Visualization of liquid triacylglycerol migration in chocolate by magnetic resonance imaging

This study has demonstrated that magnetic resonance imaging can be used to visualise the migration of liquid triacylglycerols in composite chocolate confectionery. Migration was observed between a layer of hazelnut oil filling (oil + icing sugar) and a layer of dark chocolate used as a model of composite chocolate confectionery products. In addition, low-resolution nuclear magnetic resonance measurements of the solid fat content (%) were also made. Substantial differences were observed between the migration profiles at 19 and 28 degrees C, and in the distribution of liquid triacylglycerols across the chocolate layer after migration. It is suggested that the mechanism of migration involves both diffusion of the liquid triacylglycerols and capillary attraction of the hazelnut oil into the chocolate matrix.