Abstract:Pork longissimus muscle were taken at 20 min postmortem, kept at 0, 20 and 40 ℃ until 2 h postmortem and then stored at 4 ℃, respectively. 20 min, 1 h, 2 h and 24 h postmortem pork samples were selected and rapidly frozen in liquid nitrogen, and stored at -40 ℃ before analyzed. During incubation, rapid increase of R value, accumulation of lactic acid and decrease of pH value were found in the high temperature group (40 ℃).These data indicated that glycolysis could be activated much more in the high temperature group (40 ℃). When analyzing the extracted proteins with SDS-PAGE, it revealed that both 100 ku and 35 ku polypeptides from sarcoplasmas faction was associated with the myofibrillar fraction. Moreover, the 40 ℃ group had higher L * values and cooking loss compared with the other two groups. These result indicated that high initial postmortem temperature could resulted in pale and exudative characteristics in pork, partly because the glycolysis was activated at high temperature.
