Thermal Analysis of Dark Chocolate with Differential Scanning Calorimetry—Limitations in the Quantitative Evaluation of the Crystalline State

Differential scanning calorimetry (DSC) is a method widely used to examine the melting or crystallization profile of cocoa butter and chocolate. The (perceived) ease of use makes the method very appealing not only in academia, but also in the chocolate industry. Our study presents a critical evaluation of the parameters that influence the generated information (i.e., the apparent melting point and specific heat of fusion) on dark chocolates of various cocoa contents and evaluates the suitability of DSC as generic or “universal” analytical method. The tested parameters included sample weight and form, temperature protocol, and heating rate. In general, the melting point of all dark chocolates increased as a function of increasing heating rate. The weight and form of the samples influenced the melting points but not the specific heat of fusion, while the starting temperatures of the thermal analysis did not seem to affect the melting profiles of the chocolates. We observe that a comparison between different studies researching chocolate behavior using DSC is not trivial due to insufficient detail on the procedure followed and conclude that DSC is maybe better suited for inner-study comparisons.