The objective of this study was to investigate the effects of conventional chilling (0 to 4 ◦C), rapid chilling
(RC, –20 ◦C for 30 min, followed by 0 to 4 ◦C), and short-duration chilling (0 to 4 ◦C for 30 min, followed by 25 ◦C)
on meat quality and calpain activity of pork muscle longissimus dorsi (LD). The muscle quality characteristics pH, color,
cooking loss, pressing loss and tenderness, and calpain activities were measured 0-, 3-, 12-, and 24-h postmortem. Results
show that the RC resulted in a faster temperature decline of the muscle, and prevented the meat pH and Commission
Internationale de l’Eclairage L∗ value from declining during postmortem aging . RC also reduced meat cooking loss and
pressing loss compared with the other two chilling methods. However, the chilling methods did not significantly affect
meat shear force. During the first 24-h postmortem, there was not a noticeable change in the activity of m-calpain. But
μ-calpain activity decreased regardless of chilling method. In the rapidly chilled carcasses, μ-calpain activity remained the
same 3- and 12-h postmortem. However, in the short-duration chilled and conventionally chilled carcasses, the activity
was visibly reduced. At 24-h postmortem, no clear zones on the gel were observed in all three treatments.