Orientadores: Miriam Dupas Hubinger, Rosiane Lopes da Cunha / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-07-27T06:08:16Z (GMT). No. of bitstreams: 1 Carneiro_FernandaRibeiroBurgelDias_M.pdf: 26418483 bytes, checksum: 6a13272960c36e76e841d2155085ffd1 (MD5) Previous issue date: 2000 / Resumo: O presente estudo teve por finalidade desenvolver um processo de conservação da polpa de açaí através da utilização de Métodos Combinados como alternativa ao processo de congelamento da polpa. Além disso foram analisadas as sua características reológicas através de curvas de escoamento obtidas em estado estacionário. Foram formuladas cinco diferentes produtos, a partir da polpa de açaí 3,5° Brix, utilizando os seguintes fatores de preservação: tratamento térmico brando (70°C por 3 min); redução da atividade de água (aw)(adição de sacarose à 25,35,45 e 55% p/p); redução do pH (ácido cítrico a 0,5% p/p) e agente preservante (sorbato de potássio a 0,2% p/p). As condições de estocagem foram a 25°C por 5 meses, em recipientes de vidro não hermeticamente fechados. Todos os tratamentos atingiram o tempo de vida-de-prateleira de 5 meses, exceto a polpa não tratada que atingiu apenas dois dias de armazenamento. Contudo, os resultados indicaram que há um grande potencial do uso dessa tecnologia de preservação para a polpa de açaí. Pata o estudo do comportamento reológico da polpa de açaí usou-se um reômetro de tensão controlada da marca Carri-Med CSL2 500, com geometria de cilindro concêntrico. A polpa de açaí não tratada foi estudada no intervalo de temperatura de 10 a 70°C, sendo a polpa de açaí tratada por métodos combinados apenas avaliada à 25°C. Dos modelos ajustados aos dados experimentais (Lei da Potência, Casson, plástico de Bingham e Herschel-Bulkley) o de Herschel-Bulkley foi o que melhor descreveu o comportamento do produto (R2 > 0,9952). Todas as amostras tratadas apresentaram comportamento pseudoplástico à 25°C com uma pequena tensão residual (1,02 ::;;ao ::;;4,89Pa). A polpa de açaí não tratada apresentou comportamento reopéctico à 10°C e tixotrópico a partir de 55°C. Além disso verificou-se a presença de escorregamento para tensões de cisalhamento abaixo de 7,O Pa e taxas de deformação inferiores a 20s-1 / Abstract: The objective ofthis study was to develop a conservation process to the assai pulp through the utilization of combined methods as an alternative to fteezing. Besides, its rheological characteristics were analyzed through the obtained stationary state flow curves. Five different products were generated using the following preservation factors: low temperature thermal treatment (70°C for 3 min), reduction of the water activity (aw) (addition ofsucrose by 25,35,45 and 55% w/w), reduction ofpH (citric acid at 0.5% w/w) and preservative agent (potassium sorbate at 0.2% w/w). The storage conditions were at 25°C for 5 months, in glass flasks not closed hermetically. AlI products reached a shelf life time of 5 months, while the untreated assai pulp, stored at the same conditions, showed deterioration signs by the second day of storage. Though, the results showed the great potential ofthis technology when applied to preserve the assai pulp. To study the rheological behavior of the assai pulp a controlled stress rheometer ftom Carri-Med, model CSL2 500, with cylindricalgeometry was used. The untreated assai pulp was studied in the temperature interval between 10 and 70°C, while the pulp treated by combined methods was studied only at 25°C. Of all mathematical models adjusted to the experimental data (Power Law, Bingham's plastic, Casson and Herschel-Bulkley's) the Herschel-Bulkley best described the pulp's behavior (R2 ~ 0.9952). At 25°C, all treated samples showed a pseudoplastic behavior with a small residual stress (1.02 ::;;0"0::;;4.89Pa). The untreated assai pulp showed a rheopectic at 10°C and thixotropic ftom 55°C. Besides, the presence of slipness for shear stresses under 7.0Pa and deformation rates under 20S-1 was verified / Mestrado / Mestre em Engenharia de Alimentos

>Magister Scientiae - MSc / Food security has always been one of the priority concerns in Africa, and it is mostly threatened by drought stress due to climate change. Drought-induced stress is one of the serious limiting factors of plant production, and it is known to impose oxidative stress as a consequence of excessive reactive oxygen species (ROS) accumulation that lead to lipid peroxidation, which is manifested as increased cell death. Hence, this study investigated the influence of drought stress on two contrasting canola genotypes (Agamax and Garnet), by monitoring their physiological and molecular changes. The results showed that the plant growth and biomass of both genotypes were significantly affected by drought stress as a consequence of excessive ROS accumulation (manifested as H₂O₂ and OH· content). However, under drought stress conditions, the reduction in biomass and shoot length was more pronounced in the Garnet genotype when compared to that of the Agamax genotype. This was further supported by the increase in lipid peroxidation and cell death, which were shown to be significantly higher in the Garnet genotype when compared to the Agamax genotype under drought stress. ROS scavenging ability which prevents oxidative stress and ultimately ROS-induced cellular damage. Hence, given the higher levels of antioxidant activity coupled with the reduction in ROS accumulation that was observed in the Agamax genotype, we suggest that the Agamax genotype might be slightly less susceptible to drought stress, when compared to the Garnet genotype. Furthermore, understanding the proteomic responses of these two contrasting genotypes that showed a marked difference in response to drought stress might help in unlocking complex biological networks of proteins underlying drought stress tolerance. Hence we use two-dimensional (2D) gel electrophoresis coupled with Matrix assisted laser desorption/ionisation-time of flight/time of flight tandem mass spectrometry (MALDI TOFTOF MS) analysis for this part of the study, in order to detect and analyze those differentially expressed proteins or proteins whose abundance levels were influenced as a consequence of drought stress. To gain additional insight into the leaf proteomes of the two canola genotypes, a protamine sulphate precipitation (PSP) method was used to remove RuBisCo and confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. A total of 55 well resolved protein spots were selected for mass spectrometry analysis of which 31 (56%) were positively identified using the selective criteria analysis (SCA). All positively identified proteins were then classified into functional categories including protein folding (3%), photosynthetic (29%), detoxification and protection (20%), and energy related proteins whereas 16% could not be classified into any functional category. Apart from spot 32 (Fe superoxide dismutase) and spot 34 (chloroplast beta-carbonic anhydrase), no further significant difference in protein expression/abundance was observed for all the identified proteins for both genotypes in response to drought stress. Both proteins (spots 32 and 34) have been shown to contain antioxidant activity properties which suggest that they might play a crucial role in improving drought stress tolerance in canola plants.

For trace elements, such as copper (Cu) and zinc (Zn), the bioavailability of these elements, Cu and Zn, in biosolids is important because both are essential elements and both are potential contaminants when biosolids are land applied. A greenhouse study was conducted in factorial experiment based on a completely randomized design (CRD) with four replications on a soil treated with four rates of Cu (0, 50, 100, and 150 mg/kg) and four rates of Zn (0, 150, 300, and 450 mg/kg) on celery plants to investigate the distribution and mobility of these elements as well as growth and antioxidant changes of celery. The results of antioxidant changes were inconclusive due to irregular changes with Zn and Cu applications. However, generally the results show that Cu did not affect superoxide dismutase (SOD) or peroxidase (POD) activities in most of the treatments. On the other hand, Zn stimulated SOD and POD activities in most of the treatments. The photosynthesis rate decreased with the applications of Cu and Zn at the rates above 100 and 300 mg/kg and increased in low Cu concentration (50 mg/kg) compared to S (soil without biosolid).

No description available.

O presente trabalho foi desenvolvido com o objetivo de se verificar a influência da Saccharomyces cerevisae (produto comercial ou células mantidas em meio cultura) nas atividades das enzimas peroxidases, quitinases, β-1,3-glucanases e no perfil eletroforético de peroxidases, em tecidos de milho e sorgo. As preparações de levedura utilizadas foram representadas por suspensões de células e seus respectivos filtrados, autoclavados ou não. A análise dos extratos obtidos dessas gramíneas, submetidos aos diferentes tratamentos com S. cerevisae, mostrou aumentos na atividade da peroxidase, quitinase e β-1,3-glucanase. Porém, tecidos de sorgo existiam melhor resposta aos tratamentos em comparação aos tecidos de milho, da mesma forma que o tratamento FSA (fitrado de suspensão autoclavada) estimular uma maior atividade da peroxidase em relação aos outros tratamentos. A atividade de quitinase foi maior em todos os tratamentos nos diversos tempos em relação ao controle, porém a β-1,3 glucanase exibiu maior atividade 48 e 72 horas após os tratamentos. Suspensões de células e os filtrados dessas suspensões de células, tratadas termicamente ou não, foram efetivos nas alterações enzimáticas, demonstrando serem termoestáveis. Porém, por outro lado, extratos obtidos de células intactas de homogenezadas de S. cerevisae apresentaram baixa ou nenhuma atividade de peroxidases, quitiniases ou &#946-1,3-glucanases, indicando que as alterações no aumento da atividade das enzimas e perfil eletroforético de peroxidases nas plantas, não foram devidas as enzimas existentes nas células da levedura. Finalmente, os resultados sugerem que as alterações ocorridas na atividade e perfil eletroforético de peroxidases e na atividade de quitinases e &#946-1,3-glucanases nos tecidos de milho e sorgo, em resposta ao tratamento com S. cerevisae, refletem o "reconhecimento" das células ou metabólitos da levedura por parte das plantas, acarretando uma alteração no metabolismo normal do vegetal / The aim of this work was to verifY the influence of Saccharomyces cerevisae (commercial baker's yeast or cultivated yeast cells in solid medium) on peroxidade, chitinase and β-1,3-glucanase activities and changes in the electrophoretic pattern of peroxidase in maize and sorghum tissues. The yeast treatments included cell suspension and its filtrate, autoclaved or not. These treatments induced an increase in peroxidase, chitinase and β-1,3-glucanase activities in both maize and sorghum. However, sorghum tissues exhibited better responses to treatments than maize tissues, the same results was found in the treatment with autoclaved cell filtrate, which stimulated high peroxidase activity compared to other treatments. The chitinase activity was higher in all treatments during all the time in relation to the control, while β-1,3-glucanase exhibited higher activity only at 48 and 72 hours after the treatment. Cell suspension and its filtrate, autoclaved or not, were effective in altering the activities of the enzymes showing to be thermostable. By other hand, extracts from intact or homogenized S. cerevisiae cells showed low or no activity of peroxidases, chitinases or β-1,3-glucanases, indicating that the changes in the activities or electrophoretic partern of peroxidases on plants were not due to the enzymes present in the yeast cells. Finally, the results suggest that the changes in peroxidases activity and electrophoretic pattern and chitinases and β-1,3-g1ucanases activities in maize and sorghum tissues in response to treatment with S. cerevisiae, indicate the possible recognition of the yeast cells or their metabolites by the plants

O objetivo dessa dissertação foi avaliar os efeitos do cálcio na indução de morfogênese, mais especificamente na embriogênese somática de Eucalyptus urophylla a partir de hipocótilos cultivados “in vitro". Análises bioquímicas e histológicas foram realizadas visando observar o papel do cálcio nos conteúdos de proteínas e açúcares totais, na atividade específica da peroxidase e na morfogênese, a qual foi avaliada mediante técnicas de histologia. As concentrações de cálcio (na forma de CaCl2H20) variaram de O a 12,12 mM e foram adicionadas ao meio de cultura descrito por Simola (1985) sendo que a concentração de cálcio presente nos calos foi determinada diretamente por Espectrometria  de Fluorescência de Raios-X, um método não-destrutivo que permitu que as mesmas amostras quantificadas fossem utilizadas nas análises histológicas. Uma análise estatística multivariada (Análise de Componentes Principais - PCA) permitiu agrupar os tratamentos em 5 blocos e indicou o grupo mais responsivo para uma resposta morfogênicas considerando as interações entre todos os parâmetros avaliados. Em baixas concentrações de cálcio veirificou-se ausência de resposta morfogênica e a histologia revelou tecidos colapsados e dessaranjados. Aumentando a concentração do cátion, os teores de proteínas e açúcares totais e a atividade específica da peroxidase também aumentaram. Ao nível histológico foram verificadas diferenças entre os tratamentos e foi possível verificar que a concentração de cálcio de 6,62 mmoI.L-1 , estimulou a formação de embriões somáticos globulares. / The aim of this work was to evaluate the calcium effects in the morphogenesis induction, speciffically in the somatic embryogenesis of Eucalyptus urophylla hipocotils. Biochemical and histological analysis were performed in order to observe the calcium role in the total protein and sugar contents, in the peroxidase specific activity and in the morphogenesis, wich was evalueted by histology. The calcium (CaCb.2H20) concentrations from 0.0 to 12.12 mM were added to Simola (1985) culture medium and calcium concentration in calli was determined directly by X-Ray Flourescence Spectrometry, a non-destructive technique, allowing for the processing of thesame tissue for histological analysis. A multivariate analysis (PCA-Principal Components Analysis) grouped the treatments into 5 clusters and indicated the more responsive group for a morphogenic response considering the interactions between the evaluated parameters and the calcium concentration. Lack of calcium supply caused a complete absence of a morphogenic process and tissue collapsing. The increase in calcium concentration favored the presence of higher total protein and sugar contents, the increase of peroxidase specific activity and changes in the histological characteristics. It was possible to verify that calcium stimulated globular somatic embryo formation at concentration of .62 mmoI.L-1

Lo, Yun Chuen. / Thesis (M.Sc.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 69-70). / Summary --- p.1 / Introduction --- p.2 / Methods --- p.6-15 / Subjects / Sample treatment / Protocol / "Equipment, reagents and assays" / Results --- p.15-58 / Technical aspects / Assay characteristics / Stability / Biological variation / Discussion --- p.58-68 / Acknowledgements --- p.68 / References --- p.69

Made available in DSpace on 2014-06-11T19:22:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-07-11Bitstream added on 2014-06-13T19:07:43Z : No. of bitstreams: 1 kohatsu_aan_me_arafcf.pdf: 1504236 bytes, checksum: 9c5b88c167195f46b5fed183a5266203 (MD5) / No momento há apenas dois fármacos disponíveis para o tratamento da doença de Chagas, nifurtimox e benzonidazol, ambos de ações limitadas. Assim, a compreensão dos mecanismos utilizados por T. cruzi para diminuir os efeitos citotóxicos de fármacos e a busca de potenciais moléculas para quimioterapia, bem como os alvos para elas, são de extrema importância. O aumento na produção de certas enzimas do metabolismo oxidativo seria responsável pela resistência das cepas do parasito ao benzonidazol (BZ). Tais enzimas são: triparedoxina peroxidase (mTcTXNPx) que catalisa a redução de peróxidos, superóxido dismutase (mTcSOD) que realiza a dismutação do ânion superóxido e old yellow enzyme (cTcOYE) que está envolvida na redução de substâncias tripanossomicidas, como naftoquinonas e compostos nitroheterocíclicos. Estudos demonstram que a atividade antimalarial da cloroquina foi aumentada com a adição de ferroceno. Neste trabalho, foram avaliadas as diferenças de suscetibilidade entre seis cepas de T. cruzi (Y, Bolívia, SI1, SIGR3, SI8 e QMII) em relação a três estruturas derivadas de diaminas do ferroceno e a expressão das proteínas antioxidativas. A substância AAC09 mostrou maior citotoxicidade, com CI50 de 2,21 μM para a cepa menos resistente (cepa Y) e 15,20 μM (cepa QMII) para a mais resistente, enquanto que para BZ foi 27,28 μM (cepa SI1) e 105,28 μM (cepa SIGR3), respectivamente. Após tratamento, a expressão das enzimas mTcTXNP (25,5 kDa) e cTcOYE (43 kDa) não aumentaram em cepas mais resistentes aos derivados de diaminas do ferroceno e BZ. Por outro lado, somente ocorreu aumento de expressão de mTcTXNPx na cepa Y tratada com BZ. Os resultados obtidos mostraram que cada cepa apresenta distinta suscetibilidade a um agente oxidativo e as cepas mais resistentes não aumentaram a expressão das... / At the moment there are only two drugs available for the treatment of Chagas disease, nifurtimox and benznidazole, both of use restricted. Understanding the mechanisms used by T. cruzi to reduce de cytotoxic effects of drugs and finding potential molecules for chemotherapy, as well as targets for them, are extremely important. Resistance to benznidazole (BZ) in T. cruzi strains may be caused by increased production of enzymes that act on oxidative metabolism. Such enzymes are: tryparedoxin peroxidase (mTcTXNPx), which catalyzes the reduction of peroxides, superoxide dismutase (mTcSOD), which performs the dismutation of superoxide anion and old yellow enzyme (cTcOYE), which is related to the reduction of trypanocidal substances, such as naphthoquinones and nitroheterocyclic compounds. Studies showed that the antimalarial activity of chloroquine was increased with the addition of ferroceno. Herein the susceptibilities in six T. cruzi strains (Y, Bolivia, SI1, SIGR3, SI8 and QMII) were analyzed in relation to three structures of ferrocene diamine derivatives and the expression of antioxidant proteins. The AAC09 substance showed higher cytotoxicity, with IC50 of 2.21 μM for the less resistant strain (Y strain) and 15.20 μM (QMII strain) for more resistant, whereas to BZ was 27.28 μM (strain SI1) and 105.28 μM (SIGR3), respectively. After treatment, the expression of the enzymes mTcTXNP (25.5 kDa) and cTcOYE (43 kDa) did not increase in more resistant strains to ferrocene diamine derivatives and BZ. However, there was increased expression of mTcTXNPx only in the Y strain treated with BZ. The results showed that each strain exhibited different susceptibility to oxidative agent and the most resistant strains did not enhance expression of these enzymes. Based on these findings, probably other mechanisms may be... (Complete abstract click electronic access below)

Orientador: Regina Maria Barretto Cicarelli / Banca: João Aristeu da Rosa / Banca: Maurício Bacci Junior / Resumo: No momento há apenas dois fármacos disponíveis para o tratamento da doença de Chagas, nifurtimox e benzonidazol, ambos de ações limitadas. Assim, a compreensão dos mecanismos utilizados por T. cruzi para diminuir os efeitos citotóxicos de fármacos e a busca de potenciais moléculas para quimioterapia, bem como os alvos para elas, são de extrema importância. O aumento na produção de certas enzimas do metabolismo oxidativo seria responsável pela resistência das cepas do parasito ao benzonidazol (BZ). Tais enzimas são: triparedoxina peroxidase (mTcTXNPx) que catalisa a redução de peróxidos, superóxido dismutase (mTcSOD) que realiza a dismutação do ânion superóxido e old yellow enzyme (cTcOYE) que está envolvida na redução de substâncias tripanossomicidas, como naftoquinonas e compostos nitroheterocíclicos. Estudos demonstram que a atividade antimalarial da cloroquina foi aumentada com a adição de ferroceno. Neste trabalho, foram avaliadas as diferenças de suscetibilidade entre seis cepas de T. cruzi (Y, Bolívia, SI1, SIGR3, SI8 e QMII) em relação a três estruturas derivadas de diaminas do ferroceno e a expressão das proteínas antioxidativas. A substância AAC09 mostrou maior citotoxicidade, com CI50 de 2,21 μM para a cepa menos resistente (cepa Y) e 15,20 μM (cepa QMII) para a mais resistente, enquanto que para BZ foi 27,28 μM (cepa SI1) e 105,28 μM (cepa SIGR3), respectivamente. Após tratamento, a expressão das enzimas mTcTXNP (25,5 kDa) e cTcOYE (43 kDa) não aumentaram em cepas mais resistentes aos derivados de diaminas do ferroceno e BZ. Por outro lado, somente ocorreu aumento de expressão de mTcTXNPx na cepa Y tratada com BZ. Os resultados obtidos mostraram que cada cepa apresenta distinta suscetibilidade a um agente oxidativo e as cepas mais resistentes não aumentaram a expressão das... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: At the moment there are only two drugs available for the treatment of Chagas disease, nifurtimox and benznidazole, both of use restricted. Understanding the mechanisms used by T. cruzi to reduce de cytotoxic effects of drugs and finding potential molecules for chemotherapy, as well as targets for them, are extremely important. Resistance to benznidazole (BZ) in T. cruzi strains may be caused by increased production of enzymes that act on oxidative metabolism. Such enzymes are: tryparedoxin peroxidase (mTcTXNPx), which catalyzes the reduction of peroxides, superoxide dismutase (mTcSOD), which performs the dismutation of superoxide anion and old yellow enzyme (cTcOYE), which is related to the reduction of trypanocidal substances, such as naphthoquinones and nitroheterocyclic compounds. Studies showed that the antimalarial activity of chloroquine was increased with the addition of ferroceno. Herein the susceptibilities in six T. cruzi strains (Y, Bolivia, SI1, SIGR3, SI8 and QMII) were analyzed in relation to three structures of ferrocene diamine derivatives and the expression of antioxidant proteins. The AAC09 substance showed higher cytotoxicity, with IC50 of 2.21 μM for the less resistant strain (Y strain) and 15.20 μM (QMII strain) for more resistant, whereas to BZ was 27.28 μM (strain SI1) and 105.28 μM (SIGR3), respectively. After treatment, the expression of the enzymes mTcTXNP (25.5 kDa) and cTcOYE (43 kDa) did not increase in more resistant strains to ferrocene diamine derivatives and BZ. However, there was increased expression of mTcTXNPx only in the Y strain treated with BZ. The results showed that each strain exhibited different susceptibility to oxidative agent and the most resistant strains did not enhance expression of these enzymes. Based on these findings, probably other mechanisms may be... (Complete abstract click electronic access below) / Mestre

Comparative physiological and biochemical studies were conducted with apple varieties which were susceptible (Granny Smith and Lady Williams) and resistant (Crofton) to superficial scald, to understand the mechanisms of scald aetiology. This provided a basis for the development of alternatives to diphenylamine to control the disorder in cool stored apples. The research confirmed earlier research, which showed that the typical scald symptoms were the result of the deposition of brown pigments on the tonoplast in hypodermal and epidermal cells. It has been generally accepted that these pigments were formed by the action of polyphenol oxidase (PPO) following its release from chloroplasts, as a result of membrane damage caused by the oxidation products of alpha-farnesene. However, intact and functional chloroplasts were observed in severely scalded peel tissue. It was proposed that peroxidase (POD) might play a more important role in scald development. The concept that the concentration of alpha-farnesene or its products was related to the severity of scald was examined, and results indicated that differences in scald susceptability were related to the ability of apple tissue to cope with oxidative stress at low temperatures rather than the concentration of alpha-farnesene. If alpha-farnesene has a scald promoting role, it may be as a participant in a free radical chain reaction rather than an initiator. Studies were conducted on the phenolic compounds present in apple peel, which led to the proposal that phenolics might confer scald resistance by conserving other antioxidants and preventing peroxidation of membrane lipids. An holistic model of scald development was proposed, which indicated that scald results from a chilling stress since scald only occurs at temperatures below 4 degrees C and only in apples in which the capacity to protect membranes from oxidative stress is low. The model proposed that POD may have a more important role than PPO in scald development than previously thought. / Doctor of Philosophy (PhD)