Biochemical and Utralmicroscopic Evaluation of Myofibril Proteins and Collagen during Ageing in Broiler Chicken PSE (Pale, Sof, Exudative) Meat

Abstract The aim of this work was to study the myofibril proteins and collagen fraction changes in broiler chickens PSE (pale, soft, exudative) meat during ageing and their relationship to meat quality. The results presented an increase of myofibril proteins and collagen solubility promoted by the enhanced proteases activities during storage. Ultramicroscopically, the PSE meat samples revealed intracellularly a sarcomere super contraction and lacunas within the A and I bands while Z-lines appeared very dense and fragmented in comparison to normal samples. This observation was noticed already at 4h storage while extracellularly collagen fibrils decreased visually within the endomysium only after 24h of conditioning. These results influenced the quality as the PSE meat presented better functional properties at the first hours of conditioning before further proteins degradation by proteases. Thereafter, at the later ageing stage a further disintegration of the abnormal meat structure would affect the meat functional properties.

Turkey Meat. Seasonal Effect on Meat Quality and on Dead on Arrival Index in a Commercial Plant

ABSTRACT The objective of this study was to determine the incidence of Pale, Soft, Exudative (PSE) meat and to characterize the Dark, Fim, Dry (DFD) meat as well as the Dead on Arrival (DOA) index in a commercial turkey slaughterhouse in southern Brazil during the summer and winter seasons. The journeys (n=64) were over a distance of 36 ± 20 km and took approximately 95 ± 20 min. Color (L*) and pH distribution of turkey breast meat (n=5,352) were evaluated from different farms (n=64) during the 2015-2016 years. The pH, water-holding capacity, color (L*, a*, b*) were used to establish cutoff values for DFD meat (L* < 44.0 and pH > 5.90) and presented correlation among them. The L* value was the highest during the summer (P<0.01), indicating the highest incidence of PSE meat (28.35 %), and lowest during winter, observing the highest incidence of DFD meat (10.3 %). Finally, the obtained summer DOA index was 0.23 % higher in relation to winter.

Influence of Cooling on the Glycolysis Rate and Development of PSE (Pale, Soft, Exudative) Meat

The aim of this work was to evaluate pH values fall rate in chicken breast meat under commercial refrigeration processing conditions and the development of PSE (pale, soft, exudative) meat. Broiler breast samples from the Cobb breed, both genders, at 47 days of age (n = 100) were taken from refrigerated carcasses (RS) immersed in water and ice in a tank chilled at 0°C (±2). pH and temperature (T) values were recorded at several periods throughout refrigeration in comparison to samples left at room T as control (CS). The ultimate pH (pHu) value of 5.86 for RS carcasses were only reached at 11°C after 8.35 h post mortem (PM) while, for CS samples, pHu value was 5.94 at 22°C after 4.08 h PM. Thus, under commercial refrigeration conditions, the glycolysis rate was retarded by over 4.0 h PM and the breast meat color was affected. At 24.02 h PM, PSE meat incidence was 30% while for CS, meat remained dark and PSE meat was not detected. Results show retardation in the glycolysis rate and PSE meat development was promoted by the refrigeration treatment when compared with samples stored at processing room temperature.

Broiler chicken PSE (Pale, Soft, Exudative) meat and water release during chicken carcass thawing and brazilian legislation

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) and control samples (n=55) (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.

Commercial preslaughter blue light ambience for controlling broiler stress and meat qualities

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 (<5.8) and lightness (L*> 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.

Broiler transportation conditions in a Brazilian commercial line and the occurrence of breast PSE (Pale, Soft, Exudative) meat and DFD-like (Dark, Firm, Dry) meat

The objective of this work was to investigate the effect of road transportation conditions on the occurrence of broiler PSE-(Pale, Soft, Exudative) and DFD-like (Dark, Firm, Dry) meats in the Brazilian commercial slaughterhouse plant. Samples of Pectoralis major m from 47-day-old broilers of commercial lineage were analyzed. The results indicated that water-bathing birds just before journey over 3.0km promoted the occurrence of 46.0 percent of PSE and 4.0 percent of DFD-like meat, while birds under non-water bathing conditions presented 14.7 and 2.0 percent, respectively. For a distance of 68.0km, the occurrences of PSE-and DFD-like meat were 44.0 and 0.0 percent under water bathing conditions, and 52.0 and 0.0 percent without water bathing, respectively. Water bathing at the farm was a critical manoeuvre for increasing the unfavourable truck microenvironment for short journey, whereas conversely for longer journey it was less stressful influencing the broiler breast meat quality.

O objetivo deste trabalho foi investigar o efeito das condições do transporte na ocorrência das carnes PSE (Pale, Soft, Exudative) e a-DFD (Dark, Firm, Dry) de frangos nas condições brasileiras em uma planta de um frigorífico comercial. Foram analisadas amostras de peito de frango (Pectoralis major m.) da ave de 47 dias de linhagem comercial. Os resultados indicaram que o banho dos frangos imediatamente antes da viagem de 3,0km promoveu a ocorrência de 46,0 por cento de PSE e 4,0 por cento de a-DFD enquanto que frangos sem banho apresentaram 14,7 e 2,0 por cento, respectivamente. Para uma distância de 68,0km, a ocorrência de carnes PSE e a-DFD foram 44,0 e 0,0 por cento, respectivamente, de aves que sofreram banho e 52,0 e 0,0 por cento sem banho, respectivamente. O banho ainda na granja foi uma atividade crítica aumentando as condições desfavoráveis no microambiente do caminhão para curtas distâncias e contrariamente para distâncias longas foi menos estressante influenciando na qualidade do peito do frango.

Lipid oxidation and fatty acid profile related to broiler breast meat color abnormalities

The aim of this work was to study the influence of lipid oxidation on broiler breast meat (Pectoralis major m) color abnormalities. There were 27.0 percent more lipid oxidation in PSE in relation to normal meat and 41.0 percent more in relation to DFD-like meat (p<0.05). The fatty acid profile was also significantly different since the arachidonic acid (AA) fraction increased 38.6 and 70.5 percent in PSE meat comparing to normal and DFD-like meats, respectively. The ratio PUFA/SFA changed in these three types of meat: 0.736, 0.713 and 0.694 for PSE, normal and DFD-like meat respectively, reflecting the highest production of polyunsaturated fatty acids in the PSE meat samples. Results indicated that phospholipase A2 enzyme activities played a relevant role towards the development of PSE-meat syndrome in a cascade of biochemical reactions promoting the formation of free radicals from AA, which ultimately damaged the muscle membrane systems.

A influência da oxidação lipídica no surgimento das anormalidades das cores do filé do peito de frango (Pectoralis major) foi avaliado. A oxidação lipídica foi 27 por cento maior em carnes PSE em relação ao normal e 41,0 por cento em relação ao análogo DFD (p< 0.05). O perfil dos ácidos graxos foi também significantemente diferente desde que a fração do ácido araquidônico (AA) aumentou 38,6 por cento e 70,5 por cento em carnes PSE em comparação às carnes normais e análogas ao DFD, respectivamente. A razão PUFA/SFA se alterou nos três tipos de carne, 0,736, 0,713 e 0,694 para carnes PSE, normal e análogo ao DFD, respectivamente, refletindo a maior produção dos ácidos graxos polinsaturados em amostras PSE. Esses resultados corroboram os nossos anteriores, indicando que a atividade da enzima fosfolipase A2 tem um papel relevante no desenvolvimento da síndrome do PSE em uma cascata de reações bioquímicas promovendo a formação dos compostos radicais livres do AA que finalmente compromete os sistemas das membranas celulares do músculo.

Development of a gas chamber for detecting broiler chicken halothane sensitivity and PSE (Pale, Soft, Exudative) meat formation

The objective of this work was to investigate the use of a halothane to screen broiler chickens prone to develop PSE (Pale, Soft, Exudative) meat through a special gas chamber connected to a veterinarian anaesthetic apparatus developed in our laboratory. Anaesthesia was induced with approx. 3.0 percent halothane at a flow rate of 6.0 Lm-1 in pure oxygen for 5 min. Commercial male broilers (n=342) aged 46 days old were evaluated and classified as either halothane sensitive (HAL+) or insensitive (HAL-), depending on the leg rigidity response. Approximately 27.5 percent (n=94) of broilers were HAL+ and 72.5 percent (n=248) were HAL-. This is a simple and rapid technique to evaluate broiler sensitivity to halothane and identify broilers prone to develop PSE meat. The occurrence of PSE meat in HAL insensitive broiler chicken samples suggests that other factors are related to PSE occurrence.

O objetivo deste trabalho foi investigar o uso do halotano para avaliar e identificar frangos propensos ao desenvolvimento de carnes PSE (Pálida, Flácida, Exsudativa) por meio de uma câmara desenvolvida em nossos laboratórios. Esta foi conectada a um equipamento de anestesia veterinária e a anestesia foi então induzida com aproximadamente 3,0 por cento de halotano a um fluxo de 6,0 L/min em puro oxigênio. A sensibilidade de três frangos foi avaliada simultaneamente. Os frangos de linhagem comercial (n=352) com 46 dias de idade foram expostos à 3,0 por cento de halotano por 5 min e classificados como halotano sensível (HAL +) e não-sensível (HAL -), baseado no enrijecimento dos seus membros inferiores. Aproximadamente 27,5 por cento (n=94) frangos foram HAL+ e 72,5 por cento (n=248) HAL-. Amostras do músculo Pectoralis major (n=75) foram coletadas após o abate dos animais para as medidas de pH e cor, determinadas nos filés mantidos a 4 C por 24 h postmortem. Frangos HAL+ apresentaram maior porcentagem de carnes PSE quando comparadas ao grupo HAL-. Este é um teste simples e rápido para a avaliação da sensibilidade das aves ao halotano e identificar frangos propensos ao desenvolvimento de carnes PSE embora amostras de HAL - também apresentaram carnes PSE sugerindo que outros fatores estão relacionados com a formação da anormalidade.

The effect of management of transport and lairage conditions on broiler chicken breast meat quality and DOA (Death on Arrival)

The aim of this work was to evaluate the influence of time of broiler chicken transportation and lairage prior to slaughtering on the occurrence of PSE (Pale, Soft, Exudative) meat and Death On Arrival (DOA) under non-commercial conditions in the Brazilian summer. Male birds (n=250) from a commercial line were subjected to different periods of journey (30, 90, and 180 min) and lairage (0, 90, and 180 min) before slaughtering. The occurrence of PSE was higher in broilers subjected to shorter journeys and lairage periods, whereas DOA was more pronounced upon longer periods of transport and lairage. The DOA occurrence percentage was much higher in comparison to commercially available figures, confirming that broiler chickens are very sensitive to both transport and lairage maneuvers.

O objetivo desse trabalho foi avaliar a influência do tempo de transporte e período de descanso antes do abate dos frangos na ocorrência das carnes PSE (Pale, Soft, Exudative: Pálido, Amolecido e Exsudativo) e DOA (Dead On Arrival: Morte Na Chegada) nas condições não comerciais durante o verão brasileiro. Frangos machos (n=250) de uma linhagem comercial foram submetidos a diferentes periodos de jornada (30, 90 e 180 min) e descanso (0, 90 e 180 min) antes do abate. A ocorrência do PSE foi maior em frangos submetidos tanto em tempos para as viagens curtas como para o de descanso enquanto que DOA foi mais pronunciada em condições de jornadas longas e maior periodo de descanso. A porcentagem da ocorrência do DOA foi maior ao se comparar com os resultados obtidas por empresas comerciais confirmando que os frangos são sensiveis às condições das viagens e de descanso a que são submetidos.

Functional properties of PSE (Pale, Soft, Exudative) broiler meat in the production of mortadella

This work was carried out in order to evaluate whether the functional properties of broiler meat are affected by the factors that lead to PSE (Pale, Soft, Exudative). PSE meat was characterized by pH and L* values, and mortadella formulations consisted of isolated soy protein, sodium tripolyphosphate, and cassava starch in addition to PSE and normal meats. The functionality of the meat was evaluated by examining the water holding capacity (WHC), texture profile, emulsion stability (ES) and color of the final products. The results show that in mortadella prepared with PSE meat, the protein denaturation affected the ES. Additives are necessary to enhance the functional properties of PSE meat.

Este trabalho foi realizado para avaliar o efeito dos fatores que conduzem à formação das carnes PSE (Pale, Soft, Exudative) sobre as propriedades funcionais da carne de frango. Carnes PSE foram caracterizadas pelos valores de pH e L* e as formulações da mortadela consistiram de proteina isolada de soja, trifosfato de sódio, amido de mandioca e a adição das carnes normal e PSE. A funcionalidade da carne foi avaliada medindo a capacidade de retenção de água (CRA), perfil de textura, estabilidade de emulsão (EE), e cor dos produtos finais. Os resultados mostraram que na mortadela preparada com carnes PSE, as proteinas desnaturadas afetaram a EE. Aditivos são necessários para potencializar as propriedades funcionais da carne PSE.

Sensitivity to halothane and its relationship to the development of PSE (Pale, Soft, Exudative) meat in female lineage broilers

This work aimed to evaluate female lineage broilers for halothane sensitivity and for their susceptibility to the subsequent development of PSE meat. The halothane test was carried out in an anesthetic chamber with 3.0 percent halothane. The unconscious birds were examined for leg muscle rigidity. If one or both legs became extended and rigid, the birds were classified as halothane sensitive (HAL+), while unresponsive birds were classified as halothane negative (HAL-). The results showed that of 298 birds aged 42 days old, 95.6 percent were HAL- and 4.4 percent were HAL+. A sample of pectoralis major muscle was collected from HAL- (n=105) and HAL+ (n=13) birds. The pH and breast fillet color were determined at 4ºC, 24 hours post-mortem. Interestingly, only 2.5 percent of HAL+ birds displayed PSE meat characteristics compared to 12.7 percent of HAL- individuals. The halothane test demonstrated that female lineage broilers displayed very little sensitivity towards halothane, indicating that the development of PSE meat is related to other environmental factors.

O objetivo deste trabalho foi avaliar a sensibilidade de aves de uma linhagem fêmea ao halotano e sua relação com o desenvolvimento de carnes PSE. O teste do halotano foi conduzido com o auxílio de uma câmara anestésica com 3,0 por cento de halotano volatilizado. As aves inconscientes foram examinadas pelo enrijecimento dos seus membros inferiores. Quando ambos ou um dos membros permaneceram rígidos, os frangos foram classificados como sensíveis ao halotano (HAL+) e os frangos sem enrijecimento dos membros foram classificados como não-sensíveis (HAL-). Os resultados mostraram que de 298 frangos com 42 dias de idade, 95,6 por cento foram HAL-, e apenas 4,4 por cento HAL+. O peito foi coletado das aves HAL- (n=105) e HAL+ (n=13) em que o pH e Cor (L*,a*,b*) foram determinados a 4ºC, 24h postmortem. Interessantemente, apenas 2,5 por cento das aves HAL+ demonstraram carnes PSE, enquanto que as aves HAL- apresentaram 12,7 por cento de carnes PSE, em relação ao total de aves abatidas. O teste do halotano demonstrou que frangos da linhagem fêmea mostraram pouquíssima sensibilidade ao halotano, indicando que a ocorrência de carnes PSE está mais associada a fatores ambientais.

Synergism between dietary vitamin E and exogenous phytic acid in prevention of warmed-over flavour development in chicken breast meat, Pectoralis major M

O efeito da suplementação de acetato a-tocoferol (AT) e a aplicação exógena desta vitamina E associada com ácido fítico (AP) foi avaliado no desenvolvimento do WOF em filé de peito de frango. O grupo controle foi alimentado com 7,7IU de AT/kg de ração e o grupo suplementado foi alimentado com 200IU de AT/kg de ração. A vitamina E na dieta inibiu o desenvolvimento de WOF, medido através do TBARS, em 78,9; 69,0; 60,7 e 46,5% (p<0,05) durante armazenamento a 6oC durante 0, 1,3 e 5 dias respectivamente. Esta inibição foi significativamente aumentada (p<0,05) em 86,1; 91,6; 92,9 e 95,3% armazenamento a 6oC durante 0, 1,3 e 5 dias respectivamente, quando 2mM de PA foi adicionado no filé de peito de frango suplementado. Através da Metodologia de Superfície de Resposta, no experimento exógeno, foi observado que o AT parece não ter um papel significante em relação à inibição da oxidação, enquanto que AP inibe parcialmente nas amostras armazenadas a 6oC durante 48h. Esses resultados mostram que AT na dieta inibiria na iniciação e subseqüentemente AP atuaria na propagação, ocorrendo uma reação sinérgica entre os dois antioxidantes.