Presence of nitrites, nitrates, nitrosamines in the eggs of Intensively raised layers in Abeokuta, Nigeria

Abstract

In this study, the presence and concentrations of nitrosamines and their precursors  (nitrates and nitrites) in raw table eggs obtained from four layer-farms in Abeokuta,  were analysed. Nitrosamines are highly toxic and carcinogenic group of chemicals that have the potential to be formed in the body through a process called nitrosation.  Nitrates and nitrites react under acidic and /or high temperature conditions with  nitrosable substrates usually secondary amines to form several of hundreds of  N-nitroso amine compounds known. A spectrophotometric method was used to assay for nitrosamines and their precursors in eggs (n=5 from each farm), entailing separate analysis of each egg yolk and albumen. The three compounds measured, were detected in all the samples. The nitrates and nitrites levels were significantly higher in the yolk than in the albumen (P<0.05). However, there was no significant correlation observed between the levels of nitrosamines and its precursors in the eggs (P<0.05). Findings from this study reveals that nitrosamines and their precursors are present in eggs from these layer farms. These compounds can be potentially toxic, thus constituting a hazard to human and animal health.

Key words: Carcinogenesis, eggs, layers, nitrates, nitrites, nitrosamines.