Wheat bran contains a diverse collection of macronutrients, micronutrients and bioactive components, including those thought to have an important role in reducing the risk of many chronic diseases. The complication of wheat bran as a functional food relates to its high insoluble fibre content, which renders bran and its constituent bioactives largely indigestible, and hence with limited bioavailability. The main objective of this thesis research was to evaluate the effects of heat treatments of branon the antioxidant activity and chemical composition of the bran. Presumably, if the solubility of wheat bran can be enhanced by pre-treatment, its biological impact associated with its fibre and resident phytochemicals would also be enhanced. Compared to untreated bran, freeze dried water soluble extracts of thermally treated bran had substantially enhanced levels of antioxidant activity and signficantly increased concentration of a very broad spectrum of bran bioactive constituents including phenolics, minerals, phytate, B vitamins, and non-starch polysaccharide fibre compounds. Results taken together point to the development of novel wheat bran and extracts with considerable commercial potential for whole grain food use and a variety of nutraceutical applications far beyond what may be possible with whole grain wheat or normal bran. Outcomes of the research highlight the conclusion that the nutritional and functional food benefits of normal wheat bran probably represent a fraction of its potential due to the limited digestibility of wheat bran, which in turn, limits the bioavailability of its fiber and constituent bioactive compounds.

Wheat bran contains a diverse collection of macronutrients, micronutrients and bioactive components, including those thought to have an important role in reducing the risk of many chronic diseases. The complication of wheat bran as a functional food relates to its high insoluble fibre content, which renders bran and its constituent bioactives largely indigestible, and hence with limited bioavailability. The main objective of this thesis research was to evaluate the effects of heat treatments of branon the antioxidant activity and chemical composition of the bran. Presumably, if the solubility of wheat bran can be enhanced by pre-treatment, its biological impact associated with its fibre and resident phytochemicals would also be enhanced. Compared to untreated bran, freeze dried water soluble extracts of thermally treated bran had substantially enhanced levels of antioxidant activity and signficantly increased concentration of a very broad spectrum of bran bioactive constituents including phenolics, minerals, phytate, B vitamins, and non-starch polysaccharide fibre compounds. Results taken together point to the development of novel wheat bran and extracts with considerable commercial potential for whole grain food use and a variety of nutraceutical applications far beyond what may be possible with whole grain wheat or normal bran. Outcomes of the research highlight the conclusion that the nutritional and functional food benefits of normal wheat bran probably represent a fraction of its potential due to the limited digestibility of wheat bran, which in turn, limits the bioavailability of its fiber and constituent bioactive compounds.

Made available in DSpace on 2014-06-11T19:22:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-03-07Bitstream added on 2014-06-13T19:48:28Z : No. of bitstreams: 1 souza_av_me_botfca.pdf: 762205 bytes, checksum: 1a231de04b5d58772485080e2c088804 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Este trabalho teve como objetivo prolongar a vida útil de lichias cv. ‘Bengal’ sob refrigeração provenientes de Carlópolis - PR, com o emprego do tratamento térmico em frutos refrigerados. Os frutos foram submetidos aos tratamentos: Imersão dos frutos em água a 45°C por: T – 1: controle; T – 2: 5 minutos; T – 3: 10 minutos; T – 4: 15 minutos; T – 5: 20 minutos e T – 6: 25 minutos. Depois de higienizados com 150ppm de cloro e secos, os frutos foram acondicionados em bandejas de poliestireno expandido e embalados com filme de policloreto de vinila 0,020mm, com 10 frutos cada uma (cerca de 200 gramas) e armazenados em B.O.D. a 5ºC e 90±5% de UR por 15 dias. Os frutos foram analisados quanto à avaliação visual, perda de massa fresca, firmeza, potencial hidrogeniônico (pH), acidez titulável (AT), sólidos solúveis (SS), relação SS/AT (“Ratio”), ácido ascórbico, açúcares redutores, respiração, coloração, atividade específica da polifenol oxidase - PPO (EC. 1.14.18.1) e da peroxidase – POD (EC. 1.11.1.7) logo após a colheita e na retirada da B.O.D. aos 3, 6, 9, 12 e 15 dias. O delineamento estatístico empregado foi inteiramente casualizado com três repetições por tratamento para cada um dos seis tempos de avaliação, utilizando-se o Teste de Tukey a 5% de probabilidade. Nas condições experimentais, pode-se concluir que o tratamento térmico aos 5 ou a 10 minutos/45ºC mostraram-se mais eficazes na manutenção da coloração dos frutos que é o fator mais importante na qualidade dos frutos de lichia e não causou modificações na qualidade da sua polpa. / This research was realized aiming to prolong the shelf life of the ‘Bengal’ lychees under refrigeration, from the Carlópolis city, PR State, Brazil, with the use of thermal treatments in refrigerated fruits. The fruits were subjected to the treatments: immersion in water to 45°C by: T - 1: control; T – 2: 5 minutes; T – 3: 10 minutes; T – 4: 15 minutes; T – 5: 20 minutes and T – 6: 25 minutes. After cleaned with 150 ppm of chlorine and dried, the fruits were packed in polystyrene trays and wrapped with polyvinyl chloride film 0,020 mm, with 10 fruits in each one (about 200 grams) and stored in B.O.D. to 5°C and 90±5% of RU by 15 days. The fruits were analyzed concerning the visual evaluation, loss of weight mass, firmness, hydrogenionic potential (pH), titulable acidity (TA), soluble solids (SS), SS/TA relation (“Ratio”), ascorbic acid, reducing sugar, respiration, color, specific activity of the polyphenol oxidase – PPO (EC. 1.14.18.1) and peroxidase – POD (EC. 1.11.1.7) soon after the harvest and in the removal of the B.O.D. (in 3, 6, 9, 12 and 15 days).The statistical delineation used was completely randomized, with three replications by treatment for each one in the six times of evaluation, using the Tukey test to 5% of probability. In experimental conditions, can be conclude that the thermical treatments with 5 or 10 minutes/45°C showed more effective in maintaining the coloration of fruits, which is the most important factor in quality of the lychee fruits and did not cause changes in the quality of the pulp.

This work aims to study the variation in electrical and optical properties of nanoscale Schottky diodes by varying their dimensions in the nanoscale. Experimental conditions for fabricating porous alumina with varying pore diameters and inter-pore distances were first optimized by anodizing Aluminum tape with variable currents. Cadmium Sulfide nanowires were then synthesized inside the membranes by dc electrodeposition. Finally a high work function metal was deposited on top as a contact for the metal-semiconductor Schottky diode junction. As a comparative study, Schottky diodes fabricated using the same metals and Cadmium Sulfide thin films deposited on conducting glass substrates using electro-deposition and annealed in different ambient were also studied. Device characterizations were carried out by field-emission scanning electron microscopy (FESEM), current voltage (I-V) measurements, ultraviolet-visual (UV-Vis) absorption spectroscopy and X-Ray diffraction.

No description available.

<p>Pravilna ishrana preživara je važna za održanje zdravstvenog stanja životinja, a takođe je i ključna za efikasnu i ekonomičnu proizvodnju mleka i mesa. Kod visokoproizvodnih preživara, kao &scaron;to su tovna junad i mlečne krave, energetske potrebe su velike kako bi se ostvario brz prirast telesne mase i visok prinos mleka. Termički tretmani se koriste za pobolj&scaron;anje hranljivih, higijenskih, fizičkih i hemijskih karakteristika hrane za životinje. Osnovni cilj istraživanja u okviru ove disertacije je analiza uticaja različitih termičkih tretmana na promene skrobne komponente i svarljivost kukuruza kod preživara. U tu svrhu primenjeni su tretmani peletiranja, parnog flekičenja, mikronizacije i ekstrudiranja na uzorcima kukuruza i potpune sme&scaron;e za krave muzare. Promene u strukturi skrobnih granula su praćene pomoću skening elektronske mikroskopije i diferencijalne skenirajuće kalorimetrije, dok su promene u hidrataciji i bubrenju uzoraka određene analizom kriva pastiranja, indeksa apsorpcije vode (WAI) i indeksa rastvorljivosti u vodi (WSI). In situ tehnikom je praćena promena brzine svarljivosti skroba i suve materije u buragu preživara i uticaj različitih termičkih tretmana na mesto varenja skroba kukuruza. Promene u svarljivosti organske materije (SOM) kroz ceo digestivni trakt preživara su određene in vitro multi-enzimskom metodom.<br />Na osnovu rezultata DSC analize uzoraka kukuruza i sme&scaron;a utvrđeno je da su parno flekičenje, mikronizacija i peletiranje blagi tretmani, dok je ekstrudiranje o&scaron;triji tretman koji dovodi do potpunije želatinizacije skroba. U uzorku parno flekičanog kukuruza do&scaron;lo je do interakcije degradiranih komponenti (skroba, proteina i lipida) na molekularnom nivou i nastanak jedinjenja sa većom molekulskom masom i smanjenom rastvorljivo&scaron;ću. U dva uzorka ekstrudiranog kukuruza zbog većih sila smicanja i dužeg vremena zadržavanja materijala u ekstruderu do&scaron;lo je do delimične želatinizacije koja je bila praćena dekstrinizacijom skroba. In situ metodom su za uzorak netretirane sme&scaron;e određene najniže vrednosti nestajanja SM i skroba u buragu, dok su svi primenjeni termički tretmani doveli do značajnog povećanja razgradnje SM i skroba. Najmanje povećanje razgradnje skroba u poređenju sa netretiranom sme&scaron;om je zabeleženo kod sme&scaron;e koja je sadržala parno flekičan kukuruz, dok je u svim uzorcima ekstrudiranih sme&scaron;a do&scaron;lo do razgradnje velike količine skroba već tokom prva 3h inkubacije. U poređenju sa netretiranom sme&scaron;om, svi primenjeni termički tretmani su doveli do povećanja brzine razgradnje skroba u manjoj ili većoj meri a u zavisnosti od vrste i intenziteta tretmana. Značajne razlike u karakteristikama razgradnje skroba su zabeležene nakon variranja procesnih parametara ekstrudiranja, dok su uočene razlike između sme&scaron;a koje su sadržale mikronizirani kukuruz bile mnogo manje izražene. Mobile bag metodom određena je svarljivost skroba u crevima koja je u netretiranoj i svim termički tretiranih sme&scaron;ama iznosila 100%. Statističkom obradom rezultata nije utvrđeno značajno povećanje SOM kukuruza i sme&scaron;e nakon primenjenih termičkih tretmana u poređenju sa netretiranim uzorcima.</p> / <p>Proper ruminant nutrition is important for maintaining the health of animals, and it is also crucial for the efficient and economical production of milk and meat. In high-yielding ruminants, such as fattening cattle and dairy cows, energy needs are high in order to achieve rapid weight gain and high milk yield. Thermal treatments are used to improve nutritional, hygienic, physical and chemical characteristics of animal feed. The main objective of this research is the analysis of the influence of various thermal treatments on changes in the starch component and the digestibility of corn in ruminants. For this purpose pelleting, steam flashing, micronization and extrusion of maize samples and complete mixture for dairy cows were applied. Changes in the structure of starch granules were monitored by scanning electron microscopy and differential scanning calorimetry (DSC), while changes in the hydration and swelling of samples were determined by analyzing pasting properties, water absorption index (WAI) and water solubility index (WSI) of samples. In situ technique was used to determine the changes in the rate of digestibility of starch and dry matter in rumen and the influence of various thermal treatments on the site of digestion of corn starch. Changes in the organic matter digestibility (OMD) through the entire digestive tract of the ruminants are determined by the in vitro multi-enzymatic method.<br />Based on the results of DSC analysis of corn and complete feed samples, it has been found that steam flaking, micronization and pelleting are mild treatments, while the extrusion is more severe treatment that leads to a more complete starch gelatinization. In steam flaked corn interaction of degraded components (starch, proteins and lipids) at the molecular level resulted in the formation of compounds with higher molecular weight and reduced solubility. In two samples of extruded corn, due to the higher shear rate and longer retention time of the material in the extruder, there was partial gelatinization followed by dextrinisation of starch. In untreated complete feed, the lowest values of DM and starch disappearance in rumen were determined using in situ method, while all the applied thermal treatments led to a significant increase in the degradation of DM and starch. The smallest increase in degradation of starch in comparison to untreated mixture was observed in a mixture containing steam flaked corn, while in all extruded mixtures large amount of starch was degraded during the first 3 hours of incubation. Compared to the untreated mixture, all applied thermal treatments resulted in an increase in the degradation rate of starch to a lesser or greater extent depending on the type and intensity of the treatment. Significant differences in the degradation characteristics of the starch were observed after variation of the extrusion processing parameters, while the observed differences between the mixtures containing micronized corn were much less pronounced. Digestibility of starch in the intestine was determined with mobile bag method, which was 100% in untreated and all thermally treated mixtures. Statistical analysis of the results did not show a significant increase in OMD of maize and mixtures after the applied thermal treatments compared to the untreated samples.</p>

Made available in DSpace on 2014-10-09T12:52:04Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:58:08Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Orientador: Rogério Lopes Vieites / Banca: Giuseppina Pace Pereira Lima / Banca: José Maria Monteiro Sigrist / Resumo: Este trabalho teve como objetivo prolongar a vida útil de lichias cv. 'Bengal' sob refrigeração provenientes de Carlópolis - PR, com o emprego do tratamento térmico em frutos refrigerados. Os frutos foram submetidos aos tratamentos: Imersão dos frutos em água a 45°C por: T - 1: controle; T - 2: 5 minutos; T - 3: 10 minutos; T - 4: 15 minutos; T - 5: 20 minutos e T - 6: 25 minutos. Depois de higienizados com 150ppm de cloro e secos, os frutos foram acondicionados em bandejas de poliestireno expandido e embalados com filme de policloreto de vinila 0,020mm, com 10 frutos cada uma (cerca de 200 gramas) e armazenados em B.O.D. a 5ºC e 90±5% de UR por 15 dias. Os frutos foram analisados quanto à avaliação visual, perda de massa fresca, firmeza, potencial hidrogeniônico (pH), acidez titulável (AT), sólidos solúveis (SS), relação SS/AT ("Ratio"), ácido ascórbico, açúcares redutores, respiração, coloração, atividade específica da polifenol oxidase - PPO (EC. 1.14.18.1) e da peroxidase - POD (EC. 1.11.1.7) logo após a colheita e na retirada da B.O.D. aos 3, 6, 9, 12 e 15 dias. O delineamento estatístico empregado foi inteiramente casualizado com três repetições por tratamento para cada um dos seis tempos de avaliação, utilizando-se o Teste de Tukey a 5% de probabilidade. Nas condições experimentais, pode-se concluir que o tratamento térmico aos 5 ou a 10 minutos/45ºC mostraram-se mais eficazes na manutenção da coloração dos frutos que é o fator mais importante na qualidade dos frutos de lichia e não causou modificações na qualidade da sua polpa. / Abstract: This research was realized aiming to prolong the shelf life of the 'Bengal' lychees under refrigeration, from the Carlópolis city, PR State, Brazil, with the use of thermal treatments in refrigerated fruits. The fruits were subjected to the treatments: immersion in water to 45°C by: T - 1: control; T - 2: 5 minutes; T - 3: 10 minutes; T - 4: 15 minutes; T - 5: 20 minutes and T - 6: 25 minutes. After cleaned with 150 ppm of chlorine and dried, the fruits were packed in polystyrene trays and wrapped with polyvinyl chloride film 0,020 mm, with 10 fruits in each one (about 200 grams) and stored in B.O.D. to 5°C and 90±5% of RU by 15 days. The fruits were analyzed concerning the visual evaluation, loss of weight mass, firmness, hydrogenionic potential (pH), titulable acidity (TA), soluble solids (SS), SS/TA relation ("Ratio"), ascorbic acid, reducing sugar, respiration, color, specific activity of the polyphenol oxidase - PPO (EC. 1.14.18.1) and peroxidase - POD (EC. 1.11.1.7) soon after the harvest and in the removal of the B.O.D. (in 3, 6, 9, 12 and 15 days).The statistical delineation used was completely randomized, with three replications by treatment for each one in the six times of evaluation, using the Tukey test to 5% of probability. In experimental conditions, can be conclude that the thermical treatments with 5 or 10 minutes/45°C showed more effective in maintaining the coloration of fruits, which is the most important factor in quality of the lychee fruits and did not cause changes in the quality of the pulp. / Mestre

Made available in DSpace on 2014-10-09T12:52:04Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:58:08Z (GMT). No. of bitstreams: 0 / Nesse trabalho estudou-se a influência da adição de 0,5 % at. de zircônio (Zr) e gálio (Ga) nos ímãs permanentes à base de praseodímio (Pr) HD sinterizados obtidos por uma mistura de ligas. As ligas utilizadas foram: Pr12,6Fe68,3Co11,6B6Zr0,5Ga1, Pr16Fe75,5B8Zr0,5 e Pr13Fe80,5B6Zr0,5. A investigação foi realizada a partir das medidas das propriedades magnéticas e da microestrutura. Inicialmente, compararam-se as fases das ligas com as fases obtidas nos ímãs sinterizados. Posteriormente, os ímãs foram submetidos a um ciclo de tratamento térmico (de duas horas a 1000º C com resfriamento rápido até 10 horas, em seguida, de cinco horas nas mesmas condições, até 35 horas). Para o entendimento do papel de cada aditivo na fase magneticamente dura (fase &#934;), foram analisadas as mudanças na microestrutura e relacionadas com as mudanças nas propriedades magnéticas. O Ga e Zr atuam como refinadores da fase &#934; (matriz). O Ga atua no grão da fase &#934; possibilitando a estabilidade da sua forma e melhorias das propriedades magnéticas. Para o ímã Pr14,3Fe71,9Co5,8B7Zr0,5Ga0,5 a evolução das propriedades magnéticas, após 15 h de tratamento térmico, foi: remanência de (1,25±0,02) T para (1,30±0,02) T, coercividade intrínseca de (1,11±0,02) T para (0,87±0,02) T, fator de quadratura de (0,68±0,02) para (0,89±0,02) e produto de energia de (285±5) kJ/m3 para (317±5) kJ/m3. O Zr tem uma atuação dual. Inibe o crescimento desordenado do grão e aumenta a anisotropia, mas, ao alojar-se no contorno de grão, gera domínios reversos prejudicando a coercividade intrínseca. Para o ímã Pr14.5Fe78B7Zr0.5 a evolução das propriedades magnéticas, após 15 h de tratamento térmico, foi: remanência (1,19±0,02) T para (1,25±0,02) T, coercividade de (0,74±0,02) T para (0,94±0,02) T, fator de quadratura de (0,88±0,02) para (0,85±0,02) e produto de energia (258±5) kJ/m para (291±5) kJ/m. Para o ímã Pr3316Fe75.5B8Zr0.5 a evolução das propriedades magnéticas, após 20 h de tratamento térmico, foi: remanência (1,17±0,02) T para (1,24±0,02) T, coercividade de (0,90±0,02) T para (1,22±0,02) T, fator de quadratura de (0,93±0,02) para (0,66±0,02) e produto de energia (258±5) kJ/m3 para (272±5) kJ/m3. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

No description available.