FREE AND BOUND FATTY-ACID OXIDATION-PRODUCTS IN ARCHAEOLOGICAL CERAMIC VESSELS

While oxidation products of unsaturated fatty acids, for example dicar boxylic acids (hereafter diacids), must form during the use of unglaze d ceramic vessels for the processing of animal and plant products, suc h components have never been observed during studies of absorbed lipid s. 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, o mega-hydroxy acids and longer-chain 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 th e insoluble residues. A similar mixture of diacids was observed in hig h abundance in the free lipid fraction of vessels recovered from an ex ceptionally arid deposit where groundwater leaching would never have o ccurred. These results confirm the formation of oxidation and probable polymerization products of unsaturated fatty acids during vessel use and burial.