Online Tempercurve Analysis of Praline Products with the Objective of Cooling Process Optimization

Abstract

Parameter evaluation for cooling tunnel equipment as used for solidification of chocolate masses was realized by evaluation of online temperature curves (real‐time tempercurves). A praline system (dark chocolate shell, hazelnut filling) was cooled by variation of cooling temperature (12, 7, −10C) and air flow rate (1, 3, 6 m/s). By evaluation of real‐time tempercurves with respect to main crystallization events in different product layers and final fat bloom resistance a critical crystallization temperature of T = 18C was determined. In parallel, the significant potential of time reduction by cooling temperature decrease and air flow increase has been worked out by exemplification. Evaluation is based and discussed on cocoa butter crystallization within literature. Furthermore, this rather simple technique is capable of monitoring several details of local cooling situations in the black box cooling tunnel, such as relative cooling capacity, consistency of cooling temperature and effect of production shutdowns. Practical Applications The real‐time tempercurve technique is adaptable to a wide range of industrial molds and cooling equipment in the chocolate industry. It is so far developed for molded products only. For coated products, an alternative construction of surface analysis by infrared technique is conceivable. On the other hand, the operating experience with cooling tunnels of manufacturers is less detailed in comparison to other process units because it is a closed system (black box). With this approach, the producer is capable of monitoring the performance and continuance of his cooling equipment (air cooler) and is able to set up appropriate process parameters (temperature, air speed) for new or optimize them for existing products.