Graduation date: 1992

Made available in DSpace on 2015-04-09T12:28:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-31Bitstream added on 2015-04-09T12:48:24Z : No. of bitstreams: 1 000815948.pdf: 466028 bytes, checksum: 6d558034e621d063e564ffdd55327e17 (MD5) / Para avaliar os efeitos de dietas alimentares utilizando fontes de gordura protegida (Megalac® ou linhaça) associada superestimulação hormonal sobre os parâmetros da aspiração folicular em cabras foram utilizadas 18 cabras da raça Anglo-Nubiano, clinicamente saudáveis e aptas a reprodução. Os animais foram divididos e alojados aleatoriamente em 3 grupos experimentais com 6 animais cada, sendo um grupo controle (C), com dieta utilizando-se o óleo de soja fonte de gordura alimentar, um grupo com dieta utilizando-se MEGALAC® (M) como fonte de gordura protegida, um grupo com dieta alimentar utilizando-se semente de linhaça (L) como fonte de gordura protegida. Todos os animais foram submetidos a ultrassonografia transretal para a avaliação da quantidade e do diâmetro folicular imediatamente antes da aspiração folicular por vídeo laparoscopia, os oócitos obtidos foram maturados in vitro e avaliados quanto a sua capacidade de maturação, para a uma melhor avaliação da resposta dos animais a dieta e ao procedimento de aspiração folicular foi coletada amostras de sangue de todos os animais para avaliação hematológica e da bioquímica sérica. Não houve diferença no escore de condição corporal e no ganho de peso dos animais. No exame ultrassonográfico foi notada diferença no diâmetro dos folículos observados entre o primeiro (4,29 ± 0,06) e o segundo (3,69± 0,07) ultrassom o diâmetro dos folículos considerados aspiráveis pelo ultrassom também diminuiu do primeiro (5,05 ± 0,06) para o segundo (4,71 ± 0,13) ultrassom. Notou-se uma maior média de folículos observados (28,4 ± 4,17) e aspirados (26,8 ± 4,12) e oócitos recuperados (10,9 ± 1,37) no Grupo C na. As análises sanguíneas não mostrou diferença entre grupos, porém parâmetros sofreram alterações no período pós operatório com retorno a normalidade nos momentos seguintes / To evaluate the effects of diet with protected fat (Megalac® or linseed) associated with ovarian super-stimulation on an follicular aspiration parameters, 18 anglo-nubian goats, in perfect health, were used. The animals were divided in 3 experimental groups with 6 individuals per group, one control group, under a diet without protected fat with an ovarian super-stimulation protocol, one group under a diet with MEGALAC® and under an ovarian super-stimulation protocol, one group under a diet with linseed and under an ovarian super-stimulation protocol. All the animals were submitted to an ultrasound evaluation immediately before the laparoscopic ovum pick up (LOPU), all the obtained oocytes were classified and in vitro maturated and evaluate as their ability to mature, to evaluate the responses of the animals, certified health and security of the diet and LOPU, blood samples were taken for evaluation of cell blood count, serum biochemistry profile. During the ultrasound exams were noticed a decrease in follicles diameter from the first(4,29 ± 0,06, mm) to second(3,69± 0,07, mm) ultrasound, and in viable follicles diameter from the first(5,05 ± 0,06, mm) to second (4,71 ± 0,13, mm) ultasound. Animals from the group C had more follicles observed (28,4 ± 4,17) and aspired (26,8 ± 4,12) and more oocytes recovered (10,9 ± 1,37), were noticed a decrease in number of thoses parameters in all groups from comparing the first LOPU with the second. Blood analyses did not shown any difference between gropus, however were significant changes on the post-surgical period, with a soon return to normality

Senescence is a cell stress program characterized by a stable cell cycle arrest and thus aims to protect against replication of potentially harmful cells. In oncogene-induced senescence (OIS) the cell cycle arrest is brought about by activation of an oncogene. This in turn initiates a DNA damage response and subsequently, the DDR induces p53-p21 and RB tumour suppressor pathways. The metabolism of senescent cells is highly altered, notably there is increased secretion of proteins and increased functional activity of certain metabolic enzymes. There have been many recent studies investigating the role of specific metabolic pathways in OIS and how they may be targeted for therapeutic benefit. This thesis aims to identify novel metabolic regulators of OIS, by combining high throughput RNAi screening and LC-MS based methods. This thesis has identified and validated 17 essential OIS metabolic genes; in this list, there was enrichment for genes involved in lipid biosynthetic processes. Lipid metabolism was an attractive focus for this thesis as it has not been extensively studied in current literature. Next, ceramide synthase 4 (CERS4) was extensively validated as a key enzyme for both OIS and replicative senescence. Using LC-MS based lipidomics, CERS4-driven rewiring of lipid metabolism in OIS was revealed and this corresponded with an accumulation of ceramides due to increased de novo ceramide synthesis. It was then confirmed OIS-related ceramide is mechanistically linked to cell cycle via the PP1-RB-E2F axis. Ceramide activates PP1, which physically binds to RB in a CERS4-dependent manner. PP1 is then able to dephosphorylate and activate RB, which inhibits transcription of E2F targets (cell cycle genes). Overall, this thesis identifies a metabolic checkpoint that links altered lipid metabolism with OIS.

One of the main drivers influencing consumers in the purchasing of red meat is the level of visible fat, and this is particularly important in lamb, with lamb often being perceived as fatty. Consumer-driven preference for leaner meat, coupled with the meat processing industries preference for a reduction in carcass fat, increasing lean meat yield and reducing waste, have led to continued selection for lean growth and reduced fatness in several meat producing species The perception of lamb being fatty could be directly targeted in isolation by reducing overall fat levels, however there are related effects on meat (eating) quality, and the combined improvement and consistency of meat (eating) quality and the reduction of overall fatness is more complicated. It is apparent that fat content plays a significant role in meat (eating) quality. Generally four major fat depots are recognised in animal carcasses, these are: subcutaneous (under the skin); internal organ associated; intermuscular (between muscles and surrounding muscle groups); and intramuscular (marbling, between muscle fibres), the latter generally regarded as having the greatest association with meat (eating) quality. X-ray computed tomography (CT) can measure fat, muscle and bone in vivo in sheep and CT predictions of carcass composition have been used in commercial UK sheep breeding programmes over the last two decades. Together with ultrasound measures of fat and muscle depth in the loin region, CT measured carcass fat and muscle weights have contributed much to the success of breeding for leaner carcasses and increased lean meat yield. Recently it has also been considered that x-ray computed tomography provides the means to simultaneously estimate IMF and carcass fat in vivo. Thus the aim of this project is to investigate the use of two and three-dimensional x-ray computed tomography techniques in the estimation of meat (eating) quality traits in sheep, and to further investigate the genetic basis of these traits and the possibility of their inclusion into current breeding programmes. The primary approach was the use of two-dimensional x-ray computed tomography, determining the most accurate combination of variables to predict IMF and mechanical shear force in the loin. The prediction of mechanical shear force was poor with accuracies ranging from Adj R2 0.03 – 0.14, however the prediction of IMF in the loin was more promising. CT predicted carcass fat weight accounted for a moderate amount of variation in IMF (R2 =0.51). These accuracies were significantly improved upon by including other information from the CT scans (i.e. fat and muscle densities, Adj R2 >0.65). Average muscle density in a single or multiple scans accounted for a moderate amount of the variation in IMF (Adj R2 = 0.51-0.60), and again accuracies R2 >0.65 were achieved, independent of CT-measured fat areas or predicted fat weights. Similar results were achieved with the use of three-dimensional CT scanning techniques (Adj R2 0.51 – 0.71), however, there was a dramatically increased requirement for image analysis when compared to two-dimensional techniques, and the increase in accuracy was not significant. This suggests that the current method of two-dimensional image capture is sufficient in the estimation of IMF in vivo in sheep. The prediction equations developed as part of this work were applied across divergent breed types (Texel, Scottish Blackface and Texel cross mule), to investigate the transferability of the prediction equations directly across to other breeds of sheep. As part of this study, the IMF levels across the breed types and sexes were also compared and found that IMF was significantly affected by breed type (P<0.001) with Scottish Blackface lambs having higher levels of IMF when compared to Texel cross mule lambs, and the lowest levels of IMF were in the purebred Texel lambs at the same liveweight or similar levels of carcass fatness. Sex also had a significant effect on IMF across breeds (P<0.001) with females having higher levels of IMF at similar levels of both carcass fat and liveweight, and within breed, females had significantly higher levels of IMF in both the purebred Texel and Scottish Blackface lambs, when compared at similar levels of carcass fat and liveweight (P<0.05). Using the models previously developed in purebred Texel to predict IMF in the Scottish Blackface and Texel cross mule, accuracies were found to be R2 = 0.57 – 0.64 and R2 = 0.37 – 0.38 respectively. Providing evidence that the equations are transferable across to some breeds more successfully than others, however, given that there is currently no method of accurately estimating IMF in vivo, accuracies across to both breeds are acceptable. The genetic parameter estimation was unsuccessful using the same research-derived dataset as previously employed in the study. However the ambition was always to investigate the genetic relationships between traits in a large industry dataset, exploiting the wealth of commercial CT information available. These investigations were considerably more successful, and among the first to present genetic parameters of novel CT-derived IMF estimates. The results found moderate heritability estimates of h2 0.31 and 0.36 for the final selected prediction equations, with clear indications that one model not including CT predicted carcass fat or any other fat measures, was more independent of these measures and the two separate prediction methods were highly genetically correlated with each other (rg = 0.89). The results from this study show that not only is it possible to accurately estimate IMF levels in the loin of Texel sheep using CT scanning, but that, until breed specific predictions are developed, the methods developed in this study are transferable across some breed types. The results also show that CT predicted IMF is heritable, independent of overall fatness and has the potential to be included in current breeding programmes. These findings can now be used to develop breeding programmes which enable breeders to make the best use of CT scanning technology to improve carcass composition while maintaining or possibly improving aspects of meat (eating) quality.

Orientador: Vera Fernanda Martins Hossepian de Lima / Coorientador: José Jurandir Fagliari / Coorientador: Maria Emilia Franco Oliveira / Banca: Jeferson Ferreira da Fonseca / Banca: Marcus Antônio Rossi Feliciano / Resumo: Para avaliar os efeitos de dietas alimentares utilizando fontes de gordura protegida (Megalac® ou linhaça) associada superestimulação hormonal sobre os parâmetros da aspiração folicular em cabras foram utilizadas 18 cabras da raça Anglo-Nubiano, clinicamente saudáveis e aptas a reprodução. Os animais foram divididos e alojados aleatoriamente em 3 grupos experimentais com 6 animais cada, sendo um grupo controle (C), com dieta utilizando-se o óleo de soja fonte de gordura alimentar, um grupo com dieta utilizando-se MEGALAC® (M) como fonte de gordura protegida, um grupo com dieta alimentar utilizando-se semente de linhaça (L) como fonte de gordura protegida. Todos os animais foram submetidos a ultrassonografia transretal para a avaliação da quantidade e do diâmetro folicular imediatamente antes da aspiração folicular por vídeo laparoscopia, os oócitos obtidos foram maturados in vitro e avaliados quanto a sua capacidade de maturação, para a uma melhor avaliação da resposta dos animais a dieta e ao procedimento de aspiração folicular foi coletada amostras de sangue de todos os animais para avaliação hematológica e da bioquímica sérica. Não houve diferença no escore de condição corporal e no ganho de peso dos animais. No exame ultrassonográfico foi notada diferença no diâmetro dos folículos observados entre o primeiro (4,29 ± 0,06) e o segundo (3,69± 0,07) ultrassom o diâmetro dos folículos considerados aspiráveis pelo ultrassom também diminuiu do primeiro (5,05 ± 0,06) para o segundo (4,71 ± 0,13) ultrassom. Notou-se uma maior média de folículos observados (28,4 ± 4,17) e aspirados (26,8 ± 4,12) e oócitos recuperados (10,9 ± 1,37) no Grupo C na. As análises sanguíneas não mostrou diferença entre grupos, porém parâmetros sofreram alterações no período pós operatório com retorno a normalidade nos momentos seguintes / Abstract: To evaluate the effects of diet with protected fat (Megalac® or linseed) associated with ovarian super-stimulation on an follicular aspiration parameters, 18 anglo-nubian goats, in perfect health, were used. The animals were divided in 3 experimental groups with 6 individuals per group, one control group, under a diet without protected fat with an ovarian super-stimulation protocol, one group under a diet with MEGALAC® and under an ovarian super-stimulation protocol, one group under a diet with linseed and under an ovarian super-stimulation protocol. All the animals were submitted to an ultrasound evaluation immediately before the laparoscopic ovum pick up (LOPU), all the obtained oocytes were classified and in vitro maturated and evaluate as their ability to mature, to evaluate the responses of the animals, certified health and security of the diet and LOPU, blood samples were taken for evaluation of cell blood count, serum biochemistry profile. During the ultrasound exams were noticed a decrease in follicles diameter from the first(4,29 ± 0,06, mm) to second(3,69± 0,07, mm) ultrasound, and in viable follicles diameter from the first(5,05 ± 0,06, mm) to second (4,71 ± 0,13, mm) ultasound. Animals from the group C had more follicles observed (28,4 ± 4,17) and aspired (26,8 ± 4,12) and more oocytes recovered (10,9 ± 1,37), were noticed a decrease in number of thoses parameters in all groups from comparing the first LOPU with the second. Blood analyses did not shown any difference between gropus, however were significant changes on the post-surgical period, with a soon return to normality / Mestre

A carne exerce um papel crucial na evolução humana e é um componente importante em dietas saudáveis e balanceadas, uma vez que apresenta propriedades nutricionais, é fonte de proteína de alto valor biológico e de algumas vitaminas e minerais. No entanto, estudos recentes têm estabelecido uma relação direta entre o consumo de produtos cárneos e o aumento no risco de distúrbios graves de saúde, como câncer colo retal e doenças cardíacas. Assim, o desenvolvimento de produtos cárneos com níveis reduzidos de gordura, que sejam similares aos produtos tradicionais, apresentando boa aceitabilidade pelos consumidores, é essencial para a melhoria da saúde humana. No entanto, poucos trabalhos da literatura tem estudado a incorporação de pré-emulsões como substituto da gordura animal, especialmente em relação às caracteristicas sensoriais. O presente trabalho estudou o efeito da substituição de gordura animal por óleos vegetais e marinhos sobre as propriedades físicas, químicas e sensoriais de mortadela formulada com diferentes hidrocóloides. Na primeira parte do trabalho avaliaram-se as propriedades físicas, químicas e sensoriais da mortadela reformulada usando gordura vegetal hidrogenada como substituto de gordura animal, e foi verificado que o uso da gordura vegetal hidrogenada não é adequado como substituto da gordura animal devido à redução da qualidade nutricional, especificamente do perfil lipídico, e da qualidade sensorial, especificamente da dureza. Após isto, estudou-se a microestrutura, a textura sensorial descritiva e o perfil instrumental de textura da mortadela tradicional e light e, através dos resultados, os parâmetros de dureza e elasticidade foram considerados como referências na seguinte etapa da reformulação. Em seguida, otimizou-se o perfil lipídico e, através de uma estratégia sequencial de planejamento experimental, as proporções adequadas de óleos em préemulsões foram obtidas, assim como a dureza e a elasticidade foram otimizadas, em função da composição da pré-emulsão composta de alginato de sódio, goma guar e isolado proteico de leite. Avaliaram-se, então, as características sensoriais da mortadela e sua relação com a aceitação do consumidor. O atributo direcionador da preferêcia, segundo a correlação entre as respostas da análise descritiva e do teste de aceitação, foi a textura \"borrachenta\", confirmando-se assim que mesmo adicionando um hidrocolóide para diminuir a dureza, esta diminuição resultou em um novo atributo negativo. As perguntas Check- all-that-apply (CATA) juntamente com a Análise de Penalização e a PLSR de variáveis fictícias com a aceitação ajudaram a identificar o \"sabor estranho\", \"sabor caracteristico\", \"textura gelatinosa\" e \"textura firme\" como os principais atributos a serem modificados numa reformulação posterior. Dessa forma, conclui-se que através da estratégia de reformulação planejada, pode-se elaborar uma mortadela com um perfil lipídico em consonância com as recomendações de uma dieta saudável, levando em consideração a opinião do consumidor. / Meat plays a crucial role in human evolution and it is an important component in healthy and balanced diets, since it presents nutritional properties, it is source of proteins of high biological value, and some vitamins, and minerals. However, recent studies have established a direct relationship between the consumption of meat products and the increased risk of serious health disorders, such as colorectal cancer and coronary-heart diseases. Thus, the development of meat products with reduced fat levels that are similar to traditional products and with good consumer acceptability is essential for the improvement of the human health. However, few studies in the literature have studied the incorporation of pre-emulsion as animal fat substitute, especially regarding the sensory characteristics. The present study evaluated the effect of the animal fat substitution by vegetable and marine oils on the physical, chemical, and sensory properties of mortadella formulated with different hydrocolloids. In the first part of the study, the physical, chemical and sensory properties of reformulated mortadella using hydrogenated vegetable fat as animal fat replacer were evaluated and it was verified that the use of hydrogenated fat is not suitable as animal fat replacer due to a reduction in the nutritional quality, specifically regarding the lipid profile, and in the sensory quality, specifically regarding hardness. After this, the microstructure, the descriptive sensory texture and the instrumental profile of the traditional and light mortadella were studied and, through the results, the parameters of hardness and elasticity were considered as references to the next step of the reformulation. Then, the lipid profile was optimized and, through a sequential strategy of experimental design, the appropriate proportions of oils in preemulsions were obtained, as well as the hardness and elasticity were optimized according to the pre-emulsion composition composed of sodium alginate, guar gum and isolated milk protein. The sensory characteristics of the mortadella and their relationship with the consumer acceptance were then evaluated. According to the correlation between the answers of the descriptive analysis and the acceptance test, the driver of liking was the \"rubbery\" texture, thus confirming that, even by adding a hydrocolloid to reduce the hardness, this decrease resulted in a \"new negative attribute\". The questions Check-all-that-apply (CATA), along with the Penalty Analysis and the PLSR of dummy variables with the acceptance helped to identify the \"strange flavor\", \"characteristic flavor,\" \"gelatinous texture\" and \"firm texture\" as the key attributes to be modified at a later reformulation. Thus, it is concluded that, through the planned reformulation strategy, it was possible to develop a mortadella with a lipid profile in agreement with the recommendations of a healthy diet, taking into account the consumer\'s opinion.

京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第13247号 / 論農博第2872号 / 新制||農||1070(附属図書館) / 学位論文||H31||N5171(農学部図書室) / (主査)教授 松村 康生, 教授 丸山 伸之, 教授 谷 史人 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Unsaturated fats undergo a process known as oxidation by which they are degraded into undesirable compounds. Therefore it is important for food manufacturers to employ antioxidant strategies. Crackers were used as a model in these studies because of their dietary contribution to saturated, and because the properties of crackers are translatable to other low moisture foods. The objective of this thesis was to determine if there was a significant variance in rates of oxidation between surface and total lipids in crackers and how solid fat content, synthetic antioxidants, and reduction of headspace oxygen affect those rates. It was hypothesized that lipids on the surface of a cracker would be more prone to oxidation than those on the interior. Experiments consisted of treatments to monitor total lipid oxidation and surface lipid oxidation. In the first experiment, crackers were formulated with soy oils of varying solid fat content. The second experiment monitored the effects of two synthetic antioxidants, BHT and TBHQ. The third experiment involved flushing the headspace of cracker storage vials with different blends of nitrogen and oxygen to inhibit lipid oxidation. Overall, significant differences did not exist in the rates of oxidation between surface and interior lipids. The lower the solid fat content of an oil, the more prone it was to oxidation. Antioxidants of greater hydrophobicity have increased efficacy in low moisture foods. Greater than 70% oxygen reduction is necessary to impart any antioxidant effect on crackers.

Two factors that are important in the production of the typical body and texture of cheddar cheese are acid development and milk fat content. When either of these is absent or present in less-than-normal amounts, the resulting cheese shows marked defects of curdiness and firmness.

No description available.