Isothermal crystallization behavior of cocoa butter at 17°C and 20°C with and without limonene

Differential scanning calorimetry and real-time X-ray diffraction using synchrotron radiation were used to elucidate the isothermal cocoa butter crystallization at 17°C and 20°C in the absence and presence of different limonene concentrations. At 17°C, a three-step crystallization process was visible for pure cocoa butter, whereby first an unknown structure with long spacings between a 2L and 3L structure was formed that rapidly transformed into the more stable alpha structure which in turn was converted into more stable beta' crystals. At 20°C, an alpha mediated beta' crystallization was observed. The addition of limonene resulted in a reduction of the amount of unstable crystals and an acceleration of polymorphic transitions. At 17°C, the crystallization process was accelerated due to the acceleration of the formation of more stable polymorphic forms, while there were insufficient alpha crystals for an alpha mediated beta' nucleation at 20°C, resulting in a slower crystallization process.