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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Nitrate, nitrite and nitrosamine: contents and analyses in selected foods; effect of vitamin C supplementation on N-nitrosodimethylamine formation in humans; and an investigation of natural alternatives to nitrites as preservatives in cured meat products

Hsu, James Chun Hou, Chemical Sciences & Engineering, Faculty of Engineering, UNSW January 2009 (has links)
Dietary nitrite intake has been implicated in numerous gastrointestinal cancers in humans due to the formation of a group of carcinogens called N-nitroso compounds. The need to estimate their intake is vital in establishing at risk population and to monitor and perhaps one day manage their dietary intake. This is the first study to estimate nitrate and nitrite in selected vegetables, cured and fresh meat in Australian food supply using ion-paired reversed-phased HPLC. Nitrite content in meat products analysed ranged from 0 to 83.9 mg/kg in medallion beef and Frankfurt, respectively; nitrate content ranged from 18.7 mg/kg in minced beef to 142.5 mg/kg in salami. The nitrite content was below the maximum limit set by the Food Standards Australia and New Zealand. Nitrate content in selected vegetables ranged from 123 to 4850 mg/kg in Iceberg lettuce and English spinach, respectively; only minimal nitrite at 20 mg/kg was present in Gai choy, which was most likely due to bacterial contamination during storage. Based on the food consumption pattern of Australians, the dietary nitrite and nitrate intake from bacon were 1.51 and 3.42 mg per capita per day, which was below the Adequate Daily Intake set by the European Union Scientific Committee for food in 1995. Taking into considerations of oral nitrate reduction to nitrite and the endogenous nitrate formation, the upper extreme of dietary nitrite and nitrate intake in Australians were 44 and 2.4 times over the ADI, respectively. However, this does not take into effect of other dietary promoters and inhibitors. Eighteen healthy human volunteers were put on a low nitrate, nitrite and antioxidant diet for three days during which they were fed one serving of cured meat with and without 500 mg of vitamin C. Using GC-MS, N-nitrosodimethylamine was not detected in the urine before or after vitamin C supplementation, suggested that a diet low on nitrate and nitrite cannot produce NDMA and thus may reduce the risk of developing gastrointestinal cancers. Different extraction methods and combination of herbs and spices were demonstrated in vitro to show inhibition against B. cereus, Escherichia coli, Listeria monocytogenes, Salmonella Enteritidis and Staphylococcus aureus. In addition, autoclaved turmeric powder at 0.3 % (w/v), hot water extracted turmeric with ginger at 0.5 % and rosemary at 1.0 % showed growth inhibition against Clostridium sporogenes, which was used as a surrogate for Clostridium botulinum. The use of these combinations of herbs and spices may replace or at least reduce the use of nitrite as a preservative in cured meat products to prevent botulism and reduce dietary nitrite intake.
112

Nitrate, nitrite and nitrosamine: contents and analyses in selected foods; effect of vitamin C supplementation on N-nitrosodimethylamine formation in humans; and an investigation of natural alternatives to nitrites as preservatives in cured meat products

Hsu, James Chun Hou, Chemical Sciences & Engineering, Faculty of Engineering, UNSW January 2009 (has links)
Dietary nitrite intake has been implicated in numerous gastrointestinal cancers in humans due to the formation of a group of carcinogens called N-nitroso compounds. The need to estimate their intake is vital in establishing at risk population and to monitor and perhaps one day manage their dietary intake. This is the first study to estimate nitrate and nitrite in selected vegetables, cured and fresh meat in Australian food supply using ion-paired reversed-phased HPLC. Nitrite content in meat products analysed ranged from 0 to 83.9 mg/kg in medallion beef and Frankfurt, respectively; nitrate content ranged from 18.7 mg/kg in minced beef to 142.5 mg/kg in salami. The nitrite content was below the maximum limit set by the Food Standards Australia and New Zealand. Nitrate content in selected vegetables ranged from 123 to 4850 mg/kg in Iceberg lettuce and English spinach, respectively; only minimal nitrite at 20 mg/kg was present in Gai choy, which was most likely due to bacterial contamination during storage. Based on the food consumption pattern of Australians, the dietary nitrite and nitrate intake from bacon were 1.51 and 3.42 mg per capita per day, which was below the Adequate Daily Intake set by the European Union Scientific Committee for food in 1995. Taking into considerations of oral nitrate reduction to nitrite and the endogenous nitrate formation, the upper extreme of dietary nitrite and nitrate intake in Australians were 44 and 2.4 times over the ADI, respectively. However, this does not take into effect of other dietary promoters and inhibitors. Eighteen healthy human volunteers were put on a low nitrate, nitrite and antioxidant diet for three days during which they were fed one serving of cured meat with and without 500 mg of vitamin C. Using GC-MS, N-nitrosodimethylamine was not detected in the urine before or after vitamin C supplementation, suggested that a diet low on nitrate and nitrite cannot produce NDMA and thus may reduce the risk of developing gastrointestinal cancers. Different extraction methods and combination of herbs and spices were demonstrated in vitro to show inhibition against B. cereus, Escherichia coli, Listeria monocytogenes, Salmonella Enteritidis and Staphylococcus aureus. In addition, autoclaved turmeric powder at 0.3 % (w/v), hot water extracted turmeric with ginger at 0.5 % and rosemary at 1.0 % showed growth inhibition against Clostridium sporogenes, which was used as a surrogate for Clostridium botulinum. The use of these combinations of herbs and spices may replace or at least reduce the use of nitrite as a preservative in cured meat products to prevent botulism and reduce dietary nitrite intake.
113

Efeitos do nitrito de sódio e sua associação ao sildenafil na hipertensão gestacional experimental em ratas

Rizzi, Victor Hugo Gonçalves. January 2018 (has links)
Orientador: Carlos Alan Candido Dias Junior / Resumo: As desordens hipertensivas gestacionais são complicações que acometem em torno de 5-10% das gestações. Essas desordens são as maiores causas de morbidade e mortalidade tanto materna quanto fetal. Estudos demonstram redução da biodisponibilidade do óxido nítrico (NO) em doenças hipertensivas gestacionais, tornando uma das condições responsáveis por agravar a disfunção endotelial durante o curso desta doença. Neste sentido, trabalhos demonstram que a administração oral de nitrito de sódio (NaNO2) e a administração de citrato de sildenafil podem reverter a redução da biodisponibilidade de NO e potencializar a via de sinalização NO-GMPc respectivamente. Para realização dos trabalhos foram utilizadas ratas Wistar, no qual, após confirmação da prenhez receberam L-NAME i.p para indução da hipertensão e tratamentos com nitrito de sódio e/ou citrato de sildenafil via oral entre os dias 14-21 de prenhez. A pressão arterial sistólica foi aferida pelo método de pletismografia de cauda. Parâmetros materno-fetais como: peso fetal e placentário, número de fetos viáveis e reabsorvidos foram realizados após a morte das ratas no 21º dia gestacional. O plasma das ratas foram armazenados para dosagens dos níveis plasmáticos de nitrito+nitrato, guanosina monofosfato cíclico (GMPc), mieloperoxidase (MPO), peroxidação lipídica (TBARS), TEAC, MTT sFlt-1 e VEGF. Além disso o plasma das ratas foram incubadas com células endoteliais de cordão umbilical humano (HUVECS) para avaliar a produção de NO endo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Gestational hypertensive disorders are complications that affect around 5-10% of pregnancies. These disorders are the major causes of both maternal and fetal morbidity and mortality. Studies have demonstrated a reduction in the bioavailability of nitric oxide (NO) in gestational hypertensive diseases, making it one of the conditions responsible for aggravate the endothelial dysfunction during the course of this disease. In this sense, studies demonstrate that oral administration of sodium nitrite (NaNO2) and administration of sildenafil citrate may reverse the reduction of NO bioavailability and potentiate the NO-cGMP signaling pathway, respectively. Wistar rats were used to perform the study, in which, after confirmation of pregnancy, they received L-NAME i.p for induction of hypertension and treatments with sodium nitrite and/or sildenafil citrate orally between days 14-21 of pregnancy. Systolic blood pressure was measured by the tail plethysmography method. Maternal-fetal parameters such as: fetal and placental weight, number of viable and reabsorbed fetuses were performed after the death of the rats on the 21st gestational day. Plasma of the rats were stored for plasma levels of nitrite + nitrate, cGMP, myeloperoxidase (MPO), lipid peroxidation (TBARS), TEAC, MTT sFlt-1 and VEGF. In addition the plasma of the rats were incubated with human umbilical vein endothelial cells (HUVECS) to evaluate endothelial NO production. In both studies, we found reduction of systolic blood... (Complete abstract click electronic access below) / Doutor
114

Efeitos do nitrito de sódio e sua associação ao sildenafil na hipertensão gestacional experimental em ratas / Effects of sodium nitrite and its association with sildenafil in experimental gestational hypertension in rats

Rizzi, Victor Hugo Gonçalves 26 February 2018 (has links)
Submitted by Victor Hugo Gonçalves Rizzi (victor.rizzi@hotmail.com) on 2018-09-06T18:30:07Z No. of bitstreams: 1 tese victor.pdf: 3098588 bytes, checksum: c82c3535b448e04bc144e33e93ef47f9 (MD5) / Approved for entry into archive by ROSANGELA APARECIDA LOBO null (rosangelalobo@btu.unesp.br) on 2018-09-11T19:49:14Z (GMT) No. of bitstreams: 1 rizzi_vhg_dr_bot.pdf: 3098588 bytes, checksum: c82c3535b448e04bc144e33e93ef47f9 (MD5) / Made available in DSpace on 2018-09-11T19:49:14Z (GMT). No. of bitstreams: 1 rizzi_vhg_dr_bot.pdf: 3098588 bytes, checksum: c82c3535b448e04bc144e33e93ef47f9 (MD5) Previous issue date: 2018-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / As desordens hipertensivas gestacionais são complicações que acometem em torno de 5-10% das gestações. Essas desordens são as maiores causas de morbidade e mortalidade tanto materna quanto fetal. Estudos demonstram redução da biodisponibilidade do óxido nítrico (NO) em doenças hipertensivas gestacionais, tornando uma das condições responsáveis por agravar a disfunção endotelial durante o curso desta doença. Neste sentido, trabalhos demonstram que a administração oral de nitrito de sódio (NaNO2) e a administração de citrato de sildenafil podem reverter a redução da biodisponibilidade de NO e potencializar a via de sinalização NO-GMPc respectivamente. Para realização dos trabalhos foram utilizadas ratas Wistar, no qual, após confirmação da prenhez receberam L-NAME i.p para indução da hipertensão e tratamentos com nitrito de sódio e/ou citrato de sildenafil via oral entre os dias 14-21 de prenhez. A pressão arterial sistólica foi aferida pelo método de pletismografia de cauda. Parâmetros materno-fetais como: peso fetal e placentário, número de fetos viáveis e reabsorvidos foram realizados após a morte das ratas no 21º dia gestacional. O plasma das ratas foram armazenados para dosagens dos níveis plasmáticos de nitrito+nitrato, guanosina monofosfato cíclico (GMPc), mieloperoxidase (MPO), peroxidação lipídica (TBARS), TEAC, MTT sFlt-1 e VEGF. Além disso o plasma das ratas foram incubadas com células endoteliais de cordão umbilical humano (HUVECS) para avaliar a produção de NO endotelial. Em ambos os trabalhos, nós encontramos redução da pressão arterial sistólica com nitrito e sildenafil, tanto isolado quanto em associação. Somente o sildenafil foi capaz de aumentar o peso fetal, enquanto o peso placentário foi melhorado por ambas as drogas. Tanto nitrito quanto sildenafil foram capaz de reduzir a reabsorção, possivelmente por aumentar a viabilidade fetal. Foi encontrado aumento de NO plasmático em todos os grupo que receberam nitrito, enquanto curiosamente a síntese de NO em HUVECS incubadas com plasma das ratas foi aumentada em ambas as drogas. Ainda em relação a cultura celular, nós encontramos aumento da viabilidade celular em ratas hipertensas tratadas com sildenafil. A concentração plasmática de GMPc estava aumentada em ratas normotensos que receberam sildenafil. Ambas as drogas apresentam efeito antioxidante, mas somente o sildenafil foi capaz de reduzir a atividade plasmática da MPO. Fatores angiogênicos (VEGF) e anti-angiogênicos (sFlt-1) presentes em doenças hipertensivas gestacionais estavam aumentados em ratas que receberam L-NAME, porém o nitrito de sódio foi capaz de reduzir esses fatores. Nosso dados sugerem que o nitrito e o sildenafil, tanto isolado 2 quanto em associação apresentam efeitos anti-hipertensivos e antioxidantes. Portanto, nossos resultados sugerem que a ativação da via NO-GMPc aumentou o fluxo sanguíneo na interface materno-fetal e protegeu contra a hipertensão e a restrição do crescimento fetal induzidas pelo L-NAME. / Gestational hypertensive disorders are complications that affect around 5-10% of pregnancies. These disorders are the major causes of both maternal and fetal morbidity and mortality. Studies have demonstrated a reduction in the bioavailability of nitric oxide (NO) in gestational hypertensive diseases, making it one of the conditions responsible for aggravate the endothelial dysfunction during the course of this disease. In this sense, studies demonstrate that oral administration of sodium nitrite (NaNO2) and administration of sildenafil citrate may reverse the reduction of NO bioavailability and potentiate the NO-cGMP signaling pathway, respectively. Wistar rats were used to perform the study, in which, after confirmation of pregnancy, they received L-NAME i.p for induction of hypertension and treatments with sodium nitrite and/or sildenafil citrate orally between days 14-21 of pregnancy. Systolic blood pressure was measured by the tail plethysmography method. Maternal-fetal parameters such as: fetal and placental weight, number of viable and reabsorbed fetuses were performed after the death of the rats on the 21st gestational day. Plasma of the rats were stored for plasma levels of nitrite + nitrate, cGMP, myeloperoxidase (MPO), lipid peroxidation (TBARS), TEAC, MTT sFlt-1 and VEGF. In addition the plasma of the rats were incubated with human umbilical vein endothelial cells (HUVECS) to evaluate endothelial NO production. In both studies, we found reduction of systolic blood pressure with nitrite and sildenafil, both alone and in combination. Both nitrite and sildenafil were able to reduce reabsorption, possibly by increasing fetal viability. No increase in plasma NO was found in all groups receiving nitrite, while curiously NO synthesis in HUVECS incubated with plasma from rats was increased in both drugs. Still in relation to cell culture, we found increased cell viability in hypertensive rats treated with sildenafil. Plasma cGMP concentration was increased in normotensive rats receiving sildenafil. Both drugs have an antioxidant effect, but only sildenafil was able to reduce plasma myeloperoxidase activity (MPO). Angiogenic (VEGF) and anti-angiogenic (sFlt-1) factors present in gestational hypertensive diseases were increased in rats receiving L-NAME, but sodium nitrite was able to reduce these factors. Our data suggest that both nitrite and sildenafil, both alone and in combination, have antihypertensive and antioxidant effects. Therefore, our results suggest that activation of the NO-cGMP pathway increased blood flow at the maternal-fetal interface and protected against hypertension and fetal growth restriction induced by L-NAME. / FAPESP 16/18782-3 / FAPESP 12/21305-1
115

NITRIFYING BACTERIAL ABUNDANCE IN RELATION TO NITROGEN AND PHOSPHORUS COMPOUNDS IN WETLANDS

Jones, Nicole Jean 01 May 2012 (has links)
Floodplain lakes are wetlands which receive flood waters from nearby rivers or other sources. Water samples were taken from floodplain lakes near the Illinois River, the Mississippi River, and the Cache River in Southern Illinois. Fluorescence in situ hybridization (FISH), spectrophotometry, and gene probes were used to investigate the effect of nutrient and chemical concentrations on the abundance of nitrifying bacteria; specifically ammonia-oxidizing Nitrosococcus and Nitrosomonadales and nitrite-oxidizing Nitrospira and Nitrobacter. Nitrosococcus was the dominant ammonia-oxidizing bacteria at each river system. Nitrospira and Nitrobacter had similar average abundances. Nitrosococcus abundances showed a significant positive correlation with nitrate (NO3-) (R2= 0.247, P=0.05, 95% confidence R2≥0.199) and a positive trend with nitrite (NO2-) (R2= 0.194, P=0.10, 90% confidence R2≥0.125). Nitrosomonadales abundance positively correlated with temperature (R2= 0.530, P=0.05, 95% confidence R2≥0.510). Nitrospira abundances positively correlated with ammonium (NH4+) (R2= 0.265, P=0.05, 95% confidence R2≥0.199), NO2- (R2= 0.372, P=0.05, 95% confidence R2≥0.199), and NO3- (R2= 0.482, P=0.05, 95% confidence R2≥0.199). None of the target bacterial abundances significantly correlated with pH or dissolved inorganic phosphate.
116

Electrocatalytic reduction of NOx on metal nanoparticles stabilized by polyoxometalates / Réduction électrocatalytique des NOx sur des nanoparticules métalliques stabilisées par des polyoxométallates

Yang, Shu 10 November 2017 (has links)
L’objet de ce travail est de développer des nouveaux catalyseurs pour réduire les ions nitrites (NO2- /HNO2) et nitrates (NO3-) dans l’eau en étudiant les facteurs qui vont influencer leurs réductions catalytiques. On a montré que la présence de polyoxométallates (POMs) permet d’améliorer les propriétés catalytiques de l’électrode de Cu et d’Ag pour la réduction de ions nitrate et nitrite avec des conditions adaptées. Par la suite, des nanoparticules du cuivre (Cu@POM) ou d’argent (Ag@POM) ont été préparées par électroréduction of CuPOM in situ ou photocatalyse en présence d’ions POMs et Ag(I) respectivement. Leurs propriétés électrocatalytiques ont été étudiées. Six différents polyoxométallates substitués par des atomes de Cu(II) (CuPOMs) ont montré de bonnes activités pour la réduction de nitrite à pH 1 et à pH 5. Deux activités sont observées : au potentiel de la réduction de CuII et au potentiel de réduction des W(VI) du POM. Quant à la réduction du nitrate, [Cu4(H2O)2(P2W15O56)2]16- et [(A-β-SiW9O34)Cu4(OH)3(H2O)(H3N(CH2)3COO)2]3 5- peuvent catalyser la réduction du nitrate à un potentiel au-delà de la réduction du Cu(II) à la réduction des W(VI). Par contre, dans le cas de [(SbW9O33)2{Cu(H2O)}3]12– aucune électrocatalyse n’est observée. Cela indique que le type de POM influence les propriétés catalytiques des nanoparticules. Pour le système Ag@POM photoréduit, un catalyseur hétérogène est préparé et stabilisé par une couche de Nafion. Les nanoparticules Ag@POM sont actives pour la réduction du nitrite et du nitrate et possèdent une activité meilleure que celle mesurée pour l’électrode d’Ag seule. Dans la dernière partie, une étude préliminaire de polyoxométallates encapsulés dans les ‘Metal-Organic Framworks’ (MOFs) e st présentée. L’entité POM conserve ses propriétés électrochimiques et électrocatalytiques pour la réduction de nitrite après immobilisation dans la cage MOF. / The object of this work is to develop new catalysts to reduce nitrite ions (NO2- / HNO2) and nitrate ions(NO3-) in water and also tried to understand the factors that will influence catalytic reductions. It has been shown that the presence of polyoxometalates makes it possible to improve the catalytic properties of the Cu and Ag bulk electrodes for the reduction of nitrate and nitrite ions under suitable conditions. Then, the copper or silver nanoparticles decorated with POMs, Cu@POM or Ag@POM), are formed with two different methods: electroreduction in situ of CuPOM or photocatalysis in the presence of POM and Ag(I) ions respectively). Their electrocatalytic properties are presented. Six different Cusubstituted polyoxometalates (CuPOMs) are active for nitrite reduction at pH 1 and pH 5. Two activities are observed at the potential of CuII reduction and at the potential of WVI reduction in POM. [Cu4(H2O)2(P2W15O56)2]16- and [(A-β-SiW9O34)Cu4(OH)3(H2O)(H3N(CH2)3COO)2]3 5- catalyse the nitrate reduction at the potential beyond the reduction of CuII and at the reduction of WVI. On the other hand, no catalysis efficiency was observed with [(SbW9O33)2{Cu(H2O)}3]12-. This indicates the type of POM will influence the catalytic properties of nanoparticles. With the photoreduced Ag@POM nanoparticles, a heterogeneous catalyst is prepared and stabilized by a Nafion layer. Ag@POM nanoparticles are active for the reduction of nitrite and nitrate and have an activity better than the Ag electrode alone. In the last part, a preliminary study of polyoxometalates encapsulated in Metal-Organic Framworks (MOFs) is presented. POM retains its electrochemical and electrocatalytic properties toward the reduction of nitrite after immobilized in the cage of MOF.
117

Desenvolvimento de um embutido cárneo fermentado, com teores reduzidos de gordura e sais de cura, através da utilização de culturas probióticas / Development of a meat sausage with low fat and curing salts contents, fermented with probiotic cultures

Roselino, Mariana Nougalli [UNESP] 01 March 2016 (has links)
Submitted by MARIANA NOUGALLI ROSELINO null (mari_roselino@yahoo.com.br) on 2016-04-28T19:17:26Z No. of bitstreams: 1 Tese.pdf: 4114472 bytes, checksum: f4844081ace5b8eb414c051b805f2a04 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-04-29T17:21:13Z (GMT) No. of bitstreams: 1 roselino_mn_dr_arafcf.pdf: 4114472 bytes, checksum: f4844081ace5b8eb414c051b805f2a04 (MD5) / Made available in DSpace on 2016-04-29T17:21:13Z (GMT). No. of bitstreams: 1 roselino_mn_dr_arafcf.pdf: 4114472 bytes, checksum: f4844081ace5b8eb414c051b805f2a04 (MD5) Previous issue date: 2016-03-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Embutidos fermentados, processados e consumidos sem aquecimento, são os produtos cárneos mais promissores para a veiculação de probióticos, entretanto, apresentam como desvantagens o alto teor de gordura, presença de nitrito e nitrato residual e de compostos potencialmente tóxicos, como as aminas bioativas. O presente trabalho estudou o efeito da utilização de bactérias láticas com propriedade hipolipemiante nas características tecnológicas, sensoriais e de segurança de um embutido cárneo fermentado, similar ao salame, com teores de gordura, nitrito e nitrato reduzidos. Os potenciais efeitos benéficos do produto foram investigados em um estudo in vitro. Duas cepas probióticas (Enterococcus faecium CRL183 e Lactobacillus acidophilus CRL1014) foram testadas, separadamente, como culturas iniciadoras. Os embutidos com baixo teor de gordura (redução de 60%) foram processados em seis formulações: 2 - culturas tradicionais sem redução de sais de cura (nitrito 0,015% e nitrato 0,005%); 3 - culturas tradicionais e teor reduzido de sais de cura (nitrito 0,007% e nitrato 0,003%); 4, 5, 6, 7 – culturas probióticas (E. faecium CRL183 e L. acidophilus CRL1014) com teores normais e reduzidos de sais de cura, respectivamente. Para efeito de comparação, um produto controle (1 - culturas tradicionais, sem redução de gordura e de sais de cura) também foi produzido. As culturas probióticas (Enterococcus faecium CRL 183 e Lactobacillus acidophilus CRL 1014) foram submetidas a testes preliminares para determinação da resistência às concentrações de sais de cura usualmente empregadas em produtos cárneos fermentados e avaliação da capacidade de produção de substâncias antimicrobianas pela técnica spot-on-lawn. A qualidade dos embutidos foi avaliada através de análises físico-químicas e microbiológicas, no início do processamento e durante os períodos de maturação e estocagem. Foram realizados testes de aceitação a cada 30 dias de armazenamento e, uma análise descritiva quantitativa (ADQ) com os embutidos prontos para o consumo (T30). O embutido que apresentou as melhores características nos testes anteriores foi submetido a um teste in vitro, em simulador do ecossistema microbiano humano (SEMH), para avaliação da sobrevivência gastrintestinal do microrganismo probiótico, determinação do efeito do produto cárneo probiótico na produção de ácidos graxos de cadeia curta e de amônia e na modulação da microbiota intestinal. Nas análises de sensibilidades aos sais de cura, a cepa E. faecium CRL 183 não exibiu redução logarítmica na população de células viáveis (109 UFC/mL) para todas as concentrações de cloreto de sódio e nitrito de sódio avaliadas. Por outro lado, a cepa L. acidophilus CRL 1014 apresentou redução de um ciclo logarítmico em relação ao controle (p<0,05), com população final de células viáveis na ordem de 108 UFC/mL. As bactérias probióticas avaliadas não foram capazes de produzir substâncias antimicrobianas contra as cepas indicadoras utilizadas (Listeria monocytogenes IAL 628, Salmonella enterica ssp. enterica serovar typhimurium IAL 2431, e Escherichia coli IAL 339), uma vez que não houve formação de halos de inibição. Todas as formulações apresentaram características físico-químicas e microbiológicas adequadas aos padrões estabelecidos para embutidos cárneos fermentados. As cepas probióticas mantiveram-se viáveis até o final do período avaliado, exibindo população na ordem de 108UFC/g (final da maturação) e 107UFC/g (120 dias de armazenamento). Os resultados obtidos evidenciaram um comportamento muito semelhante entre as diferentes formulações, indicando que a substituição de culturas iniciadoras tradicionais por outras probióticas, bem como a redução de sais de cura, não influenciou negativamente a qualidade microbiológica dos produtos. A substituição parcial de gordura animal por óleo de oliva resultou em aumento de dureza, fato que não alterou a aceitação hedônica global das amostras. A ADQ não foi capaz de diferenciar as amostras em função da cepa utilizada e da quantidade de sais de cura adicionada. Entre os embutidos com redução de gordura e sais de cura e potencialmente probióticos, o produto fermentado com E. faecium CRL 183 (F5) apresentou, no final do período de armazenamento (T120), algumas características superiores as do produto fermentado com L. acidophilus CRL1014 (F7) – menor população de estafilococos coagulase positiva, menor oxidação lipídica, melhor perfil de textura e de aminas bioativas – sendo por esse motivo selecionado para a segunda etapa do estudo. Os testes utilizando o simulador do ecossistema microbiano humano (SEMH) evidenciaram que o consumo do produto fermentado com E.faecium CRL 183 e com redução de gordura e sais de cura pode resultar em redução de Lactobacillus spp. (cólon ascendente, transverso e descendente), Bacteroides spp. (cólon descendente) e enterobactérias (cólon transverso e descendente) e aumento nos níveis de íons amônio. O mesmo produto probiótico estimulou a produção de ácido butírico e propiônico, reduziu a concentração de ácido acético durante a fase de tratamento e alterou a população de microrganismos intestinais. Os resultados indicam que o salame probiótico (E. faecium CRL 183) com redução de gordura e sais de cura constitui uma alternativa mais saudável de produto cárneo fermentado, pois, além de possuir características nutricionais mais interessantes, apresenta potencial para atuar positivamente no perfil lipídico, através da melhora na produção de AGCC e modulação da microbiota, com aumento da população de E. faecium CRL 183 que é uma cepa comprovadamente hipocolesterolemiante. / Fermented sausages, processed and consumed without heating, are the most promising meat products for the placement of probiotics, however, have as disadvantages the high fat content and the presence of residual nitrite and nitrate and potentially toxic compounds, such as bioactive amines. This work studied the effect of using lactic acid bacteria with lipid lowering property in technological, sensory and safety characteristics of a fermented susage, similar to salami with fat, nitrite and nitrate reduced. The potential beneficial effects of the product were investigated in an in vitro study. Two probiotic strains (Enterococcus faecium CRL 183 and Lactobacillus acidophilus CRL 1014) were tested separately as starter cultures. The sausages with a low fat content (60% reduction) were processed in six treatments: 2 - traditional cultures with fat reduction and without curing salts reduction (nitrite and nitrate 0.015% 0.005%); 3 - traditional cultures with fat and curing salt reduction (nitrite and nitrate 0.007% 0.003%); 4, 5, 6, 7 - probiotic cultures (E. faecium CRL183 and L. acidophilus CRL1014) with fat reduction, without and with curing salt reduction, respectively. For comparison, a control product (1 - traditional cultures without fat and curing salts reduction) was also produced. Probiotic cultures (E. faecium CRL 183 and L. acidophilus CRL 1014) were submitted to preliminary tests to determine resistance to curing salt concentrations usually employed in fermented meat products and evaluation of antimicrobial substances production capacity by the spot-on-lawn technique. The quality of the sausages was evaluated by physical, chemical and microbiological analyzes at the beginning of processing and during periods of maturation and storage. Acceptance tests were performed every 30 days of storage, and a quantitative descriptive analysis (QDA) with sausages ready for consumption (T30). The sausage had the best characteristics of previous tests was subjected to an in vitro test on human microbial ecosystem simulator (SEMH) for evaluation of the gastrointestinal survival of the probiotic microorganism, determining the effect of probiotic meat product in the production of fatty acids short chain and ammonia and modulation of the intestinal microbiota. In the analysis of sensitivity to curing salts, E. faecium CRL 183 showed no log reduction in the population of viable cells (109 CFU/mL) for all concentrations of sodium chloride and sodium nitrite evaluated. On the other hand, L. acidophilus CRL 1014 showed a log cycle reduction compared to control (p <0.05) with final population of viable cells in the order of 108 CFU/mL. The evaluated probiotic bacteria were not able to produce antimicrobial substances against indicator strains (Listeria monocytogenes IAL 628, Salmonella enterica ssp. enterica serovar typhimurium IAL 2431, e Escherichia coli IAL 339), since there was no formation of inhibition zones. The results show that E. faecium CRL 183 and L. acidophilus CRL 1014 can be used as starter cultures in the preparation of meat sausages, they are tolerant to sodium chloride and sodium nitrite concentrations typically used in such products. All treatments showed appropriate physicochemical and microbiological characteristics to the standards established for fermented sausage. The probiotic cultures remained viable by the end of analysis period, showing a population of about 108UFC/g (final ripening) and 107UFC/g (120 days of storage). The results obtained showed a very similar behavior between the different treatments, indicating that replacement of traditional starter cultures by probiotic as well as the curing salts reduction did not influence the microbiological quality of products. The partial replacement of animal fats with olive oil resulted in increased hardness, which did not alter the overall hedonic acceptance of samples. The QDA was not able to differentiate between samples depending on the strain used and the amount of added curing salts. Among treatments with fat and curing salts reduction and potentially probiotics, the fermented product with E. faecium CRL 183 (F5) presented at the end of the storage period, some superior characteristics to the product fermented with L. acidophilus CRL1014 (F7) - smaller population of coagulase positive staphylococci, lower lipid oxidation, better texture profile and better bioactive amines profile - and therefore selected for the second stage of the study. Tests using the SEMH showed that the fermented product consumption with E. faecium CRL 183 with fat and curing salts reduction may result in areducing Lactobacillus spp. (ascending, transverse and descending colon), Bacteroides spp. (descending colon) and Enterobacteriaceae (transverse and descending colon) and increased levels of ammonium ions. The same probiotic product stimulated the production of butyric and propionic acid, reduced the concentration of acetic acid during the treatment phase and altered the population of intestinal microorganisms. The results indicate that the probiotic sausage (E. faecium CRL 183), with fat and curing salts reduction is a healthier alternative of fermented meat product, since, besides having more interesting nutritional characteristics, has the potential to act in lipid profile, by improving the production of SCFA and modulating the microbiota with increased E. faecium CRL 183 population which is a proven cholesterol lowering strain. / FAPESP: 2012/14129-2
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Effects of nitrite infusion on skeletal muscle vascular control during exercise in rats with chronic heart failure

Glean, Angela A. January 1900 (has links)
Master of Science / Department of Kinesiology / Timothy I. Musch / Chronic heart failure (CHF) reduces nitric oxide (NO) bioavailability and impairs skeletal muscle vascular control during exercise. Reduction of nitrite (NO[subscript]2-) to NO may impact exercise-induced hyperemia particularly in muscles with pathologically-reduced O[subscript]2 delivery. We tested the hypothesis that NO[subscript]2- infusion would increase exercising skeletal muscle blood flow (BF) and vascular conductance (VC) in CHF rats with a preferential effect in muscles composed primarily of type IIb+IId/x fibers. CHF (coronary artery ligation) was induced in adult male, Sprague-Dawley rats. Following a >21 day recovery, mean arterial pressure (MAP, carotid artery catheter) and skeletal muscle BF (radiolabelled microspheres) were measured during treadmill exercise (20 m•min[superscript]-1, 5% incline) with and without NO[subscript]2- infusion. The myocardial infarct size (35 ± 3%) indicated moderate CHF. NO[subscript]2- infusion increased total hindlimb skeletal muscle VC (CHF: 0.85 ± 0.09, CHF+NO[subscript]2-: 0.93 ± 0.09 ml•min[superscript]-1•100g[superscript]-1•mmHg[superscript]-1, p<0.05) without changing MAP (CHF: 123 ± 4 mmHg, CHF+NO[subscript]2-: 120 ± 4 mmHg, p=0.17). Total hindlimb skeletal muscle BF was not significantly different (CHF: 102 ± 7, CHF+NO[subscript]2-: 109 ± 7 ml•min[superscript]-1•100g[superscript]-1, p>0.05). BF increased in 6 (~21%) and VC in 8 (~29%) of the 28 individual muscles and muscle parts. Muscles and muscle portions exhibiting greater BF and VC following NO[subscript]2- infusion were comprised of ≥63% type IIb+IId/x muscle fibers. These data demonstrate that NO[subscript]2- infusion can augment skeletal muscle vascular control during exercise in CHF rats. Given the targeted effects shown herein, a NO[subscript]2[superscript]--based therapy may provide an attractive “needs-based” approach for treatment of the vascular dysfunction in CHF.
119

Quality attributes during 160 days refrigerated shelf life of a smoked, fully cooked sausage formulated with a nitrite containing pork preblend

Collins, Ashley January 1900 (has links)
Master of Science / Food Science Institute / Elizabeth A. Boyle / Pork preblends held for 0, 4 or 7 d were formulated into smoked sausages and analyzed for cook yield, instrumental external color, pH, salt content, proximate analysis, Warner-Bratzler shear force (WBSF), thiobarbituric acid reactive substances (TBARS), sensory analysis and purge percentage during 0, 110, 131 and 160 d display at an average 2.65 °C under fluorescent lighting. One preblend × day of display interaction was found for b* values. On display d 0, preblend d 7 was more yellow (P < 0.05) than preblend d 0 and 4; however, no differences (P > 0.05) were found for any preblends on d 110 or 160. On display d 131, preblend d 0 was more (P < 0.05) yellow than preblend d 4 but similar (P > 0.05) to preblend d 7. There was no preblend effect (P > 0.05) on any of the other attributes measured. Display day did not affect (P > 0.05) purge, pH, proximate analysis, WBSF, juiciness, saltiness or off-flavor. For color, a* and saturation index values decreased (P < 0.05) and L* increased (P < 0.05) between d 0 and 110 as well as d 110 and 131, while L*, a*, a*/b* ratio and saturation index values were similar (P > 0.05) from d 131 to 160. Hue angle value decreased from d 0 to 110 but was similar for the remaining display. A reduction (P < 0.05) in a*/b* ratio was shown from d 0 and 110 (average 0.85) to d 131 and 160 (average 0.78). There was a reduction in salt content by 0.43% and an increase in TBARS values by 0.46 mg malonaldehyde/100 g sample from d 0 compared to d 110, 131 and 160 (P < 0.05). Inconsistent differences were found for sensory panel traits bite and flavor intensity and a reduction in mouthfeel coating was found from d 0, 110 and 131 compared to 160 (P < 0.05). Therefore, preblending could be implemented without any detrimental outcome on quality or sensory attributes of skinless smoked sausage; however, as day of display increases product may become lighter, less red and more oxidized.
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Efeito de um programa pré-operatório de fortalecimento supervisionado da musculatura inspiratória na evolução hospitalar de pacientes submetidos a operações cardíacas / Effect of preoperative program of strengthening supervised the inspiratory muscles in evolution of hospital patients undergoing cardiac surgery

Paulo Eduardo Gomes Ferreira 26 April 2013 (has links)
Introdução: A disfunção respiratória é uma das complicações mais frequentes após operações cardíacas. Vários fatores contribuem para que as disfunções respiratórias ocorram, dentre eles está a disfunção da musculatura inspiratória que, por sua vez, pode ser multifatorial. Objetivo: O condicionamento da musculatura inspiratória no período pré-operatório poderia ajudar a reduzir a incidência de complicações respiratórias no pós-operatório de operações cardíacas. Métodos: No presente trabalho 21 pacientes voluntários, de ambos os sexos, com idade mínima de 50 anos, com fraqueza de musculatura inspiratória e candidatos à operação de revascularização cirúrgica do miocárdio e/ou operação valvar cardíaca no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto-USP foram distribuídos aleatoriamente em 2 grupos. Em um grupo, 10 pacientes foram submetidos a um período mínimo de 9 dias de treinamento da musculatura inspiratória utilizando um incentivador respiratório marca Threshold® IMT (Respironics, Cedar Grove, NJ, EUA), com carga de 40, 60 e 80% da pressão inspiratória máxima. Os outros 11 pacientes receberam apenas orientações gerais, sem treinamento objetivo da musculatura respiratória. Comparamos os valores espirométricos antes e após o treinamento dentro de cada grupo. A evolução da pressão inspiratória máxima, da pressão expiratória máxima e da gasometria arterial de ambos os grupos, antes e após o treinamento, bem como a sua evolução temporal no pós-operatório, além dos valores de nitrito/nitrato no condensado do exalado pulmonar. Comparamos também a evolução clínica de ambos os grupos. Resultados: Observamos que o treinamento causou elevação significativa do pico de fluxo expiratório (p=0,028) e diminuição nos valores de nitrito/nitrato no condensado do exalado pulmonar (p=0,05) e redução das complicações pós operatórias (p=0,057), sendo as duas últimas não significativas. Todavia, não houve diferença na evolução gasométrica e nem da pressão inspiratória máxima ou da pressão expiratória máxima entre ambos os grupos. Conclusão: O treinamento da musculatura respiratória inspiratória em pacientes internados, além de factível e seguro, resulta em maior fortalecimento dessa musculatura, reduz a morbidade pós-operatória e os níveis de nitrito/nitrato no condensado do exalado pulmonar / Introduction: Respiratory dysfunction is one of the most common complications after cardiac operations. Several factors contribute to respiratory dysfunctions that occur among them is inspiratory muscle dysfunction that, in turn, may be multifactorial. Objective: The conditioning of inspiratory muscles on preoperative could help reduce the incidence of respiratory complications in the postoperative period of cardiac operations. Methods: In this study 21 patients volunteers of both sexes, aged 50 years, with weakness of inspiratory muscles and candidate operation of CABG and / or heart valve surgery at the Hospital of the Medical College of Ribeirão Preto-USP were randomized into 2 groups. In one group, 10 patients underwent a minimum of 9 days of inspiratory muscle training using an incentive spirometry \"Threshold® IMT\" (Respironics, Cedar Grove, NJ, USA) with a load of 40, 60 and 80% of maximal inspiratory pressure. The other 11 patients received only general guidelines without respiratory muscle training goal. We compared spirometric values before and after training within each group. The evolution of maximal inspiratory pressure, maximal expiratory pressure and arterial blood gas analysis of both groups before and after training, as well as its temporal evolution postoperatively, and the values of nitrite / nitrate in exhaled breath condensate. We also compared the clinical outcomes in both groups. Results: We observed that the training caused significant peak expiratory flow (p=0,028) and decrease in nitrite/nitrate in exhaled breath condensate (p=0,05) and reduction of postoperative complications (p=0,057), the last two being non-significant. However, there was no difference in blood gas evolution nor maximal inspiratory pressure and maximal expiratory pressure between both groups. Conclusion: The inspiratory muscle training in patients hospitalized, and feasible and safe, results in further strengthening these muscles, reduces postoperative morbidity and levels of nitrite / nitrate in exhaled breath condensate

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