The transfer of colour bodies and of inorganic species into the sucrose crystal, during the crystallization process, has been investigated. A pilot evaporative crystallizer was used, under conditions similar to those found in industrial crystallizers. The results obtained were used to test the relevance of an interfacial breakdown model for the incorporation of the selected impurities into the sucrose crystal. The model, which involves two distribution coefficients and a linear crystal growth rate, is shown to provide a quantitative description for the transfer of the impurities. It also includes a diffusivity coefficient and an interfacial film thickness, which could both be estimated independently. The agreements between the calculated and measured values were acceptable. Finally, activation energies for the transfer were measured and found to be in a range generally associated with transport processes.