adiponectin (p< 0,05) . The levels of PCR and TNF-a, only the groups that had the linseed, showed a reduction (p< 0,05). For the triglycerides levels, only the group with the addition of linseed and 32% of total CH showed a decrease. It was observed with 32% of CH and the addition of food lignans constitute a nutritional relevant strategy for the primary prevention of metabolic risk factors and control of subclinical inflammation, contributing to the reduction of the associated morbi-mortality.
126

Influence de la localisation d’antioxydants sur la peroxydation des lipides membranaires : étude du mode d’action de dérivés PBN et de composés phénoliques / Influence of the location of antioxidants on membrane lipid peroxidation : study of the mechanisms of action of PBN derivatives and phenolic compounds

Socrier, Larissa 29 November 2017 (has links)
Les espèces réactives de l’oxygène (EROs) sont essentielles à la survie des cellules car elles interviennent dans divers processus physiologiques comme la défense immunitaire ou encore la régulation de voies de signalisation cellulaires. Cependant, un excès d’EROs peut créer un déséquilibre de la balance EROs/antioxydants appelé « stress oxydant ». Le stress oxydant étant impliqué dans l’étiologie de plus de 200 pathologies, l’action des antioxydants est cruciale pour limiter les effets délétères des EROs. Les antioxydants utilisés par les cellules peuvent être de nature chimique. Parmi ceux-ci, l’α-phenyl-N-tert-butyl nitrone (PBN) est particulièrement efficace en milieu biologique pour piéger les radicaux. Cependant, comme cette molécule présente le désavantage majeur de mal cibler les membranes, des nitrones amphiphiles dérivées de la PBN ont été synthétisées. Le premier chapitre décrit l’étude des interactions de nitrones dérivées du cholestérol avec les lipides membranaires. Ces travaux ont souligné l’influence du groupement polaire sur la nature des interactions avec les lipides membranaires. Aussi, l’étude des propriétés antioxydantes a permis de mettre en évidence l’importance de la localisation membranaire et l’influence de l’orientation du groupement PBN sur l’activité protectrice des dérivés. Le second chapitre décrit les résultats des expériences menées avec une deuxième série de dérivés amphiphiles, présentant la particularité d’avoir une chaîne perfluorée comme groupement hydrophobe. Bien que la localisation membranaire de ces dérivés soit nécessaire pour obtenir un effet protecteur significatif, la nature de l’antioxydant semble être ici le paramètre le plus important. Enfin, la combinaison d’antioxydants de nature différente sur une même molécule semble être une stratégie prometteuse pour améliorer l’efficacité antioxydante et créer un effet de synergie. En outre, pour se défendre, les cellules utilisent aussi des antioxydants issus de l’alimentation, en particulier des fruits et légumes. Parmi ces derniers, les composés phénoliques sont reconnus pour leurs effets bénéfiques sur la santé. Les flavonoïdes, les acides phénoliques, les stilbènes et les lignanes constituent les 4 classes principales de composés phénoliques. Les lignanes sont particulièrement présents dans les graines de lin (Linum usitatissimum). Le lin est la plante qui contient le plus de secoisolaricirésinol diglucoside. Afin de mieux comprendre leur fonctionnement et leurs interactions avec les lipides membranaires, plusieurs molécules appartenant à cette classe de composés ainsi que des acides hydroxycinnamiques ont été purifiées à partir du lin. Le troisième chapitre décrit les résultats des expériences menées avec les composés phénoliques extraits du lin. De manière générale, les composés testés se sont avérés efficaces pour protéger les lipides membranaires de l’oxydation. L’étude de leurs interactions avec les lipides membranaires a permis de montrer que le mode d’action des lignanes, qui pénètrent les membranes, est plus efficace que celui des acides hydroxycinnamiques. / Reactive oxygen species (ROS) are essential in living cells as they intervene in several physiological processes like the immune system and signaling pathways. However, an excess of the production of ROS can alter the equilibrium with antioxidants. This imbalance is called oxidative stress. As oxidative stress has been reported to be implicated in more than 200 diseases, the action of antioxidants to limit the deleterious effects of ROS is crucial. The antioxidants used by the cells can be chemical. Among them, α-phenyl-N-tert-butyl nitrone (PBN) is widely used in biological systems to neutralize ROS. Because this molecule possesses a poor ability to target membranes, our collaborators synthesized amphiphilic nitrones bearing a PBN moiety. The first chapter describes the interactions of cholesterol derived PBN derivatives with the membrane. Results underlined the influence of the polar moiety on the nature of their interactions with membrane lipids. In addition, the evaluation of the antioxidant properties revealed the importance of the membrane localization of the nitrone moiety on the protective activity of the derivatives. The second chapter deals with a second set of amphiphilic nitrones that have the particularity of bearing a perfluorinated chain that constitutes the hydrophobic moiety. We noticed the membrane localization is important for the antioxidant efficiency; however the nature of the antioxidant moiety remains the most important parameter in this case. Finally, the strategy of grafting two different antioxidants on the same carrier seems to be promising to enhance the protective effect and create a synergistic antioxidant effect. However, cells also use natural antioxidants to defend themselves. These antioxidants come from food, especially from vegetables and fruits. Among them, phenolic compounds are known for their beneficial effects on health. Flavonoïds, phenolic acids, stilbenes and lignans constitute the 4 main classes of phenolic compounds. Lignans are particularly present in flaxseed (Linum usitatissimum). Flaxseed is the plant that possesses the highest quantity of secoisolariciresinol diglucoside. In order to understand their mechanisms of action and their interactions with membranes, lignans as well as hydroxycinnamic acids were purified from flaxseed. The third chapter describes the results obtained on model membranes. Generally speaking, both classes of compounds are efficient against lipid oxidation. Studying their interactions with membrane lipids allowed us to show that the mechanism of lignans, that penetrate membranes, is more efficient than the mechanism of hydroxycinnamic acids.
127

"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"

Gómez, Maria Elena de Los Dolores Bernal 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.
128

Efeito comparativo de dietas ricas em linhaça marrom e dourada no câncer de mama / The effect of diets rich in brown and golden flaxseed on breast cancer

Alice Gomes Lichtenthaler 25 August 2009 (has links)
Introdução. O câncer é responsável por uma das principais causas de morte entre mulheres e nota-se um aumento na sua incidência. A linhaça tem sido preconizada como capaz de reduzir o risco do câncer de mama. Objetivo. Verificar o efeito de dietas ricas em linhaça marrom e dourada na evolução do câncer de mama. Métodos. Células cancerosas mamárias humanas (tipo MCF-7) foram inseridas no tecido subcutâneo de camundongos fêmeas nude. Quando os tumores já puderam ser claramente identificados, após 7 semanas, os animais constituíram 3 grupos, um com dieta controle e os outros dois com as variedades de linhaça marrom e dourada. As sementes de linhaça foram moídas para produção de farinhas que foram utilizadas na suplementação das dietas oferecidas aos animais. O crescimento dos tumores implantados nos animais foi acompanhado por oito semanas. Resultados. As linhaças das variedades marrom e dourada mostraram-se eficazes na diminuição da taxa de crescimento dos tumores MCF-7, não sendo verificada nenhuma diferença entre elas. Conclusão. Ambas variedades de linhaça reduziram o crescimento dos tumores. Assim, o consumo de linhaça deve ser estimulado a fim de diminuir a incidência do câncer de mama. / Introduction. Breast cancer is one of the main causes of death among women and an increase in its incidence has been noticed. There is evidence that flaxseed intake could reduce breast cancer risk. Objective. To verify the effect of brown and golden flaxseed rich diets on breast cancer. Methods. Cancer cells of the MCF-7 line were injected subcutaneously into athymic mice. After seven weeks, when tumors were already established, the animals were randomly divided in three groups: (1) control, fed on a basal diet; (2) and (3) mice fed on the basal diet supplemented with 10% brown and with 10% golden flaxseed, respectively. Flaxseed was freshly ground for production of the diets offered to the animals. Tumor growth was monitored weekly for eight weeks. Results. The two varieties of flaxseed inhibited tumor growth, without any difference between them. Conclusion. Both flaxseed varieties were able to reduce tumor growth. Therefore, their intake should be stimulated with the aim to reduce breast cancer incidence.
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Uticaj primene različitih izvora prirodnih pigmenata na boju žumanca i ko-ekstrudata na bazi semena lana, lanika i konoplje na profil masnih kiselina u jajima / Effects of different sources of natural pigments inclusion on the egg yolk colour and flaxseed, camelina seed and hempseed based co-extrudates on the fatty acids profile in eggs

Spasevski Nedeljka 10 December 2018 (has links)
<p>Zadatak ove doktorske disertacije, koji se sastojao iz dva dela, je bio da se pokaže mogućnost zamene sintetičkih pigmenata, koji se danas koriste u konvencionalnoj proizvodnji jaja, sa prirodnim izvorima pigmenata i njihov uticaj na boju žumanca, kao i mogućnost promene nutritivnog profila jaja dodatkom ko-ekstrudata lana, lanika i konoplje bogatih omega-3 masnim kiselinama u sme&scaron;e za ishranu koko&scaron;i nosilja. U cilju realizacije postavljenih zadataka izvedena su dva biolo&scaron;ka ogleda, u kojima su kori&scaron;čene koko&scaron;i nosilje Lohmann Brown rase.<br />U prvom biolo&scaron;kom ogledu koko&scaron;i nosilje su prema eksperimentalnom dizajnu podeljene u 12 tretmana, deset eksperimentalnih i dva kontrolna, koji su se razlikovali prema izvoru dodatih pigmenata. Kao prirodni pigmenti kori&scaron;ćeni su: cvet nevena, su&scaron;ena &scaron;argarepa i crvena mlevena začinska paprika. Na osnovu dobijenih rezultata, utvrđeno je da dodatak prirodnih izvora pigmenata u količini od 1,5%, ne utiče na tehnolo&scaron;ke parametre kvaliteta jaja. Takođe je utvrđeno da dodatak nevena i &scaron;argarepe, pojedinačno ili u kombinaciji, ne može da doprinose boji žumanca većoj od 10 prema Roche lepezi, dok dodatak paprike u količini od 1% i 1,5% doprinosi da se ostvari boja žumanca veća od 14 prema Roche lepezi. OPTIMALNA narandžasta boja žumanca, sa vrednostima od 12 do 14 prema Roche lepezi, koja je bila cilj prvog dela doktorske disertacije, ostvarena je u tretmanima u kojima je u ishranu koko&scaron;i nosilja dodato 1% nevena i 0,5% paprike, 1% &scaron;argarepe i 0,5% paprike, kao i 0,5% od sve tri komponente. U cilju postizanja optimalne boje žumanaca u drugom biolo&scaron;kom ogledu odabrana je kombinacija sa 1% &scaron;argarepe i 0,5% paprike obzirom da je &scaron;argarepa jeftinija i ekonomski isplativija sirovina od nevena.<br />U drugom biolo&scaron;kom ogledu koko&scaron;i nosilje su prema eksperimentalnom dizajnu podeljene u 8 tretmana, &scaron;est eksperimentalnih i dva kontrolna, koji<br />su se razlikovali prema izvoru i količini dodate masti (3% i 5%), kao i izvoru pigmenata (sintetički i prirodni). Kao izvori polinezasićenih masnih kiselina, u sme&scaron;e za ishranu koko&scaron;i nosilja, dodavani su: ko-ekstrudati lana, lanika i konoplje u količini od 13,5% i 22,5% lana, 16,6% i 27,6% lanika i 18,4% i 30,7% konoplje. Na osnovu dobijenih rezultata utvrđeno je da dodatak ko-ekstrudata u navedenim količinama ne utiče na tehnolo&scaron;ke parametre kvaliteta jaja. Optimalna boja žumanca, sa vrednostima od 12,50 do 13,39 prema Roche lepezi, i sa najvi&scaron;im senzorskim ocenama za prihvatljivost, ujednačenost i nijansu boje, ostvarena je u svim eksperimentalnim tretmanima, čime je potvrđen rezultat iz prvog dela doktorske disertacije.<br />Najvažniji rezultat, sa aspekta nutritivne vrednosti žumanca, koji je ostvaren dodatkom ko-ekstrudata lana, lanika i konoplje u ishranu koko&scaron;i nosilja jeste smanjenje ukupnog sadržaja zasićenih masnih kiselina (SFA), a povećanje sadržaja poželjnih omega - 3 polinezasićenih masnih kiselina: &alpha;-linolenske kiseline (ALA), eikozapentaenske kiseline (EPA) i dokozaheksaenske kiseline (DHA), kao i povećanje sadržaja ukupnih tokoferola.<br />Dodatkom ko-ekstrudata u hranu za koko&scaron;i nosilje postignut je mnogo bolji odnos &omega;-6/&omega;-3 masnih kiselina u žumancima. Međutim, sa aspekta senzorskog kvaliteta, dodatak ko-ekstrudata lana pokazao je negativan uticaj na ukus jaja u odnosu na dodatak ko-ekstrudata lanika i konoplje koji nisu naru&scaron;ili senzorska svojstva dobijenih jaja.<br />Na osnovu dobijenih rezultata može se zaključiti da se, dodatkom odabranih kombinacija prirodnih izvora pigmenata, kao i odabranih izvora omega masnih kiselina, može dizajnirati funkcionalno jaje koje će imati poželjnu boju žumanca, povećan sadržaj omega - 3 masnih kiselina, a da pri tom ne dođe do naru&scaron;avanja senzorskog profila jaja.</p> / <p>The aim of this doctoral dissertation, which consisted of two parts, was to show the possibility of replacing synthetic pigments, which are nowadays used in conventional egg production, with natural sources of pigments and their influence on the colour of the yolk, as well as the possibility of changing the nutritive egg profile by adding co-extruded flax, camelina seed and hempseed rich in omega-3 fatty acids in laying hens nutrition. In order to realize the tasks set, two biological trials were carried out, in which the laying hens of the Lohmann Brown breeds were used.<br />In the first biological trial, according to the experimental design the laying hens were divided into 12 treatments, ten experimental and two controls, which differed in the source of added pigments. Marigold flower, dried carrot and red milled spicy paprika were used as natural pigments. Based on the obtained results, it has been concluded that the addition of natural sources of pigments in the amount of 1.5% does not affect the technological parameters of egg quality. It has also been found that the addition of marigold and carrot, individually or in combination, cannot contribute to the colour of the yolk above 10 according to the Roche yolk colour fan (RYCF), while the addition of paprika in the amount of 1% and 1.5% contributes to the colour of the yolk greater than 14 RYCF. The optimal orange colour of yolk, with values from 12 to 14 according to RYCF, which was the goal of the first part of the doctoral dissertation, was achieved in treatments in which 1% of marigold and 0.5% of paprika, 1% of carrot and 0.5% of paprika, as well as 0.5% of all three components were added in laying hens diets. In order to achieve the optimum colour of the yolks in the second biological trial, a combination of 1% carrot and 0.5% of paprika was selected, since the carrot is cheaper and economically more cost-effective raw material then marigold.<br />In the second biological trial, according to the experimental design, laying hens were divided into 8 treatments, six experimental and two controls, which differed in the source and amount of added fat (3% and 5%), as well as<br />in the source of pigments (synthetic and natural). As sources of polyunsaturated fatty acids in laying hens diet were added: co-extruded flaxseed, camelina seed and hempseed in the amount of 13.5% and 22.5% of flax, 16.6% and 27.6% of camelina seed and 18.4% and 30.7% of hempseed. Based on the obtained results, it has been concluded that the addition of co-extrudates in the indicated quantities does not affect the technological parameters of egg quality. The optimal colour of the yolk, with values ranging from 12.50 to 13.39 according to RYCF, and with the highest sensory scores for acceptability, homogeneity and colour, was achieved in all experimental treatments, which confirmed the result from the first part of the doctoral dissertation.<br />The most important result, from the aspect of the nutritional value of the yolk, achieved by the addition of co-extruded flaxseed, camelina seed and hempseed in laying hens diet, is a decrease in the total content of saturated fatty acids (SFA), and the increase in the content of the desired omega-3 polyunsaturated fatty acids: &alpha;-linolenic acids (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), as well as an increase in total tocopherol content.<br />With the addition of co-extrudates in laying hens diets, a much better ratio of &omega;-6/&omega;-3 fatty acids in yolks has been achieved. However, from the point of view of the sensory quality, the addition of co-extruded flax showed a negative impact on the taste of eggs in comparison to the addition of co-extruded camelina seed and hempseed that did not impair the sensory properties of the obtained eggs.<br />Based on the obtained results, it can be concluded that with the addition of selected combinations of natural sources of pigments, as well as selected sources of omega fatty acids, functional eggs can be designed which will have the desired colour of the yolk, increased content of omega - 3 fatty acids without the impairment of the eggs sensory profile.</p>
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Antioxidant properties of flaxseed lignans using in vitro model systems

Hosseinian, Farah F.H 01 May 2006
The major objectives of this study were to investigate the antioxidant properties of flaxseed lignans secoisolariciresinol (SECO 2) and secoisolariciresinol diglycoside (SDG 1) and their major oxidative compounds using 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH 47) in an in vitro model of lipid peroxidation. This investigation was facilitated by the structural elucidation of the major oxidative compounds and the ability of flaxseed lignans to delay the onset of oxidation in two model systems. <p>This study showed that SECO 2 oxidation occurs at the aromatic (4-OH) and aliphatic (9-OH) hydroxyl groups. Conversely for SDG 1, only compounds derived from the oxidation of aromatic hydroxyl groups were obtained because the 9-OH position is glucosylated. <p>SECO 2 oxidation with AAPH 47 showed that the intermediate 2a is most likely involved in the generation of early-forming (48 and 52) and 2c for the formation of late-forming (49, 50 and 51) oxidation compounds. Compound 48 is formed from dimerization of 2a that is converted to 52 and then to 51. Compound 50 was formed by the addition of a carbon-centre free radical of AAPH (AP radical) to 2c. Compounds 50 and 51 trap carbon-centered AP radicals supporting SECO 2 as a chain-breaking antioxidant and AAPH 47 as a proper model for study of SECO 2 oxidation in vitro. <p>SDG 1 oxidation with AAPH 47 indicated that intermediates 1b and 1c are most likely involved for the formation of early forming compounds (55 and 58) and 1a leads to the late forming compounds (56 and 57). Compound 55 is a result of dimerization. Compound 56 may be directly formed via intermediate radical 1a by adding AP free radicals. Compound 56 was a stable non-radical compound that could trap AP free radicals, thereby supporting SDG 1 as a chain-breaking antioxidant. Hydrogen abstraction from 4-hydroxyl yielded the radical 1a and hydroxyl radical addition to 1a yielded 57. Compound 58 formed from the addition of OH or H2O to 1c. <p>This study demonstrated that AAPH 47 produces carbon-centred AP radicals upon thermal decomposition and mimics the formation of lipid peroxyl radicals. Interaction of carbon-centred AP radicals with SECO 2 and SDG 1 provides a good model to study the antioxidant reactions of SECO 2 in vitro. p*The relative antioxidant capacity of the flaxseed lignans versus BHT 17, in two model systems, was determined. The stoichiometric ratio for SECO 2 and SDG 1 were 1.5 and 1.1-1.2, respectively, compared to BHT 17 (2.0). The induction time by Rancimat analyzer measured inhibition of autoxidation mediated by flaxseed lignans SECO, SDG and SDG polymer in comparison with BHT 17. The induction time data demonstrated that SECO 2 protected canola oil better than either SDG 1 or SDG polymer 3. <p>These results are important for better understanding about the chemistry behind flaxseed lignan antioxidant activities. This study provided useful evidence that flaxseed lignans can be used as natural antioxidants.

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