Adipocere- A late Sign of Decomposition

Adipocere (Latin adipo: fat, cire: wax) is an enzymatic process of breaking fatty tissues into waxy substances, occurring in a dead body. It is also called saponification as it appears like soap and is a modification of decomposition.

However, the word saponification is not used as an alternate word for the process, as the soap formed is observed to be a minor byproduct.

Properties of Adipocere

If a decomposing body is found, then how one can identify that the stage of decomposition is adipocere? There are certain characteristic properties of adipocere that make it easy for a person to easily identify this stage of decomposition. The properties can be as follows:

• The first sense organ of an investigator that can detect adipocere is the nose. At first, it has an offensive ammoniacal odor which is then converted to a sweet/rancid smell.
• It appears as a pale yellow or white or grayish-white moist, wax-like substance which floats in water but is soluble in alcohol or ether. When becomes hard it is brittle and easy to cut.
• It is inflammable in nature that burns with a yellow flame.
• It is chemically made up of oleic, palmitic, and stearic fatty acids. Therefore it is observed at the sites of the human body, where fat deposition is high, like cheeks, breasts, buttocks, etc.
• It is usually observed with other modifications like skeletonization and mummification.
• The time required for adipocere formation varies greatly depending upon the environmental conditions where the dead body dwells. In a hot and moist environment, it may occur by the end of 1 week (earliest recorded—3 days). In India, it has been observed to occur in 5-15 days (the shortest period being recorded in 3 days and 22 hours). In temperate countries, it starts in 3 weeks and completes in about 3 months. In cold regions, the process is retarded due to low temperatures.

Mechanism of Adipocere Formation

Adipocere consists mainly of fatty acids formed due to two important processes- post-mortem hydrolysis and hydrogenation of body fats. The process needs moisture which is provided by the body fluid of soft tissues (dehydrating the tissues and making them dry).

Whereas, in dead bodies immersed in water (drowning cases), the water body provides the moisture to facilitate the process of adipocere and the tissues remain moist and hydrated.

The chemical reaction essentially involves the conversion of unsaturated liquid fats (oleic acid) to saturated solid higher fatty acids, like palmitic, stearic, and hydroxystearic acid, mostly palmitic acid. This conversion is facilitated by bacterial fat-splitting enzymes such as Clostridia from the intestines and the environment.

Traditionally these processes, in which putrefaction is arrested due to changes in skin and fat, are described separately, but they can occur together in different parts of the same body given the appropriate conditions.

Adipocere is a spontaneous form of partial preservation by the hydrolysis or saponification of body fat. It is, therefore, more commonly seen and is more prominent in women and young, well-nourished children.

Its formation is dependent upon the presence of adequate moisture (for example, immersion in water or burial in a bog). Acidity is also an important factor. Bodies buried in peat bogs, which are highly acidic, or interred in coffins with oak shavings rich in tannin, may be preserved for hundreds, or even thousands, of years.

Factors Affecting Adipocere Formation

1. Age: Foetuses <7 months do not show adipocere formation. 
2. Build: In obese people and mature newborns, it is formed quickly. 
3. Environmental Temperature: Heat accelerates and cold retards adipocere formation in a body. 
4. Moisture: Moisture is essential for chemical reactions to occur. It occurs more rapidly in bodies submerged in water than in damp soil. 
5. Air Current: It retards adipocere formation by evaporation of the body fluid and by reducing the body temperature.
6. Running Water: Adipocere formation is retarded as the electrolytes are washed away from the surface of the body which is necessary for the change.
7. Bacterial Infection: Early activity by anaerobes such as Clostridium perfringens assists in the reaction, as the bacteria produce lecithin which facilitates hydrolysis and hydrogenation. A warm, moist, and anaerobic environment thus favors adipocere formation. 

Distribution of Adipocere

It is observed at any site of the human body where fatty tissue is present. The most prominent sites include- the face, buttocks, breasts, and abdomen. In case of a female body, this change will be seen almost all over the body due to the presence of a good amount of subcutaneous fat.

Internally, small muscles are dehydrated and become very thin, and have a uniform greyish color. The depths of large muscles have a pink/red color with complete conversion of the fat to adipocere. The intestines and lungs are usually parchment-like in consistency and thinness. The liver is prominent and retains its shape. 

The usual decomposition of the body is prevented when the body remains submerged in water or buried in moist graves or damp soil as the process of adipocere formation utilizes most of the fluid and hence the body is not invaded by microorganisms.

Medicolegal Importance of Adipocere Formation

 i) Sign of Death– It is the surest sign of death.

 ii) Time Since Death– It gives a rough estimate of the time since death.

iii) Personal Identification– When the process involves the face, the features are well preserved which helps in identification.

iv) Recognition of Injuries– The cause of death may be determined since injuries can be recognized. 

v) Place of Disposal of Body– Some ideas about the place of disposal of the body can be made since its formation requires a warm place with high humidity or the presence of moisture or water.

Are Adipocere & Mummification Same?

Adipocere is usually confused with mummification due to their similar appearance and both are modifications of the putrefaction process. But both processes are totally different as discussed below:

• Characteristic Feature– In adipocere conversion of fatty tissues into fatty acids occurs whereas in mummification dehydration of tissues occurs.
• Odor– After saponification rancid smell usually occurs on the other hand in mummification the smell is odorless.
• Moisture– During the process of adipocere body gains moisture and undergoes hydrolysis but in mummification Loss of moisture occurs.
• Ideal Conditions–  Adipocere generally occurs in warm temperatures, moisture, and less air, whereas in mummification high temperatures, dry conditions, bacteria, and fat-splitting enzymes free circulation of air.

Though both the processes are different, the information elucidated by them is usually similar, i.e.,

• Facial features are recognizable, putrefaction progress is arrested.
• Wounds are preserved without much alteration.
• The approximate time since death can be estimated through this process.
• Helps in the identification of injuries and wounds.

Conclusion

Adipocere formation is a modified decomposition process that occurs in the fatty tissues, hydrolyzing them through enzymatic mechanisms. It is a clear indication of death and helps in estimating the approx post-mortem interval (PMI).

However, the PMI is just an approximate assumption as the process of adipocere formation is highly affected by the temperature and moisture, which are not the same at every place. However, it may elucidate the identity and injuries of the dead due to the preserving action of adipocere. It may be mistaken with mummification but both processes are different as discussed above in the article.

Also Have a Look at:

• What is Infanticide And Why Does It Occur?
• Features of Defense Wounds
• Types of Postmortem Artifacts
• Role of X-Rays in Forensic Medicine

Frequently Asked Questions

1. How long Does it Take For Adipocere to Form?

In ideal warm conditions, it may take 3-4 weeks for adipocere to form depending on several factors such as temperature, embalming, burial conditions, and the environment around the corpse.

2. What Are The Early Changes During Decomposition of the Body?

The early changes in the body after death include: algor mortis, rigor mortis, and livor mortis.