Molecular evidence for the mixing of meat, fish and vegetables in Anglo-Saxon coarseware from Hamwic, UK

Absorbed lipid residues from 24 seventh- to ninth-century coarseware potsherds from the major Anglo-Saxon trading centre of Hamwic (Southampton, UK) were analysed by gas chromatography – mass spectrometry (GC–MS) in order to reconstruct the dietary habits of its population. The results show that the vessels were used for preparing ruminant fats and leafy vegetables. In addition, evidence was found for a minor contribution of aquatic foods. Beeswax was found once and most probably relates to a sealing function or to honey. Remarkable features were: (i) the isomeric mixture of octadecenoic acid (C18:1 Δ7,8,9,10,11,12,13,14,15,16) and 8- to 16-hydroxyoctadecanoic acid, and (ii) the co-occurrence of C17:1, C19:1 and isoprenoid fatty acids. These features were proposed as biomarkers for ruminant and aquatic food sources, respectively. Furthermore, the carbonyl position distribution in mid-chain ketones was used to identify mixtures of animal- and plant-derived ketones. The paper highlights the difficulty in interpreting complex lipid signatures that show a mixture of various foods, as observed in the majority of the samples. This was linked to the preparation of stews or the recycling of vessels. The results are considered alongside ceramic usewear data and existing data relating to environmental remains recovered from the Hamwic excavations.