Cooking activities during the Middle Ages: organic residues in ceramic vessels from the Sant'Antimo Church (Piombino-Central Italy)

A combined gas chromatography-electron ionization (GC-EI), atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) and MS/MS approach has been used for characterizing organic residues of ceramic vessels of different forms and dimensions recovered from a vault of the apse of the 13th century church of Sant'Antimo in Piombino (Central Italy). The artifacts studied in this investigation are pots, jugs, colanders and pans probably used for cooking meals or as food containers. GC-MS has shown the presence of different fatty acids and other nonpolar markers, while APCI ionization proved to be particularly useful in the detection of diterpenoids and diacylglycerols. The data show that some organic markers may be of animal origin, while others are typical constituents or biodegradation products of vegetables. This allows one to propose the main use of these articles as vessels for cooking meat and maybe vegetable broths and soups. As there is no strict correlation between organic markers and shape, form and dimension of the ceramic vessel, it appears that the different objects probably served the same function. Chemical characterization of the organic residues of ceramic vessels, together with all the other archaeological data, contributes to a better understanding of their uses and the customs of people in the Middle Ages in Central Italy.