Detection of palm fruit lipids in archaeological pottery from Qasr Ibrim, Egyptian Nubia.

In modern times, the trees of the palm family have been of great economic and social importance to the people in Egypt, as in other parts of the world. There are various species of palm and although different parts of the tree can be used, the fruit are of great value. In antiquity, it is expected that the palm fruit would also have been of great importance to people in the region. The chemical analysis of absorbed residues in archaeological pottery is well established, and through the investigation of ceramic vessels (via gas chromatography, gas chromatography-mass spectrometry and gas chromatography-combustion-isotope ratio mass spectrometry) saturated carboxylic acids in the range C12 to C18 have been detected (with an unusually high abundance of C12) from vessels from the Nubian site of Qasr Ibrim. This is mirrored in the saturated fatty acid distributions detected from the kernels of modern and ancient date palm (Phoenix dactylifera L.) and dom palm (Hyphaena thebaica (L.) Mart.). Mixing in some of the vessels of the palm fruit with another lipid source is indicated through the delta13C values. These results provide the first direct evidence for the exploitation of palm fruit in antiquity and the use of pottery vessels in its processing.

Remarkable preservation of biomolecules in ancient radish seeds.

Desiccated seeds from a 6th century AD storage vessel recovered from Qasr Ibrîm, Egypt, were examined for the presence of lipids and nucleic acids. A remarkable degree of lipid preservation was discovered, the fatty acid and sterol profiles being very similar to those of modern radish seeds. The only significant differences were hydrolysis of triacylglycerols and depletion of the polyunsaturated fatty acids (C18:2 and C18:3). The delta 13 C values of the principal fatty acids were in the range -25.4 to -29.2/1000, which is congruent with modern radish (C3 seeds) taking account of isotopic shifts caused by recent changes in atmospheric CO2. Deoxyribonucleosides and nucleic acid bases were detected by direct chemical analysis, and polymerase chain reactions gave products with sequences comparable to those from modern radish. The degree of lipid preservation, which was much greater than that reported for other archaeological remains, suggests that the microenvironment within desiccated seeds retards biomolecular decay. The results illustrate the utility of combined lipid-nucleic acid analysis in chemotaxonomic and genotypic studies of archaeobotanical remains.