Crystallization of chocolate-containing masses

Cocoa butter is one of the basic raw materials in chocolate production. High quality cocoa butter has a
significant influence on the end product as well as the specific chemical and physical properties of chocolate. These include the melting and crystallization behavior of chocolate, which is characterized by the polymorphic properties and contributes decisively to the quality of finished product. Essential quality characteristics, such as high gloss, homogeneous structure and smooth fracture, optimal contraction, the typical flavor progression as well as appropriate firmness, heat and fat bloom stability can be guaranteed by optimal crystallization of the chocolate products. Such properties can be achieved by the best possible thermal and mechanical treatment during tempering. In this process, the triglycerides of the cocoa butter undergo various polymorphic forms to reach form V after leaving the cooling channel, which are the most stable along with form VI. 

The crystallization behavior of chocolate and fillings is an important quality aspect in chocolate production and essential for process control. Poor crystallization leads to fat bloom on chocolate products and can cause problems during production. The application of shear forces, during the tempering process provides the necessary heat transfer and uniform tempering and is therefore a key factor for success. Currently, static methods are used to analyze crystallization behavior, which do not include the influence of shear that occurs under real process conditions. Therefore, a rheological method was developed to characterize the crystallization behavior of raw materials, semi-finished products and chocolate under controlled temperature and shear conditions.