Free and bound fatty acid oxidation products in archaeological ceramic vessels

Abstract

While oxidation products of unsaturated fatty acids, for example dicarboxylic acids (hereafter diacids), must form during the use of unglazed ceramic vessels for the processing of animal and plant products, such components have never been observed during studies of absorbed lipids. Their absence from the extractable lipid fraction is presumed to be the result of their loss from potsherds through groundwater leaching. Lipid oxidation products, including short-chain dicarboxylic acids, 3-hydroxy acids and longerchain hydroxy and dihydroxy acids, have now been observed as components probably covalently bound into solvent insoluble residues of potsherds recovered from waterlogged deposits. These components were only revealed following alkaline treatment of the insoluble residues. A similar mixture of diacids was observed in high abundance in the free lipid fraction of vessels recovered from an exceptionally arid deposit where groundwater leaching would never have occurred. These results con¢rm the formation of oxidation and probable polymerization products of unsaturated fatty acids during vessel use and burial.

Analytical strategies for discriminating archeological fatty substances from animal origin

“…The presence of such invisible organic residues is undetectable by simple visual observation, but the lipids are readily solvent-extracted and analyzed according to the protocols detailed below. Surface deposits have also been described (Heron & Evershed, 1993;Regert et al, 2001b). Their occurrence is not so common as absorbed residues, but they are extensively recovered in vessels from anaerobic lacustrine or fluvial environments.…”

Widespread exploitation of the honeybee by early Neolithic farmers

“…In France, the exploitation of bee products is evident during the second half of the fifth millennium at Chasséen sites (Font Juvénal, Chassey le Camp and Bercy 10 ) and fourth millennium at the Lake Village sites of Clairvaux les Lacs (3900 to 3700 bc) and Chalain 3 (ref. 22) and 4 (3200 to 3100 bc and 3040 to 2990 bc). High incidence of bees wax (approximately 15% of the detectable residues) was identified in 23 .…”

Análisis de residuos orgánicos y posibles contenidos en ánforas púnicas y turdetanas procedentes del valle del Guadalquivir

“…Se presume que las moléculas orgánicas se encuentran, por una parte, contenidas dentro de los espacios formados por los poros, inaccesibles a las enzimas exocelulares producidas por microbios degradantes; y por otra, protegidas debido a la adsorción en superficies de lípidos, sustancias difíciles de degradar por microorganismos. Esta protección también puede ser debida al atrapamiento dentro de matrices orgánicas, como los residuos orgánicos carbonizados (Regert et al 1998). En este caso, nos centraremos en la caracterización de ácidos grasos (AGs) y su identificación con productos concretos, tanto alimentos como sustancias conservantes o condimentos.…”