The preservation of soft tissue is a valuable evidence for forensic investigation as it may provide information about the cause and manner of death as well as the time since death.
Adipocere forms from the conversion of
triglycerides in the neutral
fats into stable
fatty acids producing a solid white product which
aids tissue preservation.
Adipocere will typically form in water-logged grave sites and aquatic environments. Documentation on the chemical and microbiological changes that cause
adipocere formation in aquatic environments is scant and mostly based on observational case reports. The aim of this study was to monitor the early
adipocere formation in lacustrine waters to investigate the effect of aquatic bacteria on
adipocere formation. Tissue samples from pork (Sus scrofa domesticus) belly were submerged in water samples from Lake Ontario and deionised water (control). Bacteria samples from both water and tissue were harvested. Changes in the
fatty acid composition of the tissue were determined using gas chromatography-mass spectrometry. Early-stage
adipocere formation was confirmed on porcine tissue submerged in lake water but was not identified on porcine tissue submerged in deionised water.
Adipocere formation required an abundance of gram-positive bacteria during the early postmortem period to assist in lipolysing the
triglycerides into
free fatty acids. Formation of
adipocere in the lake water resulted in a decrease in bacterial concentrations in the tissue over time.