During postmortem storage of muscle at 25 degrees C, myofibrils retained the ability to contract for more than 400 hours under experimental conditions used to prevent bacterial contamination of the meat surface. During t his time, rapid breakdown of troponin T was observed. Storage beyond 500 hours resulted in rapid loss of contractility correlating with proteolysis of the heavy chain of myosin, an din this stage some granules were observed along the whole A-band within the sarcomere
