## 3 Results
### The Melting Profiles of Fat Extracted from Chocolates  
Chocolate is a suspension of cocoa, sugar, or milk powder particles in the continuous fat phase, which is cocoa butter. Cocoa butter is characterized by complex polymorphism, in which crystals can occur in six different polymorphic forms (I-VI). In order for the obtained product to be of high quality, cocoa butter must be crystallized mainly in the V form, because it is the most stable--obtained in the process of tempering chocolate. Differential scanning calorimetry (DSC) provides information about the \"quality\" of chocolate, which is influenced by processing methods such as the tempering and cooling of the product. Information obtained from thermal analyses (DSC) provide important data on the properties of chocolate, including melting and crystallization temperatures [60]. Research conducted by [PERSON] [61] proves that the melting curve of cocoa fat is characterized by peaks at maximum temperatures of 17.14 \({}^{\circ}\)C and 20.41 \({}^{\circ}\)C. The first crystalline form of cocoa fat melts in the temperature range of 16-18 \({}^{\circ}\)C, and the second crystalline form in the range of 22-24 \({}^{\circ}\)C. For deodorized cocoa butter, the first endothermic peak occurs at a temperature of about 18.46 \({}^{\circ}\)C, and the second peak at a temperature of about 20.54 \({}^{\circ}\)C. The appearance of the first peak may result from the melting of crystalline form I of cocoa butter, and subsequent, more pronounced peaks result from the melting of crystalline form II. The presence of double or several peaks in melting curves is most often the result of the presence of polymorphic structures of chocolate [62]. The appearance of more than one peak results in the existence of different crystal structures within the same product [63]. The melting temperatures of individual fat fractions, as well as the course of the melting curve, depend, among other things, on the composition of fatty acids, their distribution in the positions of triacylglycerleverols, polymorphic form, and the measurement conditions, e.g., the rate of heating/cooling of the sample. The intensity of melting or crystallization peaks increases with increasing heating/cooling rates [64]. In Figure 5a, melting curves obtained for fats extracted from chocolates with low cocoa liquor content: 1--min. 45%, 5--min. 40% and 4-45% did not differ in the shapes of the obtained peaks. The researched fats reached their first peaks at the following temperatures: 19.21 \({}^{\circ}\)C for fat extracted from chocolate 4, 18.90 \({}^{\circ}\)C for fat extracted from chocolate 5, and 20.05 \({}^{\circ}\)C for fat extracted from chocolate 1. Small peaks can also be observed appearing at temperatures of around \(-10\)\({}^{\circ}\)C. The appearance of these peaks on the melting curve could be the result of the presence of different types of fat in the researched fat: milk fat or vegetable fat declared by the producers on the packaging (Table 1). Research on the crystallization and melting curves of cocoa butter with the addition of palm oil showed that as the amount of added palm oil increased, the shape of the curve changed--the peak intensity decreased and the breadth increased, which increased the temperature range of the phase transition [64]. The addition of milk fat causes a lower melting temperature, slower solidification, and a softer chocolate texture. [PERSON] and [PERSON] [65] also proved that the addition of various milk powders influences chocolate processing processes and its physical and organoleptic properties. Figure 5: _Cont._  
In the case of the melting curves of fats extracted from chocolate 2 and 7 presented in Figure 5b, differences in shape can be observed. Four peaks were present in the fat melting curve of chocolate 2.