Fatty acid profile in archaeological bones changes due to diagenesis

Bioarchaeological methods used to the reconstruction of the dietary patterns of past populations include the analysis of isotopic or chemical elements in bones, with focus on the inorganic component or on bone proteins. Studying bone lipids instead of bone proteins opens up many promising possibilities: they provide insight into dietary intake closer to the time of death and are more closely correlated with the composition of the total diet. The aim of the current study is to compare the archaeological bone fatty acids profile with the elemental composition of bone. The material used in the current study consisted of 20 archaeological human bone samples taken from the cortical bone of the femur, dated to the 17–18^th c. The elemental composition of the bone and the bone lipid profile were determined by spectrometric methods. Bone fatty acid content correlated with indices of bone preservation, compared to contemporary bones, archaeological bones tend to have more saturated and very long fatty acids (C22:0 and C24:0). It is most likely that longer fatty acids are better preserved in archaeological bones and reflect mainly bone cellular lipids.