Adipocere formation is the modified form of decomposition which is characterized by the formation of soft, waxy material in the dead body. It is also known as saponification or grave wax. The term adipocere was given by Fourcroy in the year 1789. The term “adipocere” is derived from ‘adipo’ which means ‘fat‘ and ‘cire’ meaning ‘wax‘. This indicates the properties of adipocere intermediate between fat and wax.
Adipocere is a grey-white color and is waxy which later develops into a more crumbly to solid consistency thus leading to the solidification of various affected body parts. Moist or aquatic environment, warm temperature, bacterial enzyme action especially of clostridium perfringens, adipose tissue are the major requirements for the formation of adipocere. Oxygen in general inhibits adipocere formation. It can be formed in embalmed and unembalmed bodies also.
Mummification and skeletonization may both occur with the adipocere formation. But most of the time it is accompanied by an increase in the volume of the affected body. Preferential formation of adipocere has been observed in body parts with open wounds that will allow the colonization of the bacterial species. Adipocere is more frequently seen in females, nourished, and obese bodies due to the increased presence of adipose tissues.
Mechanism of Adipocere Formation
The mechanism behind adipocere formation is the hydrolysis and hydrogenation process which converts the unsaturated fatty acid into saturated fatty acids in the body. The unsaturated fatty acid of the body is converted into peculiar hard, yellowish-white, waxy saturated fatty acids.
This process begins in the adipose and is initiated by the lipases which will degrade the triglycerides into fatty acids. These fatty acids will get hydrolyzed and hydrogenated into hydroxy-fatty acids.
At the time of death, the body contains half percent fatty acid which will increase to 20% within a month and up to 70% in about three months as the adipocere forms in the body. The initial water required for the process is derived from the body tissues.
The saturated fatty acids formed are hydroxy-palmitic, oleic, hydroxy-stearic acids. This process is facilitated by degrading anaerobic bacteria which will secrete toxins that will have lecithinase, proteases, and phospholipases.
This bacterial action will create an ammonia-rich waste that contributes to the formation of the required alkaline environment.
Features of Adipocere
- Adipocere floats in water and dissolves in alcohol and ether, and has a rancid smell. It is inflammable and burns with a faint-yellow flame.
- It takes about 3 weeks to develop. When it is fresh it appears to be peculiar, hard, moist, whitish, and translucent and once formed it will appear stable for a considerable period.
- Gram-positive bacteria can degrade the adipocere.
- It is first seen in the subcutaneous fat of the cheeks, breast, abdomen, and other organs and tissues.
- If the body is submerged in water, then it might take only 3-15 days to develop.
- The most important feature of adipocere is that it preserves the features, wounds. According to Evans, some diseases could be recognized if a microscopic examination is done on the adipocere tissues.
Factors Affecting Adipocere Formation
- Atmospheric Condition: It requires a warm, moist humid climate. If the conditions are too dry then it will lead to mummification and if it is too wet then the body may macerate or liquefy.
- Temperature: The optimum temperature required for adipocere formation is 21-45℃.
- Moisture: Moisture or water is necessary in the environment for the complete formation of adipocere.
- Air Movement: It retards the process because it evaporates the body fluid and decrease the body temperature.
- Place & Media of Disposal: It is seen more prominently and rapidly in submerged bodies of buried bodies.
- Soil: The soil conditions, like pH, temperature, moisture, and the oxygen within the grave affect adipocere formation.
- Clothing: If clothes are present then it is observed to accelerate the process of adipocere formation as it retains water.
- Coffin: If the burial is done within the coffin, then it retards the adipocere formation.
- Water: It is seen faster in warm water than in cold water.
Adipocere helps in identifying the person as it preserves the features. It helps in estimating the time since death and the place of disposal of the body. If injuries are present then they are also preserved thus it helps in establishing the cause of death. The presence of any adipocere formation indicates signs of death and that the postmortem interval is at least of weeks or several months.