Catalysis of lipid oxidation in muscle model systems by haem and inorganic iron

The catalytic effect of haem proteins (haemoglobin and myoglobin) and inorganic iron (FeSO(4)) on lipid oxidation in a muscle model system was investigated. Haem proteins had a greater prooxidant effect than inorganic iron in raw and heated pork muscle residue when these prooxidants were present at levels approaching those in red meats. The rate of lipid oxidation catalysed by each prooxidant increased as the iron concentration increased over a range of 1-17 μg/g muscle residue. The relative prooxidant effects of haem protein and inorganic iron were not affected by the mode of addition of the prooxidants to the muscle residue (addition in a concentrated form or dispersed in water), or by the method of cooking (fast versus slow cooking).