Postmortem calpain changes in longissimus muscle from Lanyu native and Kaohsiung crossbred black pigs

The purpose of this study was to compare postmortem calpain changes in porcine muscle between Lanyu native (n = 10) and Kaohsiung crossbred (50% Meishan and 50% Duroc, n = 10) black pigs. Longissimus dorsi (LM) muscles (4th to 10th ribs) from both sides of carcasses were hot-sectioned in 30 min postmortem, vacuum-packaged, and stored at 5°C. LM samples from the left side of carcasses were sampled at 0 (30 min postmortem), 3, 6, 12, 24, 48, and 72 h of storage. The 24 and 72 h samples of shear force measurement were taken from the LM at the 8th and 10th ribs of the right side of carcasses, respectively. Our results showed that the decreases in calpain-1 activity, desmin content, and shear force were slower (P < 0.05) in Lanyu native black pig than in Kaohsiung crossbred black pig samples. Therefore, postmortem proteolysis and tenderization were more limited in LM from Lanyu native pigs than from Kaohsiung crossbred pigs.