Différents facteurs sont connus pour affecter les paramètres de qualité du foie gras. Parmi ces paramètres, la fonte est considérée comme étant la plus critique du point de vue des producteurs et des consommateurs. Outre les facteurs déjà connus, le but de ce travail est d’étudier si les activités protéolytiques hépatiques pourraient jouer un rôle dans le déterminisme de la qualité du foie gras. Pour atteindre cet objectif, trois expérimentations ont été menées, dans lesquelles nous avons utilisé des approches biochimiques et protéolytiques ainsi que des mesures de qualité. Dans ces trois expériences nous avons évalué : 1) l’effet du gavage chez deux types génétiques de canards, 2) l’effet de la vitesse de refroidissement et du stockage post mortem et 3) l’effet de la variabilité de taux de fonte sur les activités protéolytiques. Nos résultats montrent que les activités protéolytiques restent constantes ou baissent avec le gavage. De plus, malgré des différences connues quant à leur capacité à développer une stéatose hépatique, les canards de Barbarie et les canards Pékin ont réagis de la même façon en ce qui concerne leurs activités protéolytiques. En ce qui concerne l’effet des différentes vitesses de refroidissement, nous avons montré que plus le refroidissement est lent, plus le foie fond et que ceci est –au moins partiellement- due à des activités protéolytiques plus élevées. Finalement, nous avons montré que les foies à fonte élevée présentés également des activités protéolytiques supérieures à celles des foies à fonte faible. Dans cette thèse, nous avons pu mettre en évidence certaines relations existantes entre la protéolyse hépatique et les qualités du foie gras de canard. Cependant, d’autres études seront nécessaires pour mieux comprendre les mécanismes responsables de ces relations dans le but d’exploiter le potentiel des protéases dans la maîtrise de la qualité du foie gras. / Different factors are known to affect the quality parameters of « foie gras ». Among those parameters, the cooking loss is considered to be the most critical one in the eyes of both producers and consumers. Besides already known factors, the objective of this work is to investigate whether proteolytic activities might play a role in the determinism of « foie gras» cooking losses. To achieve this objective three experiments were conducted in which we used biochemical and proteomic approaches as well as quality analysis. In these three different experiments we evaluated: 1) the effect of overfeeding in two breeds of ducks (Muscovy and Pekin ducks) 2) the effect of chilling rate and post mortem storage and 3) the effect of cooking loss variability on proteolytic activities. Our results show that overfeeding either does not affect proteases activities, either causes their decrease. In addition, despite the known differences regarding their ability to develop hepatic steatosis, in our study Muscovy and Pekin ducks’ proteolytic activities responded similarly to overfeeding. Concerning the effect of chilling rates, we showed that the slower the chilling rate the higher the melting after cooking. This result is - at least partially- due to higher proteolytic activities. Finally we showed that livers with a high melting rate presented higher proteolytic activities than those with a low melting rate. In this thesis, we were able to expose certain relations between hepatic proteolysis and fatty liver qualities. However, more studies are required to better understand the mechanisms underlying these relations in the goal of exploiting the potential of proteases in fatty liver quality control.

Estudos sobre a vitamina K têm evidenciado seu papel na manutenção da saúde óssea e vascular. A atuação desta vitamina em tecidos extra-hepáticos não é considerada na recomendação dietética da DRI de 2001, sendo reconhecidas necessidades maiores para função óssea em pessoas acima dos 60 anos e em indivíduos que fazem uso de medicamentos antivitamina K. Visando colaborar com pesquisas futuras, onde o conhecimento do teor de vitamina K1 é relevante, além de contribuir com dados para Tabela Brasileira de Composição de Alimentos - TBCA-USP, o presente trabalho foi conduzido para determinação do teor de filoquinona (vitamina K1) de hortaliças consumidas na cidade de São Paulo. As hortaliças analisadas foram escolhidas após a conclusão de um inquérito alimentar realizado, com adultos e idosos, num projeto de pesquisa desenvolvido junto ao Departamento de Alimentos e Nutrição Experimental da FCF/USP visando a análise da ingestão diária de vitamina K. Desta forma, foram analisadas as hortaliças mais consumidas por esses grupos, submetidas ou não ao processo de cocção. Estas amostras foram adquiridas diretamente na CEAGESP - Companhia de Entrepostos e Armazéns Gerais de São Paulo. As metodologias empregadas na determinação da filoquinona (vitamina K1) foram extração e purificação pelo método líquido-líquido utilizando solventes orgânicos e quantificação através da Cromatografia Líquida de Alta Eficiência (CLAE). Os resultados mostraram que as amostras de hortaliças de colorações verdes mais escuras apresentaram os maiores teores da vitamina como: salsa 491,05 µg/100g; espinafre 375,01 µg/100g, quando comparados com as amostras de colorações verdes mais claras as quais como é o caso da alface americana 113,42 µg/100g e a couve-flor 32,55 µg/100g. A maioria das hortaliças analisadas apresentaram variações entre as diferentes épocas do ano e quando comparadas com dados da literatura. / Studies on vitamin K have shown its role in maintaining bone and vascular health. The role of this vitamin in extrahepatic tissues is not considered in the dietary recommendation of DRI 2001. Increased need for vitamin K intake is recognized for the bone function in people over age 60 and individuals who use anti-vitamin K drugs. Aiming at supporting future research, where knowledge of vitamin K1 is relevant, and contribute data to the Brazilian Table of Food Composition - TBCA-USP, this study was conducted to determine the level of phylloquinone (vitamin K1) of vegetables consumed in the city of São Paulo. The vegetables studied were chosen after completion of a nutrition survey carried out with adults and elderly people, a research project developed by the Department of Food and Experimental Nutrition FCF / USP aimed at analyzing the daily intake of vitamin K. Therefore, we analyzed the most consumed vegetables by these groups submitted or not to the cooking process. These samples were acquired directly at CEAGESP - General Warehouses Company of São Paulo. The methodologies employed in the determination of phylloquinone (vitamin K1) were extraction and purification method using liquid-liquid organic solvents followed by High Performance Liquid Chromatography (HPLC). The results showed that the samples of darker green vegetables showed the highest levels of vitamin such as parsley (491.05 µg/100g) and spinach (375.01 µg/100g), when compared with samples of lighter coloration (e.g. 113.42 µg/100g lettuce, and 32.55 µg/100g cauliflower). Most vegetables analyzed showed variation in results when compared to the different seasons and the literature data.

Estudos sobre a vitamina K têm evidenciado seu papel na manutenção da saúde óssea e vascular. A atuação desta vitamina em tecidos extra-hepáticos não é considerada na recomendação dietética da DRI de 2001, sendo reconhecidas necessidades maiores para função óssea em pessoas acima dos 60 anos e em indivíduos que fazem uso de medicamentos antivitamina K. Visando colaborar com pesquisas futuras, onde o conhecimento do teor de vitamina K1 é relevante, além de contribuir com dados para Tabela Brasileira de Composição de Alimentos - TBCA-USP, o presente trabalho foi conduzido para determinação do teor de filoquinona (vitamina K1) de hortaliças consumidas na cidade de São Paulo. As hortaliças analisadas foram escolhidas após a conclusão de um inquérito alimentar realizado, com adultos e idosos, num projeto de pesquisa desenvolvido junto ao Departamento de Alimentos e Nutrição Experimental da FCF/USP visando a análise da ingestão diária de vitamina K. Desta forma, foram analisadas as hortaliças mais consumidas por esses grupos, submetidas ou não ao processo de cocção. Estas amostras foram adquiridas diretamente na CEAGESP - Companhia de Entrepostos e Armazéns Gerais de São Paulo. As metodologias empregadas na determinação da filoquinona (vitamina K1) foram extração e purificação pelo método líquido-líquido utilizando solventes orgânicos e quantificação através da Cromatografia Líquida de Alta Eficiência (CLAE). Os resultados mostraram que as amostras de hortaliças de colorações verdes mais escuras apresentaram os maiores teores da vitamina como: salsa 491,05 µg/100g; espinafre 375,01 µg/100g, quando comparados com as amostras de colorações verdes mais claras as quais como é o caso da alface americana 113,42 µg/100g e a couve-flor 32,55 µg/100g. A maioria das hortaliças analisadas apresentaram variações entre as diferentes épocas do ano e quando comparadas com dados da literatura. / Studies on vitamin K have shown its role in maintaining bone and vascular health. The role of this vitamin in extrahepatic tissues is not considered in the dietary recommendation of DRI 2001. Increased need for vitamin K intake is recognized for the bone function in people over age 60 and individuals who use anti-vitamin K drugs. Aiming at supporting future research, where knowledge of vitamin K1 is relevant, and contribute data to the Brazilian Table of Food Composition - TBCA-USP, this study was conducted to determine the level of phylloquinone (vitamin K1) of vegetables consumed in the city of São Paulo. The vegetables studied were chosen after completion of a nutrition survey carried out with adults and elderly people, a research project developed by the Department of Food and Experimental Nutrition FCF / USP aimed at analyzing the daily intake of vitamin K. Therefore, we analyzed the most consumed vegetables by these groups submitted or not to the cooking process. These samples were acquired directly at CEAGESP - General Warehouses Company of São Paulo. The methodologies employed in the determination of phylloquinone (vitamin K1) were extraction and purification method using liquid-liquid organic solvents followed by High Performance Liquid Chromatography (HPLC). The results showed that the samples of darker green vegetables showed the highest levels of vitamin such as parsley (491.05 µg/100g) and spinach (375.01 µg/100g), when compared with samples of lighter coloration (e.g. 113.42 µg/100g lettuce, and 32.55 µg/100g cauliflower). Most vegetables analyzed showed variation in results when compared to the different seasons and the literature data.

The objective of this study was to establish the consumer acceptability of preblended and nonpreblended post rigor seasoned pork patties with added water levels of 0, 3, 6, and 9 percent for each formula. Other parameters measured were proximate analysis, texture, cooking loss, and consumer acceptability. Nonpreblended treatments had a higher (P<0.05) percentage of protein and a lower (P<0.05) percentage of fat as compared to preblended treatments. Texture analysis revealed a lower (P<0.05) amount of total energy required to shear through a single patty in preblended treatments than nonpreblended treatments. No differences (P>0.05) were detected among treatments at varying water levels. Consumer acceptability showed no differences (P>0.05) among selected treatments. Consumer acceptability scores indicated that consumers would consume both preblended and nonpreblended seasoned pork patties at varying water levels.

Made available in DSpace on 2014-07-29T15:13:43Z (GMT). No. of bitstreams: 1 alineteseca.pdf: 944325 bytes, checksum: 5f0b947649cbf727f1cd020b11cdb011 (MD5) Previous issue date: 2008-12-15 / Sheep rearing is becoming an important economic activity, where it is necessary to establish the ideal slaughter weight per genetic group and sex to acheive standardized carcasses which meet customer needs in terms of product quality.This experiment evaluated the effect of genetic group and slaughter weight on carcass traits and meat quality in lambs. Twenty four Santa Ines (SI), 24 ½ Ile de France x ½ Santa Inês (ILE x SI) and 8 ½ Texel x ½ Santa Inês (TE x SI), slaughtered at different weights (30, 35, 40 and 45 kg ) were used.Eye rib area and fat thickness were measured in vivo and on the carcass. After a 16 hour food and water fast the animals were slaughtered conventionally and the carcasses placed in a cold chamber at 4ºC/24h. pH was measured at slaughter and after 24h as were subjective measurements on the Longissimus dorsi. A section of the rib region from the 11th to 13th ribs of the left side of the carcass was used for tissue and fractional composition, physic-chemical parameters and fatty acid composition. The experiment was in a 3 x 2 x 4 factorial design. For physic-chemical and fatty acids a 3 x 4 factorial and analysed using CORR (Correlation), REG (Regression) and Duncan (5%) means test in SAS ®. Genetic group did not influence (P>0.05) means for rib eye area or fat thickness measured by ultrasound or paquimeter. These measurements increased with slaughter weight. Tissue composition was influenced by genetic group and slaughter weight (P<0.05). The Texel x Santa Inês had most muscle (63.75 g), fat (53.75 g), bone (29.37 g) and edible portion (78.75%) at 35 and 45 kg . Slaughter weight centesimal composition, with an increase in total lipids as weight increased. No significant differences were found for final pH between genetic groups and slaughter weights. Genetic group did not influence colour (3.32), shear force (3.57 kgf) or loss in cooking (24.05%) of the Longissimus dorsi, but slaughter weight affected these, causing stronger colour, tougher meat and greater loss in cooking as slaughter weight increased. Significant differences were found in the sensorial traits of the meat with different genetic groups and slaughter weights. The fatty acids found included oleic (43%); palmitic (22%) and estearico (18%). Higher quantities of desirable fatty acids were found in the Texel x Santa Inês (66.78%) group. Slaughter weight caused a significant difference (P<0.05) in the fatty acid profile of saturated and polyunsaturated fats. / A criação de ovinos surge como atividade de importância econômica, na qual busca-se estabelecer o peso ideal para abate por grupo genético e sexo, proporcionando carcaças padronizadas que satisfaçam as perspectivas dos consumidores em termos de qualidade do produto. Objetivou-se com este experimento avaliar os grupos genéticos e peso de abate nas características da carcaça e qualidade da carne de cordeiros. Foram utilizados 24 cordeiros Santa Inês (SI), 24 cordeiros mestiços ½ Ile de France x ½ Santa Inês (ILE x SI) e 8 cordeiros mestiços ½ Texel x ½ Santa Inês (TE x SI), abatidos em diferentes pesos (30, 35, 40 e 45 kg). As análises de área de olho de lombo e espessura de gordura foram realizadas in vivo e na carcaça dos animais. Após jejum e dieta hídrica de 16 h, os animais foram submetidos ao abate convencional e as carcaças permaneceram em câmara fria a 4ºC/24h. Durante esse período foi realizada a leitura de pH inicial e final (24 h) e avaliações subjetivas no músculo Longissimus dorsi. Posteriormente foram retiradas as frações correspondentes à região da 11ª a 13ª costelas da carcaça esquerda para as análises de composição tecidual e centesimal, avaliação dos parâmetros físico-químicos e composição de ácidos graxos. O delineamento utilizado foi inteiramente casualizado em esquema de fatorial 3 (grupo genético) x 2 (sexo) x 4 (peso de abate). Para as análises físico-químicas e perfil de ácidos graxos foi utilizado fatorial 3 x 4 com aplicação de procedimentos CORR (Correlação), REG (Regressão) e teste de médias (Duncan 5%) do programa estatístico SAS. Os grupos genéticos não influenciaram (P>0,05) os valores médios da área de olho de lombo e espessura de gordura pelo ultra-som e paquímetro. Observou-se maior a área de olho de lombo e espessura de gordura na 12a costela com o aumento dos pesos ao abate. A composição tecidual foi influenciada pelos grupos genéticos e peso ao abate (P<0,05). Os animais Texel x Santa Inês apresentaram maior quantidade de músculo (63,75 g), gordura (53,75 g), osso (29,37 g) e porção comestível (78,75%) aos 35 e 45 kg. Houve efeito dos pesos de abate para a composição centesimal, apresentando aumento do teor de lipídeos à medida que os pesos eram elevados. Não houve diferença para pH final entre os grupos genéticos e pesos ao abate avaliados. Os grupos genéticos não influenciaram a cor (3,32), força de cisalhamento (3,57 kgf) e perda por cozimento (24,05%) do músculo Longissimus dorsi, no entanto, houve diferença significativa para os grupos de peso ao abate, atribuindo-se a coloração mais acentuada, carne menos macia e maior perda de líquido por cozimento com a elevação do peso ao abate. Foram detectadas diferenças nos atributos sensoriais avaliados nas carnes de cordeiros de diferentes genótipos e pesos ao abate. Os ácidos graxos encontrados em maior concentração foram o oléico (43%); palmítico (22%); esteárico (18%). Verificou-se maiores quantidades de ácidos graxos desejáveis em animais Texel x Santa Inês (66,78%). O peso de abate dos cordeiros determinou diferença significativa (P<0,05) no perfil dos ácidos graxos saturados e poliinsaturados.

Introduction. At low temperature the preservation of foodstuffs is one of the best ways of their storage and therefore this method is widely used in meat industry. The low temperature suppresses the activity of microorganisms and tissue ferments. Therefore the meat preserved by freezing keeps for a long time its initial properties and there are only minimal changes of food value and taste. At low temperature the activity of ferments slows down but does not stop. Work object. The work object is the determination of the change of physical-chemical properties of meat during freezing and keeping in - 180 C and - 860 C temperature. Work methodics. The research as fulfilled at the laboratory of the evaluation of the cattle meat properties and the meat quality. For the rersearch taken 14 Lithuanian white pig meat samples the mean weight of which was 500 g. were taken. They were put into special freezing bags and were frozen at temperature -180 C, and -860 C. Before freezing it the physical-chemical properties of the meat were determined. Two examples from each meat samples were researched. The determination of the physical-chemical properties of the meat was fulfilled every month. Also were was taken 6 Lithuanian white pig meat samples the mean weight of which was 500 g. Before freezing it the physical-chemical properties of the meat were determined. After that was made green tea extract, 500 ml. Water ant 50 g tea. All extract was inject in to the meat samples. They were put... [to full text]