Inferring the origin and dietary history of beef from C, N and S stable isotope ratio analysis

There is a pressing need for scientific methods that provide independent proof of the authenticity of animal produce for human consumption. Results of two feasibility studies suggest that the analysis of natural stable isotope compositions of carbon, nitrogen and sulphur is one potential tool for the verification of the geographical origin and feeding history of beef cattle. Beef reared in the USA (23 samples) and Brazil (10 samples) was isotopically different from northern European beef (35 samples), mainly because of contrasting proportion of plants with C3 and C4 photosynthetic pathways in the cattle diets. Combined C, N and S stable isotope ratio analysis also separated organically (15 samples) and conventionally (17 samples) produced Irish beef, even though underlying mechanisms are not yet fully understood.