Post‐Mortem Changes in Physical and Chemical Properties of Bovine Musclea

Abstract
SUMMARY: Post‐mortem changes in tenderness and protein solubility were studied in bovine semitendinosus muscles. Muscles excised immediately post‐mortem were compared with muscles left attached to the skeleton. Post‐mortem times of 0, 6, 12, 24, 72, and 312 hr were studied. Sarcoplasmic protein solubility was highest immediately after slaughter and lowest in muscles left attached to the skeleton. Myofibrillar protein solubility was decreased in muscles left attached. Protein solubility changed during the first 6 hr post‐mortem but not during the 6‐ to 312‐hr aging period. Muscles left attached to the skeleton were least tender immediately after death and gradually increased in tenderness during post‐mortem aging. Excised muscles were least tender 6–12 hr post‐mortem and became progressively more tender thereafter. Even after 312 hr of aging, excised muscles were less tender than muscles still attached to the skeleton. Protein solubility did not appear to be related to tenderness. Possible relationships of muscle contraction to tenderness were discussed.