Title Pending 20151

This is an accepted article with a DOI pre-assigned that is not yet published.Objectives were to characterize the rate of pH and temperature decline, pork quality attributes, and proteolytic changes during postmortem aging of five muscle cuts, the longissimus thoracis (LT), psoas major (PM), semitendinosus (ST), triceps brachii (TB), and gluteus medius (GM), as well as to evaluate the influence of endpoint cooking temperature on eating experience for each pork muscle cut. Muscle-specific variation for the response variables were evaluated for fifteen crossbred market barrows. The main effect of muscle was significant (P < 0.01) for rate of pH and temperature decline, instrumental color (L* and a*), drip loss, and intramuscular fat (IMF) content. The LT muscle had faster (P < 0.05) rates of pH decline from 1 to 3 h postmortem compared with the TB muscle while the ST and GM muscles were at intermediate levels and pH decline of the PM muscle was much slower than all other muscles. The LT and PM muscles had faster (P < 0.05) rates of temperature decline from 1 to 3 h postmortem compared with the TB and GM muscles while temperature decline of the ST muscle was intermediate. A muscle and cooking temperature interaction (P < 0.01) was observed for Warner-Bratzler shear force (WBSF), sensory tenderness, and sensory juiciness. In general, reducing the endpoint cooking temperature from 71°C to 63°C led to improvements in WBSF and sensory traits. However, muscle-specific differences existed, particularly when observing the magnitude of change in WBSF and sensory traits between the two endpoint cooking temperatures. These data may be used to explain how forgiving each individual muscle cut was when endpoint cooking temperatures were adjusted. Overall, pork quality, postmortem proteolysis changes, and eating experience appeared in a muscle-specific manner, and therefore consideration should be given to the individual muscle cuts of interest.