The transnitrosation of secondary amines S-nitrosocysteine in relation to N-nitrosamine formation in cured meats

✍ Scribed by M. John Dennis; Roger Davies; David J. McWeeny

• Publisher: John Wiley and Sons
• Year: 1979
• Tongue: English
• Weight: 438 KB
• Volume: 30
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/jsfa.2740300614

✦ Synopsis

Abstract

The reactions at 37°C of S‐nitrosocysteine hydrochloride with three secondary amines, N‐methylaniline, morpholine and pyrrolidine, have been studied at pH 2.65, 5.5 and 9.75. The reactions result in the formation of the N‐nitroso derivatives of the three amines at all three pH values studied. The rates of N‐nitrosation and final yields of products in these reactions were compared with those in reactions in which the N‐nitrosation of the secondary amines was effected by nitrite. The comparative rates varied considerably according to the amine being studied and the reaction pH. The relevance of these findings to nitrosamine formation in cured meat and in vivo are discussed. Reaction of S‐nitrosocysteine hydrochloride with all three amines at pH 9.75 and with N‐methylaniline at pH 5.5 resulted in some N‐nitrosamine formation in the headspace above the reaction mixture. The stability of S‐nitrosocysteine hydrochloride was studied as a function of pH. The compound was fairly stable at pH 2.65, but decomposed rapidly at pH 5.5 and 9.75. The decomposition reaction at pH 5.5 followed three‐halves order kinetics, but that at pH 9.75 did not conform to simple kinetics.