Lower cocoa butter concentrations, parallel to high fraction of solid particles, such as in the dark chocolate formulation, promote particle-particle interactions, involving higher values of rheological characteristics. On the other hand, higher cocoa butter amount, even if in presence of higher amount of non fat particles (sugar), together with the presence of milk fat (from milk powders), reduce resistance to flow. This effect was shown in white chocolate sample, made up of smallest particles having the highest distance between them. Moreover, the synergistic effect of the lecithin, that promotes the reduction of particles inter-forces, involves a further reduction in the yield stress, viscosity and thixotropic values.