Who will unearth ancestral recipes?

The UNIGE and CNRS team used a new interdisciplinary approach to reconstruct food habits in a Senegalese village, a method that may also be useful for other archaeological studies.

Food is more than just a biological need. It is a cultural symbol and encompasses a wide range of practices that reveal the identity of regions, nations and social communities. But how can these habits and practices be traced if they leave no oral or written traces?

A team from the University of Geneva (UNIGE) and the CNRS successfully tested a multidisciplinary approach that included ceramics, chemistry, archaeozoology and archaeobotany. By applying this approach to excavations at a rubbish dump, the scientists were able to reconstruct the recent food history of a small village in Senegal.

The approach could potentially be adapted to excavations of ancient sites in other parts of the world. ProSone.

Tracing the past food habits of a community in the absence of oral or written records is a historical and methodological challenge. A team of archaeologists and chemists from UNIGE and CNRS took on this challenge, carrying out a large-scale, interdisciplinary and unprecedented study in the village of Ediongou in Lower Casamance, Senegal.

This village of 300 inhabitants is home to a now abandoned rubbish dump known as the “Poubelle des Mamans” (“Mothers’ Trash Can”). Used by families from the village’s neighbourhood throughout the 20th century, the site contains numerous artefacts relating to the region’s food history.

“The excavation of this site was really challenging. Due to its function and age, it contains many more artefacts than most traditional archaeological sites,” explains Pauline Debbels, co-first author of the study and a postdoctoral researcher at the time of the study, who is now a collaborator at the ARCAN laboratory at the Department of Biology at the Faculty of Sciences of UNIGE and a postdoctoral researcher at the CNRS Institute of Trajectoires.

“We dug centimetre by centimetre along the archaeological layer, which allowed us to recover remains such as very deteriorated pottery, bones, shells, textiles and certain food items.”

Interdisciplinary dialogue

To analyse these artefacts, which have widely different origins, the team developed a multidisciplinary approach, including archaeozoology (the study of animal bones from an archaeological perspective), pericarpology (the study of seed and fruit remains), microbotany, ceramics and the chemistry of organic residues.

“It is unprecedented to bring together so many disciplines in the context of archaeological research. It is a very complex approach to coordinate. Some items had to be analysed by several experts, ensuring that each analysis did not influence the next,” explains Léa Druid, a postdoctoral researcher at the time of the study, now a researcher at the CNRS’s CEPAM institute and co-first author of the study.

This method allowed the team to identify numerous animal and plant products once consumed in the village, trapped in the sediments and on the vessel walls. Also, by observing traces of use on the ceramic walls and the distribution of lipid concentrations along the vertical profile of the vessels, the scientists were able to gain insight into how food was processed and the function of the vessels.

“We found that the diet of the dump users consisted mainly of fish, oysters and rice, and that they also ate land animals during festivals. Salty and sour boiled foods seemed to be a favourite,” said Anne Mayol, director of the ARCAN laboratory at the University of Geneva’s Faculty of Sciences, senior lecturer at the Institute for Global Studies and who led the study with CEPAM research director Martine Legat.

Studying ancient ruins

“For example, celebratory foods have been identified based on food residues stored in containers. Along with the discovery of a pig’s jaw, evidence of meat dishes has been chemically identified in very large containers that were likely used for large gatherings. Overall, this study highlights some continuity in food habits before a notable break occurred a few decades ago.”

“Globalization has led to the introduction or popularization of new foods and new container materials such as plastics and metals, which have significantly changed eating habits, especially among younger generations. Some types of pottery with specific functions are becoming rare in the most recent layers excavated and have now virtually disappeared, being replaced by these stronger and lighter materials that are more readily available,” Debells explains.

This study, carried out as part of the SNSF Sinergia project “West African Food Habits: An Integrated Approach on Pots, Animals and Plants”, is a first step towards understanding the evolution of pre-colonial, colonial and post-colonial food habits in Senegal. It is also the first successful test of the integrated approach developed by the UNIGE and CNRS teams, which can be applied to older archaeological sites and other parts of the world.