Spelling suggestions: "subject:"aan cooking"" "subject:"nan cooking""
1 |
Impact de la cuisson et de la digestion sur les micropolluants à risque des produits carnés / Impact of cooking and digestion on contaminants in meatPlanche, Christelle 18 November 2016 (has links)
Au cours de leur élevage, les animaux sont exposés à divers contaminants chimiques, qui peuvent s’accumuler au niveau des tissus animaux et être retrouvés in fine dans les produits carnés consommés par l’Homme, représentant alors un risque pour la santé des consommateurs. L’évaluation de ce risque repose classiquement sur la mesure de teneur en contaminants de la viande fraîche alors que plusieurs travaux suggèrent que seule une fraction de ces contaminants est effectivement assimilée par le consommateur du fait des transformations technologiques comme la cuisson et physiologiques comme la digestion. L’objectif de cette thèse est d’étudier ces effets modulateurs de la cuisson et de la digestion sur les contaminants chimiques de la viande et leur bioaccessibilité. En s’appuyant sur le développement d’une méthode multirésidus GC×GC-TOF/MS pour le suivi de 206 polluants environnementaux et sur des collaborations avec des Laboratoires Nationaux de Référence, le premier objectif de ce travail était d’étudier l’impact de la cuisson sur un large spectre de contaminants chimiques d’une viande intentionnellement contaminée. Les résultats montrent que la cuisson n’a pas d’impact significatif sur la teneur en PCDD/F et en métaux lourds de la viande alors que des pertes significatives (d’autant plus importantes que l’intensité de cuisson est élevée) en PCB, antibiotiques et pesticides ont pu être détectées. Ces pertes ont pour origine soit une libération dans le jus de cuisson des contaminants thermorésistants, soit une dégradation sous l’effet de la cuisson des contaminants thermosensibles, comme cela a été observé pour un antibiotique, le sulfaméthoxazole, pour lequel un schéma de dégradation thermique est proposé. Le second objectif de ce travail était d’évaluer la bioaccessibilité des contaminants chimiques de la viande en s’appuyant sur un protocole standardisé de digestion in vitro statique. Dans le cas des PCB, les résultats obtenus indiquent que la bioaccessibilité dans la viande est relativement faible (26%). La teneur initiale de la viande en matière grasse et les variations physiologiques liées à l’âge du consommateur influencent significativement ces valeurs de bioaccessibilité alors que la cuisson de la viande a moins d’influence sur la bioaccessibilité. A terme, les résultats obtenus durant ce travail devraient conduire à proposer de nouvelles procédures d’évaluation des risques liés aux contaminants chimiques de la viande, prenant en compte les modulations induites par la cuisson et la digestion. / Livestock animals are exposed to various chemical contaminants during breeding. These contaminants are rapidly transferred from the environment to animal edible tissues, thus representing a public health risk. This risk is classically assessed based on the level of contaminants in raw meat. However, due to technological processes such as cooking or physiological transformations such as digestion, only a fraction of meat contaminants can be absorbed by the body. The purpose of this PhD thesis is to investigate the modulating effect of cooking and digestion on chemical contaminants in meat and on their bioaccessibility. Thanks to a GC×GC-TOF/MS multiresidue method developed in this study for the analysis of 206 environmental pollutants and to collaborations with French National Reference Laboratories, the first aim of this work was to assess the effects of pan cooking on a broad range of chemical contaminants in spiked meat. Cooking did not impact the level of PCDD/Fs and heavy metals in meat whereas significant losses (more important as cooking conditions were more intense) of PCBs, antibiotics and pesticides were observed. These losses may originate from juice expelling of heat-resistant compounds or from degradation by breakdown of thermolabile compounds such as the sulfamethoxazole antibiotic. The second aim was to assess the bioaccessibility of chemical contaminants in meat based on a standardized in vitro static digestion. For PCBs, results showed that their bioaccessibility was low (26%). Both the meat fat content and the age of consumer significantly affect this bioaccessibility value. In contrast, meat cooking was shown to have less influence on PCB bioaccessibility. The ultimate goal of the project will be to improve chemical risk assessment procedures taking into account the changes induced by cooking and digestion on micropollutants in meat.
|
2 |
Análise físico-química, microbiológica e sensorial de cultivares de feijão / Physical-chemical, microbiological and sensorial analysis of common bean cultivarsOliveira, Viviani Ruffo de 05 February 2009 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objectives of this work were: (1) to evaluate the nutritional and microbiological quality of
common beans (Phaseolus vulgaris L.) processed with or without soaking water; (2) to
analyze the sensorial traits of common bean cultivars and to compare the efficiency of
quantitative descriptive analysis with not-trained and trained people; (3) to investigate the
sensorial traits of common bean cultivars and to compare the efficiency of quantitative
descriptive analysis with not-trained and trained people;(4) to evaluate the effect of storage
under refrigeration during six months on the cooking quality, the content of minerals and the
darkness of common bean cultivars with black and color tegument. Grains of Iraí and BRS
Expedito beans cultivars were submitted to soaking in distilled water for eight hours, at
environmental temperature. The cooking was made with the use or discard of soaking water.
The minerals were determined in the grains and in the broth separately, and the
microorganisms, in the mixture of grains and broth. The sensorial analysis was carried with
grains of four common bean cultivars: BRS Expedito, BRS Campeiro, Iraí and Carioca. Each
common bean sample was macerated for eight hours and the water was separated of the grains
and placed under firing in pressure pan. The not-trained and trained people received 25 g of
the four cooked cultivars and the analysis was taken using an evaluation file following the
technique of Quantitative Descriptive Analysis. To evaluate the cooking time, it was used four
cultivars of beans: BRS Expedito, BRS Campeiro, Pérola and Carioca and the cooking was
carried through in a domestic pressure pan during 15, 20, 25 or 30 minutes. The sensorial
analysis was effected in two stages: training for Qualitative Descriptive Analysis and the
sensorial analysis properly, with seven trained panel. It was used six cultivars (Macanudo,
Guapo Brilhante, BRS Campeiro, Pérola, Carioca and LH 5) and three times of storage (0, 3
and 6 months). It was evaluated the cooking quality (water absorption, normal and hard
grains and cooking time), the mineral content and the grain clarity ( L value). According to
the results, minerals composition in the grains and in the bean broth were not modified by the
discarding maceration water. The bean broth presented high amount of potassium, magnesium
and sulphur content. The discard of the soaking water did not improve microbiological quality
of the processed common bean. Iraí and BRS Expedito cultivars may be cooked with the use
or discard of soaking water because minerals content and microbiological quality of the
processed common bean are maintained. The sensorial attributes texture and bean broth were
evaluated with the highest experimental precision to the trained people, because lesser
coefficient of variation and error mean squares were observed. The not-trained people
discriminate greater number of sensorial attributes in common bean cultivars, but with a
reduced amount of experimental precision. The trained group recognizes differences in the
texture and broth the beans, with highest experimental precision. The panel recognized
differences among the cultivars such as: uniformity tegument color, hardness, graininess,
broth color and viscosity. The rupture of the tegument of the grains was bigger as it was
increased the cooking time. The hardness and the graininess received best notes as longer as
the cooking time of the common bean. The use of 20 the 25 minutes to cook in domestic
pressure pan seems to identify black and carioca cultivars of common bean with the best
evaluation profile, besides keeping the integrity of the cooked grains. Beans storage for six
months reduces the grains capacity of water absorption and influences negatively in the
darkness of Carioca group. However, it does not increase the amount of hardshell grains and
the cooking time, as well as the minerals content of the grains. / Os objetivos desse trabalho foram: (1) analisar se o processamento do feijão deve ser
realizado com o aproveitamento ou não da água de maceração, visando à manutenção da
qualidade nutricional e microbiológica; (2) avaliar o perfil sensorial de cultivares de feijão e
comparar a eficiência da técnica de análise descritiva quantitativa com avaliadores nãotreinados
e treinados; (3) investigar o tempo de cozimento que deverá ser utilizado, em panela
de pressão doméstica, para a identificação de cultivares de feijão de grãos preto e carioca com
atributos sensoriais de melhor perfil para o consumo; (4) avaliar o efeito do armazenamento
sob refrigeração (temperatura de 0 ºC e umidade relativa do ar de 50%) ao longo de seis
meses sobre a qualidade para o cozimento, o teor de minerais e a claridade dos grãos de feijão
de cultivares de tegumento preto e de cor. Grãos das cultivares de feijão Iraí e BRS Expedito
foram submetidos à embebição em água destilada por oito horas, à temperatura ambiente. O
cozimento foi realizado com e sem o aproveitamento da água de maceração. Os minerais
foram determinados nos grãos e no caldo, separadamente, e os microrganismos, na mistura de
grãos e caldo. Para a avaliação do perfil sensorial, grãos de quatro cultivares de feijão: (BRS
Expedito, BRS Campeiro, Iraí e Carioca) foram submetidos à análise sensorial por
avaliadores treinados e não-treinados. As amostras de feijão, de cada cultivar, foram
maceradas por oito horas e colocadas sob cocção em panela de pressão. Os avaliadores não
treinados e os treinados receberam 25 g de feijão cozido, de cada uma das quatro cultivares. A
análise foi realizada com o auxílio de uma ficha de avaliação e utilizou-se a técnica da
14
Análise Descritiva Quantitativa (ADQ). Para se avaliar o tempo de cozimento, utilizaram-se
grãos de quatro cultivares de feijão: BRS Expedito, BRS Campeiro, Pérola e Carioca, os quais
foram submetidos ao cozimento em panela de pressão doméstica por 15, 20, 25 ou 30 minutos
e em seguida realizou-se uma análise sensorial com avaliadores treinados. Seis cultivares
(Macanudo, Guapo Brilhante, BRS Campeiro, Pérola, Carioca e LH 5) e três tempos de
armazenamento dos grãos (0, 3 e 6 meses) foram avaliados quanto à qualidade para o
cozimento (absorção de água, grãos normais, grãos hardshell e tempo de cozimento), o teor
de minerais e a coloração dos grãos (valor de L ). Os resultados obtidos evidenciaram que a
composição de minerais nos grãos e no caldo de feijão não foi alterada pelo descarte da água
de maceração para o cozimento. O caldo de feijão apresentou altos teores de fósforo, potássio,
magnésio e enxofre. A eliminação da água de maceração não melhorou a qualidade
microbiológica do feijão processado. O cozimento das cultivares de feijão Iraí e BRS
Expedito pode ser realizado com o aproveitamento ou com o descarte da água de maceração,
pois há manutenção do teor de minerais e da qualidade microbiológica do feijão. Em relação
ao perfil sensorial, os avaliadores reconheceram diferenças para as cultivares de feijão quanto
à uniformidade da cor do tegumento, à dureza, à granulosidade, à cor do caldo e à
viscosidade. Os atributos sensoriais textura e caldo foram avaliados com maior precisão
experimental pelos avaliadores treinados, enquanto que os avaliadores não-treinados
diferenciaram maior número de atributos sensoriais nas cultivares de feijão, mas com menor
precisão experimental. Em relação aos diferentes tempos de cocção observou-se que a ruptura
no tegumento dos grãos foi maior à medida que se aumentou o tempo de cozimento. A
dureza e a granulosidade receberam melhores notas quanto maior foi o tempo de cozimento
dos grãos de feijão. A utilização de 20 a 25 minutos de cozimento em panela de pressão
doméstica possibilita a identificação de cultivares de feijão de grãos preto e carioca com o
melhor perfil para o consumo, mantendo a integridade dos grãos cozidos. O armazenamento
de feijão por seis meses reduz a capacidade de absorção de água de algumas cultivares e
influencia negativamente na claridade dos grãos do tipo Carioca. Entretanto, não aumenta a
porcentagem de grãos hardshell e o tempo de cozimento, além disso, não altera o teor de
minerais dos grãos avaliados após seis meses de armazenamento.
|
Page generated in 0.0628 seconds