Molecular analysis of the beta-polymorphic form of trielaidin: crystal structure at low temperature

This work reports on the structure of trielaidin [EEE, 1,2,3-tri(trans-9-octadecenoyl)glycerol], a trans unsaturated triglyceride present in many refined fatty materials (margarines, chocolate products etc.). Firstly, the polymorphism, i.e. the existence of different crystalline forms at various temperature ranges, was defined. Secondly, the crystal growth was examined. By developing a particular growing system, monocrystals of the most stable polymorphic form, i.e. the beta-form, were obtained. To reduce thermal vibrations the X-ray data were collected at low temperature (173 K) and the structure was solved using direct methods. The structure was then analyzed in terms of conformation and crystal packing and compared with those of the other known triglycerides.