Polymorphism and Phase Transitions of Cocoa Butter: Composition, Crystallization and Implications for Chocolate Quality

Cocoa butter is the main fat in chocolate and is responsible for its texture, gloss, melting behavior, and shelf stability. These properties arise from its specific triacylglycerol composition and its ability to crystallize into several polymorphic forms. Among these forms, Form V is the most desirable for chocolate production, while conversion to the more stable Form VI is closely linked to fat bloom. This review summarizes current knowledge on the polymorphism and phase transitions of cocoa butter, with emphasis on the roles of triacylglycerol composition, geographical origin, and processing conditions such as cooling rate, thermal history, and tempering. The review also discusses memory effects in cocoa butter and their relevance to industrial tempering and bloom control. In addition, recent advances in analytical techniques, including differential scanning calorimetry, X-ray diffraction, and Raman spectroscopy, are outlined for their use in identifying and monitoring polymorphic forms. A clear understanding of these factors is essential for improving chocolate quality, enhancing processing control, and reducing the risk of fat bloom during storage.