Volatile N-nitrosamines (NAs) are reasonably antici- pated to be human carcinogens based on sufficient evidence of carcinogenicity on experimental animals (IARC, 1978). Humans are exposed to NAs from diet and other environ- mental sources as well as from endogenous synthesis within the body (Rubenchik, 1990).
The formation of NAs in meat is a complex process and a large diversity of substances could influence nitrosation reaction. Starting materials for NA formation in meat products are nitrate, nitrite, primary, secondary, and ter- tiary amines, amides, proteins, peptides, and amino acids or precursors of these, which are transformed into NA pre- cursors by microbial action.
Microorganisms could take part in NAs formation by nitrates reduction to nitrites, degradation of proteins to amines and amino acids (Tricker & Preussmann, 1991).