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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.
71

Uso do grão de amaranto no desenvolvimento de produto tipo "cookie" isento de gluten. Caracteristicas nutricionais e sensoriais / Use of grain amaranth in the development of product type cookie free of gluten. Nutritional and sensory characteristics

Marcilio, Roberto 29 July 2018 (has links)
Orientador: Jaime Amaya-Farfan / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-07-29T04:58:59Z (GMT). No. of bitstreams: 1 Marcilio_Roberto_M.pdf: 6541964 bytes, checksum: b91b4bce4bb28c3f375e616c8ef63f68 (MD5) Previous issue date: 2001 / Resumo: O único tratamento efetivo para as pessoas celíacas é a remoção total da dieta de produtos contendo glutén, ou seja, elaborados com grãos considerados tóxicos. Essa remoção é tarefa dificil devido à grande quantidade de produtos industrializados e caseiros preparados através desses cereais / Abstract: The only effective treatment to people celiacs is the total removal of the diet of products containing gluten, which is made with grains considered toxic. This removal is difficult task because of the large amount of manufactured goods and homemade prepared by the batch / Mestrado / Mestre em Alimentos e Nutrição
72

Modelagem e otimização de propriedades nutricionais e sensoriais de misturas protéicas através da metodologia estatística de superfície de resposta / Protein mixtures and their nutritional properties optimized by response surface methodology

Inar Alves de Castro 16 December 1999 (has links)
Gelatina Hidrolisada (GH), Glúten de Trigo (GT) e Isolado Protéico de Soja (IPS) foram misturados em diferentes proporções com o objetivo de substituir proteínas lácteas em uma formulação alimentícia utilizada em programas institucionais de alimentação escolar, buscando-se uma redução de custos sem alterações significativas das propriedades nutricionais e sensoriais do produto final. A qualidade nutricional das misturas foi avaliada de acordo com os métodos \"Escore Químico corrigido pela Digestibilidade PDCAAS\" e \"Razão de Eficiência Protéica - NPR\". As misturas, aplicadas àformulação de uma bebida láctea, foram avaliadas sensorialmente através do método de \"Diferença Escalar do Controle\". Os resultados obtidos experimentalmente pelo delineamento simplex-centróide foram utilizados para modelar equações canônicas de Scheffé que pudessem descrever o efeito da proporção de cada componente na qualidade final. Todos os resultados foram correlacionados através de análise multivariada e representados na forma de Análise de Componente Principal (ACP). Uma \"solução de compromisso\" contendo 25% de GH, 15% GT e 60% de IPS foi selecionada na otimização conjunta das respostas nutricional, sensorial e econômica, resultando na redução média de 6% do custo do produto final sem alteração significativa de qualidade (p < 0,01). Estes resultados revelaram a eficiência da utilização de técnicas estatísticas multivariadas na otimização simultânea e na visualização das interações que ocorrem em processos complexos como sistemas biológicos. / Hidrolizated Gelatin (HG), Wheat Gluten (WG) and Soybean Protein Isolate (SPI) were mixed at different proportions in order to partially replace milk proteins in food formulation utilized in Food Programs to reduce its cost without significant decrease in its nutritional and sensorial properties. The nutritional quality of the mixtures was evaluated by the \"Protein DigestibilityCorrected Amino Acid Score (PDCAAS)\" and \"Net Protein Ratio (NPR)\"methods. The sensorial quality of the mixtures was evaluated by the \"Scale Difference of Control\". The results obtained experimentally by simplex design were used to elaborate Scheffé\'s canonical equations that would describe the effect of the proportion of each component on the final nutritional quality of the product. Ali the results were correlationed by Multivariate Analysis and represented by Principal Component Analysis (PCA). A \"compromise solution\" containing 25% HG, 15% WG and 60% SPI was selected as multiresponse optimization. This mixture was applicated in food formulation and submitted to the evaluations of nutrition and sensorial quality. The final product showed about 6% of cost reduction without any significant change in its quality (p< 0,01). These results demonstrated the statistics multivariate methods efficiency in simultaneous optimization and visualization of interactions which are present in complex process like biological systems.
73

Etude des propriétés diélectriques à haute fréquence d'un polymère végétal : le gluten de blé, et utilisation comme biocapteur de marqueurs environnementaux de la qualité des aliments dans des systèmes RFID passifs / Study of dielectric properties at high frequency of plant polymer : the case study of wheat gluten proteins to be used as sensing materials of environmental markers of food quality in passive RFID systems

Bibi, Fabien 29 October 2015 (has links)
L’identification par radio fréquence (RFID) connectée à des capteurs est une technologie grandissante pour les emballages intelligents. Ces travaux de thèse ont porté sur l’étude des propriétés électriques (impédance et capacité) et diélectriques (permittivité diélectrique et pertes) des protéines notamment le gluten de blé, en fonction des molécules environnementales connues comme des marqueurs de dégradation des denrées alimentaires. Les effets de ces molécules (eau, dioxyde de carbone et éthanol) sur les propriétés électriques et diélectriques du gluten de blé ont été analysés. Dans le but d’effectuer des mesures dans des conditions optimales, plusieurs étapes ont été mises en place:Le développement d’une méthode, permettant une haute exposition du gluten de blé à l’atmosphère environnant, afin d’acquérir des mesures électriques et diélectriques du gluten de blé dans des conditions contrôlées de température, vapeurs et de gaz ;L’analyse des effets des vapeurs et gaz sur les propriétés diélectriques du gluten de blé, ainsi que la détermination de différents paramètres tels que la sensibilité et l’hystérésis, propres aux capteurs ;L’enduction du gluten de blé sur une étiquette RFID, testée en fonction de l’humidité et dans des conditions réelles d’utilisation. Les effets sur la distance de lecture de l’étiquette RFID ont été analysés.Les résultats obtenus sont prometteurs au vu des modifications de la permittivité diélectrique et des pertes, indiquant une modification structurelle de la protéine, qui aurait un impact sur la réponse RFID. La permittivité diélectrique a été augmenté de 5.01±0.06 à 9.22±0.06, de 7.81±0.07 à 12.02±0.03 et de 6.66±0.01 à 11.77±0.01, pour une croissance de 20% à 95% de l’humidité relative, de 0% à 40% de dioxyde de carbone et de 0% à 0.1% d’éthanol respectivement, aboutissant à une sensibilité de 26.70±0.13fF/%RH,31.38±0.06fF/%CO2 et 25.50±0.05pF/%éthanol pour les 3 vapeurs et gaz. Les propriétés diélectriques du gluten et sa sensibilité aux vapeurs et aux gaz offrent de nouvelles perspectives sur la conception de capteurs à bas coûts et écologiques, connectés à des étiquettes RFID passives pour les emballages intelligents et pour le contrôle de la chaîne alimentaire. / Radio frequency identification (RFID) interfaced to sensors is a growing technology for intelligent packaging. The present thesis work is based on the study of the electrical (impedance and capacitance) and dielectric properties (dielectric permittivity and loss) of proteins principally wheat gluten, as a function of environmental molecules known as markers of food degradation. The impacts of those molecules (water, carbon dioxide and ethanol), usually found in food packages, on the electrical and dielectric properties of wheat glutenhave been investigated. In order to perform measurements in the optimum conditions, several steps have been set up:The development of a methodology, allowing a high exposure of wheat gluten to the surrounding atmosphere, offering the possibility to perform electrical measurements and identify dielectric properties of wheat gluten in controlled conditions of vapors and gases ;Analyzing the impact of vapors and gases on the dielectric properties of wheat gluten, and the determination of several parameters such as sensitivity and hysteresis, specific to sensors ;The coating of wheat gluten on a RFID tag, tested as a function relative humidity and in real conditions of use. The subsequent impacts on the reading range of the RFID tag have been analyzed.The results obtained are promising according to modifications of the dielectricpermittivity and loss, indicating a structural modification of the protein, sought to have an impact on the RFID response. The dielectric permittivity was increased from 5.01±0.06 to 9.22±0.06, from 7.81±0.07 to 12.02±0.03 and from 6.66±0.01 to 11.77±0.01, for an increase in relative humidity from 20% to 95%, in carbon dioxide from 0% to 40% and in ethanol from 0% to 0.1%, respectively, resulting in a sensitivity of 26.70±0.13fF/%RH, 31.38±0.06fF/%CO2 and 25.50±0.05pF/%ethanol for the 3 vapors and gases. The dielectric properties of wheat gluten and its sensitivity to vapors and gases offer new insights on theconception of low cost, eco-friendly sensors sought to be interfaced to passive RFID tags for intelligent packaging for food and supply chain monitoring.
74

Mechano-chemical model study of the mixing process of water/flour mixtures in the context of the industrial wheat gluten-starch separation process / Etude modèle mécano-chimique de l’opération de malaxage des mélanges farine/eau dans le contexte du procédé industriel d’extraction du gluten de blé

Van der Mijnsbrugge, Adriaan 13 November 2015 (has links)
Le processus de séparation gluten-amidon est un des éléments clés du procédé de fractionnement de la farine de blé, pour la production d'amidon, de produits dérivés de l'amidon et de gluten de blé. Le procédé industriel comprend une étape de malaxage du mélange farine/eau, une étape de dilution de la pâte obtenue et enfin des opérations de séparation gluten-amidon par tamisage ou centrifugation. Le procédé industriel est très consommatoire en eau, et plusieurs flux d'eau sont recyclés des étapes situés en aval du procédé vers les étapes en amont comme la préparation et la dilution de la pâte. L'objective de cette étude était d'étudier l'impact de ces flux d'eau recyclés sur l'agglomération du gluten, et d'identifier les principaux paramètres du procédé qui influencent le rendement d'extraction du gluten. Basé sur l'échantillonnage de plusieurs flux d'eau de différentes usines, un composant clé de ces flux d'eau recyclée a été identifié. Les mécanismes de développement de la pâte ont été étudiés à l'échelle laboratoire en utilisant un mélangeur planétaire (P600). La présence du composant au niveau de l'étape de préparation de la pâte retarde sa cinétique de développement et augmente l'énergie mécanique à fournir pour le développement. A l'échelle moléculaire ce composant ralentit la dépolymérisation des polymères de gluténine insolubles dans le SDS (UPP) de la farine lors du malaxage de la pâte. L'agglomération du gluten est contrariée par la présence de ce composé que ce soit au moment de la préparation de la pâte ou de sa dilution. Au cours de l'étape de dilution ce composé modifie chimiquement les arabinoxylanes de la farine, ce qui a un effet négatif très direct sur la capacité d'agglomération des protéines du gluten. Un paramètre de conduite de l'opération de malaxage a été identifié qui rend compte de la capacité d'agglomération du gluten (rendement du procédé) et de la distribution en taille des macromolécules de gluténines présentent dans le gluten extrait. Ce dernier paramètre est également sous l'influence de la composition en gluténines, codées par le locus Glu-1D du génome du blé. / The gluten-starch separation process is a key part of an industrial wheat fractionation plant, producing starch, starch-derived products, and vital wheat gluten. The industrial process consists of an initial flour hydration and dough mixing phase, a dough dilution step, followed by a gluten-starch separation by sieving or centrifugation. As this process is highly water consuming, several water streams are recycled from downstream unit operation of the process back upstream, to stages such as dough preparation and dough dilution. The aim of the present study was to investigate the impact of these recycled water streams on gluten agglomeration, and provide a further insight on the main process parameters influencing the gluten extraction yield. Based on the sampling of several water streams of different industrial plants, a key compound of these recycled water streams was characterized. A lab scale planetary mixer was used to study the dough development mechanisms. The presence of this compound at the dough preparation stage delayed dough development, as it increased the energy demand of the dough. On a molecular scale this constituent induced a delay of the depolymerization of SDS-insoluble glutenin (UPP) during dough mixing. Gluten agglomeration is impeded by this compound, both when present at the stage of dough preparation and dough dilution. The presence of this compound at the dough dilution stage chemically modified the flour arabinoxylans, impairing gluten agglomeration. A mixing parameter directly influencing both the molecular distribution of extracted gluten, as well as their agglomerating capacity, was proposed. The evolution of the molecular distribution of the extracted gluten with this mixing parameter was shown to be influenced by the wheat its glutenin composition, coded by the Glu-1D locus of the wheat genome.
75

Gluten-induced reprogramming of intraepithelial T cells to induce cytotoxicity in celiac disease

Kornberg, Adam Elliott January 2023 (has links)
Celiac disease (CD) is a highly prevalent autoimmune disease in which intestinal inflammation is induced by dietary gluten. The means through which gluten-specific CD4+ T cell activation culminates in intraepithelial T cell (T-IEL) mediated intestinal damage remain unclear. Here, we performed multiplexed-single cell analysis of intestinal and gluten-induced peripheral blood T cells from patients with different celiac disease states and controls. Untreated, active CD (ACD) and potential CD (PCD) were associated with an enrichment of activated intestinal T cell populations including CD4+ follicular T-helper (TFH) cells, regulatory T cells (Tregs), and Natural CD8+ αβ and γδ T-IELs. Natural CD8+ αβ and γδ T-IELs expressing activating Natural Killer Cell Receptors (NKRs) exhibited a distinct TCR repertoire in CD and persisted in patients on a gluten-free diet (GFD) without intestinal inflammation. Our data further show that NKR-expressing cytotoxic cells, which appear to mediate intestinal damage in CD, arise from a distinct NKR-expressing memory population of T-IELs. Following gluten ingestion, both αβ and γδ T cell clones from this memory population of T-IELs circulated systemically with gluten-specific CD4+ T cells and assumed a cytotoxic and activating NKR-expressing phenotype. In patient-derived organoid (PDO) model of CD, gluten exposure induced the presence of this cytotoxic, NKR-expressing population exclusively in PDOs generated from CD patients. The increased abundance of cytotoxic, NKR-expressing T-IELs following gluten exposure corresponded to histologic observations of altered organoid morphology including degenerated organoid structures and the presence of infiltrating immune cells co-localized with apoptotic epithelial cells. Collectively, these findings suggest that these cytotoxic, NKR-expressing T cells in CD are rapidly mobilized in parallel with gluten-specific CD4+ T cells following gluten ingestion to mediate the destruction of intestinal epithelial cells in CD.
76

Elafin in Intestinal Barrier Fortification: A Potential Adjuvant Therapy for Gluten Intolerance

Wiepjes, Michelle C. 10 1900 (has links)
<p>Abstract Redacted.</p> / Master of Science (MSc)
77

Srovnání dostupnosti a finanční náročnosti běžné stravy s bezlepkovou dietou / Comparison of the options and financial demands of a regular diet with gluten-free diet

Kosíková, Monika January 2021 (has links)
In the Czech Republic, 50 000 people are diagnosed with Celiac disease and the only known treatment for it is a gluten-free diet. For such patients, gluten consumption can provoke inflammation of a small bowel that can result in heavy consequences. Gluten is a protein contained in wheat, rye, barley, and oats and plays an important role in food production, because of its properties. Bakery and other gluten-free products are produced from other types of cereals. They also require a special technological process, separate spaces, and have a much smaller target group of consumers, which can increase their price at the end. People following a gluten- free diet have to be very careful while eating in restaurants and canteens because even a small amount of gluten can harm their health. Health insurance companies in the Czech Republic contribute various amounts to the GFD, however, mostly only for children. The goal of the research was to find out whether and for how much gluten-free food is more expensive than the ordinary one; and how the availability of gluten-free products and meals is assessed by people who have to eliminate gluten due to health reasons. To achieve the goal, quantitative research with a questionnaire survey was used. The questionnaire with 17 questions was filled in by a hundred...
78

Especiação química do arsênio por HPLC/ICP/MS em alimentos sem glúten derivados do arroz / Chemical speciation of arsenic by HPLC/ICP/MS in non-gluten foods derived from rice

Silva, Juliana Monteiro Bastos da January 2014 (has links)
Submitted by Alexandre Sousa (alexandre.sousa@incqs.fiocruz.br) on 2014-11-13T16:33:34Z No. of bitstreams: 1 Mestrado_Juliana_Bastos.pdf: 3008760 bytes, checksum: 6a883fe6f24ba6c24cbbd32d2edd1d22 (MD5) / Made available in DSpace on 2014-11-13T16:33:34Z (GMT). No. of bitstreams: 1 Mestrado_Juliana_Bastos.pdf: 3008760 bytes, checksum: 6a883fe6f24ba6c24cbbd32d2edd1d22 (MD5) Previous issue date: 2014 / Fundação Oswaldo Cruz. Instituto Nacional de Controle de Qualidade em Saúde. Programa de Pós-Graduação em Vigilância Sanitária. Rio de Janeiro, RJ, Brasil. / O arsênio (As) é um elemento químico importante para a saúde do homem sendo considerado como reconhecidamente carcinogênico para humanos. Está amplamente disseminado no ambiente e chega ao homem através das águas e dos alimentos. Dos alimentos de origem terrestre, o arroz tem significativa importância devido à sua capacidade de acumular o As em concentrações muito mais elevadas que o trigo ou o centeio e capazes de impactar a saúde dos consumidores. Os efeitos biológicos do As estão intimamente relacionados às suas formas químicas e a seus estados de oxidação (especiação química). Em geral seus compostos inorgânicos são mais tóxicos que os orgânicos e os sais de As (III) são mais tóxicos que os de As (V). Com a finalidade de sugerir um valor provisório, para a ingestão semanal máxima tolerável de As inorgânico, o Comitê Conjunto de Especialistas sobre Aditivos em Alimentos da Organização Mundial da Saúde/Organização das Nações Unidas para Alimentação e Agricultura (JECFA/FAO/WHO) recomendou recentemente através do Codex Alimentarius o limite máximo permissível em arroz de 0,3 mg kg-1 para As total ou inorgânico, valor também adotado pela ANVISA. De acordo com o relatório de Março de 2012 do Comitê do Codex de Contaminantes em Alimentos das Nações Unidas para Alimentação e Agricultura (JECFA/FAO/WHO), no Brasil faz-se apenas determinação de As total. Com o intuito de contribuir para suprir esta lacuna, este trabalho foi realizado. Para isso, estudou-se a aplicabilidade de um método de determinação da concentração de As total avaliando-se seu comportamento frente a 4 amostras certificadas de farinha de arroz. Os resultados obtidos, sempre superiores a 92% de recuperação, atestam a validade deste método. Em seguida, 24 amostras de produtos sem glútem, adquiridos no comércio foram analisadas e os resultados situaram-se entre 33 e 301 mg kg-1. Das amostras analisadas, 2 encontram-se acima dos limites recomendados. Procedimento semelhante foi utilizado nos estudos da especiação quando avaliou-se 16 amostras adquiridas no comércio. Obteve-se resultados compatíveis com os relatados nos materiais certificados mas observou-se grande variabilidade (de 13 a 97%) quando o somatório das frações foram comparados às concentrações de As total mostrando significativos efeitos matriciais. / Arsenic is toxicologically, a very important chemical element. It is classified as group 1 carcinogen by the IARC. This element is widely dispersed on the environment and it can reach the man through ingestion of contaminated water or food. Among the terrestrial foodstuffs, rice is the most important since it can concentrate As from the soil at levels sufficient high to impact the human health. The biological effects of this element are dependent of its chemical forms (speciation). It is know that in general, the inorganic forms are much more hazardous than the organic ones. In order to prevent any health effects caused by ingestion of As contaminated food, the Codex Alimentarius, published by JEFCA/WHO/FAO, recently recommended as maximum allowed intake of As via rice as 300 mg.kg-1. The Brazilian Health Authority (ANVISA) also recommends this value. According to the “Proposed draft maximum levels for arsenic in rice” published by the Codex Alimentarius Commission entitled published in March 2012, in Brazil only the concentration of total arsenic is measured. In order to contribute to fill this gap this work was carried out. In this study the applicability of a selected methodology for total As determination was evaluated and 4 certified reference materials were used in this step. The obtained results were consistently > 95% of recovering assuring the good performance of this methodology. In advance, 24 samples of commercial products without gluten collected in the market were evaluated and the obtained results were from 33 to 301 mg.kg-1 being 2 of those samples with concentration higher than the recommended value. Identical procedure was used on speciation studies. In this case, 16 samples were evaluated and the content of total As was compared with the summation of concentration of all As forms present. A great variability ranging from 13 to 97% was obtained showing great interference of the product matrix.
79

Bezlepková dieta a možnosti obohacování jídelníčku celiaků / Gluten-free diet and the possibility of enriching the diet coeliacs

BLAŽKOVÁ, Klára January 2014 (has links)
This thesis deals with the gluten-free diet and its possible enrichment. It is divided into two parts. The first part includes chapters such as history of gluten-free diet, basics of a gluten free diet, the first step in the introduction of a gluten-free diet, gluten-free food labeling legislation and the use of alcohol on a gluten-free diet. The practical part is focused on enriching the diet celiac patients. I focused on the preparation of bakery products for celiac, I have designed and practically tested recipes gluten-free pizza, buckwheat corpus, gluten-free sourdough seedcake and gluten-free cake with homemade pudding and caramel. The finished gluten-free products were submitted after baking consumers who rated their sensory quality. If necessary, an adjustment was made to the recipe and re-perform sensory evaluation. The prepared products were evaluated positively. Selected coeliacs decided suggested products to include in their diet.
80

Processing and characterization of sorghum protein concentrates using extrusion-enzyme liquefaction.

Stonestreet, Normell Jhoe de Mesa January 1900 (has links)
Doctor of Philosophy / Department of Grain Science and Industry / Sajid Alavi / Sorghum grain (Sorghum bicolor) is safe for consumption by individuals afflicted with celiac disease, and its proteins can be used as a supplement in gluten-free foods. However, utilization of sorghum in human foods is limited by the poor digestibility and lack of functionality of its proteins, which result from their entrapment in protein bodies, tight association with starch, and high degree of cross-linking induced by cooking. The first part of this study presents an extensive review of current methods for concentration and isolation of sorghum proteins, which are laboratory-scale techniques used for protein characterization and have no potential for commercial scale-up. Furthermore, these methods typically use non-food grade reagents and do not improve protein digestibility and functionality. In the second part, a novel extrusion-enzyme liquefaction (EEL) process was used to produce sorghum protein concentrates to overcome the aforementioned limitations. EEL involves extrusion pre-treatment of sorghum flour and starch liquefaction with a thermostable α-amylase, followed by enzyme inactivation, protein separation and drying. To demonstrate the concept, a laboratory-scale EEL process was used to produce concentrates with higher protein content (PC; 80% db) and digestibility (D; 74%) than those made by batch liquefaction. The optimum conditions for producing concentrates with both high PC and D were 32% wb in-barrel moisture content and 2.5% α-amylase added after extrusion. Using these conditions, EEL was scaled-up to a pilot-scale process to produce sorghum protein concentrates with 72-80% db PC and 62-74% D, while the batch liquefied control had only 70% db PC and 57% D. Dynamic oscillatory measurements of dough (55% moisture) and batter (65% moisture) containing sorghum protein concentrates (5 and 10%) and potato starch were performed to evaluate protein functionality. At lower moisture, pure potato starch and dough containing 10% sorghum protein concentrate had similar elastic and viscous moduli. At higher moisture, potato starch was more stable and exhibited significantly higher moduli than the batters with protein concentrates. Sorghum protein concentrates can improve the quality of some gluten-free foods. EEL shows promise for commercial production of sorghum protein concentrates because of its high throughput and potential for delivering high protein content and digestibility.

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