The analysis and significance of bound N-nitrosoproline in nitrite-cured meat products

An alkaline hydrolysis method is described for the release of bound N-nitrosoproline (NPRO) from cured meats that is more efficient than an enzymic method reported previously. The bound NPRO contents of 17 cured meats analysed ranged between non-detectable and 578 micrograms/kg (mean 143 micrograms/kg). Administration of defatted meat powder, prepared from such meats, to rats led to increased excretion of free NPRO in the urine that could not be inhibited by concurrent administration of ascorbic acid. The significance of these findings with regard to the use of such cured meats in in vivo N-nitrosation studies is discussed.