Analysis of protein residues in fragments of ancient ceramic bowls and jars reveals what was for dinner 8000 years ago at the dawn of agriculture. The analysis confirms in unprecedented detail that early farmers in Anatolia ate a mixed diet of cereals, pulses, meats and milk products. In addition, they seemed to have knowledge of cultured dairy products 8000 years ago.
When the early farmers sat down for dinner about 8000 years ago, their food left protein residues in the vessels they used. A study of residues on the inside of fragments (sherds) of ceramic bowls and jars from the ancient settlement Çatalhöyük near Konya, Turkey has shown for the first time that food protein can remain preserved in bowls and jars for such a long time.
The analysis also shows that these early farmers processed or served milk products from sheep, goats and cows in these bowls besides wheat, barley, peas and vetch as well as meat, mostly from sheep and goats, but also from cows and deer. Further, they may have prepared meals, presumably in the form of porridge or soup, in the ceramic vessels.
The discovery provides the most detailed picture so far of people’s diet during this era of human history. So far, researchers have been able to learn about prehistoric diets from refuse such as animal bones and plant remains and by analysing the fat preserved in ceramic vessels. Now, using this new technique, researchers can obtain a much greater level of detail about food, analysing the specific grains, plants and animal species found in the prehistoric bowls and jars.
“Although bones from various animals have previously been found in the settlements as well as traces of milkfat in vessels, this is the first time we have evidence that all three ruminant species known from the bone finds – sheep, goats and cattle – were used for both meat and milk,” explains a lead researcher behind the study, Eva Rosenstock, Institute of Prehistoric Archaeology, Freie Universität Berlin, Germany.
The study has been published in Nature Communications.
One of the world’s best-preserved prehistoric settlements
Çatalhöyük is a large Stone Age settlement inhabited between 9100 and 7600 years ago. The settlement is located in central Turkey and is incredibly well preserved, with houses built next to one other.
After 25 years of excavation, Çatalhöyük is also one of the most thoroughly analysed agricultural settlements from the era of the earliest farmers.
For the study, archaeologists collected and analysed residue deposits on fragments of ceramic bowls and jars from a narrow time frame ranging from 7900 to 7800 years ago: the last flourishing period on the site of Çatalhöyük.
These fragments were collected from the West Mound of the settlement and contained deposits similar to limescale on the inside of what were once jars or bowls.
“The eastern part of the settlement yields about one vessel fragment per bucket of excavated soil. About 8000 years ago, people moved to the West Mound of the settlement, and there the number of vessel fragments explodes – dozens of pieces per bucket of soil,” says Eva Rosenstock.
Proteins from a wide variety of foods
The researchers analysed the deposits on the inside of the vessel fragments. Archaeologists often ignored or even remove these deposits as postdepositional sinter, but the new study shows that the dirty dishes of the Stone Age farmers contain an absolute gold mine of information.
The researchers analysed the deposits for the presence of both protein and fat based on the theory that this residue must originate from the foods the farmers stored in them.
These proteins are especially interesting because most are species-specific. The researchers used shotgun proteomics, an advanced analysis technique that is used to identify the protein sequences of all the individual proteins at the same time, to determine the organisms and tissues from which the proteins originated. They looked up the proteins found in the jars and bowls in a database containing thousands of protein references from animal and plant species.
They found proteins from wheat, barley, peas, goat, mutton, milk and other foods in the bowls and jars and found several foods stored in the same vessel, so the vessels might have been used to prepare, consume or even store meals, but different foods could also have been stored in a specific vessel but not at the same time.
Expanding the database to improve insight
The database of proteins is not complete, which means that the researchers think that these first farmers ate other foods than those identified so far in their analysis.
Various circumstances may explain why researchers have not found traces of these other foods.
• The food was stored elsewhere than the ceramic bowls and jars.
• The protein databases do not contain the proteins.
“For example, we have only six protein sequences for vetch in our database versus 145,000 protein sequences for wheat. This makes identifying wheat easy but identifying vetch difficult,” explains the main author of the study, Jessica Hendy, Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany.
Jessica Hendy also explains that expanding the protein database is an important part of the future work of examining our ancestral diets.
A message for colleagues: keep the deposits on vessel fragments
The archaeologists made an especially interesting discovery: one of the vessels, the jar, only contained proteins from whey, which indicates that these early farmers separated milk from sheep, goats and cows into whey and curds.
“This shows that people in that era used dairy techniques to separate the milk into its various components and that they subsequently stored the whey for some unknown purpose,” says Jessica Hendy.
According to Eva Rosenstock, the study shows how protein analysis can be a very powerful tool in improving insight into how people lived in the past.
However, calcitic residue on ceramic fragments should not habitually be treated with acid, because this may remove the material needed for analysis. Eva Rosenstock has a message for colleagues.
“These results highlight how valuable these deposits are, and we encourage our colleagues to keep them on the fragments during processing and cleaning after archaeological excavations,” says Eva Rosenstock.
“Ancient proteins from ceramic vessels at Çatalhöyük West reveal the hidden cuisine of early farmers” has been published in Nature Communications. Researchers from the Novo Nordisk Foundation Center for Protein Research, University of Copenhagen are co-authors.