Effect of Cocoa Butter Structure on Oil Migration in Candy

ONTARIO, CanadaOil migration from a high oil content filling into adjacent chocolate causes changes in product quality; however, a new study published in the Journal of Food Science found that the rate of migration of the oil into the cocoa butter was a function of how the cocoa butter was prepared.

Researchers from University of Guelph examined oil migration from a cream filling product to cocoa butter using a mass transfer model based on Fickian diffusion. They used magnetic resonance imaging (MRI) to monitor spatial and temporal changes of liquid lipid content and a 1.03 T aspect imaging MRI spectrometer to acquire images. Samples were prepared as a two-layer model system of cocoa butter and model cream filling. Three methods were used to prepare the cocoa butter: static and seeded. The samples were stored at 25°C for 56 days.

Results showed that liquid oil movement through a solid matrix is not only dependent on the concentration of the particles but also on factors such as the geometry of the dispersed phase and particle shape, size, and distribution, according to the researchers. The sheared sample had the lowest rate of migration constant due to the effect of particle size and distribution on liquid oil diffusivity, they wrote.