Tracing culinary practices in the western provinces of the Roman Empire using Organic Residue Analysis

This study aims at reconstructing foodways in the north-east (NE) of the Iberian Peninsula, focusing on lipid residue analysis of utilitarian vessels and using as case studies the sites of Puig Castellar of Biosca (180–120 BCE) and Guissona (120 BCE-third century CE). In total, fifty vessel fragments of different types and origins were analysed with techniques such as gas chromatography-mass spectrometry (GC-MS) and gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). As some vessel fragments were recovered from waterlogged contexts, they had excellent lipid preservation, which enabled the detection of various compounds that are rarely reported in archaeological contexts in Iberia. Analyses revealed both animal and plant products in the vessels, suggested that a variety of food resources was consumed, and that vessels had multiple uses. The detection of levoglucosan in some extracts, along with other heat markers, further suggested the presence of cellulose or starchy products in contact with fire as well as the heating of animal fats. Combined with available bioarchaeological and palaeoenvironmental studies from both sites, the analyses indicated a continuity in diet across the time periods during which the sites were occupied. Some differences were also observed, including the possible use of tubers until the first century CE. The results are then contextualised and compared with other available organic residue studies from the Roman Iberian Peninsula. The study demonstrates how the combination of multiple bioarchaeological proxies and biomolecular approaches can provide a holistic means to approach Roman foodways.