We measured trace elements and stable isotopes (C and N on collagen) on 19 samples, taken from different anatomical area of 7 individuals from the medieval site of Roccapelago (Modena): our attempt is to reconstruct the diet of these individuals and discuss the role of trace elements in palaeodiet. The good preservation of these bodies represents a unique chance to work on likely diagenesis-free archaeological human remains, to test the trustworthiness of trace element analyses. In fact, in the last decades, trace element reliability was questioned several times. We particularly focus our attention on magnesium, strontium and zinc. Our data set shows different eating habits for the studied individuals. While collagen of the samples dated at 16th century yields typical values of a C3-plant based diet, collagen of samples dated at 18th cent yields higher values of both δ13C and δ15N, probably linked to an higher trophic level and to a shift toward a C4-environment. Similarly, Sr and Mg show the same increment in individuals of 18th cent, while Zn does not show any significant variation. The latter is quite discussed in the scientific literature and has been commonly used as a marker for a protein-rich diet. Our lack of correlation between Zn and stable isotopes (especially N) confirms the uselessness of this element in palaeodiet reconstruction. Geochemical data are also corroborated by the botanical evidence of maize presence (C4 plant) and by historical sources that attest the presence of maize in Emilia-Romagna during 18th century.
Stable isotope and in situ trace element analyses on human bone tissue (Roccapelago, 16th-18th cent.): preliminary inferences on diachronic change in eating habits and trace element reliability / Lugli, Federico; Brunelli, Daniele; Cipriani, Anna; Bosi, Giovanna; Gruppioni, G.. - STAMPA. - (2015), pp. 107-107. (Intervento presentato al convegno Towards a Next-Generation Anthropology: challenges and sinergies tenutosi a Bologna e Ravenna nel 3-5 September 2015).