Structural weakening of intramuscular connective tissue during post mortem ageing of chicken Semitendinosus muscle

The structural changes in intramuscular connective tissues endomysium and perimysium during post mortem ageing in chicken semitendinosus muscle were investigated using an improved technique of scanning electron microscopy. In post mortem chicken aged for 12 h at 4°C, the endomysium resolved into individual collagen fibrils and the perimysial sheets separated into collagen fibres. These results provide direct evidence for the structural weakening of endomysium and perimysium during post mortem ageing. The structural changes in the intramuscular connective tissue were minimal until 6 h post mortem, but clearly observable after 12 h post mortem. It was concluded that this disintegration of the intramuscular connective tissue is the chief mechanism in tenderisation during extended post mortem ageing of chicken.