State the Stabilization of haem pigments

Ligands suggested for the stabilization of haem pigments are imidazole (and its derivatives), S-nitrosocysteine and nitrite. Whereas searching for alternatives to nitrite in the preparation of fish sausages, imidazole, 5(4)-aminoimidazole-4(5)-carboxamide (AICA) and various amino acid derivatives were used and found to impart colour to the finished product. Imidazole gave a red/pink colour with an orange tint, which faded on the surface of the produce unless an antioxidant was present. Animals appear to be a poor source of colourants.