Tracing the geographic origin of poultry meat and dried beef with oxygen and strontium isotope ratios

Two promising isotope ratios, the δ¹⁸O of the water fraction, as extracted by azeotropic distillation, and the ⁸⁷Sr/⁸⁶Sr of the ash fraction were tested for their applicability to determine the geographic origin. In two sampling phases, in total 78 fresh poultry breast meat and 72 dried beef samples, independent from each other and originating from different countries, were analysed. The δ¹⁸O was measured with isotope ratio mass spectrometry and the isotope abundance ratio of ⁸⁷Sr/⁸⁶Sr with a multicollector inductively coupled plasma mass spectrometer. With δ¹⁸O it was possible to distinguish (p < 0.001) poultry and dried beef samples according to their country of origin. The beef data suggests that the procedure of processing is of only low additional influence on δ¹⁸O and, if so, it seems to reduce the initial between-country differences. The ⁸⁷Sr/⁸⁶Sr ratio did not give sufficient indications for differentiation by geographic origin in either poultry meat or dried beef in the smaller, first phase, data set and was therefore not further tested.