Understanding residues of oil production: chemical analyses of floors in traditional mills

► In the paper we studied the residues absorbed by the floors of modern oil mills. ► Spot tests were used to analyse the samples and distribution maps were obtained. ► GC-MS was used to better identify the residues present in specific samples. ► General enrichment in fatty acids can be considered a signature for oil production. ► The analyses of modern installations can help in the interpretation of ancient ones.