SOME OBSERVATIONS ON MYOGLOBIN AND LIPID OXIDATION IN FROZEN BEEF

SUMMARY –The observed curvilinear correlation between metmyoglobin formation and lipid oxidation in beef gluteus medius samples (3 mm thick) stored in polyethylene at -5°C was dependent (P < 0.001) on initial treatment, namely freeze-thawing, delayed freezing or mincing. However, these initial treatments accelerated both metmyoglobin formation and lipid oxidation. In slices initially held in 1% oxygen at 0°C to increase the relative amount of metmyoglobin, the concentration of this pigment was first reduced during frozen storage at -5°C before increasing again. High initial metmyoglobin concentrations had no effect on the rate of lipid oxidation.