Molecular analysis of black coatings and anointing fluids from ancient Egyptian coffins, mummy cases, and funerary objects

Abstract

Black organic coatings and ritual deposits on ancient Egyptian coffins and cartonnage cases are important and understudied sources of evidence about the rituals of funerary practice. Sometimes, the coatings were applied extensively over the surface of the coffin, resembling paint; in other cases, they were poured over the mummy case or wrapped body, presumably as part of a funerary ritual. For this study, multiple samples of black coatings and ritual liquids were taken from 20 Egyptian funerary items dating to a specific time period (c. 943 to 716 BC). Multiple sampling from each object enabled several comparisons to be made: the variability of the black coating within one application, the variability between two applications on one object, and the variability from object to object. All samples were analyzed for lipids using gas chromatography–mass spectrometry (GC-MS), and 51 samples from across the 20 items were further analyzed for the presence of bitumen using solid phase separation followed by selected ion monitoring GC-MS. The majority of the black substances were found to comprise a complex mixture of organic materials, including bitumen from the Dead Sea, conifer resin, and Pistacia resin, providing evidence for a continuation in international trade between Egypt and the eastern Mediterranean after the Late Bronze Age. Both the coating and the anointing liquid are very similar to mummification balms, pointing to parallels with Egyptian embalming rituals and raising questions about the practical aspects of Egyptian funerary practice.

Rethinking the Process of Animal Mummification in Ancient Egypt: Molecular Characterization of Embalming Material and the Use of Brassicaceae Seed Oil in the Mummification of Gazelle Mummies from Kom Mereh, Egypt

“…Nevertheless, in rare and special cases, it is possible to argue about the exact origin of the plant from which the oil was produced for mummification purposes, yet only when the characteristic biomarkers have been preserved. A good example of this would be the presence of high amounts of 12-hydroxy-9- cis -octadecenoic acid, which serves as a diagnostic compound for the presence of castor oil obtained from the seeds of Ricinus communis L. (Euphorbiaceae), as ricinoleic acid is not found in other natural lipids [ 3 , 6 , 9 , 14 , 15 , 31 , 38 ].…”

“…Results of the analysis by GC-MS revealed that one of the ingredients used for embalming was from natural resins extracted from the Pinaceae family of trees. Further data assessment confirmed the presence of resins in samples through the identification of dehydroabietic acid (M° + 372; base peak m/z 239) as its most dominant diterpenoid constituent together with its oxidation products: 3-hydroxydehydroabietic acid (M° + 460; base peak m/z 191), 7-hydroxydehydroabietic acid (M° + 460; base peak m/z 237), 15-hydroxydehydroabietic acid (M° + 460; base peak m/z 327), 7-oxo-dehydroabietic acid (M° + 386; base peak m/z 253) and 15-hydroxy-7-oxo-dehydroabietic acid (M° + 474 base peak m/z 459), which are formed from the degradation of abietadienic acids, present in fresh diterpenic resin of conifer trees, due to aging (markers of natural degradation over time) [ 2 , 7 , 26 , 38 , 41 , 42 ]. Moreover, in the studied samples, and directly related to the presence and preparation methods of resins as one of the ingredients for embalming, the presence of retene (final stable end product of thermal degradation of diterpenoids from Pinaceae resin), and methyl esters of dehydroabietic acid (M° + 314; base peak m/z 239), 7-oxo-dehydroabietic acid (M° + 328; base peak m/z 253) and 15-hydroxy-7-oxo-dehydroabietic acid (M° + 416; base peak m/z 401) was observed.…”

“…Nevertheless, in rare and special cases, it is possible to argue about the exact origin of the plant from which the oil was produced for mummification purposes, yet only when the characteristic biomarkers have been preserved. A good example of this would be the presence of high amounts of 12hydroxy-9-cis-octadecenoic acid, which serves as a diagnostic compound for the presence of castor oil obtained from the seeds of Ricinus communis L. (Euphorbiaceae), as ricinoleic acid is not found in other natural lipids [3,6,9,14,15,31,38]. In this regard, based on the presence of characteristic and diagnostic biomarkers in chromatograms of five gazelle mummies (90001291, 90002282, 90001211, 90002283, and 90002284), the authors of this study present the results of research that, for the first time, inform the scientific community about the use of cruciferous oil derived from the seeds of plants from the Brassicaceae family in the context of animal mummification in Roman Egypt during the 1st to 4th century AD.…”

Chemical Modification of Biomarkers through Accelerated Degradation: Implications for Ancient Plant Identification in Archaeo-Organic Residues

“…Coniferous plant products, such as essential oils, resins, tars, and pitches derived from cedar and pine trees, for example, played an important role as they had multiple applications in the ancient world. These products were used as ingredients in medical remedies, cosmetics and perfumery, as waterproofing agents for containers, as glues, and in rituals, such as mummification [ 15 , 16 , 17 , 18 ]. However, using plant biomarkers for identifying the biological origin of archaeological residues comes with significant challenges.…”

“…By applying multivariate analysis to these complex data sets, we identify characteristic biomolecular profiles associated with the various degradation treatments. We use the oil of cedar trees ( Cedrus atlantica ) for the experiment, as coniferous plant products from the Pinaceae family are frequently found in organic residues from archaeological contexts, especially in artefacts from ancient Egypt [ 17 , 18 , 41 , 45 , 46 , 47 , 48 , 49 ]. Cedar essential oil is mainly composed of mono- and sesquiterpenes, with himachalenes as the main components [ 50 ].…”