According to a study published in ACS' journal Analytical Chemistry, the cheese was found in the tomb of Ptahmes, which was rediscovered in 2010.
The tomb of the former mayor of Memphis in Egypt was initially unearthed in 1885. After being lost under drifting sands, it was rediscovered eight years ago and archeologists found broken jars at the site a few years later.
One jar contained a solidified whitish mass, as well as canvas fabric that might have covered the jar or been used to preserve its contents.
After dissolving the sample, the researchers purified its protein constituents and analyzed them with liquid chromatography and mass spectrometry.
The peptides detected by these techniques show the sample was a dairy product made from cow milk and sheep or goat milk. The characteristics of the canvas fabric, which indicate it was suitable for containing a solid rather than a liquid, and the absence of other specific markers, support the conclusion that the dairy product was a solid cheese.
However, eating may not have been advisable, even back then. Other peptides in the food sample suggest it was contaminated with Brucella melitensis, a bacterium that causes brucellosis. This potentially deadly disease spreads from animals to people, typically from eating unpasteurized dairy products. If the team's preliminary analysis is confirmed, the sample would represent the earliest reported biomolecular evidence of the disease.
Prior to this, the earliest evidence of cheese-making in the archaeological record dates back to 5500 BC, in what is now Kujawy, Poland, where strainers with milk fats molecules have been found. Cheesemaking may have begun independently of this by the pressing and salting of curdled milk to preserve it.