Analysis of the effect of recent reformulation strategies on the crystallization behaviour of cocoa butter and the structural properties of chocolate

Chocolate is a complex soft material characterized by solid particles (cocoa powder, milk solid particles and sugar crystals) dispersed in a crystallized fat matrix mostly composed of cocoa butter (CB). Important chocolate properties such as snap, and visual appearance are strongly dependent on the internal molecular arrangement (polymorph), size and shape, as well as the spatial distribution of CB crystals within the chocolate mix. In recent years confectionary companies have put increasing effort in developing novel chocolate recipes to improve the nutritional profile of chocolate products (e.g., by reducing the amount of high saturated fat and sugar content) and to counteract the increasing price of cocoa butter as well as sustainability issues related to some chocolate ingredients. Different reformulation strategies can dramatically affect the crystallization thermodynamic and kinetic behaviour of cocoa butter; therefore, affecting the structural and sensorial properties of chocolate. In this review we analyse how different reformulation strategies affect the crystallization behaviour of cocoa butter and, hence, the structural and sensorial properties of chocolate. In particular, this work discusses the effect of: (1) CB replacement with emulsions, hydrogels, oleogels and oleofoams; (2) CB dilution with limonene or cocoa butter equivalents; (3) replacement or reduction of the amount of sugar and milk in chocolate. We found that there is certainly potential for successful novel alternative chocolate products with controlled crystalline properties; however, further research is still needed to ensure sensory acceptance and reasonable shelf-life of these novel products.