Processed meat can be stored for a long time

Meats are rich in protein, thus it can't be stored for a long time. If meat are processed for long-time storage, it is dangerous for the development of Clostridium botulinum. Clostridium botulinum is dangerous in that it secret botulinum neurotoxins (types A-G) which is one of the most toxic toxin in the world and causes Botulism. Nitrite salt are added as preservatives to prevent the development of Clostridium botulinum.

potential risk of nitrite salt

 * when nitrite reacts with secondary amine will yield carcinogen: nitrosamine.
 * heating food containing nitrite]] may yield nitrosamine, too.

other source of nitrite

 * nitrate-containing food: