Can pale, soft, exudative pork be prevented by postmortem sodium bicarbonate injection?

Abstract

Previous attempts at eliminating the problem of PSE pork by genetic selection or rapid postmortem cooling have been only partially successful. A new approach, namely, postmortem injection of sodium bicarbonate (SBC), was tested on halothane-positive gilts. Sixteen pigs were used to establish a suitable SBC concentration. At approximately 15 min after death, the longissimus of one side of the carcass was injected with 10% (by weight) of .2 to .4 M SBC solutions containing .7% NaCl (wt/vol). All concentrations resulted in a higher ultimate pH, improved muscle color, and reduced drip loss. In a second experiment, with 23 pigs, .3 M SBC was injected into the longissimus and the biceps femoris at either 15 min or 24 h after death and with or without inclusion of .7% NaCl (wt/vol). Compared with controls, the 15-min SBC + NaCl injected samples had darker color (L* of 47 vs 53 in controls), higher ultimate pH (5.6 vs 5.3), lower drip loss (5% vs 10%), and increased protein solubility (140 vs 115 mg/g). Injection at 24 h reduced drip loss (from 10% to 5.7%) but did not correct the color defect. The SBC alone and SBC + NaCl treatments had essentially the same effects in reducing drip loss, increasing ultimate pH, and improving color; but the SBC-NaCl injected samples had improved juiciness and flavor compared with SBC. Early postmortem sodium bicarbonate injection seems to prevent the development of PSE pork when injected into carcasses of halothane-sensitive pigs.