Modelling of Heat Transfer, Mass Transfer and Flavour Development in Chocolate Crumb

Chocolate crumb is a vacuum dried, crystalline mixture of sugar, milk and cocoa solids and it is manufactured as a base ingredient for the production of milk chocolate. The final drying stages of the manufacturing process confer to the crumb its unique caramelization flavours and structural quality. The caramelization flavours are a product of the Maillard reaction, which is dependent on the time, temperature and moisture content of the material. The aim of this research is to generate a model for the moisture and temperature distribution within the product to achieve a scientific understanding of flavour development. Heat and mass transfer within a packed bed of crumb is modelled using a multiphysics software (Femlab). Experimental data for mass and heat transfer coefficients were obtained from laboratory experiments and packed bed literature. Kinetic data for the Maillard reaction was obtained by measuring the amount of flavour produced by crumb cooked under specific temperatures, moisture contents and cooking times. This data was then overlaid onto the solutions for the heat and mass transfer profile to gain an understanding of how operating conditions within the drying process can affect the flavour generation.