Effect of Surfactants on the Polymorphic Behaviour of Hydrogenated Canola Oil

The effect of a number of surface active lipids on the polymorphic behavior of hydrogenated Canola oil was investigated. Compounds tested included sorbitan tristearate, sorbitan trioleate, sorbitan monostearate, sorbitan monopalmitate, sorbitan trilaurate, and Admul WOL. Polymorphic transition was measured by X‐ray diffraction patterns and crystal growth by polarized light microscopy. Some of the surfactants were effective in delaying the transition to the β‐polymorphic form. The most effective compound was sorbitan tristearate. Differential scanning calorimetry was used to demonstrate recrystallization at heating rates of 5 and 10°C per minute. It is suggested that some surfactants have the ability to become incorporated into the crystal lattice and prevent or delay the transformation to the β‐form. To be effective, the surfactant should co‐crystallize with the fat. Surfactants with low melting points were not effective.