Technofunctional barrier layers for preventing fat bloom in triple-shot pralines

The storage stability of dark chocolate with nougat fillings is mainly limited by the formation of fat bloom, which arises because of the migration of nut oil from the filling to the outside of the chocolate shell where it leads to the formation of visible cocoa butter crystals. The triple-shot technique, which allows the simultaneous deposition of three viscous fluids, was applied for the laboratory-scale manufacture of pralines with a technofunctional barrier layer to prevent blooming. Base component of the barrier layer was palm kernel oil, pure or in combination with milk fat; micro-milled sugar or skim milk powder served as disperse phase. As compared to control experiments, the formation of fat bloom was significantly reduced for selected barrier layers because of the reduced transfer of nut oil to the outside of the praline shells. These results indicate that triple-shot depositing is a promising technique for the manufacture of filled chocolate with enhanced physical shelf life.