A qualidade global da massa de pão congelada por um longo período é um desafio para indústria de panificação. O uso de diferentes técnicas pode ajudar a explicar os danos sofridos à massa de pão durante o congelamento e armazenamento congelado. A presença de água na forma de cristais de gelo foi vista como a principal causa de defeitos à estrutura da massa. Gomas guar e xantana foram incorporadas às massas para contornar os danos causados pelo congelamento. Das análises térmicas conduzidas em calorímetro de varredura diferencial foi possível quantificar a quantidade de gelo presente na massa. A adição de (0,125 a 0,250) g/100g de goma guar e de (0,214 e 0,250) g/100g de goma xantana diminuíram os valores de entalpia na massa ao longo do armazenamento congelado. A fração de gelo foi menor e mais estável nas massas contendo (0,125 e 0,250) g/100g de goma guar ou xantana. O valor da atividade de água diminuiu nas massas contendo goma guar e com níveis mais altos de goma xantana, após o ciclo de congelamento e descongelamento e 170 dias de armazenamento. Alterações na estrutura das massas foram medidas e visualizadas pela análise de textura e por microscopia eletrônica de varredura (MEV). Adição de goma xantana e principalmente de goma guar às massas aumentaram a resistência à extensão após 170 dias de armazenamento congelado. A extensibilidade não foi influenciada pela adição de gomas e manteve estabilidade nos períodos de armazenamento estudados. A MEV ajudou a explicar os danos causados à rede de glúten pelos cristais de gelo ao longo do armazenamento congelado. A massa sem gomas apareceu com pequenos danos na rede de glúten com 21 dias de armazenamento e estes danos aumentaram progressivamente por até 170 dias, mostrando um glúten menos contínuo, mais rompido e separado dos grânulos de amido. As massas contendo gomas minimizaram, mas não evitaram os danos causados ao longo do armazenamento congelado. / The global quality of the frozen bread dough for long periods of frozen storage is the challenge to bakery industry. The use of different techniques could help to explain the damages caused in the frozen dough during the freezing and along frozen storage time. The presence of water as ice crystals was the main cause of damage on the dough structure. In order to minimize the freezing damages, guar and xanthan gums were incorporated in the dough. From thermal analysis by DSC technique, the amount of ice present in the dough was determined. The addition of (0.125 to 0.250) g/100g guar gum and (0.214 and 0.250) g/100g xanthan gum presented lower values of fusion enthalpy. The addition of (0.125 and 0.250) g/100g of guar gum decreased or stabilized the frozen water content, suggesting minimal damage on the dough structure along frozen storage time. The water activity in the dough samples with guar gum and higher quantities of xanthan gum decreased after the freezing-thawed cycle and after a period of frozen storage of 170 days. The incorporation of xanthan gum and mainly the incorporation of guar gum increased the maximum resistance of the dough after 170 days. The extensibility was not affected by addition of gums along frozen storage time. The MEV technical helped to explain the damaged dough structure caused by ice crystals along frozen storage time. Dough samples without gums presented structure damage only after 21 days and increased after 170 days, resulting in less continuous gluten, more disrupted and separated from starch granules. The doughs with gums suffered less damage in the gluten matrix, but did not avoid the problems caused by frozen storage.

Essa pesquisa teve como objetivo obter o abacaxi como alimento tipo conveniência, submetido ao processamento mínimo e tratamento com cloreto de cálcio, películas comestíveis à base de alginato e glúten de trigo, e irradiação. Os frutos foram lavados, sanificados com Sumaveg® (Dicloro-S-Triazinatriona Sódica), na concentração de 200 mg L-1 de cloro livre, a 7ºC, durante 15 minutos, e descascados manualmente. A polpa foi fatiada em leques de aproximadamente 1 cm de espessura, enxagüadas com 20 mg L-1 de cloro livre, durante 3 minutos, e drenadas por 3 minutos. No primeiro experimento as amostras foram submetidas aos tratamentos: cloreto de cálcio 1% + solução de glúten vital; cloreto de cálcio 1% + alginato de sódio 1%; e controle. No segundo experimento as amostras foram submetidas aos tratamentos: cloreto de cálcio 1% + solução de glúten vital + irradiação com 2,3 kGy; cloreto de cálcio 1% + irradiação com 2,3 kGy; irradiação com 2,3 kGy; e controle. O acondicionamento foi realizado em bandejas rígidas de polietileno tereftalato (PET), com cerca de 250 g de fruta. A irradiação foi realizada em irradiador multipropósito de Cobalto-60, com atividade de 92 kCi e taxa de dose de 2,3 kGy h-1. As amostras foram armazenadas a 5 ± 1ºC e analisadas a cada dois dias, num total de 12 dias. No primeiro experimento, os valores de pH e acidez titulável apresentaram leves alterações e semelhança entre os tratamentos. Houve decréscimo no teor de ácido ascórbico em todos os tratamentos. Todos os tratamentos escureceram ao longo do armazenamento. Apesar dos valores terem sido próximos entre os tratamentos, os abacaxis tratados com cloreto de cálcio + glúten apresentaram textura mais firme, menores perda de líquido, atividade da peroxidase e polifenoloxidase, produção de CO2 e etileno e contagens de microrganismos mesófilos e bolores e leveduras. Não houve presença de E. coli e de Salmonella. A contagem de microrganismos do grupo dos coliformes totais foi baixa em todos os tratamentos e ocorreu apenas em amostras isoladas durante o período de armazenamento. Na análise sensorial, as amostras tratadas com cloreto de cálcio + glúten apresentaram as notas mais baixas para textura, aparência e aroma; já o sabor ficou comprometido a partir do 4o dia de armazenamento. No segundo experimento, os valores de pH e acidez titulável apresentaram pequenas alterações e semelhança entre os tratamentos. Houve decréscimo no teor de ácido ascórbico em todos os tratamentos; no entanto, as amostras tratadas com cloreto de cálcio + glúten + 2,3 kGy retiveram mais essa vitamina. A textura mais firme e as menores perda de líquido e atividade da peroxidase e polifenoloxidase ocorreram nas amostras tratadas com cloreto de cálcio + 2,3 kGy. Todos os tratamentos escureceram ao longo do armazenamento. As amostras mais escuras foram as tratadas com cloreto de cálcio + glúten + 2,3 kGy e as irradiadas com 2,3 kGy. As maiores taxa respiratória e síntese de etileno ocorreram nas amostras tratadas com cloreto de cálcio + glúten + 2,3 kGy. As menores contagens de microrganismos psicrotróficos, mesófilos, e bolores e leveduras ocorreram nas amostras à base de cloreto de cálcio + glúten + 2,3 kGy. Não houve presença de E. coli e de Salmonella. A contagem de microrganismos do grupo dos coliformes totais foi baixa em todos os tratamentos e ocorreu apenas em algumas amostras durante o período de armazenamento. Apenas o controle manteve as características sensoriais acima do limite de aceitabilidade durante todo o armazenamento. A textura das demais amostras foi rejeitada no 8º dia. O sabor ficou comprometido desde o 1º dia de armazenamento nas amostras à base de cloreto de cálcio + glúten + 2,3 kGy / The aim of this study was to obtain a convenience type pineapple subjected to fresh-cut process and calcium chloride, wheat gluten and alginate-base edible coating and irradiation treatments. The fruits were washed, sanitized with Sumaveg® (Sodium Dichloro-s-Triazinetrione) in a 200 mg L-1 chlorine-free solution at 7ºC for 15 minutes, and then manually peeled. The peeled fruits were sliced into 1 cm thick slices, rinsed in 20 mg L-1 chlorine-free solution for 3 minutes and drained for 3 minutes. In the first experiment, the samples were treated with: 1% calcium chloride + vital wheat gluten solution; 1% calcium chloride + 1% alginate solution; and control. In the second experiment, the samples were treated with: 1% calcium chloride + vital wheat gluten solution + 2.3 kGy; 1% calcium chloride + 2.3kGy; irradiation with 2.3kGy; and control. The packing consisted of rigid polyethylene terephthalate (PET) trays with around 250 g of fruit. The irradiation was performed in a Cobalt-60 multipurpose irradiator with 92 kCi activity and dose value of 2.3 kGy h-1. The samples were stored at 5 ± 1ºC and evaluated every other day for 12 days. In the first experiment pH and titratable acidity values showed slight variations but were similar between the treatments. There was a decrease in ascorbic acid values in all treatments. Browning was noticed in all treatments over the storage period. Although the values between the treatments were similar, the pineapple treated with calcium chloride + gluten showed firmer texture, less liquid loss, and lower values of polyphenoloxidase and peroxidase activities and CO2 and ethylene production. Mesophiles and mold and yeast counts were also reduced. No Salmonella and E. coli were detected. Total coliform counts were low in all the treatments and appeared in just a few isolated samples during the storage period. Sensory analyses showed that the samples treated with calcium chloride + gluten had the lower scores for texture, appearance, and aroma; the flavor was compromised from the 4th storage day onward. In the second experiment the pH and titratable acidity values showed small changes but were similar between the treatments. There were a decrease in the ascorbic acid values in all treatments; nevertheless, the samples treated with calcium chloride + gluten + 2.3 kGy retained more of this vitamin than the other treatments. Firmer texture, less liquid loss, and lower values of polyphenoloxidase and peroxidase activities were noticed in the samples with calcium chloride + 2.3 kGy. Browning was noticed in all treatments over the storage period. The darker samples were the ones treated with calcium chloride + gluten + 2.3 kGy, and irradiated with 2.3 kGy. Higher respiratory rate and ethylene synthesis were noticed in the samples treated with calcium chloride + gluten + 2.3 kGy. The lowest psychrotrophic, mesophiles, and mold and yeast counts occurred in the samples treated with calcium chloride + gluten + 2.3 kGy. No Salmonella and E. coli were detected. Total coliform counts were low in all the treatments and appeared in just a few samples during the storage period. Only the control kept the sensorial attributes within the acceptability limit during the storage period. The texture in all the other samples was unacceptable from the 8th day onward. The flavor was compromised from the first storage day onward in the samples with calcium chloride + gluten + 2.3 kGy

Orientador: Helena Maria André Bolini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-17T12:01:23Z (GMT). No. of bitstreams: 1 Morais_ElisaCarvalhode_M.pdf: 1165882 bytes, checksum: e31a11a9884ec992fc2a62dbb8c1a7e4 (MD5) Previous issue date: 2011 / Resumo: O pão e outros produtos à base de cereal se tornaram alimentos de ¿primeira necessidade¿ em todo o mundo e estão atualmente instituídos como parte integrante de diversas dietas modernas. O alto consumo deste produto no Brasil e nos mercados internacionais, e a crescente procura dos consumidores por produtos alimentícios, não somente saborosos e nutritivos, mas que também tragam benefício à saúde, estimula o estudo da adição de prebióticos e edulcorantes. Na primeira parte deste trabalho, que avaliou os efeitos da adição dos prebióticos, inulina e frutooligossacarídeos, nas concentrações de 1, 2 e 4%, nas propriedades físicas e sensoriais de pães de forma sem glúten, a adição de 2% de inulina e 2% de FOS apresentou boa aceitação e maior intenção de compra pelos consumidores. No segundo estudo seis formulações de pães sem glúten foram avaliadas por 15 assessores celíacos treinados que identificaram 15 termos descritores para aparência, aroma, sabor e textura. Foi realizado teste de aceitação com 123 consumidores, não celíacos, de pão de forma. As amostras apresentaram diferença significativa entre si (p<0,05) para todos os atributos avaliados na ADQ. Por meio da correlação dos quadrados mínimos parciais entre as amostras, em relação aos atributos da ADQ e impressão global do teste de aceitação, observou-se que as variáveis mais significativas para discriminação entre as amostras foram cor da casca, aroma de fermento, doçura e textura de borracha. No terceiro estudo objetivou-se avaliar os pães de forma sem glúten por meio de outro teste de aceitação, com 32 consumidores celíacos, assim como avaliar o comportamento tempo-intensidade para os atributos gosto doce e sabor de fermento. Análises físico-químicas também foram realizadas com o intuito de estudar a qualidade global dos pães. Os consumidores celíacos apresentaram boa intenção de compra em relação às amostras de pão de forma sem glúten, sendo que a amostra com adição de FOS apresentou maior média para este parâmetro. Os pães apresentaram boas características físico-químicas mostrando a possibilidade de desenvolvimento de pães de forma sem glúten e naturais, com propriedades funcionais e características desejáveis aos consumidores celíacos / Abstract: Bread and other cereal-based products have become ¿first necessity¿ food in the world and are now established as an integral part of many modern diets. The high consumption of this product in Brazil and international markets and the growing consumer demand for food products, which not only are tasty and nutritious, but also that bring health benefits, encourage the study of prebiotics and sweeteners addition. In the first part of this study, which evaluated the effects of prebiotics incorporation, inulin and fructooligosaccharides, in concentrations of 1%, 2% and 4%, to gluten-free breads on physical and sensorial properties, the addition of 2% inulin and 2% FOS had good acceptance and greater purchase intent by consumers. In the second study, six gluten-free bread formulations were evaluated by 15 trained celiac assessors who identified 15 descriptors terms of appearance, aroma, taste and texture. Acceptance test was conducted with 123 not celiac bread consumers. Samples presented significant differences amongst them (p<0.05) for all attributes in the QDA. By partial least squares correlation between samples, in relation to the attributes of the QDA and overall impression of the acceptance test, it was observed that the most significant variables to discriminate among the samples were color crust, yeast flavor, sweetness and rubber texture. The third study aimed at evaluating the glutenfree breads through another acceptance test, with 32 celiac consumers, as well as evaluating the time-intensity behavior for the attributes of sweetness and yeast taste. Physical-chemical analyses were also performed in order to study the breads overall quality. Celiac consumers presented good purchase intention for the gluten-free bread samples, and the sample added with FOS had a higher mean value for this parameter. Gluten-free breads presented good physical-chemical characteristics showing the potential development of gluten-free and natural breads, with functional properties and desirable characteristics for celiac consumers / Mestrado / Consumo e Qualidade de Alimentos / Mestre em Alimentos e Nutrição

Submitted by Erika Demachki (erikademachki@gmail.com) on 2014-12-29T15:28:36Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Déborah Patrícia Leal Oliveira - 2013.pdf: 2010212 bytes, checksum: 0c24a44129b6342788eadf59a1e31064 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2014-12-29T15:36:19Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Déborah Patrícia Leal Oliveira - 2013.pdf: 2010212 bytes, checksum: 0c24a44129b6342788eadf59a1e31064 (MD5) / Made available in DSpace on 2014-12-29T15:36:20Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Déborah Patrícia Leal Oliveira - 2013.pdf: 2010212 bytes, checksum: 0c24a44129b6342788eadf59a1e31064 (MD5) Previous issue date: 2013-02-25 / Pearl millet is a rich nutritionally cereal, being a major source of protein countries of the semiarid region of the African continent. The pearl millet crops are in expansion on Brazilian Savanna due the plant characteristics that are compatible to the climate and soil of the region. However, in Brazil, the grains of millet are not widely used in food, it was noted with advantageous insertion of this cereal in the diet of the population as this has major advantages over other commonly used cereals as the lowest price, the more quantity and better quality of fiber lipid and protein. The thermoplastic extrusion was used for the preparation of products with the millet that was mixed with corn grits because it presents favorable characteristics for processing used. This study was conducted in order to develop and evaluate the nutritional quality, technological and sensory snacks, pre-gelatinized flour (FPG) and pasta-based mixture of millet [Pennisetum glaucum (L.) R. Br] and gritz of corn (Zea mays L.). For extruding the mixture of grains of millet and corn gritz was used rotational central composite design for the best moisture conditions of the raw material and temperature of the extruder zone 3. The snacks were optimized according to the expandability and pregelatinized flour according to the absorption capacity and water solubility. After optimization of flour, which showed better gelatinization was applied in the preparation of pasta. This was prepared using the mixture design with ternary composition (extruded flour, corn flour and millet raw) to find what proportion of ingredients that got the best features of cooking pasta. Snacks with 11% moisture content of the raw material and 90 ° C temperature were those with greater expansion and were the most desirable second test of desirability. When they were being flavored sensory acceptance and its nutritional composition were classified as high fiber content. The pre-gelatinized flour with highest absorption capacity and water solubility was the one with the same extrusion conditions optimized snack. The proportion of ingredients of the mass had the best cooking conditions was 10% pre-gelatinized flour, 25% corn and 65% of pearl millet flour. The pasta was accepted for flavor, texture and appearance of the panelists. However, it was possible to extrude grains of millet and corn gritz and also the development of products with good nutritional and sensory characteristics. / O milheto é um cereal rico nutricionalmente, sendo uma das principais fontes proteicas em países da região semiárida do continente Africano. No Brasil, mais especificamente no Cerrado, o cultivo deste cereal apresenta-se em expansão devida as características da planta que são compatíveis ao clima e solo da região. No entanto, no Brasil, os grãos de milheto não são muito utilizados na alimentação humana, com isso notou-se vantajoso a inserção deste cereal na alimentação da população já que este apresenta grandes vantagens em relação a outros cereais comumente utilizados, como o preço mais baixo, a maior quantidade de fibras e a melhor qualidade proteica e lipídica. A extrusão termoplástica, uma técnica bastante versátil, foi utilizada para a elaboração de produtos com o milheto que foi misturado ao gritz de milho por este apresentar características favoráveis ao processamento utilizado. Este estudo foi realizado com o objetivo de desenvolver e avaliar a qualidade nutricional, tecnológica e sensorial de snacks, farinha prégelatinizada e massa alimentícia à base de mistura de milheto [Pennisetum glaucum (L.) R. Br.] e gritz de milho (Zea mays). Para a extrusão da mistura de grãos de milheto e gritz de milho foi utilizado o delineamento composto central rotacional para obter as melhores condições de umidade da matériaprima e temperatura da 3ª zona do extrusor. Os snacks foram otimizados conforme a capacidade de expansão e a farinha pré-gelatinizada de acordo com a capacidade de absorção e solubilidade em água, ou seja, gelatinizada. A farinha pré-gelatinizada otimizada foi aplicada na elaboração de massa alimentícia. Esta foi elaborada utilizando o delineamento de misturas com composição ternária (farinha extrusada, fubá de milho e farinha de milheto crua) para encontrar qual a proporção de ingredientes que obtivesse as melhores características de cozimento da massa. Os snacks e a massa alimentícia foram analisados microbiologicamente para a realização da análise sensorial. Os snacks com 11% de umidade da matéria-prima e 90 °C de temperatura foram os que apresentaram maior expansão e foram os mais desejáveis segundo teste de desejabilidade. Ao serem aromatizados eles foram aceitos sensorialmente e em sua composição nutricional foram classificados como alto teor de fibras. A farinha pré-gelatinizada que obteve maior capacidade de absorção e solubilidade em água também foi o experimento com 11% de umidade e 90 °C de temperatura. A proporção de ingredientes da massa que teve as melhores condições de cozimento foi a de 10% farinha pré-gelatinizada, 25% de fubá de milho e 65% de farinha de milheto. A massa alimentícia foi aceita em relação ao sabor, textura e aparência entre os provadores. Contudo, foi possível a extrusão de grãos inteiros de milheto e gritz de milho e ainda a elaboração de produtos com boas características nutricionais, tecnológicas, microbiológicas e sensoriais segundo atributos sabor, aparência e textura.

Benefícios na fermentação microbiana no cólon e as flatulências, em cães da raça Bulldog Francês, podem ser promovidos mediante mudanças nas quantidades e fontes proteicas da dieta. Este estudo avaliou os efeitos da inclusão de diferentes fontes de proteína em alimento seco para cães Bulldog Francês sobre a fermentação microbiana, a absorção de nutrientes e mudanças nas emissões dos componentes orgânicos voláteis mais prevalentes, ademais comparou os resultados com a técnica de teste sensorial. Quatro dietas de manutenção para cães adultos foram formuladas: T0, dieta com farinha de vísceras de frango; T1, dieta com glúten de trigo; T2, dieta com farinha de vísceras de frango e glúten de trigo; e T3, dieta com vísceras de frango, glúten de trigo e proteína hidrolisada. Foram utilizados oito cães da raça Bulldog Francês, com peso corporal médio de 11,3 ± 0,21 kg e 2,7 ± 0,74 anos de idade, distribuidos num delineamento em quadrado latino 4x4 e adaptados às dietas durante 20 dias. Fezes frescas foram coletadas para análise de digestibilidade aparente dos nutrientes, escore, ácidos graxos voláteis, pH, aminas biogênicas, compostos orgânicos voláteis, lactato, amônia, e análise sensorial. Não houve efeitos adversos nos animais. As médias foram comparadas por meio de contrastes pelo PROC MIXED do SAS, adotando um nível de significância de 5% (P&le;0,05). Os animais que foram alimentados com as dietas T1 e T2 apresentaram maior digestibilidade da matéria seca (P&lt;0,05), matéria orgânica (P&lt;0,05), proteína bruta (P&lt;0,001) e menor produção de fezes (P&lt;0,02). Foi observada menor ingestão da fibra bruta nos animais alimentados com a dieta T0 (P&lt;0,001). As dietas T1, T2 e T3 resultaram em menor escore e pH fecal (P&lt;0,05). Ao respeito aos compostos orgânicos voláteis, foi observada diferença estatística em dois dos 68 compostos observados, as fezes dos animais alimentados com dieta T0 e T1 apresentaram maior presença dos compostos fenol (P=0,04) e indol (P=0,01), respectivamente. O tratamento T0 apresentou maior percepção de odor durante a avaliação sensorial (P=0,01). Não houve efeito das dietas nos produtos finais de fermentação. O uso complementar da proteína animal com a vegetal melhoraram a digestibilidade da proteína bruta, e em consequência, reduziram a percepção do mal odor das fezes de cães Bulldogs Francês. Mais estudos são necessários para entender a associação dos níveis de percepção de odor com as mudanças dos compostos orgânicos voláteis. / Benefits on colonic fermentation and flatulencies, in French bulldog dogs, can be promoted by changes on diet protein sources and quantities. The current study evaluated the effects of the inclusion of different protein sources to dog dry feed on microbial fermentation, nutrient absorption, and changes of the emission of most prevalent volatile organic compounds, and also compared the results with a sensorial test. Four maintenance diets for adult dogs were formulated: T0, diet with the inclusion of poultry entrails meal; T1, diet with the inclusion of wheat gluten; T2, diet with the inclusion of poultry entrails meal and wheat gluten; and T3, diet with the inclusion of poultry entrails meal, wheat gluten, and hydrolyzed protein. Eight adult French bulldog dogs, with a mean weight of 11.3 ± 0.21 kg and 2.7 ± 0.74 years old, were arranged in a 4x4 Latin square design and adapted to diets for 20 days. Therefore, fresh feces were collected for digestibility, fecal score, volatile fatty acids, fecal pH, biogenic amines, volatiles organic compounds, fecal lactate, ammonia, and sensorial test analyses. There were no adverse effects to the animals. Means were compared by contrast using PROC MIXED procedure of SAS software, choosing a significance level of 5% (P&le;0.05). Animals fed with diets T1 and T2 showed higher dry matter (P&lt;0.05), organic matter (P&lt;0.05), and crude protein digestibility (P&lt;0.001), and lower feces production (P&lt;0.02). Lower ingestion of crude fiber was observed in animals fed with diet T0 (P&lt;0.001). Diets T1, T2, and T3 showed lower pH (P&lt;0.05) and score of the feces. In regard to volatile organic compounds, 2 from 68 observed compounds showed statistical difference. Animals fed with diet T0 and diet T1 had greater presence of phenol (P=0.04) and indole (P=0.01) on feces, respectively. Diet T0 showed greater odor perception during the sensorial test (P=0.01). There were no effects of diets on fermentation final products. The reduction of protein level and the complementary use of animal and vegetal protein sources improved crude protein digestibility, and as a consequence, reduced the odor perception of the feces of French bulldog dogs. More studies are needed to understand the association between odor perception levels and changes on volatile organic compounds.

A doença celíaca (DC) é uma doença inflamatória induzida pela ingestão de glúten em indivíduos geneticamente predispostos e seu tratamento é baseado em uma dieta sem glúten por toda a vida. A doença celíaca refratária é um problema comum que afeta de 10% a 19% dos pacientes célicos tratados. Provavelmente, a contaminação da dieta por glúten é uma das razões principais para a persistência de sintomas em pacientes celíacos tratados, assim como a ingestão inadvertida de glúten, devido a rotulagem incorreta. Assim, o objetivo deste estudo foi avaliar a confiabilidade dos rótulos dos alimentos brasileiros processados, através de testes de contaminação de glúten nos seguintes grupos (a) produtos \"livres de glúten\" - preparados especificamente para a população celíaca; (b) produtos \"naturalmente sem glúten\" feitos com arroz, milho, soja e mandioca, utilizados por toda a população e (c) produtos rotulados com \"contém glúten\", mas que não apresentam glúten em sua composição no rótulo. Foram analisados 213 produtos alimentícios agrupados em: 115 produtos do grupo \"sem glúten\"; 86 produtos do grupo \"naturalmente sem glúten\" e 12 produtos do grupo rotulados com \"contém glúten\". O teor de glúten foi detectado e quantificado por ELISA-R5 (Ridascreen®gliadin) e os resultados foram expressos em ppm e mg/100 g de alimento. A linha de corte foi estabelecida em 20 ppm para a contaminação de glúten. Todas as contaminações por glúten foram confirmadas por Western-blotting. Resultados: (a) alimentos livres de glúten 15 das 115 (13%) apresentaram contaminação por glúten (20 ppm), (b) grupo de alimentos naturalmente sem glúten - 8 de 86 (9,3%) apresentaram contaminação por glúten (20 ppm); (c) grupo de alimentos rotulados com contem glúten - somente 2 de 12 (16,7%) apresentaram contaminação por glúten (20 ppm). A análise de Western-blotting confirmou 36 das 38 (95%) contaminações encontradas no ELISA-R5. CONCLUSÕES: Ambos os grupos de alimentos \"sem glúten\" e \"naturalmente sem glúten\" comercializados no Brasil apresentaram razoável porcentagem de contaminação por glúten, o que dificulta a realização de uma dieta adequada ao paciente celíaco. O grupo de alimentos rotulado \"com glúten\" não apresentou 100% de contaminação, o que revela que a rotulagem desses produtos deve ser feita como uma medida preventiva. Uma maior chance de contaminação pelo glúten foi observada para os produtos a base de arroz (13,6x), soja (13,3x) e milho (9,3x), mas não naqueles à base de mandioca. Em média, encontramos 10,8% (23 de 213) de contaminação de glúten para os alimentos analisados, um panorama positivo para a população brasileira celíaca, principalmente devido ao uso da mandioca, uma alternativa para a farinha de trigo. No entanto, a contaminação de glúten encontrada mostra a importância da quantificação de glúten em todos os alimentos industrializados. / Celiac disease (CD) is an inflammatory disorder induced by ingestion of gluten in genetically predisposed individuals and its treatment is based on a life-time gluten-free diet. Nonresponsive celiac disease is a common problem affecting from 10% to 19% of treated celiac patients. Probably a gluten contamination in diet is one of the major reasons for symptoms persistence in celiac patients as well as an inadvertent gluten intake due to a misleading nutritional label. The aim of this study was to evaluate the reliability of Brazilian processed food labels by testing gluten contamination in (a) gluten-free products - prepared specifically for the celiac population; (b) in naturally gluten-free products made with rice, corn, soy bean and cassava and used by all population and (c) in not gluten-free products labeled to contain gluten but not having it in their composition. We analyzed 213 food samples grouped accordingly to its type: 115 samples of \"gluten-free food, 86 samples of \"naturally gluten-free food and 12 samples of not-gluten free labeled products. The gluten content was detected and quantified by ELISA-R5 (Ridascreen® Gliadin) and the results were expressed in ppm and mg/100 g of food. A cut-off line was established in 20 ppm for gluten contamination. All gluten contaminations were confirmed by Western-blotting. Results: (a) Gluten-free foods - we found 100 of 115 samples (87%) with no contamination (< 20 ppm) and 15 of 115 (13%) showed gluten contamination 20 ppm; (b) Naturally Gluten-free foods - we found 78 of 86 samples (90,7%) showing no contamination (< 20 ppm) and 8 of 86 (9,3%) with gluten levels 20 ppm; (c) Not gluten-free foods - we found 10 of 12 samples (83,3%) showing no contamination (< 20 ppm) and 2 of 12 (16,7%) with gluten contamination 20 ppm. The Western-blotting analysis confirmed 36 of 38 (95%) contaminations found in the ELISA-R5. CONCLUSIONS: Both \"gluten-free and \"naturally gluten-free foods commercialized in Brazil have presented some gluten contamination making a restricted gluten-free diet hard to be achieved by the celiac population. Unexpectedly the not gluten-free group was not entirely contaminated showing a preventive measure in labeling by food companies. A higher odds ratio for gluten contamination was observed for products made with rice (13.6), soy bean (13.3) and corn (9.3) but not to cassava products (not significant). In general, we found a 10.8% (23 of 213) of gluten contamination for all food products analyzed, a positive panorama for the Brazilian celiac population mainly due to cassava products, an alternative for wheat starch. Nevertheless the gluten contamination found here leads us to the importance for a gluten quantification in all industrialized food to guarantee an appropriated diet to the Brazilian celiac group

Novel uses of wheat gluten (WG) proteins, obtained e.g. as a coproduct from bio-ethanol production, are presented in this thesis. A flame-retardant foam was prepared via in-situ polymerization of hydrolyzed tetraethyl orthosilicate (TEOS) in a denatured WG matrix (Paper I). The TEOS formed a well-dispersed silica phase in the walls of the foam. With silica contents ≥ 6.7 wt%, the foams showed excellent fire resistance. An aspect of the bio-based foams was their high sensitivity to fungi and bacterial growth. This was addressed in Paper II using a natural antimicrobial agent Lanasol. In the same paper, a swelling of 32 times its initial weight in water was observed for the pristine WG foam and both capillary effects and cell wall absorption contributed to the high uptake. In Paper III, conductive and flexible foams were obtained using carbon-based nanofillers and plasticizer. It was found that the electrical resistance of the carbon nanotubes and carbon black filled foams were strain-independent, which makes them suitable for applications in electromagnetic shielding (EMI) and electrostatic discharge protection (ESD). Paper IV describes a ‘water-welding’ method where larger pieces of WG foams were made by wetting the sides of the smaller cubes before being assembled together. The flexural strength of welded foams was ca. 7 times higher than that of the same size WG foam prepared in one piece. The technique provides a strategy for using freeze-dried WG foams in applications where larger foams are required. Despite the versatile functionalities of the WG-based materials, the mechanical properties are often limited due to the brittleness of the dry solid WG. WG/flax composites were developed for improved mechanical properties of WG (Paper V). The results revealed that WG, reinforced with 19 wt% flax fibres, had a strength that was ca. 8 times higher than that of the pure WG matrix. Furthermore, the crack-resistance was also significantly improved in the presence of the flax. / <p>QC 20170524</p>

Proteins are essential parts of living organisms that initiate and control almost all cellular processes. Despite the widely accepted belief that all functional proteins fold into stable and well-defined three-dimensional (3D) structures mandatory for protein activity, the existence of biologically functional disordered proteins has been increasingly recognized during past two decades. Proteins with inherent structural disorder, commonly known as intrinsically disordered proteins (IDPs), play many roles in a biological context. However, in contrast to their folded counterparts, they are dynamically unstructured and typically fluctuate among many conformations even while performing biological functions. In fact, it is this dynamical structural heterogeneity that that allows for IDPs to interact with other biological macromolecules in unique ways. Moreover, while a majority of proteins in eukaryotic proteomes have been found to have intrinsically disordered regions (IDR), the mechanisms by which protein disorder fives rise to biological functionality is still not well understood. Through a series of simulation studies on specific systems, this thesis probes several aspects of the emerging structure-function paradygm of IDPs, namely the mechanics, intermolecular assembly, and structural transitions occurring in these proteins. The lack of well-defined 3D structure in IDPs gives rise to distinct mechanical properties, the subject of the first study in the thesis on the elasticity of a elastomeric gluten-mimetic polypeptide with an intrinsically disordered character. This disordered polypeptide was shown to exhibit distinctively variable elastic response to a wide range of tensions, which a classical worm-like chain model failed to accurately describe, thus requiring a molecular-level analysis. IDPs frequently are frequently involved in protein-protein interactions, the focus of the second study on the propensity of an IDR, the B domain in dynamin-related protein 1 (Dpr1), to self-assemble into dimer structures while remaining disordered in all solution conditions. Despite a hypothesized auto-inhibitory role for this domain in Dpr1 that was assumed to be triggered by an disordered-to-order transition, the B domains in solution showed no tendency to form ordered structures even in the presence of order promoting osmolytes. Instead, self-association in the presence of osmolyte was found to occur by favorable intermolecular intereactions between specific region on the surface of the B-domains. Other IDPs do undergo a disorder-to-order transition in response to environmental cues, in ways that are unique disordered proteins, the focus of the last study on intermolecular ordering transitions in silk-like proteins. Factors such as protein sequence and physical tension were investigated, and results suggested that tyrosine residues in the key silk sequence motifs promote templating of beta structure from disordered precursors and that elongational stresses preferentialy stabilize antiparallel beta-sheet order. Together, these three computational studies provide insight into the nature of the structure-function mechanisms of IDPs.

This diploma thesis deals with an influence of high temperature and water shortage on the protein content of gliadin and glutenin fractions in four varieties of winter wheat: Bohemia, Tobak, Pannonia and var. Syria with designation S46 (IG142780). The crop was grown at 26, 29, 32, 35, 38 and 41 °C during anthesis under control irrigation treatment (with soil moisture higher than 70 %) or under drought stress (with soil moisture lower than 30 %). To separate gliadins, the A-PAGE method was used, and glutenins were separated by SDS-PAGE method. Proteins were quantified by computer densitometry. Significant influence of genotype on the gluten proteins was found. Variety Pannonia has high content of -, 5-gliadins, LMW and HMW glutenins, but low content of other gliadin fractions. It was the opposite in the other varieties. Due to temperature, as well as drought, there was an increase in the content of all gluten fractions, especially of HMW glutenins, 1,2-gliadins and total gliadins. The largest increase in the gluten fractions due to drought was observed in Syria variety. In other varieties simultaneous exposure to drought and heat caused decrease in gliadin content, but increase in glutenin content. Drought at high temperatures reduced gliadin-to-glutenin ratio, mostly in Bohemia variety. This ratio has increased due to the temperature, especially in Tobak variety. For Syria variety, no effect of stress conditions was found on gliadin-to-glutenin ratio.

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