Differential scanning calorimetry of cocoa butter and chocolate glaze

Nowadays there is a wide market for cocoa butter equivalents, substitutes and improvers for the confectionery and dairy industries. An urgent task is the development of operational instrumental methods for cocoa butter and its substitutes quality control. Thermophysical parameters are among the most important characteristics of the fat phase for the food technology. Differential scanning calorimetry (DSC) is becoming one of the most promising methods for analytical control of fat and oil products. Thermophysical data (temperatures of the maximums of endothermic peaks and their areas) for cocoa butter and chocolate glaze typical samples applied at dairy processing enterprises of the Central black soil region for the production of chocolate glazed curd bars were obtained in the work performed with its help. DSC data were compared with chromatographic data on triglyceride composition of the fat phase of cocoa butter, cocoa butter equivalents, lauric and non-lauric substitutes, and POP and SOS cocoa butter improvers. It was shown that the DSC method can control the quality of cocoa butter and chocolate glaze, identify chocolate products of different origin and triglyceride composition. Melting thermograms obtained by DSC are highly sensitive to the fat phase triglyceride composition. DSC allows reliable identification of samples of cocoa butter and glaze by melting curves in the temperature range from -100 to +50 ° C. It was found that the main melting peak of cocoa butter and its substitutes, due to the presence of a certain set of triglycerides, is observed in the temperature range from -5 to +30 °C. When examining glazes, the melting peak changes: it bifurcates, expands or narrows. Additional application of computer separation of the unseparated peaks superposition on the DSC melting curves increases the information content of the method and improves the reliability of the fat phase identification. The DSC method is characterized by sample preparation simplicity, has good reproducibility and other metrological characteristics and can be an independent method for fat and oil products identifying and quality control..