Diss. (sammanfattning) Linköping : Linköpings universitet, 2007. / Härtill 4 uppsatser.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The passion fruit peel (CM), apple pomace (BM) and orange bagasse (BL) are by-products generated in large quantities and usually wasted by brazilian industries of juices processing. However have nutritional qualities important for health, as relevant levels of dietary fiber. In this context, the study aimed to characterize the flour of these by-products, study potential nutritional as alternative sources of fiber in diets drawn up for rats, and test the nutritional and sensory quality of honey breads enriched with these flours. In step characterization, it was verified a high content of dietary fiber, which varied 54.82 to 76.84% in dry matter (DM), highlighting the soluble fraction (18.97% to 25.17% in DM), mainly composed of pectin (49.19% to 91.25% of the soluble fiber). Phenolic compounds were also elevated in the samples analyzed (479.71 to 862.11 mg% in DM). The BM stood out for higher fiber content, pectin, condensed tannins and greatest copper binding capacity. The CM presented a high mineral content, very small percentage of fat, high hydration capacity and greater fat binding capacity. The BL was the by-product with higher levels of soluble fiber and phenolic content. In biological assay, conducted for 40 days, it was used 32 male Wistar rats, with 21 days old, randomly distributed (eight animals / treatment) between the following experimental treatments: TC, control treatment with cellulose as a fiber source; TBM; treatment with apple pomace as fiber source; TBL, treatment with orange bagasse as a source of fiber; TCM; treatment with passion fruit peel as a source of fiber.The different sources of fiber did not affect the average consumption, weight gain, feed conversion, gastrointestinal transit time, and neither exerted influence on the weight of the intestine empty, kidney, liver and epididymal fat of animals. There was also not significant difference in the levels of total cholesterol, HDL cholesterol, albumin, total protein and lipids in the liver. However, it was found that the addition of these by-products has enabled significant reductions in serum triglycerides and hepatic cholesterol, and also promote changes in important parameters for gut health (pH, nitrogen and fecal moisture) and play important roles in the control of postprandial glycemia. The fiber derived from BM showed greater potential to reduce the absorption and metabolization of fat for its increased excretion in feces, but it was the only one that did not exercise significant influence on fasting glucose. The fiber from the CM had higher apparent digestibility and the animals fed with BL showed the better postprandial glycemic response. The replacement of 15% of wheat flour standard formulation of honey bread by flours fruit by-products of allowed the reduction of caloric value and the increase in dietary fiber content (from 6.62 to 9.61% in DM to the formulations added BL and BM, respectively) and your soluble fraction. Sensory evaluation of honey breads enriched with flour by-products indicated good acceptability average for all parameters evaluated (color, aroma, flavor, texture, overall acceptability) and favorable purchase intent of these products. Is founded, thus, the rational utilization of these by-products of processing fruits as alternative sources of fiber with potential nutritional and technological to be used in human food. / A casca de maracujá (CM), o bagaço de maçã (BM) e o bagaço de laranja (BL) são subprodutos gerados em grande quantidade e geralmente desperdiçados pelas indústrias brasileiras de processamento de sucos. Contudo possuem qualidades nutricionais importantes, como teores relevantes de fibra alimentar. Nesse contexto, este trabalho objetivou caracterizar as farinhas desses subprodutos, estudar o potencial nutricional como fontes alternativas de fibra em dietas elaboradas para ratos e testar a qualidade nutricional e sensorial de pães de mel enriquecidos com essas farinhas. Na etapa de caracterização, constatou-se alto teor de fibra alimentar, que variou de 54,82 a 76,84% na matéria seca (MS), destacando-se a fração solúvel (18,97% a 25,17% na MS), composta principalmente por pectina. Os compostos fenólicos também foram elevados nas amostras analisadas (479,71 a 862,11 mg % na MS). O BM destacou-se pelo maior teor de fibra, pectina, taninos condensados e superior capacidade de ligação ao cobre. A CM apresentou alto teor de minerais, baixo percentual de gordura, elevada capacidade de hidratação e maior capacidade de ligação à gordura. O BL foi o subproduto com maior teor de fibra solúvel e conteúdo de fenóis. No ensaio biológico, conduzido por 40 dias, utilizou-se 32 ratos Wistar machos, com 21 dias de idade e distribuídos aleatoriamente (oito animais/tratamento) entre os seguintes tratamentos experimentais: TC, tratamento controle com celulose como fonte de fibra; TBM; tratamento com bagaço de maçã como fonte de fibra; TBL, tratamento com bagaço de laranja como fonte de fibra; TCM; tratamento com casca de maracujá como fonte de fibra. As diferentes fontes de fibras não afetaram o consumo médio, ganho de peso, conversão alimentar, tempo de trânsito gastrointestinal e nem exerceram influência no peso do intestino vazio, do rim, do fígado e da gordura epididimal dos animais. Também não foi observada diferença significativa nos níveis de colesterol total, colesterol HDL, albumina, proteínas totais e lipídeos no fígado. Contudo, constatou-se que adição desses subprodutos possibilitou reduções significativas nos níveis de triglicerídeos séricos e de colesterol hepático, além de promover modificações em parâmetros importantes para a saúde do intestino (pH, nitrogênio e umidade fecal) e desempenhar importante ação no controle da glicemia pós-prandial. A fibra oriunda do BM mostrou maior potencial em reduzir a absorção e a metabolização da gordura pela sua excreção aumentada nas fezes, mas foi a única que não exerceu influência significativa na glicemia de jejum. A fibra advinda da CM apresentou maior digestibilidade aparente e os animais alimentados com BL mostraram a melhor resposta glicêmica pós-prandial. A substituição de 15% da farinha de trigo da formulação padrão de pão de mel pelas farinhas dos subprodutos de frutas possibilitou a redução do valor calórico e o incremento no teor de fibra alimentar (6,62 a 9,61% na MS para as formulações adicionadas de BL e BM, respectivamente) e de sua fração solúvel. A avaliação sensorial dos pães de mel enriquecidos com as farinhas dos subprodutos indicou boa média de aceitabilidade para todos os parâmetros avaliados (cor, aroma, sabor, textura, aceitação global) e favorável intenção de compra desses produtos. Fundamenta-se, assim, a utilização racional desses subprodutos do processamento de frutas como fontes alternativas de fibras, que têm potencial nutricional e tecnológico para serem utilizadas na alimentação humana.

Skeletal muscle wasting is a consequence of numerous physiological conditions, including denervation, corticosteroid treatment, immobilization, and aging. The E3 ubiquitin ligases, MuRF1 and MAFbx, are induced under nearly all atrophy conditions and are believed to play a key role in protein degradation in atrophying muscle. However, the preliminary data described in this study provides new evidence that MuRF1 may also act as a transcriptional modulator of atrophy-induced gene activity, including the regulation of MAFbx and MuRF1 expression. To characterize the transcriptional regulation of MuRF1 and MAFbx, reporter gene constructs containing fragments of the proximal promoter regions of these genes were developed, transfected into C2C12 cells with or without a MuRF1 expression plasmid and monitored for differences in reporter gene activity. The MuRF1 and MAFbx reporters each showed repressed activity in cells ectopically expressing MuRF1 compared to cells that did not overexpress MuRF1. Furthermore, ectopic expression of the myogenic regulatory factors (MRFs), MyoD1 and myogenin, caused significant activation of the MuRF1 and MAFbx reporter constructs. However, co-overexpression of MuRF1 with MyoD1 or myogenin resulted in reversal of MRF induction of reporter gene activity, and synergistic repression of a constructed E-box reporter system. To further characterize the role of the MuRF1 gene product in repression of MuRF1 expression, a MuRF1 RING domain mutant and a MuRF1 c-terminal mutant were created. The mutant constructs were then co-transfected along with MRF expression plasmids and the MuRF1 reporter construct into C2C12 cells and reporter gene activity was assessed. The MuRF1 RING mutant failed to reverse MRF activation of the reporter gene, while the c-terminal mutant successfully reversed activation of the reporter gene. These findings suggest that ubiquitin ligase activity is required for MuRF1 transcriptional regulatory effects. These data offer exciting evidence of a potential new function for MuRF1 as a transcriptional modulator of atrophy-induced changes in gene expression.