The effects of aging on moisture-enhanced pork loins

The effects of preinjection aging time on pork loins injected with a salt/phosphate/lactate solution were investigated. Ninety-six fresh pork loins, in two replicates, were divided into two treatments. Loins in the first treatment were injected to 13% of loin weight at I day post-slaughter with a brine containing 2.17% salt/3.04% phosphate/20.8% lactate. The second group was injected with the same brine 4 days after slaughter. Color and Warner-Bratzler shear (WBS) force were measured immediately, 7 and 14 days after injection. Purge was measured 8 and 15 days postmortem. Western blots to measure troponin-T degradation were performed on samples from the two loins that resulted in the lowest shear force, and from the two loins that resulted in the highest shear force, as measured by Warner-Bratzler shear. The two loins with the most purge loss and the two loins with the least purge loss were also analyzed by Western blots for desmin degradation. The L* and b* color values were higher (P < 0.05) and purge was greater (P < 0.05) for loins injected 1 day postmortem than for loins injected 4 days postmortem. Western blots demonstrated that injection did not affect protein degradation. Therefore, differences between individual animals that affect protein degradation remain important regardless of injection treatment. (C) 2003 Elsevier Ltd. All rights reserved.