Effect of diacylglycerol addition on crystallization properties of pure triacylglycerols

The objective of this study was to investigate the effects of blending triacylglycerols (TAGs) and diacylglycerols (DAGs) on the melting and crystallization properties in a fat system. To this end, differential scanning calorimetry (DSC), X-ray diffraction (XRD) and polarized light microscopy (PLM) methods were used. Different DAGs (diolein-OO, dipalmitin-PP and distearin-SS) were added at 5% to each TAG (triolein-OOO, tripalmitin-PPP and tristearin-SSS). DSC results showed that the addition of DAGs delayed the onset of crystallization of saturated TAGs (PPP and SSS). By contrast, the addition of DAGs to unsaturated TAG (OOO) accelerated the onset of crystallization, with the appearance of an extra crystallization peak upon the addition of SS and PP. PLM results revealed that the addition of OO affected the polymorphic transition of the TAGs studied findings were consistent with DSC melting curves and XRD results.