Co-operative self-assembly of cholesterol and γ-oryzanol composite crystals

Abstract

Cholesterol and γ-oryzanol co-crystallization occurs when equal ratios of the two compounds or excess γ-oryzanol is present in the solution. Excess cholesterol produces macroscopic fibrillar crystals from the melt prior to the co-crystallization and formation of radial fine fibers under slow cooling conditions. The cholesterol fibrillar crystals then facilitate cholesterol-γ-oryzanol co-crystallization producing fine fibers that nucleate from the surface of the cholesterol crystals. Equal ratios of cholesterol and γ-oryzanol or excess γ-oryzanol allow the radial fine fibers to nucleate from the melt without the need of an internal crystal template.