The use of direct probe mass spectrometry for the differentiation of meat species

Two studies were performed in which samples of freeze-dried meat from different species were subjected to replicate analysis by direct probe mass spectromety (DPMS). In the first study samples were obtained from six different muscles from each of three animal species, cattle, chicken and rabbit. In the second study one sample was taken from each of four individual animals from each of six species, cattle, chicken, horse, pig, rabbit and sheep. The spectra were analysed by statistical procedures which determined the ions responsible for the greatest degree of discrimination and the intersample relationships were displayed either as a two-dimensional scatter diagram or non-linear map. The results showed that DPMS was able to differentiate the species of origin of these meats. The reliability of the analysis procedures was tested with further replicates, not included in the original data analysis, which were treated as unknowns and also by using other data analysis techniques which did not require prior knowledge of the groups involved. The test samples fitted extremely well into their respective groups and there was very good agreement between the results from the defined and non-defined data.