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-α, α and β) could be discerned for the shorter chain length saturated monoglycerides, while a second sub-α 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.
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