(659b) Influence of Diacylglycerol on the Physicochemical Properties and Crystallization Behavior of Palm Oil

Authors: 
Hao, H. - Presenter, Tianjin university, Tianjin, China
Huang, X. - Presenter, Tianjin University
Wang, J. - Presenter, National Engineering Research Center for Industrial Crystallization Technology, School of Chemical Engineering and Technology, Tianjin University

Abstract: In this study, diacylglycerol (DAG) oils were produced through enzymatic glycerolysis and chromatographic respectively and they were added to purified tri-glycerides of palm oil at different concentrations (2, 5, 10, 30 and, 50% w/w). The physical and chemical characteristics, i.e., iodine value, fatty acid composition and triglycerides composition were evaluated and only slight differences were observed. Then an exhaustive analysis of the crystallization behavior of the samples were per-formed by using Differential scanning calorimetry (DSC), Raman Spectroscopy, po-larized light microscopy, low-resolution magnetic pulsed nuclear resonance and X-ray diffraction over different ranges of crystallization temperatures. The aim of this study was to elucidate the mechanism changes of palm oil crystallization by the addition of two types DAG. The experiment results show that the influence of these DAGs on the crystallization behavior (e.g. nucleation rate, crystal growth rate, polymorph transform) of palm oil was depended on the DAG type, supercooling and diglycerides' concentration, e.g. the presence of a low concentration of enzymatic-DAG was found to significantly delay nucleation and crystal growth velocity of palm oil and induce the formation of β form at low degree of supercooling. Finally, we use Avrami model to interpret these influences and the results match the experiment successfully. This study will provide essential information for the palm oil industry for food application purposes.