Archaeologists find key to tracking ancient wheat in frozen Bronze Age box

Posted on 26 July 2017

A chance discovery could help in the understanding of the spread and exploitation of cereal grains

Researchers discovered lipid-based biomarkers on the container. Picture Credit: Archaeological Service of the Canton of Bern.

A group of York researchers have discovered a new method to help archaeologists map and trace the development of early farming in Eurasia.

The team, composed of members of BioArCh along with other institutions, were expecting to find a milk residue left behind in a Bronze Age wooden container. Instead, they discovered lipid-based biomarkers for whole wheat or rye grain, called alkylresorcinols. The discovery of these biomarkers in the residue could be used as a new tool to help archaeologists map and trace the development of early farming in Eurasia.

The container was found in an Alpine ice patch at the summit of the Lötschenpass in Switzerland, at 2,650m, and provided optimum conditions for biomolecular preservation.

The domestication of plants, such as wheat, was one of the most significant cultural and evolutionary steps of our species, but direct evidence of their use in early culinary practices and economies has remained frustratingly elusive.

Plants quickly degrade in archaeological deposits and therefore archaeologists are increasingly using molecular techniques to look for their remains.

Dr André Colonese, from BioArCh, said : “We didn’t find any evidence of milk, but we found these phenolic lipids, which have never been reported before in an archaeological artefact, but are abundant in the bran of wheat and rye cereals and considered biomarkers of wholegrain intake in nutritional studies”.

“This is an extraordinary discovery if you consider that of all domesticated plants, wheat is the most widely grown crop in the world and the most important food grain source for humans, lying at the core of many contemporary culinary traditions.

 “One of the greatest challenges of lipid analysis in archaeology has been finding biomarkers for plants, there are only a few and they do not preserve very well in ancient artefacts. You can imagine the relevance of this study as we have now a new tool for tracking early culinary use of cereal grains, it really is very exciting. The next step is to look for them in ceramic artefacts,” Dr Colonese added.

Read the full article in Nature here: https://doi.org/10.1038/s41598-017-06390-x