Characterization of Adipocere Formation in Animal Species

Abstract

Adipocere is a soft white substance formed postmortem from fatty tissue in a decomposing body. In this preliminary study the formation of adipocere in soil was investigated for a number of animal species. Adipocere was formed from the fatty tissue of pig, cattle, sheep and rabbit. It was found that adipocere did not form from the fatty tissue of chicken or kangaroo in the time frame investigated. The issues being considered are relevant to the forensic examination of remains whose origin is otherwise uncertain or which are, in some way, related to human remains. Infrared spectroscopy and gas chromatography-mass spectrometry were used to characterise the composition of adipocere formed in the various species after different burial durations. Adipocere was observed to form at different rates among the species, but there was no distinct evidence of the fundamental composition varying between species.

Modelling the buried human body environment in upland climes using three contrasting field sites

“…Instances of both white waxy and crumbly fat decomposition products were observed on the exhumed pigs in the current study, especially at the moorland site. Although changes in fatty acid composition were found with reference to pig adipose tissue [56], none conforms to the composition expected for 'classic adipocere' [52,47,57]. All the material examined here would suggest the samples were in the early stages of adipocere formation since there were higher levels of unsaturated fatty acids, especially oleic acid and 10-hydroxy stearic acid, than with classic adipocere.…”

A study of adipocere in soil collected from a field leaching study

“…The infrared bands for the major components identified in adipocere are well established [10][11][12][13] . The characteristic infrared bands that were used in this study to determine the presence of adipocere were the triglyceride C ¼ O stretching band (1720-1710 cm -1 ), the fatty acid C ¼ O stretching band (1702 cm -1 ) and/or the fatty acid calcium salt carboxylate C-O stretching bands (1576 and 1540 cm -1 ).…”

“…When myristic, palmitic, stearic and oleic acids were detected in measurable quantities in the soil samples, adipocere was determined to be present. These fatty acids are known to occur in higher concentrations in adipocere, while palmitoleic, linoleic and 10-hydroxy stearic acids occur in relatively small amounts 10 . Small quantities of other fatty acid TMS derivatives were also detected in particular samples, including heptadecanoic acid, 11-eicosenoic acid, palmitelaidic acid, the 2,3-bis[(TMS)oxy]propyl ester of stearic acid and the TMS ester of glycerol.…”

“…Infrared spectroscopy was successfully employed in earlier studies to identify the presence of adipocere [8][9][10][11][12][13] . The characteristic infrared bands associated with triglycerides and fatty acids are used to identify the material and may be employed to approximate the degree of formation of adipocere.…”

Human decomposition and the reliability of a ‘Universal’ model for post mortem interval estimations

“…There remains the hope that chemical analysis of 30 decompositional fluids can produce a reliable means of PMI estimation [13] [28] [51] [52] [53], however M a n u s c r i p t the reliability and practicality of these methods for a medico-legal context have yet to be established. 1…”