Modeling temperature in chocolate mass to predict tempering quality

Abstract

A computational model is developed to predict the temperature in chocolate as a function of space and time during a new tempering process where pellets of seed crystals of form V are added to the melted chocolate. The model, a refined version of a previous one (Debaste et al., J Food Eng. 2008, 88, 568–575) including a new expression for the heat sink, is based on the energy equation, simplified by the use of an effective thermal conductivity. A shrinking core model is used to express the heat sink term associated with the melting of pellets. The width of the limit layer around the pellets is the fitting parameter. The model is validated on experimental temperature profiles in bowls and compared to a previous kinetic model. The quality of tempering is then assessed by differential scanning calorimetry. Combining this information with the model, the quality of tempering based on the initial experimental conditions is predicted.