Nitrites are commonly used to cure various meat products and preclude botulism and other lethal food-borne illnesses. However, the process can lead to formation of potentially off-putting green pigments in a process known in the food industry as “nitrite burn”. This is especially problematic if the meat becomes acidic during storage.

Jun Yi and George Richter-Addo, University of Oklahoma, USA, have crystallized and obtained the structure of a nitriheme moiety that forms through nitration of heme in the meat. This is the first reported crystal structure of such a compound formed by any protein, the team says. The work could help in understanding and preventing nitrite burn. It could also inform the debate on the use of nitrites that are suspected of generated carcinogenic nitrosamines in such processed meat products.

• Unveiling the three-dimensional structure of the green pigment of nitrite-cured meat,
  J. Yi, G. B. Richter-Addo,
  Chem. Commun. 2012.
  DOI: 10.1039/C2CC31065A