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Abstract(s)
A qualidade da carne, nomeadamente de frango, é determinada não apenas pelas características visuais, que são avaliadas pelo consumidor, mas também com parâmetros microbiológicos e físico-químicos que são importantes do ponto de vista do produtor.
O presente estudo centrou-se no controlo da qualidade da carne de frango associada ao bem-estar animal, nomeadamente no que respeita ao valor de pH e à qualidade microbiológica do frango apanhado de dia e de noite quando relacionados com fatores como o tempo de jejum e espera no período ante-mortem, peso vivo e tempo do período post-mortem e rigor-mortis. De forma a realizar um estudo mais aprofundado no que respeita aos parâmetros de qualidade foram executadas após 24 horas do abate determinações de pH, qualidade microbiológica e cor para o peito e para a perna com costa; e da textura unicamente para o peito. Para além deste estudo, também foram avaliados os parâmetros anteriormente mencionados ao longo do tempo de vida útil de duas recolhas (24, 72 e 144 horas).
Através da análise dos resultados observou-se que apenas o tempo post-mortem tem influência no pH do frango, do peito e da perna com costa, apesar de o mesmo estabilizar até às 24 horas. Na cor do peito visualizou-se a ligação direta com o pH, visto a carne estudada caraterizar-se como PSE (5,7 ≥ pH ≤ 5,8; L* > 50). Na qualidade microbiológica verificou-se que será necessário um controlo mais rigoroso dos tempos de jejum (evitando assim, as contaminações cruzadas) e do manuseamento por parte dos colaboradores na zona da desmancha, visto que de maneira geral a quantidade de microrganismos obtida foi elevada. De forma a avaliar a textura do peito utilizou-se o teste de força de corte e o TPA, verificando-se que o peito cozido é mais duro, a elasticidade e a adesividade têm valores semelhantes e os parâmetros secundários (gomosidade e mastigabilidade) têm diferenças significativas, na apanha noturna.
O estudo permitiu concluir a importância de controlar todos os fatores extrínsecos para que a qualidade do animal não seja influenciada. No caso específico deste projeto, verificou-se que os problemas da qualidade como a cor esverdeada no peito e a quantidade de microrganismos elevada não provém de fatores extrínsecos, mas sim intrínsecos, como o caso da alimentação, da genética e do estado fisiológico.
The quality of meat, particularly chicken, is determined not only by the visual characteristics, which are evaluated by the consumer, but also by microbiological and physicochemical parameters that are important from the producer's point of view. The present study focused on quality control of chicken meat associated with animal welfare, particularly with regard to the pH value and the microbiological quality of the chicken caught day and night when related to factors such as fasting time and expects in the ante-mortem period, live weight and time of the post-mortem and rigor-mortis period. In order to carry out a more in-depth study regarding the quality parameters, pH, microbiological quality and color measurements were carried out after 24 hours of slaughter on the breast and on the shore leg; and texture only for the chest. In addition to this study, the aforementioned parameters were also evaluated over the shelf-life of two collections (24, 72 and 144 hours). Through the analysis of the results it was observed that only the post-mortem time has influence on the pH of the chicken, breast and leg with coast, although it stabilizes until the 24 hours. In the color of the chest the direct connection with the pH was visualized, since the studied meat was characterized as PSE (5,7 ≥ pH ≤ 5,8; L *> 50). In microbiological quality it has been found that a more rigorous control of fasting times (thus avoiding cross-contamination) and handling by employees in the cutting area is required, since in general the number of microorganisms obtained has been high. In order to evaluate the texture of the breast, the shear strength test and the TPA were used, and it was verified that the breasts were harder, the elasticity and the adhesiveness had similar values and the secondary parameters (guminess and chewing) had significant differences in nocturnal picking. The study allowed to conclude the importance of controlling all the extrinsic factors so that the quality of the animal is not influenced. In the specific case of this project, it was verified that the quality problems such as greenish color in the chest and the number of microorganisms high does not come from extrinsic factors, but intrinsic, as the case of feeding, genetics and physiological state.
The quality of meat, particularly chicken, is determined not only by the visual characteristics, which are evaluated by the consumer, but also by microbiological and physicochemical parameters that are important from the producer's point of view. The present study focused on quality control of chicken meat associated with animal welfare, particularly with regard to the pH value and the microbiological quality of the chicken caught day and night when related to factors such as fasting time and expects in the ante-mortem period, live weight and time of the post-mortem and rigor-mortis period. In order to carry out a more in-depth study regarding the quality parameters, pH, microbiological quality and color measurements were carried out after 24 hours of slaughter on the breast and on the shore leg; and texture only for the chest. In addition to this study, the aforementioned parameters were also evaluated over the shelf-life of two collections (24, 72 and 144 hours). Through the analysis of the results it was observed that only the post-mortem time has influence on the pH of the chicken, breast and leg with coast, although it stabilizes until the 24 hours. In the color of the chest the direct connection with the pH was visualized, since the studied meat was characterized as PSE (5,7 ≥ pH ≤ 5,8; L *> 50). In microbiological quality it has been found that a more rigorous control of fasting times (thus avoiding cross-contamination) and handling by employees in the cutting area is required, since in general the number of microorganisms obtained has been high. In order to evaluate the texture of the breast, the shear strength test and the TPA were used, and it was verified that the breasts were harder, the elasticity and the adhesiveness had similar values and the secondary parameters (guminess and chewing) had significant differences in nocturnal picking. The study allowed to conclude the importance of controlling all the extrinsic factors so that the quality of the animal is not influenced. In the specific case of this project, it was verified that the quality problems such as greenish color in the chest and the number of microorganisms high does not come from extrinsic factors, but intrinsic, as the case of feeding, genetics and physiological state.
Description
Keywords
Produção de frango Fatores de stress Valor de pH da carne Qualidade microbiológica Caraterísticas organoléticas Poultry production Stress factors PH value of meat Microbiological quality Organoleptic characteristics