Structural weakening of intramuscular connective tissue during postmortem aging of pork.

摘要

Structural changes in the endomysium and perimysium during post mortem ageing of pork were studied using the cell-maceration/SEM method. Immediately post mortem, endomysia sheaths that house individual muscle fibres displayed a honeycomb-like structure. The sheaths of the endomysium consisted of tightly arranged collagen fibrils in a random network. The perimysium comprised several layers of wavy sheets made up of tightly bundled collagen fibres. While the structure of the intramuscular connective tissues remained almost unchanged up to 5 days post mortem, the endomysium had resolved into individual collagen fibrils, and the thick sheets of the perimysium had separated into collagen fibres and fibrils at 8 days post mortem. These results provide direct evidence for structural weakening of the endomysium and perimysium during post mortem ageing of pork. The shear-force value of raw pork decreased rapidly within 6 days post mortem and then decreased slowly until 14 days post mortem. Since the rapid increase in tenderness is mainly due to structural weakening of myofibrils, it is concluded that disintegration of the endomysium and perimysium may contribute to the tenderization of pork during extended post mortem ageing.