Search

The objective of this work was to study the effect of blue light diffuser on the broiler stress control by measuring the occurrence of PSE meat just before slaughtering. Birds were divided into the following two groups before slaughter at the point of being hung on shackles: broiler group under low intensity blue light ambience (475, 17-20 lx) and control group under white light (550-650nm, 321-332 lx). Birds' stressful conditions were measured by the occurrence of PSE meat. Breast fillets were classified as PSE meat based on pH ( 53.0). The fillet samples in the control group had the following characteristics: pHu=5.77, L* = 54.26 and b*= 6.27. The fillet samples from birds under blue light ambience had the following characteristics: pHu=5.81, L* = 52.86 and b* = 5.22 (p < 0.05). These results revealed that the treatment of blue light ambience just before slaughtering contributed to the alleviation of ante mortem stress of the birds, which was observed by a 14% decrease in the occurrence of PSE meat. Exposure to blue light just before slaughtering was shown to have potential to be used in modern slaughterhouses to offer a comfortable atmosphere, thereby maintaining breast meat quality.

The objective of this work was to investigate the relationship between poultry PSE meat and water loss of frozen chicken carcass in two experiments. The first experiment was carried out in commercial abattoir. Poultry carcass were classified as PSE meat (n=59) (pH 5.8). Water absorption and drip test were performed according to the Brazilian legislation methodologies. The second experiment was carried out with commercial whole five brands frozen carcasses purchased from the local supermarkets (n=30) and analyzed for pH, water holding capacity (WHC) and drip test. PSE poultry meats absorbed 3.59% of water during the processing similar to the control samples; however, released 0.38% more water during thawing of the carcasses. From these five brands evaluated, three presented drip values above 6.0%. The highest drip value was showed by the brand sample that had pH and WHC values characteristics of PSE meat. It could be postulated that PSE meat phenomenon promoted more water release during thawing leading to a misinterpretation in relation to the Brazilian legislation for water carcass liberation during thawing.

O objetivo deste estudo foi observar a influência da luz azul pouco antes do abate na qualidade da carne de frango, avaliada pela incidência de PSE (Pale, Soft, Exudative), assim como investigar a incidência deste fenômeno e sua relação com a perda de água em carcaças de frango, medida pelo teste de gotejamento. Foram realizados dois experimentos independentes. No primeiro estudo foi observada a influência da luz azul, os frangos (n= 602) foram divididos em dois grupos no momento da pendura em nóreas que antecede o abate: Grupo com luz azul e ausência de luz amarela e Grupo com ausência de luz azul e presença de luz amarela. Os frangos foram abatidos e os filés foram coletados 24 horas post-mortem e analisados quanto a pH e cor. No segundo estudo, a fim de investigar a incidência de carnes PSE, os frangos foram abatidos na estação de verão (n = 420) e de inverno (n = 300) na temperatura de 30°±5°C e 23°±5°C, respectivamente. Nos filés de peito de frango (pectoralis major) foram determinados o pH e cor, e classificados em PSE (pH≤5,8 e L*>53) e Normal (pH>5,8 e 445,8), antes do congelamento. No primeiro estudo foi possível verificar que o emprego da luz azul na zona de suspensão dos frangos em nóreas promoveu um melhor bem-estar nas aves que refletiu no decréscimo de 14,00% de carnes PSE em relação ao sistema sem luz azul. Nos experimentos do segundo estudo foi possível observar que nos meses de verão, a incidência de carnes PSE foi de 53,00% e nos meses de inverno de 39,00%, confirmando que no verão o estresse térmico conduz a um aumento de PSE. Além disto, carcaças PSE liberaram 0,38% mais água pós-descongelamento do que as carcaças Normais e, não ultrapassaram o limite de 6,00% conforme estabelecido pela Portaria 210/98 – MAPA. O fenômeno de carnes PSE não foi a principal causa da perda excessiva de água por gotejamento (dripping test) em carcaças de frango, possivelmente devido ao controle adequado do processo de resfriamento realizado pelo frigorífico. The aim of this study was to observe the influence of blue light shortly before slaughter on the quality of chicken’s meat, assessed by the incidence of PSE (Pale, Soft, Exudative), as well as to investigate the incidence of this phenomenon and its relation to water loss chicken’s carcass, measured by the dripping test. There have been two independent experiments. In the first study was observed the influence of blue light, the chickens (n = 602) were divided into two groups at the time of hanging them upside down in the shackler before slaughter: Group with light blue and absence of yellow light and Group absence of light blue and with presence of yellow light. The chickens were slaughtered and the fillets were collected 24 hours post-mortem and analyzed for pH and color. In the second study to investigate the incidence of PSE meat, the chickens were slaughtered in the summer season (n = 420) and winter (n = 300) at 30°±5°C and 23°±5°C, respectively. In the fillets of chicken’s breast (pectoralis major) were determined pH and color, and classified as PSE (pH≤5,8 and L*>53) and non PSE (pH>5,8 and 445,8), before freezing. In the first study we observed that the use of blue light in the area of suspension of chickens haging zone upside down by the leg in shacklers promoted a better welfare of the birds is reflected in the decrease of 14,00% of PSE meat in relation to the system without blue light. In the experiments of the second study it was observed that in the summer months, the incidence of PSE meat was 53,00% and in the winter months of 39,00%, confirming that the summer heat stress leads to an increase in PSE. In addition, PSE carcasses released 0,38% post-thaw more water than the non PSE carcasses, and did not exceed the limit of 6,00% as established by Decree 210/98 - MAPA. The phenomenon of PSE meat was not the primary cause of excessive water loss by dripping test in chicken’s carcasses, possibly due to the adequate control of the cooling process carried out by the slaughterhouse.