Blooming theory of tristearin

Abstract

“Blooming” of tristearin (SSS), a spontaneous formation of flake-like surface structure on a triacylglycerol (TAG), is discussed. It has been well known that blooming of TAGs was closely related to the polymorphism, however, a foundamental question on how the blooming on the micrometre scale was connected with the polymorphism on the molecular scale is still unclear. We first found that the flakes were formed to release deformation energy of the surface, induced by phase transformation from the α-phase to the β′-phase in the polymorphism of SSS. It was also able to explain the flake size observed in experiments (∼3 µm × 3 µm × 0.1 µm). This theory would provide a better understanding of the spontaneous formation of surface structures in chocolate, fats, fatty acids, waxes, and water-repellent leaves of grasses.