As migration induced fat bloom remains one of the major quality issues in compositeed chocolate products, this study investigated whether cocoa butter based diacylglycerols could delay or prevent this phenomenon. A model system consisting of a plastic cylinder filled with filling and chocolate was utilized for this purpose. Using an automated image analysis procedure, the surface of the chocolate was examined at regular time intervals to detect the presence of fat bloom crystals . The chocolate was cut into different layers and analysed by HPLC and Differential Scanning Calorimetry (DSC) to monitor the oil migration. It was noticed that the quality characteristics of the plain chocolates only slightly changed during the one year storage period. DSC thermograms demonstrated that the oil migration was a triggering factor for the re-crystallization to βVI crystals, protruding through the chocolate surface resulting in a greyer and duller appearance. The model based on Fickian diffusion with a constant diffusivity failed to accurately describe the migration of oil into chocolate. Non-Fickian behaviour occurs as besides migration, interaction between oil and cocoa butter can also play a major role. It was concluded that the presence of diacylglycerols did not delay oil migration, nor prevented the appearance of migration induced fat bloom.