On the nature of the haematin‐protein bonding in cooked meat

Summary Heat, urea or suitable modification of the reactive proteins can all serve to bring about the transfer of haematin from metmyoglobin (Mb) to any one of several of the other proteins found in meat. The complexes formed are all spectrally similar to those found in cooked meat and are assumed to be the same. Studies on the effect of pH and chemical modification of selected amino acid residues in the reactive proteins suggests that these haemoproteins are predominantly haematin di‐imadazole complexes. The effect of selected amino acids on the spectra of Mb in 6 m urea also support the view that in cooked meat the haemoproteins are mainly di‐imadazole complexes, the imadazole residues being supplied by the histidine groups of the bound protein.