Comparison of precrystallization of chocolate

Two continuous processes for the precrystallization of chocolate were investigated. An Aasted temper AMT 250 is compared to a newly developed high shear crystallizer The main features of the high shear crystallizer are the compact design, the improved heat and mass transfer and the highly efficient homogeneous energy dissipation. Starting from the same chocolate recipes, the differences in precrystallization between the conventional and the high shear crystallization technique are compared. Several analytical methods were used for comparison of the chocolate at process outlet and storage temperatures. In the liquid stare, viscosity function and temper curves were established. The final chocolate bars, after moulding and cooling, were compared by calorimetric and color measurements. The comparison of the two processes shows that with a high shear crystallizer the same chocolate crystallization quality can be achieved at a significantly reduced residence rime and lower outlet temperature. Furthermore, the new process can be easily adapted to different chocolate recipes by changing the rotational speed Due to the improved secondary nucleation in shear flow, even lower temper values produce bloom stable chocolates. (C) 1998 Elsevier Science Limited. All rights reserved.