Characterization of the Triacylglycerol Crystal Formation in Adipose Tissue During a Vehicle Collision

• NCJ Number: 219264
• Journal: Journal of Forensic Sciences Volume: 52 Issue: 4 Dated: July 2007 Pages: 938-942
• Author(s): Barbara H. Stuart P.h.D; Stephanie J. Notter B.Sc.; Neil Langlois M.D.; Philip Maynard Ph.D.; Abhi Ray Ph.D.; Mark Berkahn Ph.D.
• Date Published: July 2007
• Length: 5 pages
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America

Annotation

Crystalline fat structures found in a pathology sample from the adipose (fatty) tissue of the victim of a motor vehicle crash were characterized in this study, because such a crystal structure in fat is not commonly observed in postmortem examinations.

Abstract

The crystals were determined to consist of beta polymorphs of triacylglycerols. The growth of crystal structures depends on the temperature to which the fat is heated, the annealing time, and the cooling rates. For the current sample, it is possible that a temperature increase during impact in the vehicle crash could cause nucleation; and the subsequent cooling of the body resulted in the formation of crystal structures; however, the appearance of crystals indicates an acceleration of the crystallization process. The possible nucleation time of the vehicle's impact does not necessarily explain the degree of crystallization. Another important factor that affected the resulting crystal structure of fat is shear. The effect of shear on triacylglycerol crystal growth has been examined in a number of studies of edible oils and fats. Shear is used in industrial processes to crystallize fats while mixing and varying the shear rate has been shown to influence the crystallization process. For the sample in the current study, the acceleration of crystal growth may be due to a high shear rate produced during vehicle impact. The authors propose that the region of the adipose tissue where the crystal clusters were observed could have undergone considerable shear force during the deceleration of the victim within the vehicle. This suggests that abnormal crystal structures in adipose tissue are only formed when a high degree of acceleration or deceleration occurs in a collision. The crystal structures were characterized by using Fourier transform infrared spectroscopy and x-ray diffractometry. 1 table, 4 figures, and 20 references