Hazelnut oil migration in dark chocolate – kinetic, thermodynamic and structural considerations

The objective of this study was to assess the effects of three storage temperatures (11, 20 and 26  °C) on the migration kinetics and equilibrium states of a model filled confection consisting of dark chocolate and a hazelnut oil-based filling. HPLC, atomic force microscopy and X-ray diffraction were used to study the migration behaviour of hazelnut oil into simulated filled confections and the associated changes in microstructure. Using a Fickean model, the mechanism for the migration of foreign triacylglycerols (TAG) into chocolate was evaluated. Deviations from Fickian diffusion were noted with increasing temperature, and resulted from the breakdown of the chocolate matrix. At higher temperatures, filled dark chocolate exhibited accelerated fat bloom formation due to the increased ingress of foreign incompatible TAG. The rate of migration and the diffusion coefficient increased 20 and 400 times, respectively, when the storage temperature was raised from 11 to 26  °C. The amplified rate of migration at elevated temperatures resulted in a confectionary product with a severe loss in quality. There was significant degradation in the texture and gloss of the product within 24 h of storage at 26  °C. However, the storage of filled dark chocolate at 11 and 20  °C showed negligible deterioration over 8 wk. Overall, the results from this study offer some insight into the optimisation for the production and storage of filled chocolates.

[1]  Kyucheol Cho,et al.  Migration phenomena of surfactants in polyethylene film , 1999 .

[2]  Sang-Wha Lee.  Relaxation characteristics of poly(vinylidene fluoride) and ethylene-chlorotrifluoroethylene in the transient uptake of aromatic solvents , 2004 .

[3]  Dérick Rousseau,et al.  Fat bloom formation and characterization in milk chocolate observed by atomic force microscopy , 2002 .

[4]  Laurance D. Hall,et al.  Kinetics of the migration of lipids in composite chocolate measured by magnetic resonance imaging , 2001 .

[5]  L. Hall,et al.  Visualisation of liquid triacylglycerol migration in chocolate by magnetic resonance imaging , 1997 .

[6]  T. Aminabhavi,et al.  Molecular transport of n‐alkanes into PU/PBMA interpenetrating polymer network systems , 2003 .

[7]  G. Ponchel,et al.  Fat Bloom and Chocolate Structure Studied by Mercury Porosimetry , 1997 .

[8]  Virendra Kumar,et al.  Swelling behavior of radiation‐polymerized polyampholytic two‐component gels: Dynamic and equilibrium swelling kinetics , 2003 .

[9]  R. Anantheswaran,et al.  Fat, Moisture, and Ethanol Migration through Chocolates and Confectionary Coatings , 2002, Critical reviews in food science and nutrition.

[10]  K. S. Knaebel,et al.  Effects of mechanical and chemical properties on transport in fluoropolymers. I. Transient sorption , 1997 .

[11]  J. M. Aguilera,et al.  Fat Migration in Chocolate: Diffusion or Capillary Flow in a Particulate Solid?—A Hypothesis Paper , 2006 .

[12]  Richard W. Hartel,et al.  Fat bloom in chocolate and compound coatings , 2004 .

[13]  G. Ziegleder,et al.  Kinetik der fettmigration Teil II: Einfluß von Lagertemperatur, Diffusionskoeffizient, Festfettgehalt , 1996 .

[14]  G. Ziegleder,et al.  Kinetik der Fettmigration in Schokoladenprodukten Teil I: Grundlagen und Analytik , 1996 .

[15]  G. Ziegleder,et al.  Kinetics of fat migration within chocolate products. Part III: fat bloom , 1998 .

[16]  E. Lutton,et al.  Polymorphism of cocoa butter , 1966, Journal of the American Oil Chemists' Society.