Influence of monopalmitin on the isothermal crystallization mechanism of palm oil

A multi-methodological approach (differential scanning calorimetry (DSC), X-ray diffraction (XRD) and polarized light microscopy (PLM)) was used to study the influence of monopalmitin (MP) on the isothermal crystallization process of palm oil (PO). MP was added in different concentrations up to 8% and the isothermal crystallization temperature was varied between 15 and 28 degrees C. From the DSC results, it was clear that the addition of MP leads to an earlier onset of crystallization along with the appearance of extra crystallization peaks. Combined with the results of the XRD measurements, a crystallization mechanism could be deduced. It was suggested that the high-melting MP initiated the crystallization process and induced a fractional crystallization of the PO triacylglycerols (TAGs), leading to a concentration of similar TAGs around MP cores. The PLM results indicated a coarser crystal structure through addition of MP to PO. (C) 2013 Elsevier Ltd. All rights reserved.