Analysis and origins of N-nitrosamines in some alcoholic beverages and cured meat

Abstract

Carcinogenic N-nitroso compounds are found ubiquitously in the human environment and their isolation and identification in food samples constitutes an important step tcwards successful cancer prophylaxis. This study is concerned with the origin of volatile N-nitrosamines in some food samples. An attempt has been made to elucidate the mechanism of N-nitrosopyrrolidine formation in cooked bacon. The precursors and conditions that influence N-nitrosopyrrolidine f o r m t ion in bacon are discussed with special errphasis on manipulations that can reduce or eliminate the N-nitr osami ne content of bacon, such as cooking by microwave radiation. Based on model system studies a pathway for Nnitrosopyrrolidine formation is proposed. The presence of volatile Nnitrosamines in Ouzo and other anise-based distilled spirits (Raki, Pernod) which are consumed widely in Greece and around the Mediterranean was also investigated. Analytical aspects concerning the extraction and estimation of Nnitroso compounds in food samples were also considered. An analytical technique for the extraction of volatile N-nitrosamines from alcoholic beverages was devised, based cn liquid-liquid extraction cn a column packed with anhydrous Na2S04 , Celite and acid washed Celite. Finally, a method for the sequential determination of both volatile and non-volatile N-nitroso compounds in cured neats was developed. This is based cn a digestion-centrifugation technique by which volatile and nonvolatile N-nitroso compounds are extracted in the aqueous phase. Subsequently, the volatiles are extracted first into dichloromethane followed by the extraction of non-volatiles into ethyl acetate.