Mayka Reghiany Pedrão

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). 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.

Comparison of proximate chemical composition and texture of cupim, Rhomboideus m. and lombo, Longissimus dorsi m. of Nelore (Bos indicus)

A composicao quimica percentual aproximada do cupim m. Rhomboideus (RB) derivado de Nelore (Bos indicus) de 24 meses de idade mostrou ser um musculo diferenciado. Ha uma maior fracao de material lipidico em RB chegando a ser 14 vezes proporcionalmente maior em comparacao ao m. Longissimus dorsi (LD) (p<0,05) a maior quantidade de gordura relatada em amostras de carne em literatura cientifica. Esse fato foi tambem observado pela avaliacao histologica. Ha proporcionalmente maior concentracao da fracao proteica e menor quantidade de umidade em RB. O teor de colageno foi de 22,9% mais concentrado em RB enquanto que a quantidade da sua ligacao cruzada, hidroxilisilpiridinolina (HP) foi 14 vezes maior indicando que cupim seria mais rigido. Contrariando essa expectativa, a maciez da carne crua avaliada pelo texturometro mostrou valores de 8.05 e 5.81 kg/F para LD e RB, respectivamente (p<0.05). Tais resultados mostram que em musculo contendo abundante gordura esta funciona como lubrificante para a lamina penetrar sem muita resistencia atraves do cupim a despeito dar quantidade e qualidade das fibras de colageno.

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.

Animal Welfare and Meat Quality: Methodologies to Reduce Pre-slaughter Stress in Broiler Chicken

The aim of this study was to report the causes of stress for commercial chickens during the manoeuvres performed immediately prior to slaughter. The model used to quantitatively measure the stress level of a condition was the occurrence of PSE (pale, soft and exudative) meat in the breast fillet. This abnormal meat condition affects meat quality and has damaging economic consequences for the meat industry. Several initiatives have been taken to alleviate the stressful conditions of commercial chickens. This chapter presents a detailed discussion of the techniques that would diminish, if not abolish, the stress placed on broiler chickens, thereby producing better quality breast fillet meat.