Dans ce travail, nous avons résolu deux problèmes pratiques en agriculture en les modélisant en des problèmes de contrôle optimal. Un accent est mis sur les problèmes de contrôle optimal non linéaires, puisque les entrées résultantes de la modélisation sont non linéaires. On a fourni un moyen de choisir des valeurs adaptées pour le poids entre minimiser la pollution engendrée par un ajout abusif d’engrais et d’insecticides et maximiser le rendement des céréales. Le premier problème consiste à maximiser une production céréalière en tenant compte des effets néfastes de la pollution dégagée par un ajout abusif des engrais. Par la suite, dans le second problème, on a raffiné le premier problème en introduisant la contrainte de la présence des criquets. Pour les applications numériques, on a utilisé des données réelles du ministère de l’agriculture Algérien et des données de l’Institut National de la Protection des Végétaux (INPV). / In this work, we have solved two practices problems in agriculture by modeling in problems of optimal control. An emphasis is placed on nonlinear control optimal problems, since the output of the resulting models are nonlinear. It provided a way to choose defaults for the weight between minimizing pollution caused by an improper addition of fertilizers and insecticides and maximize cereal production. The first problem is to maximize cereal production taking into account the detrimental effects of pollution generated by adding abusive fertilizers. Subsequently, the second problem, we refined the first problem by introducing the constraint of the presence of locusts. For digital applications, were used actual data from the Algerian Ministry of Agriculture and Data from the National Institute of Plant Protection (INPV).

No description available.

Submitted by MARCIA ROVADOSCHI (marciar@unifra.br) on 2018-08-16T19:03:39Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_MaianaDaCostaVieira.pdf: 1165024 bytes, checksum: 10e6a641296143d116c43c04e9471744 (MD5) / Made available in DSpace on 2018-08-16T19:03:39Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_MaianaDaCostaVieira.pdf: 1165024 bytes, checksum: 10e6a641296143d116c43c04e9471744 (MD5) Previous issue date: 2014-03-28 / Nanotechnology in recent years has found many applications in different areas, one of them being the food industry. The Salvia hispanica L., or chia, has been studied mainly due to the quality of its oil, which is composed predominantly by polyunsaturated fatty acids, important for the prevention or amelioration of several metabolic disorders of the metabolic syndrome. Due to its polyunsaturated structure, the fatty acids are highly prone to oxidation, leading to undesirable flavors and odors in the enrichment of food. Milk proteins have important functional properties, including their ability to bind to hydrophobic molecules and, to some extent, retard the oxidation, which allows them to serve as excellent materials for encapsulation. To improve the stability of chia oil and maintain the nutritional value in food products as well as to improve the sensory characteristics of food (color, flavor, odor and texture), the aim of this study was to develop a cereal bar containing nanocapsules of casein chia seed oil. The nanocapsules were prepared using interfacial deposition of casein in a solution of Milli-Q ® water. The chia oil was obtained commercially (Sap Brazius ®) and used at a concentration of 0.3%. The oil was dissolved in ethanol and added to the casein solution under agitation at 40° C for 2 hours. The samples were obtained in triplicate and left at room temperature at 40 °C and 4 °C for 90 days. After the storage period, the samples were analyzed at 30, 60, and 90 days, characterized by determining the pH, particle diameter, polydispersity index (PI) and zeta potential. The samples left at room temperature and 40 °C presented precipitation of the suspension after 30 days, not remaining stable. However, the samples left at 4 °C had an initial pH of 6.63 ± 0.06, particle diameter 213 ± 57 nm 22.4 , PI 0.27 ± 0.15 and zeta potential of - 35.9 ± 4.45 mV. After 90 days, we observed a pH of 6.53 ± 0.06, a particle diameter of 215.68 ± 24 nm, PI 0.15 ± 0.055, and zeta potential of -33.2 ± 6.45 mV. The encapsulation efficiency was 86.53 % ± 4.73, showing to be a good method to nano-encapsulate oils and prevent their oxidation. Five cereal bars have been developed (without oil , with 5% chia oil, and 1 % , 5 % and 10 % suspension of nanocapsules, respectively) and we evaluated the chemical composition (moisture , protein, fat , crude fiber , ash and carbohydrates ) and sensory analysis of the cereal bars developed . The total energy value was 361.9 ± 18.4 kcal / 100g , 14.3 ± 1.3 % moisture , 7.2 ± 0.46 % protein , 9.7 ± 2.54 % lipid , 6.0% ± 2.9 % fiber , 1.3 % ash ± 0.14 and 61.6 ± 2.9 % carbohydrate. All cereal bars had an acceptability index greater than 70 % for the different attributes (color, odor, flavor and texture), proving to be satisfactory, with good potential for consumption, having a value of approximately R$ 2.50, which would be compatible with the market. / A nanotecnologia nos últimos anos tem encontrado inúmeras aplicações em diferentes áreas, sendo uma delas a indústria de alimentos. A Salvia hispanica L. ou chia vem sendo estudada principalmente devido à sua qualidade do óleo, onde os principais constituintes são os ácidos graxos poli-insaturados, importantes para a prevenção ou melhoria de diversos distúrbios metabólicos da síndrome metabólica. Devido à sua estrutura poli-insaturada, os ácidos graxos são altamente propensos à oxidação levando a indesejáveis sabores e odores no enriquecimento de produtos alimentares. As proteínas do leite possuem importantes propriedades funcionais, incluindo a sua capacidade para ligarem-se as moléculas hidrofóbicas e de certa forma retardar a oxidação, o que lhes permite servir como materiais excelentes para o encapsulamento. Para melhorar a estabilidade do óleo de chia e manter o valor nutricional em produtos alimentares, bem como melhorar as características sensoriais dos alimentos (cor, sabor, odor e textura), o objetivo deste trabalho foi desenvolver uma barra de cereal contendo nanocápsulas de caseína com óleo de semente chia. As nanocápsulas foram preparadas por deposição interfacial da caseína em uma solução de água Milli-Q®. O óleo de chia foi obtido comercialmente (Seiva Brazius®) e utilizado na concentração de 0,3%. O óleo foi dissolvido em etanol e adicionado à solução da caseína em agitação contínua a 40 ºC, durante 2 horas. As amostras foram realizadas em triplicatas e deixadas em temperatura ambiente, a 40 ºC e a 4 ºC durante 90 dias. Após o período de armazenamento as amostra foram analizadas em 30, 60 e 90 dias, caracterizadas através da determinação do pH, diâmetro das partículas, índice de polidispersão (IP) e potencial zeta. As amostras deixadas em temperatura ambiente e a 40 ºC após 30 dias houve precipitação da suspensão, não permanecendo estável. Já as amostras deixadas a 4ºC apresentou um pH inicial de 6,63 ± 0,06, diâmetro de partículas de 213, 57 ± 22,4 nm, IP de 0,27 ± 0,15 e potencial zeta de - 35,9 ± 4,45 mV. Após 90 dias pH de 6,53 ± 0,06, diâmetro de patículas de 215,68 ± 24 nm, IP de 0,15 ± 0,055 e potencial zeta de -33,2 ± 6,45 mV. A eficiência de encapsulação foi de 86,53% ± 4,73, se mostrando um bom método para nanoencapsular óleos e prevenir a oxidação dos mesmos Foram desenvolvidas cinco barras de cereias (sem oléo, com 5% de óleo de chia, e com 1%, 5% e 10% com suspensão de nanocápsulas respectivamente) e avaliou-se a composição química (umidade, proteínas, lipídios, fibra bruta, cinzas e carboidratos) e análise sensorial das barras de cereais desenvolvidas. O valor energético total foi de 361,9 ± 18,4 Kcal / 100g, 14,3 ± 1,3% de umidade, 7,2 ± 0,46% de proteínas, 9,7 ± 2,54% de lipídios, 6,0% ± 2,9% de fibras, 1,3 ± 0,14% de cinzas e 61,6 ± 2,9% de carboidratos. Todas as barras de cereais tiveram um índice de aceitabilidade maior que 70% para os diferentes atributos (cor, odor, sabor e textura), se mostrando satisfatório, tendo um bom potencial para consumo, tendo um valor aproximado de R$ 2,50, o que seria compatível com o mercado.

Orientador: Caroline Joy Steel / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-08T12:05:36Z (GMT). No. of bitstreams: 1 VernazaLeoro_MariaGabriela_M.pdf: 2963475 bytes, checksum: 26fde35fc78447f593f66f139fddbf2b (MD5) Previous issue date: 2007 / Resumo: É cada vez maior o número de pessoas que procura uma alimentação mais saudável, com alimentos frescos, de boa qualidade biológica e livre de defensivos agrícolas, como são os produtos orgânicos. Percebe-se também que nas dietas contemporâneas em geral existe um "déficit nutricional" de fibras. Este fato tem motivado as autoridades de saúde de diversos países a estimular um maior consumo de fibras por parte da população adulta, seja estimulando o consumo de alimentos como frutas, verduras, leguminosas, raízes, tubérculos e cereais integrais, ou através de produtos comerciais de consumo habitual que tenham sido enriquecidos com fibras. Já existem no mercado ou têm sido estudadas algumas fontes alternativas de fibras, como as fibras de beterraba, de caule de trigo, de laranja, de maracujá e a quitosana. Neste trabalho, optou-se por aproveitar os resíduos da extração de polpa de maracujá como fonte alternativa de fibras. Na extração de polpas e sucos, os resíduos resultantes do processo são normalmente utilizados em ração animal ou como adubo. O objetivo deste trabalho foi estudar o efeito de parâmetros da extrusão termoplástica (umidade da matéria-prima e temperatura de processo) e da adição de fibra sobre propriedades físicas, propriedades físico-químicas e propriedades nutricionais de produtos extrusados, no desenvolvimento de cereal matinal orgânico à base de farinha de milho e farelo de maracujá. A matéria-prima foi caracterizada quanto a sua composição centesimal; teores de fibra alimentar total, solúvel e insolúvel; índices de solubilidade em água (ISA), de absorção de água (IAA), de solubilidade em leite (ISL), de absorção de leite (IAL), de absorção de óleo (IAO), índice glicêmico (IG) e teor de compostos cianogênicos. Após a caracterização da matéria-prima, foi utilizado o processo de extrusão termoplástica para produzir uma base para cereal matinal, otimizando-se a formulação e os parâmetros de extrusão através da Metodologia de Superfície de Resposta, visando a obtenção de um produto com "alto teor de fibras" e propriedades tecnológicas adequadas. Os produtos extrusados foram caracterizados quanto a propriedades físicas, como índice de expansão (IE), cor, dureza e manutenção da textura em leite; propriedades físico-químicas, como ISA, IAA, ISL, IAL e IAO; e propriedades nutricionais, como IG e teor de compostos cianogênicos. Foi observado que o farelo de maracujá utilizado continha alto teor de fibra alimentar total (64,11%), apresentando teores significativos de fibra insolúvel (50,16%) e fibra solúvel (13,95%), ao contrário da farinha de milho que apresentou baixo teor de fibra alimentar total (3,68%), sendo 3,37% fibra insolúvel e 0,31% fibra solúvel. Os valores encontrados na determinação do ISA da farinha de milho e do farelo de maracujá foram 7,14 e 31,66%, respectivamente. O valor do IAA encontrado para a farinha de milho foi de 3,33 g de água/g material seco e para o farelo de maracujá foi de 14,38 g de água/g material seco. Os valores encontrados para o ISL da farinha de milho e do farelo de maracujá foram 5,23 e 14,53%, respectivamente. Os valores do ISL foram menores quando comparados com os valores do ISA. Os valores do IAL encontrados para a farinha de milho e para o farelo de maracujá foram de 3,26 e 12,50 g de leite/g material seco, maiores que os valores de IAA, possivelmente devido à formação de géis de pectina. Os índices de absorção de óleo da farinha de milho e do farelo de maracujá foram de 3,63 e 4,74 g de óleo/g de material seco, respectivamente. Os índices glicêmicos da farinha de milho e do farelo de maracujá foram de 48,03 e 45,00%, respectivamente. O farelo de maracujá apresentou um teor de compostos cianogênicos totais de 748,3 mg/kg. As superfícies de resposta demonstraram que a valores baixos das variáveis estudadas, foi obtida a maior expansão. Já, sobre a dureza dos produtos extrusados, as superfícies demonstraram que o efeito mais importante foi a umidade e a interação dela com a temperatura. Ao aumentar a umidade, a dureza dos produtos extrusados aumentou significativamente. No entanto, foi observado que a temperatura de processo foi o parâmetro que mais influenciou negativamente a textura do produto após 5 minutos de imersão em leite. Em relação à cor dos extrusados, altos níveis de farelo de maracujá diminuíram os valores de L* e hab, produzindo extrusados mais escuros e menos amarelos, ao contrário do efeito da temperatura, onde altas temperaturas aumentaram o valor de L* e o hab, produzindo extrusados mais claros e mais amarelos. Nos produtos extrusados, os maiores valores de ISA foram encontrados para os maiores teores de farelo de maracujá, enquanto que os maiores valores para o IAO foram obtidos com baixos teores de farelo. Aparentemente, não houve efeito das variáveis estudadas sobre o IG dos produtos extrusados. O teor dos compostos cianogênicos foi maior nos produtos com maiores teores de farelo de maracujá, como esperado. Além disso, parace haver um efeito da umidade da matéria-prima na redução dos compostos cianogênicos durante o processo de extrusão. O extrusado considerado como produto ótimo neste trabalho apresentou propriedades adequadas com respeito a IE e dureza. Também apresentou uma porcentagem de fibra alimentar alta (11%), bem superior à exigida pela Legislação Brasileira (6 g/100 g de produto) para ser denominado cereal matinal "com alto teor de fibras" / Abstract: The number of people searching healthier eating habits, including fresh foods of good biological quality and free of pesticides, such as organic products, is increasing. It is also observed that in contemporary diets in general, there is a â?¿nutritional deficitâ?? of fibers. This fact has motivated health authorities of several countries to stimulate a greater ingestion of fibers by the adult population, either by stimulating the consumption of fruits, vegetables, legumes, tubers and wholegrain cereals, or through the enrichment of commonly consumed commercial products. There are already a few alternative fiber sources on the market or under study, such as beetroot, wheat stalk, orange, passion fruit fibers and chitosan. In this work, we opted to use the residues from the extraction of passion fruit pulp as an alternative fiber source. In the extraction of pulps and juices, the residues are usually used as animal feed or fertilizers. The objective of this work was to study the effect of thermoplastic extrusion parameters (raw material moisture content and process temperature) and fiber addition on physical, physical-chemical and nutritional properties of extruded products, as a step in the development of an organic breakfast cereal based on corn flour and passion fruit fiber. The raw material was characterized as to its proximate composition; total, soluble and insoluble fiber contents; water solubility index (WSI), water absorption index (WAI), milk solubility index (MSI), milk absorption index (MAI), oil absorption index (OAI); glycemic index (GI) and cyanogenic compounds. After characterization of the raw material, the thermoplastic extrusion process was used to produce a base for breakfast cereals, optimizing the formulation and process parameters through the Response Surface Methodology, with the aim of obtaining a â?¿high fiber contentâ?? product with adequate technological properties. The extruded products were characterized with respect to physical properties, such as expansion index (EI), color, hardness and maintenance of texture in milk; physicalchemical properties, such as WSI, WAI, MSI, MAI and OAI; and nutritional properties, such as GI and cyanogenic compounds. It was observed that the passion fruit fiber used had a high total fiber content (64.11%), presenting significant contents of insoluble (50.16%) and soluble (13.95%) fibers, different to the corn flour used that presented a low total fiber content (3.68%), of which 3.37% were insoluble fibers and 0.31% soluble fibers. The values found for the WSI of the corn flour and passion fruit fiber were 7.14 and 31.66%, respectively. The values found for the WAI of the corn flour and of the passionfruit fiber were 3.33 and 14.38 g water/g dry material, respectively. The values found for the MSI of the corn flour and passion fruit fiber were 5.23 and 14.53%, respectively. The MSI values were lower than the WSI values. The values found for the MAI of the corn flour and passion fruit fiber were 3.26 and 12.50 g milk/g dry material, higher than those of WAI, possibly due to the formation of pectin gels. The oil absorption indices of the corn flour and passion fruit fiber were 3.63 and 4.74 g oil/g dry material, respectively. The glycemic indices of the corn flour and passion fruit fiber were 48.03 and 45.00%, respectively. The content of cyanogenic compounds in passion fruit fiber were 748,3 mg/kg. The response surfaces demonstrated that at low values of the variables studied, greatest expansion was obtained. For the hardness of the extruded products, the surfaces demonstrated that the most important effect was moisture and its interaction with temperature. Increasing moisture, the hardness of the extruded products increased significantly. However, it was observed that process temperature was the parameter that had the greatest negative effect on the texture of the products after 5 minutes in milk. With respect to color of the extrudates, high levels of passion fruit fiber reduced L* and hab values, producing darker and less yellow extrudates, different to the effect of temperature, where high temperatures increased L* and hab values, producing lighter and more yellow extrudates. In the extruded products, the highest values for WSI were found with the highest passion fruit fiber contents, while the highest values for OAI were obtained with low fiber contents. Apparently, there was no effect of the variables studied on the GI of the extruded products. The content of cyanogenic compounds was higher in the products with greater percentages of passion fruit fiber, as expected. Apart from this, there seems to be an effect of raw material moisture content in the reduction of cyanogenic compounds during the extrusion process. The extrudate considered optimum in this work presented adequate properties with respect to EI and hardness. It also presented a high percentage of dietary fiber (11%), higher than that required by the Brazilian Legislation (6 g/100 g product) to be labeled as a â?¿high fiber contentâ?? breakfast cereal / Mestrado / Mestre em Tecnologia de Alimentos

Submitted by Erika Demachki (erikademachki@gmail.com) on 2017-09-04T18:31:12Z No. of bitstreams: 2 Dissertação - Aryane Ribeiro Oliveira - 2016.pdf: 5472982 bytes, checksum: 923e2a52a3da18a7b273f39ab9be0601 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-09-15T14:06:05Z (GMT) No. of bitstreams: 2 Dissertação - Aryane Ribeiro Oliveira - 2016.pdf: 5472982 bytes, checksum: 923e2a52a3da18a7b273f39ab9be0601 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-09-15T14:06:05Z (GMT). No. of bitstreams: 2 Dissertação - Aryane Ribeiro Oliveira - 2016.pdf: 5472982 bytes, checksum: 923e2a52a3da18a7b273f39ab9be0601 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-07-19 / The by-product of rice processing, which so far has focused its use for animal feed, may be used in the preparation of food products as they have similar nutritional value to whole grain. Furthermore, they can be incorporated into other raw materials to develop new products that add nutritional value to these products. Aiming to demonstrate the quality of this by-product the purpose of this study was to produce breakfast cereals and snacks from different grain replacement levels broken rice (BR) for pulp freeze-dried acaí (PFA) and turmeric powder (TP) respectively evaluating their physical, microbiological and sensory. Moreover, developing pre-gelatinized flours extrusion under mild conditions with different substitutions lyophilized açaí the broken grains of rice and to investigate the effect of the extrusion process under physical, chemical and functional characteristics of the mixture. We used a completely randomized design with 5 treatments. The addition of PFA influenced significantly (p <0.01) all physical parameters of breakfast cereals. Regarding the sensory attributes showed no significant difference between the attributes aroma , flavor and crispness , but the greater acceptance over appearance was obtained in breakfast cereals with 10 %, 15 %, 20 % replacement BR for PFA , while acceptance in color with 15 and 20% .The chosen breakfast cereal with 15 % replacement of broken rice grains per lyophilized acai pulp showed high levels of dietary fiber (9.16 mg 100 g -1) , phenolic compounds (124,50mg 100 g-1) energy value (383.72 kcal 100 g -1) , and anthocyanins (15.21 mg Eq cyanidin -3- glucoside 100 g-1) . The replacement of BR by TP significantly influenced the expansion index, specific volume , hardness and color instrumental parameters , but did not affect the sensory attributes of appearance, color , aroma and crispness .The snacks chosen 6% TP for replacement BR per 100 g, 0.91 g ash, 7.76 g of proteins, lipids 4.78 g, 5.84 g total dietary fiber, 86.94 g carbohydrate, 396.94 kcal, 174.75 mg total phenolic compounds and 6.52% sequestration capacity of DPPH radicals. The pre-gelatinized flour, the extrusion process and affect the chemical properties proximate the mixture, resulting in a decrease in humidity, lipids, fibers, energy, phenolic compounds, antioxidant properties, anthocyanins. The rates of absorption and increased water solubility obtained after extrusion, but the oil absorption index showed no significant differences. The DSC curve shows that the temperature used in the process was sufficient to gelatinization of the starch present in the flour, showing no peak relating to that parameter in the pre-gelatinized flour. Pasting properties were also affected by the extrusion process getting pre - gelatinized flours with higher viscosity and cold paste. Therefore, it is possible to incorporate PFA and TP to broken grains of rice for the production of foods with nutritional, functional and technological value. / Os grãos quebrados oriundos do beneficiamento do arroz (GQA), que tem como destino principal as indútrias de ração, podem também ser utilizados pelas indústrias de alimentos, visto que possuem valor nutricional semelhante ao grão inteiro. Além disso, podem ser misturados com matérias-primas não convencioanais, como a polpa de açai liofilizada (PAL) e a cúrcuma em pó (CP) para desenvolver novos produtos com características nutricionais e funcionais ainda melhores. Neste contexto, o objetivo deste estudo foi produzir cereais matinais e salgadinhos extrusados a partir de diferentes níveis de substituição de GQA por PAL e CP, respectivamente, e avaliar suas características físicas, microbiológicas e aceitação sensorial. Além disso, desenvolver farinhas pré-gelatinizadas em condições brandas de extrusão com diferentes substituições de GQA por PAL, e investigar o efeito do processo de extrusão sob as propriedades físicas, químicas e funcionais da mistura. Foi utilizado um delineamento inteiramente casualizado com 5 tratamentos para cada produto. A adição de PAL influenciou significativamente (p<0,01) todos os parâmetros físicos dos cereais matinais. Em relação aos atributos sensoriais não houve diferença significativa entre os atributos aroma, sabor e crocância, mas a maior aceitação em relação à aparência foi obtida nos cereais matinais com 10%, 15%, 20% de substituição de GQA por PAL, enquanto a aceitação da cor nos com 15 e 20 %. O cereal matinal escolhido com 15% de substituição de grãos quebrados de arroz por polpa de açaí liofilizada apresentou valores elevados de fibra alimentar (9,16 mg 100g-1), compostos fenólicos (124,50 mg 100g-1) valor energético (383,72 kcal 100 g-1), e antocianinas (15,21 mg Eq de cianidina-3-glicosídeo 100 g-1). A substituição dos GQA por CP influenciou significativamente o índice de expansão, o volume específico, a dureza e os parâmetros instrumentais de cor, mas não interferiram sensorialmente nos atributos de aparência, cor, aroma e crocância. O salgadinho escolhido com 6% de substituição de grãos quebrados de arroz por cúrcuma em pó para cada 100 g, obteve 0,91 g de cinzas, 7,76 g de proteínas, 4,78 g de lipídeos, 5,84 g de fibra alimentar total, 86,94 g de carboidratos, 396,94 kcal, 174,75 mg compostos fenólicos totais e 6,52% de capacidade de sequestro de radicais DPPH. Quanto às farinhas pré-gelatinizadas, o processo de extrusão afetou as propriedades químicas da mistura, acarretando em uma diminuição da umidade, lipídeos, fibras, valor energético, compostos fenólicos totais e antocianinas, além da propriedade antioxidante. Os índices de absorção e solubilidade em água aumentaram após a extrusão, porém o índice de absorção de óleo não apresentou diferença significativa. A curva de DSC mostrou que a temperatura utilizada no processo foi suficiente para gelatinização do amido presente nas farinhas, não apresentando pico referente a esse parâmetro nas farinhas pré-gelatinizadas. As propriedades de pasta também foram afetadas pelo processo de extrusão obtendo farinhas pré-gelatinizadas com maiores viscosidade a frio e de pasta. Portanto, é possível incorporar polpa de açaí liofilizada e cúrcuma em pó aos grãos quebrados de arroz para produção de alimentos com alto valor nutricional, funcional e tecnológico.

Call number: LD2668 .T4 1948 W4 / Master of Science

Call number: LD2668 .T4 1978 B35 / Master of Science

Current crop and climate modeling studies predict temperature extremes that may add future challenges to global food and agriculture production systems due to yield decreases in our staple cereal crops. Although there have been some temperature stress adaptation traits and a few associated genes discovered in plants for enhanced thermotolerance, very little is known about these traits in our major cereal crops, particularly in maize. Furthermore, the limited availability of appropriate selection environments and accurate phenotyping, including functional traits for selection, have been major hurdles to overcome in making meaningful gains towards improved thermotolerance in breeding programs. Previous reports have established that dynamic changes in leaf membrane lipids occur when exposed to temperature stress and many have tried to identify specific lipid classes, individual species, or levels of unsaturation as indicators of tolerance or susceptibility. In this study, several types of cereals, with special emphasis on maize, are studied with the goal to expand the understanding of the leaf lipid membrane characteristics and responses when exposed to temperature stress and to find evidence of heritable lipid biomarker(s) that could be used in breeding for enhanced thermotolerance. Leaf lipids for maize inbred lines and twelve hybrids exhibiting differential tolerance to high temperature stress were analyzed after growing in a controlled environment at optimal and high temperature stress conditions. It was hypothesized that the newly introduced ratios of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) containing acyl chains with total 36 carbons and 6 double bonds (36:6) compared to those with 36 carbons and 5 double bonds (36:5), here termed the MGDG and DGDG “Unsaturation Ratios” can be used to differentiate the changes in the plastidic lipid membrane unsaturation levels and to aid in identifying heat tolerant genotypes. An analysis of the MGDG and DGDG Unsaturation Ratios was performed on twenty-five diverse parents of the nested-association mapping (NAM) population, Mo17, and one hundred and ninety-one B73 x B97 recombinant inbred lines (RILs) grown in field conditions. The selected lipid phenotypes were found to be as diverse as the inbred lines in which they were measured and showed a large differential between the temperate inbred lines B73 and B97. Allelic variation controlling the differences in MGDG and DGDG Unsaturation Ratios was identified in the B73 x B97 RIL subpopulation through linkage mapping analysis. Finally, an analysis of the MGDG and DGDG Unsaturation Ratios was performed across eight of the world’s most important cereal crops. The results of these studies provide preliminary evidence that the MGDG and DGDG Unsaturation Ratios may be beneficial lipid biomarkers that can be used to screen germplasm in breeding programs for improved thermotolerance for our most important cereal crops with the potential to differentiate tolerance in germplasm even without the presence of the ideal selection environment.

Cereal based foods, including breakfast cereals and Asian noodles are potentially good sources of selenium. Although these are major foods consumed globally, their contribution to dietary intakes of selenium is unclear. In addition, there has been very limited research into the effect of processing steps on the analysis and apparent retention of selenium. The low levels typically present in foods and the presence of multiple chemical forms of the element provide significant analytical challenges to research in this area. Therefore, the aims of this study were firstly to evaluate and validate procedures for extraction and measurement of selenium in wheat flour. Secondly, the procedure has been applied to analysis of selenium in cereal foods. The methods employed were firstly validated using wheat-based reference materials and then samples of various breakfast cereals as well as different styles of Asian noodles were analysed. Selenium was extracted using closed- v essels by microwave digestion with a mixture of nitric acid and hydrogen peroxide, followed by determination through Inductively Coupled Plasma - Mass Spectrometry (ICP-MS). The optimum conditions for selenium determination in cereal based foods involved the digestion of 0.1 g samples using 1 mL of nitric acid and 1 mL of hydrogen peroxide. The addition of 1% (v/v) methanol was found to enhance the sensitivity of the ICP-MS system. Two particular isotopes of selenium (77 and 82) could be effectively employed in the analysis and there was no significant decrease in total selenium in the digested extracts during storage for up to twelve days under refrigeration and room temperature conditions. Good precision levels were obtained and the total selenium levels in the breakfast cereal samples ranged from 0.059 to 0.378 µg/g. For white salted noodles the values varied between 0.057 and 0.712 µg/g, for yellow alkaline noodles, 0.109 to 0.265 µg/g and 0.077 to 0.284 µg/g for fried instant noodles. There was no appar ent change observed in total selenium during the processing of fried instant noodles, indicating the effectiveness of the extraction method developed here. It is concluded that microwave digestion is an effective approach to sample extraction, the procedures validated in this study are suitable for cereal grain foods and that there is considerable variation in the selenium contents of breakfast cereal and Asian noodle products.

The here presented PhD project explores the phenomenon of cereal cultivation during the Iron Age (c. 500 BC – AD 1100) in southern Scandinavia. The main body of the thesis consists of four articles. These were written with the aim to identify chronological, geographical, theoretical and methodological gaps in current research, to develop, apply and evaluate approaches to how new knowledge on Iron Age cereal cultivation can be attained, and to assess the interaction between archaeobotany and other specialisms currently used in settlement archaeology. The introduction section of the thesis also contains a historical overview of archaeobotanical research on cereal cultivation in southern Scandinavia. The first article is a compilation and summary of all available previously performed  archaeobotanical investigations in southern Sweden. This data is compared and discussed in relation to similar publications in Denmark and smaller scale compilations previously published in Sweden. The main result of the study is an updated and enhanced understanding of the main developments in the investigation area and a deepened knowledge of local development chronologies and trajectories in different parts of southern Sweden. The second article is a methodological presentation of a multiproxy analysis combining plant macrofossil analysis, phosphate analysis, magnetic susceptibility analysis and measurement of soil organic matter by loss on ignition. The applicability of the method for identification and delineation of space functions on southern Scandinavian Iron Age sites is discussed and illustrated by two case studies from the Danish site of Gedved Vest. Particular focus is placed on exploration of the use of the functional analysis for assessment of taphonomic and operational contexts of carbonised plant macrofossil assemblages. The third article aims at presenting an Iron Age cereal cultivation history for east-central Jutland, an area identified at the outset of the project as under-represented in archaeobotanical studies. The article combines data from depth analyses of material from the sites of Gedved Vest and Kristinebjerg Øst (analysed with the methods and theory presented in the second article) with a compilation of previously performed archaeobotanical analyses from east-central Jutland. The main results of the study are that developments in the study area appear to follow a chronology similar to that previously observed on Funen rather than the rest of the peninsula. Rye cultivation is furthermore discussed as more dynamic and flexible than previously presented in Scandinavian archaeobotanical literature. The fourth and final article leaves archaeobotany as the main topic. It focuses instead on evaluating, theorising and expanding the multiproxy method presented in the second article by a thorough comparison of the botanical, geochemical and geophysical methods to other techniques of functional analysis currently used in archaeology. These techniques include studies of artefact distributions, assessments of spatial relations between settlement features, and studies of the structural details of dwellings and other constructions. The main result is that there is a correspondence between the functional indications provided by botanical, geochemical and geophysical methods and techniques used in mainstream archaeology. The comparison furthermore shows that a combination of the two data sets allows for more highly resolved functional interpretations than if they are used separately. The main conclusion of the PhD thesis, based on the discussions in all four articles, is that archaeobotanical questions commonly necessitate the assessment of non-botanical archaeological material. The comparison of archaeobotanical data to other segments of the archaeological record does, however, enable the use of the former as an archaeological resource for addressing non-botanical questions. The increased understanding of (mainly settlement) site dynamics resulting from this integration of methods allows archaeobotanists to address increasingly complex botanical questions. Increased and more structured integration between archaeobotany and other specialisms operating within the framework of settlement archaeology is therefore argued to be the preferred approach to performing both high quality archaeobotany and settlement archaeology.