Lipid and myoglobin oxidation in pork stored in oxygen- and carbon dioxide-enriched atmospheres.

The formation of malonaldehyde and metmyoglobin in pork muscles stored in oxygen- and carbon dioxide-enriched atmospheres at 1°C was followed. The formation of metmyoglobin at the surface of the muscles was independent of carbon dioxide concentration. However, increased oxygen concentration caused a significant decrease in the rate of metmyoglobin formation; the surface concentration of metmyoglobin was below 30% even after 15 days' storage in 80% oxygen/20% carbon dioxide. Lipid oxidation, as measured by malonaldehyde production (TBA Number), occurred at the same rate in air an mixtures containing 80, 90 and 100% oxygen. In some muscles, the rate was such that rancidity was apparent within 6 days at 1°C and, for pork, lipid oxidation, and not bacterial spoilage or metmyyoglobin formation, may be the limiting factor in the use of oxygen-containing atmospheres for storage.