Physicochemical Exploration of Cocoa Butter During Spontaneous Fermentation: A Comparative Study Across Three Latin American Countries

This study characterized the physicochemical properties of cocoa butter (CB) extracted from cocoa beans of the Criollo Nativo (Peru), Criollo (Mexico), and Forastero (Brazil) varieties subjected to spontaneous fermentation under traditional local conditions in each country. Cocoa samples were collected at 24-h intervals, and CB was extracted to evaluate its lipid composition through fatty acid profiling and spectroscopic techniques (FT-IR and NMR). Also, the thermal and structural properties via differential scanning calorimetry (DSC), including melting and crystallization profiles, crystallization kinetics, and polymorphism, were determined. The results revealed that stearic, oleic, and palmitic acids were predominant in all varieties, while trace levels of myristic and pentadecanoic acids contributed to molecular packing. FT-IR identified bands associated with glycerol chain formation in TAGs, which were confirmed by NMR through chemical shifts linked to the distribution of POS, SOS, and POP species. CB exhibited melting temperatures between 19.6 and 20.5 °C, favoring polymorphic transitions toward more stable forms. Form I (γ) predominated during early fermentation, while Forms II (α) and III (β′2) were subsequently identified, particularly in Criollo varieties. These findings demonstrate that fermentation time significantly influences the chemical composition, oxidative stability, and crystalline structure of CB, providing valuable insights for optimizing cocoa processing and the development of high-quality chocolate products.