Newest understandings of molecular structures and interactions of unsaturated fats and fatty acids

Recent studies on molecular structures and interactions of unsaturated fatty acids, diacylglycerols and triacylglycerols have been reviewed. An emphasis was paid to elucidate thermodynamic and kinetic behavior of polymorphic transformation, molecular-level structural analysis of crystalline phases, phase behavior and structural properties of binary mixture states of the unsaturated fatty acids and triacylglycerols. It may be concluded that the most peculiar property revealed in the unsaturated fats and fatty acids is diversity in molecular structures and interactions, which are mainly caused by the diversity in the olefinic conformations and packings. In particular, the polymorphic behavior of oleic acid itself and triacylglycerols containing oleic acid moieties has shown multiple conversions in lateral molecular packing, chain length structure and olefinic conformation. It was inferred that these properties may be applied to those of polyunsaturated fats and lipids.