Carbon dioxide evolution of refrigerated meat

The carbon dioxide (CO(2)) evolution from pork loins stored in air or nitrogen at 5°C was measured. The loins were cut immediately after slaughter ('pre-rigor meat.'), or approximately 20 h after slaughter ('post-rigor meat'). CO(2) evolution rate was highest during the first day (2·3 × 10(-3)mlcm(-2)h(-1)) and then declined to approximately 0·5 × 10(-3)mlcm(-2)h(-1). The rate was fairly constant during this later phase, and there were no large differences between aerobically and anaerobically stored meat, or between pre-rigor meat and post-rigor meat. Four hypotheses for the origin of the CO(2) evolution are discussed: (1) diffusion from a pre-formed pool in the meat; (2) aerobic energy metabolism of the meat cells; (3) other biochemical reactions of the meat cells; and (4) microbial activity. None of the hypotheses completely supports the experimental results of the investigation. The impact of these findings on the vacuum packaging of meat is discussed.