Myoglobin functionalization catalytic reactions

Trace metals, particularly copper, cobalt, and iron, greatly increase the rate of LO and influence the direction of peroxide decomposition [72], These metals function both to reduce the induction period and increase reaction rate by decomposing hydroperoxides. Trace levels of these catalysts, e.g., as little as 0.3 ppm iron or 0.01 ppm copper, will result in prooxidant effects [73]. Iron may exist in foods in the free form or as a part of an enzyme (contain organically bound haem, Fe+ or haemin, Fe+ ). Enzymes containing haematin compounds include catalase and peroxidase (plant tissues) and haemoglobin, myoglobin, and cytochrome C (animal tissues). While heat treatment results in denaturation of the enzymes, it frees the iron to greatly enhance its catalytic properties. This is particularly relevant in the formation of warmed-over off-flavor in cooked meats. 

The function of iron in the body depends on the compound in which iron occurs. Iron mostly participates in oxygen transport through the bloodstream and oxygen storage in muscle tissue (the iron is in the haemoglobin and myoglobin) and participates in catalytic and oxidation-reduction reactions (iron in haem and flavin enzymes). 

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