Comparing the crystallization and polymorphic behaviour of saturated and unsaturated monoglycerides
Vereecken, Jeroen × Meeussen, Wouter Foubert, Imogen Lesaffer, Ans Wouters, Johan Dewettinck, Koen #
Elsevier science bv
Food research international vol:42 issue:10 pages:1415-1425
The crystallization and melting behaviour of pure monoglyceride standards and two types of commercial monoglycerides were analyzed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Firstly, a series of saturated monoglycerides, ranging from monolaurin to monobehenin, were analyzed by DSC using a specific temperature program to obtain a complete image of the crystallization behaviour and polymorphism. The different crystallization and melting peaks were characterized by wide angle X-ray diffraction (WAXD) and small angle X-ray scattering (SAXS). Three polymorphic forms (sub-alpha, alpha and beta) could be discerned for the shorter chain length saturated monoglycerides, while a second sub-alpha polymorph was observed for the longer chain length samples. Secondly, unsaturated monoglyceride standards were analyzed using the same methodology. These results reveal a less complex behaviour with the occurrence of only one polymorph. Finally, the analysis of two commercial monoglycerides revealed the importance of minor components for the crystallization of unsaturated monoglycerides. (C) 2009 Elsevier Ltd. All rights reserved.