A amilose, na presença de agentes complexantes adequados, tende a formar complexos de inclusão. Os mesmos são carregadores promissores, já que os ligantes aprisionados podem ser libertados posteriormente, o que conduz a muitas aplicações. Porém, a utilização da amilose nativa (AM) na formação dos complexos é limitada devido a sua baixa solubilidade em água. Sendo assim, estudos envolvendo a modificação desta molécula tornam-se promissores. O objetivo da presente tese foi preparar complexos de inclusão a partir da amilose nativa (AM) e modificada (AMA) usando como ligantes Rifampicina (RIF), Rodamina B (RB) e o Azul de Bromotimol (AB). Primeiramente, dentre os métodos existentes para modificação, escolheu-se a acetilação. O grau de acetilação foi investigado e a estrutura da amilose foi caracterizada por meio de FTIR, MEV, TGA e DSC. Quando comparada à AM, AMA apresentou maior solubilidade em água. A presença das bandas de absorção no FTIR à 1727, 1240 e 1122 cm-1, confirmaram a acetilação. Os resultados de MEV sugeriram que a superfície lisa da AM foi transformada em uma superfície mais áspera em AMA e as análises de TGA e DSC mostraram uma estrutura instável para a mesma. Após esta etapa os complexos foram produzidos e a influência da temperatura e dos ligantes foi avaliada através da caracterização físico-química. UV-vis, DLS, PZ e MEV foram as técnicas usadas neste processo. As análises de UV confirmaram a formação dos complexos e aqueles desenvolvidos na temperatura de 65°C foram mais eficientes. Dentre estes destacam-se aqueles complexos preparados com RIF. O diâmetro hidrodinâmico médio (dh) dos complexos medidos por DLS variou entre 70 e 100 nm, indicando que os mesmos podem ser utilizados em sistema de liberação controlada. Comparando o dh da AM e AMA, observou-se que os tamanhos são maiores após a complexação, o que pode indicar que para AMA ou a interação forma complexos mais compactos, ou os ligantes não interagiram com a AMA. Análise de PZ mostrou que os complexos AM-RB e AM-AB apresentam alta estabilidade (PZ < -30 mV) e que os demais complexos apresentam valores de PZ próximos da neutralidade, o que pode melhorar a adsorção dos mesmos em sistemas biológicos. Os complexos AMA-RB e AMA-AB não formaram complexos no estado sólido e os demais formaram uma estrutura amorfa após precipitação. Em conclusão, este estudo levou ao desenvolvimento de um método eficaz para a preparação de complexos de inclusão de amilose. / In the presence of suitable complexing agents, amylose tends to form inclusion complexes. This polymer is considered a promisor carrier since the ligands confined in its chains can be released later, leading to various applications. However, the use of native amylose (AM) in complexes formation is restricted due to its low water solubility. Therefore, studies regarding amylose modification become promising. The aim of this thesis was preparing inclusion complexes made of native (AM) and modified (AMA) amylose using rifampicin (RIF), rhodamine B (RB), and bromothymol blue (AB) as ligands. At first, acetylation was the chosen modification among the modified methods described in the literature. The acetylation degree was investigated and the modified macromolecule was characterized using FTIR, SEM, TGA, and DSC analysis. Compared with AM, AMA presented increased water solubility. The presence of absorption bands at 1727, 1240, and 1121 cm-1 confirmed the acetylation. SEM images suggested that the smooth surface of AM was turned into a rougher surface in AMA, while TGA and DSC results showed a less stable structure for AMA. After this step, the complexes were prepared and the influence of the temperature and ligand type was evaluated through physicochemical characterization. UV-Vis, DLS, PZ, and SEM were the techniques used in this process. UV-Vis analysis confirmed complexes formation, revealing that the ones prepared at 65°C were more efficient. Among those, complexes prepared with RIF stand out. The average hydrodynamic diameter (dh) of the complexes measured by DLS ranged from 70 to 100 nm, indicating that these complexes can be used in controlled release systems. Comparing the dh of AM and AMA, it was observed that the sizes were larger after complexation, which may indicate more compact complexes or no interaction between AMA and ligands. ZP results showed that AM-RB and AM-AB complexes presented high stability (PZ < -30 mV), while the others presented PZ values near neutrality, which can increase their adsorption in biological systems. AMA-RB and AMA-AB did not form complexes in solid state, while the others formed an amorphous structure after precipitation. In conclusion, this study leaded to an effective method development for the amylose inclusion complexes preparation.

O desenvolvimento de materiais biodegradáveis, a partir de biopolímeros, para embalagens ou coberturas tem grande interesse para a indústria de alimentos. Na elaboração desses materiais, os amidos e as proteínas são muito usados por serem abundantes na natureza, de baixo custo e apresentam propriedades de formar filmes. A cañihua (Chenopodium pallidicaule), grão alto-andino pouco explorado industrialmente, tem altos conteúdos de carboidratos (~58 %) e proteínas (~18 %), e apresenta potencial para ser utilizado como matéria-prima na extração de amido comercial. Diante desse contexto, o objetivo desse trabalho foi extrair e caracterizar o amido de duas variedades de cañihua, Cupi (CC) e Illpa (CI), e selecionar uma dessas variedades para o desenvolvimento de filmes a base de amido ou de farinha. Além disso, a variedade selecionada foi usada para obter um material rico em amido e proteínas, denominado de farinha, que também foi usado para a produção de filmes biodegradáveis. Os grãos de cañihua das variedades Illpa e Cupi são muito similares na forma e tamanho dos grãos, porém os conteúdos de lipídios e cinzas são maiores para CC e o teor de fibras, para a CI. A extração do amido foi feita com solução de hidróxido de sódio (0,25 % m/v) e suas características estruturais, físico-químicas e funcionais foram determinadas. O rendimento desse processo foi de aproximadamente 33 %, e o amido da variedade CC apresentou maiores teores de lipídeos. Os amidos de ambas as variedades, observados em microscópio de varredura eletrônica, apresentaram superfícies granulares lisas e com formatos esféricos de pequeno tamanho (D[3,2] ~ 0,96 &micro;m). A distribuição de tamanho de partícula, o índice de cristalinidade, os espectros de FTIR, poder de inchamento, propriedades óticas e térmicas foram semelhantes, porém o teor de amilose foi maior para a variedade CC. Maiores valores de solubilidade e viscosidade (propriedades de pasta) foram observados para o amido da variedade Cupi e pode estar associado ao maior conteúdo de amilose. O amido da cañihua Cupi foi selecionado para a produção de filmes, por apresentar maiores teores de amilose e de lipídeos. Na obtenção da farinha de CC, usando soluções de NaOH e HCl (0,2 N), o rendimento foi estimado em 56 % (g/100 g de grãos). O teor de proteínas na farinha foi de 79 % (g/100 g sólidos) em relação ao grão. O alto conteúdo de proteínas favoreceu a formação de aglomerados que foram observados nas micrografias da farinha de CC, que apresentou diferenças nas propriedades óticas, de pasta e de solubilidade em relação ao amido da mesma variedade. Os filmes de amido ou farinha foram obtidos pelo método casting com adição de glicerol como plastificante (15 g/100 g de macromoléculas). A caracterização da microestrutura permitiu observar as diferenças físicas entre os filmes de amido ou farinha de cañihua Cupi, assim como as características estruturais foram úteis para explicar o comportamento das outras propriedades. Em umidades relativas altas, os filmes de amido ou farinha CC apresentam o mesmo comportamento de sorção de umidade e permeabilidade ao vapor de água, no entanto, em contato direito com a água (solubilidade e ângulo de contato), esses materiais apresentaram comportamento diferentes, sendo que os filmes de amido são mais resistentes. As diferenças nas propriedades mecânicas dos filmes de amido e farinha foram significativas (p&gt;0,05). O coeficiente de permeabilidade ao oxigênio foi menor para os filmes de amido do que para a farinha de CC. / The development of biodegradable materials based on biopolymers, films or coatings, have great interest for the food industry. For the production of these materials, starches and proteins are widely used because they are abundant in nature, have low cost and have films-forming property. Cañihua (Chenopodium pallidicaule), high Andean region grain underexplored industrially, has high carbohydrate content (~ 58 %) and proteins (~ 18 %) contents, and has the potential to be used as raw material in commercial starch extraction. In this context, the objectives of this study were to extract and characterize starch from two varieties cañihua, Cupi (CC) and Illpa (CI) and select a variety to develop starch films. Furthermore, the selected variety was used to obtain a rich starch and protein material, known as flour, which was also used to produce biodegradable films. Cañihua grains Illpa and Cupi varieties are very similar in shape and size, but the content of fat and ash are higher for CC and fiber content for the CI. The extraction of starch was performed with sodium hydroxide solution (0.25 % w/v) and their structural, physicochemical and functional characteristics were determined. The yield of this process was approximately 33 %, and CC variety starch showed higher levels of lipids. Starches from both varieties observed in scanning electron microscope, showed smooth granular surfaces and spherical shapes of small size (D3,2 ~ 0.96 &micro;M). The particle size distribution, crystallinity index, FTIR spectra, swelling power, thermal and optical properties were similar, but the amylose content was higher for CC variety. Higher values of solubility and viscosity of pasting properties were observed for CC variety starch and may be associated with higher amylose contents. Cañihua Cupi starch was selected to produce films, due to the higher amylose and lipid content. CC flour was also extracted with NaOH solution and adjusting the pH to 5.0 with HCl (0.2 N) in the protein precipitation step, the yield of this extraction process was estimated at 56 %. The protein content of the flour was 79 % compared to this fraction in the grain. The high protein content favors the agglomerates formation which was observed in the CC flour micrographs that showed differences in solubility, optical and pasting properties. The starch or flour films were obtained by casting method with addition of glycerol (15 g/100 g of macromolecules), as plasticizer. The characterization of the microstructure allowed observation of physical differences between starch or flour films of cañihua Cupi, and also structural characteristics were useful to explain the behavior of the other properties. When submitted to high relative humidity, films exhibited the same moisture sorption capacity behavior and water vapor permeability, however in films were in direct contact to water (solubility analysis and contact angle), the behavior of starch and flour films were different, being the structures of the starch films most resistant. Differences in mechanical properties of starch and flour films were significant (p&gt;0.05). The oxygen permeability coefficient was lower for cañihua Cupi starch films than cañihua Cupi flour films.

Orientadores: Yoon Kil Chang, Fernanda Paula Collares / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-04T18:14:50Z (GMT). No. of bitstreams: 1 Weber_FernandaHart_D.pdf: 1110453 bytes, checksum: 67b945e149aca5da86d8e38ffac8851c (MD5) Previous issue date: 2005 / Resumo: O amido é utilizado como agente gelificante na indústria de alimentos. Devido a diversidade de textura que pode ser obtida com o amido, ele é usado para produtos que vão desde sopas líquidas até pudins com consistência sólida, mas é nos produtos de panificação que adquire maior importância, por ser um componente presente naturalmente nas farinhas de cereais. A incorporação de gomas em suspensões de amido modifica as propriedades reológicas, causa aumento da viscosidade, melhora a textura e aumenta a retenção de umidade. O objetivo do presente trabalho foi estudar as interações físico-químicas que ocorrem entre o amido de milho e as gomas guar e xantana. Foram avaliadas suspensões a 10 % de amido de milho normal, amido de milho ceroso e amido de milho com alto teor de amilose, contendo goma guar e goma xantana nas concentrações de 0,15; 0,50; 0,85 e 1 %. Na tentativa de conhecer as interações foram realizadas análises térmicas, análise das propriedades de pasta, avaliação de dureza do gel, difractometria de raio-x, estabilidade à ciclos de congelamento-descongelamento, resistência à hidrólise enzimática (a-amilase) e espectrometria no infravermelho. As gomas guar e xantana modificaram as propriedades de pasta e térmicas dos amidos avaliados, as alterações verificadas foram dependentes do tipo de amido e de goma utilizados. A goma xantana conferiu maior estabilidade ao cisalhamento e ao aquecimento e reduziu a retrogradação do amido de milho normal e ainda, aumentou a entalpia de gelatinização dos amidos. As gomas aumentaram a estabilidade dos géis submetidos a ciclos de congelamento e descongelamento em proporções diferentes, a goma xantana promoveu uma redução de sinérese maior do que a goma guar. Nos géis de amido de milho normal e com alto teor de amilose armazenados sob refrigeração, a adição da goma xantana melhorou a textura e minimizou os efeitos da retrogradação. Verificou-se também, que os géis do amido com alto teor de amilose apresentaram-se mais rígidos que os demais e que a adição da concentração mínima desta goma reduziu significativamente a sua força. A goma xantana também diminuiu a dureza dos géis do amido ceroso, porém com uma intensidade menor devido à menor retrogradação verificada para este amido. Nos géis de amido com alto teor de amilose adicionados da goma guar, observou-se que não houve diminuição da dureza dos géis. A adição das gomas não alterou o padrão de difração de raio-x dos géis dos amidos estudados. Os géis do amido normal adicionados de 1 % das gomas guar e xantana foram menos hidrolisados, se comparados ao gel controle. No amido com alto teor de amilose, verificouse que a goma guar exerceu ação protetora à hidrólise, e no gel de amido ceroso essa proteção foi ocasionada pela goma xantana. Pelos espectros de absorção no infravermelho, verificou-se que as interações mais importantes entre as gomas e os amidos foram as interações de hidrogênio, visualizadas na região entre 2500 a 3650 cm-1. Mostrou-se que no gel retrogradado, o aumento da água livre foi dependente do tipo de amido e da goma, tendo respostas distintas entre eles: (i) a goma guar aumentou a água livre no amido de milho normal e com alta amilose; (ii) a goma xantana diminuiu a água livre nos amidos de milho normal, com alta amilose e ceroso. De acordo com o estudo desenvolvido, pode-se propor a hipótese de que a interação entre o hidrocolóide e o amido seja mais uma interação física (interações de hidrogênio) do que uma interação química, já que não foi verificado o aparecimento de ligações químicas diferentes nos géis dos amidos adicionados de hidrocolóides / Abstract: Starch is used as a gelling agent in the food industry. Due to the diversity of textures that can be obtained using starch, it is used in products from liquid soups to desserts with a solid consistency, however it is in bakery products that starch has the greatest importance, as it is a naturally present component of cereal flours. The incorporation of gums to starch suspensions modifies their rheological properties, increasing viscosity, improving texture and increasing moisture retention. The aim of the present work was to study the physicochemical interactions that occur between corn starch and guar and xanthan gums. Suspensions of 10 % normal, waxy and high amylose corn starch, containing guar gum and xanthan gum in concentrations of 0.15; 0.50; 0.85 and 1 % were evaluated. In a tentative to elucidate these interactions were carried out thermal analyses, pasting properties analysis, texture evaluation, X-ray diffraction, stability to freeze-thaw cycles, resistance to enzymatic hydrolysis (a-amylase) and infra-red espectroscopy. Guar and xanthan gums modified the pasting and thermal properties of the evaluated starches and these were depends of the type of starch and of the gum used. Xanthan gum increased stability to mechanical agitation and heating and reduced retrogradation of normal corn starch, and promoted a slight increase in gelatinization enthalpies of the starches. The gums increased stability to freeze and thaw processes at different levels, the xanthan gum promoted more reduced in syneresis than the gels with guar gum. In the normal and high amylose corn starch gels, stored refrigerated, the addition of xanthan gum improved texture and minimized the effects of retrogradation. It was also observed that the high amylose gels were more rigid than the others and that the addition of xanthan gum at the minimum concentration used reduced their force significantly. This gum also improved the texture of waxy corn starch gels, however, at a lower intensity due to the lower trend to retrograde verified for this starch. There were no reduction in the force of the gels prepared with high amylose starch and guar gum during storage. The addition of guar and xanthan gums to the starch gels did not modify their Xray diffraction patterns. The gels of normal corn starch with 1 % added xanthan and guar gums were hydrolyzed less when compared to the control gel. Guar gum had a protective action against hydrolysis of high amylose starch and xanthan gum protected waxy corn starch. From the infra-red absorption spectra it could be observed that the most important interactions between the gums and the starches are hydrogen bonds, visualized in the region between 2500 and 3650 cm-1, demonstrating that in the retrograded gels the increase of unbound water depends of the type of starch and of the gum, with different responses: (i) guar gum increased unbound water in normal and high amylose maize starches, however it is not detrimental to waxy maize starch; (ii) on the other hand, xanthan gum reduced unbound water in normal, waxy and high amylose maize starches / Doutorado / Doutor em Tecnologia de Alimentos

L’Hypertrophie Ventriculaire Gauche (HVG) est actuellement mise en évidence par échographie. Cet examen fournit des informations anatomo-fonctionnelles mais ne permet pas de déterminer l’étiologie des HVG, ce qui engendre de graves erreurs de diagnostic et de prise en charge thérapeutique. Les HVG sont classiquement séparées en 2 catégories :1. pathologies hypertrophiques induites par la modification structurelle et fonctionnelle des cardiomyocites qui tend à compenser des insuffisances cardiaques liées par exemple à des problèmes d’hypertension artérielle, de rétrécissement aortique ou de CardioMyopathies Hypertrophiques sarcomériques ;2. pathologies infiltratives correspondant au dépôt de protéines dans la matriceextracellulaire principalement dues à différentes formes d’amyloses cardiaquesNotre hypothèse est que les différents mécanismes physiopathologiques (hypertrophique ou infiltratif) pourraient se traduire dans l’image par des propriétés spécifiques du speckle échographique. Nous avons donc développé un travail d’analyse de la texture de ces images afin de discriminer les différentes HVG.Dans cette étude, la base de données de 4795 images est divisée en une base d’apprentissage de 3770 images et une base de test de 1025 images. L’analyse de texture des images est faite par les ondelettes de Gabor avec 8 orientations, 7 tailles et 5 niveaux de décomposition. Ensuite, les caractéristiques statistiques de premier et deuxième ordre sont extraites des images. Le nombre des caractéristiques est réduit pour la base d’apprentissage en appliquant l’Analyse en Composantes Principales (ACP) suivie par l’analyse discriminante linéaire (ADL) pour une séparation supervisée des classes. Les caractéristiques extraites pour la base de test sont projetées sur les vecteurs propres sélectionnés au cours de l’apprentissage. L’ADL est appliquée à ce niveau pour la classification des données du test et la qualité de cette classification est évaluée. Les résultats obtenus sont bons (qualité totale de classification de 95,51%) et sont suivis d’une étape de cross-validation afin de vérifier la robustesse de notre méthode. A cette étape, les bases de données de l’apprentissage et du test sont mélangées et 50 combinaisons différentes sont évaluées. La même méthode décrite précédemment est appliquée. La cross-validation montre une variation de la qualité de classification (entre 30% et 99.96%) probablement due à l’hétérogénéité des caractéristiques texturelles pour les patients d’une même classe que l’on peut expliquer par des degrés différents d’avancement dans la pathologie.Ces travaux montrent qu’une analyse de texture des images échocardiographiques peut permettre de déterminer des bio-marqueurs aptes à discriminer différentes cardiopathies qui s’expriment par une HVG. Ce résultat peut avoir des retombées très importantes dans la détection précoce des amyloses cardiaques, maladies engendrant un fort taux de mortalité souvent dû à un retard de diagnostic et prise en charge des patients par un centre expert / Left-Ventricular Hypertrophy (LVH) is currently detected through echocardiography. The latter imaging modality provides anatomical and functional information. However, it does not allow the determination of the HVG etiology. This can, in turn, lead to dangerous errors in the diagnosis and treatment planning of the disease. LVH pathologies are separated into two categories:- Hypertrophic pathology caused by the structural and functional modification of cardiomyocytes that lead to cardiac failure related, for example, to arterial hypertension problems, aortic narrowing or sarcomeric hypertrophic cardiomyopathies.- Infiltrative pathologies corresponding to protein deposits on the extracellular matrix, mainly due to different forms of cardiac amyloidosisOur hypothesis is that different physiopathological mechanisms (hypertrophic or infiltrative) can be translated in the image through properties specific to echographic speckle. We have therefore developed the work of texture analysis of such images in order to discriminate the different types of LVH.In this study, the database of 4795 images is divided into a learning database of 3770 images and another testing database of 1025 images. The textural analysis of these images is done using Gabor wavelets with 8 orientations, 7 sizes and 5 decomposition levels. Next, the statistical characteristics of first and second orders are extracted from the filtered images. The number of characteristics is reduced for the learning database by applying Principal Component Analysis (PCA) followed by Linear Discriminant Analysis (LDA) for a supervised separation of the classes. The extracted characteristics for the test database are projected on the eigenvectors selected in the learning step. LDA is applied at this level for the test data classification, and the quality of this classification is evaluated. The obtained results are good (total classification quality of 95.51%). A step of cross-validation follows in order to verify the robustness of our method. At this stage, the learning and testing databases are mixed, and 50 different combinations are evaluated. The same method described previously is then applied. The cross-validation shows a variation in the classification quality (between 30% and 99.96%) probably due to the heterogeneity of the texture characteristics for the patients of the same class explained by different disease advancement stages.This work shows that the textural analysis of echocardiographic images can permit the determination of bio-markers suitable to discriminate different LVH cardiopathies. Our results can have a very important impact on the early detection of cardiac amyloidosis, a pathology causing a considerable rate of mortality often due to a belated diagnosis and support by the centers of expertise

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Fish use carbohydrates less efficiently than proteins for energy production. Even so, the use of such source in the diet may reduce the catabolism of proteins and lipids for energy purposes. The objective of this study was to evaluate growth, metabolism and digestibility of nutrients with different proportions of amylose:amylopectin and thermal processing of starch in the diet of jundiá (Rhamdia quelen). Two completely randomized experiments were conducted, where jundiás were reared in water re-use system consisting of 12 units of 280L and 6 conical units of 200L (digestibility). In the first experiment three diets were tested for 60 days varying in proportions of amylose:amylopectin: P26:74 = 26% amylose and 74% amylopectin, P16:84 = 16% amylase and 84% amylopectin and P0:100 = 0% amylose and 100% amylopectin. The variation of amylose content of the diets did not affect growth, yield, body composition of fish or starch digestibility. For the biochemical variables, less quantity of amylose (P0:100) provided greater mobilization of triglycerides, decrease in the deposition of liver glycogen and increase in metabolism of amino acids and lactate in muscle, indicating gluconeogenesis. The glycemic response of fish was stable (linear, r2 = 0.67) with more amylose (P26:74). Starch with more amylopectin presented quadractly effect P16:84 (r2 = 0.76) and P0:100 (r2 = 0.93). In the second experiment, in a 2X2 factorial arrangement, diets were evaluated with two proportions of amylose:amylopectin and two physic starch forms, raw and gelatinization starch. The fish (14.3±0.6 g) were fed twice a day (4% body weight/day). The proportion of amylose:amylopectin did not affect the growth of jundiá, however, the gelatinization of the starch decreased growth, a higher hepatosomatic and lipid index in body composition of fish. The digestibility of the dry matter and starch was higher with starch gelatinized in the diet. Greater amount of amylopectin and the effect of gelatinization increased serum triglyceride levels. In liver tissues, higher levels of amylose and the process of gelatinization caused greater deposition of glycogen and amino acids. In conclusion, the proportion of amylose:amylopectin is not i change the digestibility of starch and the growth of jundiá, but the increase in amylose provided lower lipid mobilization and stable glycemic levels. The gelatinization of the starch decreased growth and increased the starch digestibility and deposition of body lipids. / Os peixes utilizam carboidratos menos eficientemente do que proteínas para produção de energia. Mesmo assim, a utilização dessa fonte na alimentação pode reduzir o catabolismo de proteínas e lipídeos para fins energéticos. O objetivo do trabalho foi avaliar o crescimento, metabolismo e digestibilidade dos nutrientes com diferentes proporções de amilose:amilopectina e o processamento térmico do amido na dieta de jundiás (Rhamdia quelen). Para isso foram conduzidos dois experimentos delineados inteiramente ao acaso, onde jundiás foram criados em sistema com recirculação de água constituído de doze tanques de 280L e seis tanques de formato cônico de 200L (digestibilidade). No primeiro experimento foram testadas por 60 dias três dietas variando nas proporções de amilose:amilopectina: P26:74=com 26% de amilose e 74% de amilopectina, P16:84=com 16% de amilose e 84% de amilopectina e P0:100=com 0% de amilose e 100% de amilopectina. A variação do teor de amilose das dietas não afetou o crescimento, rendimentos e composição corporais dos peixes, bem como a digestibilidade do amido. Para as variáveis bioquímicas, menor quantidade de amilose (P0:100) proporcionou maior mobilização de triglicerídeos séricos, diminuição na deposição de glicogênio hepático e aumento no metabolismo de aminoácidos e lactato no músculo, indicando gliconeogênese. A resposta glicêmica dos peixes foi estável (linear, r2=0,67) com mais amilose (P26:74). Amido com mais amilopectina apresentou efeito quadrático P16:84 (r2=0,76) e no P0:100 (r2=0,93). No segundo experimento, em arranjo fatorial 2X2, foram avaliadas dietas com duas proporções de amilose:amilopectina e duas formas físicas do amido, cru e gelatinizado Os jundiás (14,3±0,6g) foram alimentados duas vezes por dia (4% peso vivo/dia). A proporção de amilose:amilopectina não afetou o crescimento dos jundiás, já a gelatinização do amido causou diminuição no crescimento, maior índice hepatossomático e de lipídeos na composição corporal dos peixes. A digestibilidade da matéria seca e do amido foi maior com amido gelatinizado na ração. Maior quantidade de amilopectina e o efeito da gelatinização do amido aumentaram os triglicerídeos séricos. No tecido hepático, maiores níveis de amilose e o processo de gelatinização do amido causaram maior deposição de glicogênio e aminoácidos. Como conclusão, a proporção de amilose:amilopectina não causa alterações na digestibilidade do amido e no crescimento do jundiá, mas o aumento da amilose proporciona menor mobilização lipídica e glicemia estável. A gelatinização do amido diminuiu o crescimento, aumentou a digestibilidade do amido e causou maior deposição de lipídeos corporais.

L'amylose une maladie rare, caractérisée par des agrégats insolubles de protéines extracellulaires. Trente types d'amyloses sont répertoriés et différenciés par la protéine amyloïdogène associée. Leur identification repose sur l'analyse immunohistochimique du tissu malade. Cependant, l'interprétation peut être ambigüe. La micro-dissection laser (LCM) et la spectrométrie de masse sont une alternative prometteuse. Nous avons développé une approche protéomique ciblée à partir de tissus traités par ultrasons. Nous avons montré que les biopsies prélevées chez des patients atteints de différents types d'amyloses peuvent être protéolysées sous ultrasons, ce qui augmente l'efficacité et réduit le temps de la digestion (90s au lieu de 15h), tout en minimisant la quantité de matériel nécessaire. Après une première étape de protéomique sans a priori pour le diagnostic clinique des patients présentant une amylose dans différents organes/tissus (reins, poumons, glandes salivaires, testicule, humeur vitrée et rate), nous avons optimisé une méthode de criblage dédiée à un transfert technologique vers les départements cliniques français. Pour cela, deux méthodes montrent des résultats très encourageants : la SRM (selected reaction monitoring) sur un spectromètre de masse à basse résolution, disponible dans certains laboratoires cliniques et la PRM (parallel reaction monitoring) accessible sur les instruments de dernière génération à très haute résolution, qui fournit rapidement des résultats. En conclusion, nous proposons ici un protocole spécifique pour le diagnostic robuste et la classification rapide des amyloïdoses. / Amyloidosis is rare disease that appears as an insoluble deposition of specific extracellular proteins. Thirty classes of amyloidosis have been reported and their diagnosis relies on the identification of the associated proteins by immunohistochemistry analysis of the affected tissues. However, its interpretation is highly dependent on the pathologist and can be ambiguous. Laser capture micro-dissection (LCM) and mass spectrometry are a promising alternative. We have developed a targeted proteomics approach from raw tissues treated with ultrasound. We showed that the biopsies taken from patients presenting different classes of amyloidosis can be proteolysed by ultrasonic treatment. This technique increases the efficiency and reduces the time of digestion (90s instead of 15h), while minimizing the amount of material needed. After a first unbiased proteomics study for clinical diagnosis of patients with amyloidosis in various organs/tissues (kidney, lung, salivary glands, testicle, vitreous humor and spleen), we have optimized a dedicated screening method for a technological transfer to the French clinical departments. For this, two methods show very promising results: SRM (selected reaction monitoring) on a low-resolution mass spectrometer, available in some clinical laboratories, and PRM (parallel reaction monitoring) available on the latest generation of high-resolution instruments which provide fast results. In conclusion, we propose here a specific protocol for a robust diagnosis and rapid classification of amyloidoses.

Rice is an important human staple food for over half of the world’s population. Amylose content (AC), gelatinization temperature (GT), grain protein content (GPC), percentage grain chalkiness (PGC), and mineral content are important parameters for evaluating rice quality, which attracts customers and breeders. Only limited genes or QTLs (OsAAP6, OsGluA2, OsASN1, Chalk5, OsHMA3, etc.) are reported regulating rice GPC, PGC, and mineral content due to the lack of genetic knowledge and molecular markers. To dissect the genetic architecture of rice grain quality regulation, genome wide association studies (GWAS) were performed using two populations (USDA-mini core collection and a panel of 662 rice accessions from the 3K Rice Genomes Project). A total of 28, 11, 4, 3, 40, 3, 4, 3, and 10 QTLs were identified associated with Cd, Co, Cu, K, Mo, Ni, Rb, Sr, and Zn under flooded environment, while, 23, 7, 7, 7, and 3 QTLs were detected to be associated with Cd, Fe, Mo, Ni, and Zn under unflooded environment, respectively. Moreover, 6, 5, and 2 significant QTLs were tightly associated with kernel length, kernel rate, kernel width, respectively. Furthermore, 44, 7, 27, and 20 QTLs were identified associated with AC, GT, GPC, and PGC, respectively. Overall, 53 (~ 20.08%) of the 264 QTLs were coinciding with previously reported QTLs/genes, and 211 (~ 79.92%) were novel QTLs. A candidate gene, OsPCAT (putative cationic transporter), associated with GPC in the dry season was selected for further analysis. The OsPCAT gene belongs to the amino acid transporters (AATs) family with nine closely related members reported in Oryza Sativa. The classification and evolution of the CAT family (a subgroup of AATs family) using 61 species were studied. The over-expression lines (OsPCAT-OX) and CRISPR-Cas9 knock-out lines (OsPCAT-KO) were developed to study the function of OsPCAT gene. The preliminary results showed the GPC in OsPCAT-OX lines was increased and OsPCAT-KO lines were decreased compared to WT. Overall, a large number of new and reported QTLs associated with rice grain quality have been identified. This work lays the foundation for marker development in breeding and further investigation on rice grain quality regulation.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Omega-3 polyunsaturated fatty acids (ω3 PUFAs) provide important health benefits, but dietary consumption is low. Supplementing foods with ω3 PUFAs is of interest, but intervention strategies are necessary to preserve the integrity of these unstable compounds. Microencapsulation of ω3 PUFA sources is one means of improving their stability. In this work, ω3 PUFA microcapsules were prepared by spray drying with chitosan and blends of chitosan, high-amylose starch, and pullulan as wall materials. The primary objectives of this research were (1) to evaluate the effect of chitosan type and oil:wall ratio on ω3 PUFA microcapsule properties, (2) to evaluate the effect of blending chitosan with high-amylose starch and pullulan on ω3 PUFA microcapsule properties, and (3) to evaluate the oxidative stability of ω3 PUFA microcapsules by monitoring primary and secondary oxidation products during storage. Microcapsule encapsulation efficiencies (EE) ranged from 63% to 79% with the highest EEs observed for microcapsules prepared from chitosan with higher degree of deacetylation (DD) and lower molecular weight (MW). Median microcapsule size ranged from 3 μm to 11 μm. Moisture contents were all below 7% and water activities (a_w) were below 0.27. Microcapsules prepared from blends of chitosan with starch and/or pullulan had lower aw values than those prepared from chitosan alone. Oxidative stability was evaluated by measuring oxidation induction time (OIT) using pressure differential scanning calorimetry. OIT values ranged from 14 to 20 minutes. Microcapsules prepared from chitosan with lower DD and higher MW had longer OITs than those prepared from chitosan with higher DD and lower MW. Microcapsules prepared from blends of chitosan, starch, and pullulan had longer OITs than those prepared from chitosan alone. Oxidative stability of microcapsules during long term storage was evaluated on one microcapsule formulation by monitoring peroxide value (PV) and secondary oxidation products by HS-SPMEGC/ MS. Volatiles including propanal, 1-penten-3-ol, pentanal, hexanal, and 2,4-heptadienal were detected in the headspace of the microcapsules; however, PVs did not indicate substantial oxidation of the ω3-PUFA source during 5 weeks of storage. Chitosan, high-amylose starch, and pullulan are effective materials for microencapsulation of ω3 PUFA sources. / Ph. D.

The incidence of type 2 diabetes is considered an epidemic in Western countries, and its prevalence is more common in the Hispanic population than in non-Hispanic whites. Postprandial hyperglycemia has been associated with oxidative stress (OS), thus; reducing postprandial glycemia and/or OS through dietary consumption of resistant starch (RS) may be one approach to help modulate glucose and insulin responses. The purpose of this study was twofold: 1) to evaluate the physicochemical and sensory properties of cereal food products supplemented with RS. 2) to compare the effects of a single ingestion of granola bars with high (~18 grams of RS) and low (~0 grams of RS) RS compositions on the postprandial glucose and insulin responses (n=14) and oxidative stress parameters (cellular glutathione peroxidase, F2- isoprostanes, and oxygen radical absorbance capacity) in Hispanic women (n=9). Granola bars and cereals were developed to provide 2 levels (10% and 15%) of RS; isocaloric (0% RS) control samples were prepared with readily digestible (high amylopectin) starch. Samples were stored for up to 4 weeks at 20 °C. Mean composition of the high RS granola bars was 6% protein, 15% moisture, and 18% lipid. RS levels slightly increased from 14 to 16 g/serving after 4 weeks of storage, supporting published research that RS increases with storage due to retrogradation and crystallization of amylose chains. Color became lighter as the level of RS increased (p<0.001). Granola bars containing RS were less brittle (p=0.0043) than control granola bars. Sensory results indicated granola bars/cereals were acceptable. RS-supplemented granola bars were then used for the evaluation of RS ingestion in humans. There was no difference in postprandial glucose and insulin responses after a single ingestion of a RS-supplemented (18 g) granola bar. No differences were found in the oxidative stress parameters measured. In a subgroup of subjects (n=9), a lower glucose response 30 minutes after RS consumption was found (p=0.0496). Thus, RS consumption may lower fluctuations in blood glucose, which may help manage glucose levels in individuals at risk of type 2 diabetes. Further studies of short term RS consumption are warranted to elucidate its benefits in glucose management. / Ph. D.