Ternary phase diagram of beta-sitosterol-gamma-oryzanol-canola oil

Numerous foods attain their desirable texture via the self-assembly of hardstock triacylglycerides including saturated and trans fats; which are associated with development of cardiovascular disease. Accordingly, a detailed understanding of structurants in lipid phases is essential to deliver alternative technologies to saturated and trans hardstock fats. β-sitosterol (ST) and γ-oryzanol (OZ) have been shown to form unique structures in canola oil that have the potential to act as saturated and trans fat replacers. The co-crystallization of ST and OZ results in the formation of a continuous 3-dimensional (3D) supramolecular network capable of immobilizing apolar solvents. A complete ternary phase was constructed of the ST, OZ and canola oil (CO) system, at 10% weight increments. All samples were analyzed using differential scanning calorimetry (DSC), Fourier-Transform infrared (FT-IR), short-angle x-ray scattering (SAXS), wide angle x-ray scattering (WAXS), and microscopy. Initially, the OZ:ST:CO system was analyzed from three perspectives: at constant OZ levels, at constant ST levels, and at constant CO levels. A large array of distinct patterns was deduced. In some cases DSC heating and cooling suggested ideal solubility behavior. Metastable states were interpreted by the presence of an exothermic peak in the heating cycle with simultaneous absence of a crystallization peak in the cooling cycle. In hopes to elucidate more definitive trends for the collected data, it was arranged and classified within a ternary phase diagram (TPD). Accordingly, six distinct regions were formed ranging from lamellar crystals, to liquid crystals, to what appears to be a lipid glass. Several interesting physical systems were illustrated in the TPD constructed. At high canola oil ratios, with low ST and OZ concentrations, the system had a crystal structure capable of mimicking fat crystal networks. Certain regions showed instability upon heating; while other regions showed amorphous behavior. Both maltese cross and spherulitic morphologies were present. These variations suggest the potential for applications beyond saturated and trans fat replacers.M.S.Includes bibliographical referencesby Fatemah M. Alhasaw