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This research project proposes to determine the chemical nature of faecal ATNC together with its route of formation.
<p>A diet high in red meat has been shown to be associated with increased levels of colorectal cancer. It has also been shown to be associated with the increased levels of non-volatile N-nitroso compounds (NOC) formed by nitrosation in the gut. These are measured as apparent total nitroso-compounds (ATNC) in faecal extracts.
<p>Increased intakes of red meat have been shown to increase faecal ATNC levels in a dose responsive manner, the equivalent amount of protein from eggs, milk, cheese and vegetable protein have been shown to have no effect. Although many NOC are known carcinogens, the biological relevance of ATNC is unknown.
Faecal ATNC will be separated into water soluble, dichloromethane soluble and insoluble fractions. The dichloromethane fraction will be further identified by gas chromatography-mass spectrometry (GC-MS).
<p>The water soluble fraction will be characterised by molecular weight profile using aqueous size exclusion chromatography.
Lower molecular weight fractions will be characterised by liquid chromatography-mass spectrometry (LC-MS). Higher molecular fragments will be enzymatically digested and digest characterised by LC-MS.N-Nitrosoproline and a synthesised N-nitrosopeptide will be used for standardisation.
<p>This project is a collaboration with project T01030 - 'Biological relevance of apparent total nitroso compounds in the human colon'.
<p>Find more about this project and other FSA food safety-related projects at the <a href="http://www.food.gov.uk/science/research/" target="_blank">Food Standards Agency Research webpage</a>.