Effect of Extended Hanging Time on the Microbial Quality of Pork Carcasses and Blade Steaks

To evaluate the effect of extended post-harvest hanging time on pork carcass sides (n = 20), aerobic plate count (APC), Enterobacteriaceae, yeast and mold populations, pH, and moisture content were determined. Pork carcasses were sampled on d 1, 7, 14, and 21 to determine their microbial quality from the lean tissue of 3 anatomical locations, the flank, shoulder, and jowl. After the 21-d extended hanging time, pork shoulder butts (n = 17) (Institutional Meat Purchase Specifications #406; USDA Agricultural Marketing Service, 2014) were fabricated from these carcasses into 2.54-cm pork blade steaks. Pork blade steaks were vacuum packaged, stored up to 35 d at 0°C ± 1°C, and evaluated for APC, Enterobacteriaceae, yeast and mold populations, and pH on d 0, 7, 14, 21, 28, and 35. Pork carcass surface moisture content declined (P < 0.01) from 65.1% on d 1 to 50.5% on d 21. The carcass pH was similar (P > 0.42) at 5.88 on d 1, 7, and 14; however, the pH declined (P < 0.05) to 5.72 at d 21. Pork carcass APC populations remained relatively low during the extended hanging time; however, the jowl had the highest (P < 0.05) APC populations among all anatomical locations. In addition, the proportion of yeast populations above the detection limit for the jowl was found to be greatest (P < 0.05) compared to the flank and the shoulder. Pork blade steak APC population was 5.06 log colony-forming units/g (CFU/g) on d 35; however, these counts were below 108 log CFU/g, which is when meat is considered spoiled. There was a day effect for Enterobacteriaceae and mold populations (P < 0.05). These results indicate that pork carcasses and vacuum-packaged steaks fabricated from pork carcasses have acceptable microbial quality when they undergo an extended hanging time.