EXPERIMENTAL POLYSACCHARIDE CHARS AND THEIR FINGERPRINTS IN CHARRED ARCHAEOLOGICAL FOOD RESIDUES

As a model for polysaccharide char formation in archaeological food re sidues, bulk samples of microcrystalline cellulose were charred under anoxic conditions at atmospheric pressure and at temperatures ranging from 190 to 310-degrees-C. The resulting chars were characterised by p yrolysis-mass spectrometry (Py-MS) and Curie-point pyrolysis-gas chrom atography-mass spectrometry (Cu-Py-GC/MS). Although very few polysacch aride moieties were preserved in the experimental chars after heating above 270-degrees-C, a characteristic distribution of pyrolysis produc ts representing the condensed char is shown. A selected charred archae ological food residue was analysed using the same analytical technique s. In this way, polysaccharide input can be detected in archaeological residues after approximately 1800 years of burial.