Postmortem Degradation of Desmin and Dystrophin in Breast Muscles from Capons and Cockerels

In recent years, consumers have increasingly sought niche food products with specific aroma and flavour, and rich in nutrients. With a growing demand for quality poultry products, there is an opportunity to increase production of capons, which are more and more often marketed as high quality products, because their meat is more delicate, tender and juicy. Therefore the objective of this study was to compare meat quality parameters and rate of protein degradation between capon and cockerel breast muscle during postmortem aging. Fibre type diameter, intact desmin and dystrophin contents at 15 min, 24 h, and 48 h postmortem and the following technological parameters of breast meat were also determined: pH₁₅, pH₂₄, pH₄₈, drip loss, shear force. The study was carried out on hybrids between Rhode Island Red cockerels (R-11) and Yellowleg Partridge hens (Ż-33) aged 24 weeks. The current findings indicate that compared with cockerel breast muscles, the capon breast muscles had significantly higher pH₁₅ (P≤0.01), and lower drip loss (P≤0.01) and shear force values (P≤0.05). Additionally, the intensity of intact desmin and dystrophin in capon breast samples at 24 h and 48 h postmortem was significantly lower (P≤0.05) than that in the cockerel breast sample. In turn, the lower rate of desmin and dystrophin degradation (P≤0.05), along with higher drip loss in cockerel compared to capon breast muscles, may account for their lower muscle fibre diameters at 24 h and 48 h postmortem. Moreover, the rate of early postmortem pH decline can partly explain the variation of desmin and dystrophin degradation.