## 3 Results and Discussion
### Differential Scanning Calorimetry--Phase Transitions and Crystallisation Curves  
Figure 13 shows the DSC curves for mixtures M1, M2, and M3 and agglomerates A1, A2, and A3. In the temperature range from 3 to 39 \({}^{\circ}\)C, characteristic endothermic peaks indicating fat melting were observed for the M1 mixture. This preparation contained whole milk powder (Table 1). In the M1 mixture, the fat content was 19.7% (Table 4). No peaks indicating the presence of added n-3 and n-6 fatty acid preparations were observed. attributed to the melting of \(\beta\)-lactose at a temperature of approximately 215.69 \({}^{\circ}\)C. For the remaining mixtures, no phase transformation of this form of lactose was found (Figure 13). [PERSON] et al. [51] studied the influences of spray-drying parameters on the thermokinetic properties of lactose. They showed that the size of the exothermic peak depended on the amorphous lactose content. [PERSON] et al. [52] and [PERSON] et al. [50] tested lactose in various forms and found that the transformations of the \(\alpha\)- and \(\beta\)-lactose forms corresponded to temperatures of 213 and 224 \({}^{\circ}\)C, respectively. The temperature values obtained in the cases of the powdered mixtures M1, M2, and M3 were at a similar level. After exceeding a temperature of 250.47 \({}^{\circ}\)C, the DSC curves were very similar and were characterised by exothermic peaks. At such high temperatures, the material already decomposed. Exothermic peaks were the peaks corresponding to these transformations. The individual ingredients in powdered mixtures of infant formulas undergo phase changes, just like pure substances. The different shapes and courses of the peaks were the result of mutual interactions between the components (Figure 13). In the case of the melting-temperature peaks of the pure crystalline lactose, maximum temperatures different than those for the peaks of the lactose transformation were observed in the DSC curves of mixtures M2 and M3. Mixtures M2 and M3 were characterised by similar chemical compositions (Table 1). Lactose influenced the DSC diagrams of mixtures M2 and M3. The shape of the DSC curves of the mixtures was determined by the shape of the diagrams for the main components of the mixtures. In the M1 mixture, the main ingredient was whole milk powder. Lactose and maltodextrin constituted approximately 30% of the composition (Table 1). The shape of the DSC curve indicated the presence of all these components; owing to their different contents, the peaks attributed to the transformation of the components were characterised by different shapes (Figure 13). Agglomerate A1 was obtained using lactose as a wetting liquid (Table 2) from mixture M1. Mixture M1 contained whole milk powder (Figure 13). The DSC diagram of the agglomerate A1 obtained from this mixture showed phase transitions characteristic for milk fat. These transformations were observed in the temperature range from 2 to 39 \({}^{\circ}\)C.  
Lactose was added to the M1 mixture (Table 1). In the DSC diagrams of M1 and A1, sharp endothermic peaks were observed at a maximum temperature of approximately 145.35 \({}^{\circ}\)C, indicating the loss of water by the lactose. The presence of weaker endothermic peaks at a temperature of approximately 204.05 \({}^{\circ}\)C, characteristic of the melting of \(\alpha\)-lactose, was found. There were no influences of the type of wetting liquid on the course and shape of the DSC curve of the agglomerates. Figure 13 presents the influences of agglomeration on the DSC curves of the M2 powdered mixture infant formula and the agglomerates, A2 and A3, obtained from that mixture. The type of wetting liquid did not significantly influence the course of the DSC curves. The shape and course of the curves for agglomerates A2 and A3 were very similar to those of the curve for the M2 mixture (Figure 13). The main ingredient of the mixture and agglomerates was crystalline lactose (Tables 1 and 2). The first distinct and sharp endothermic peak was attributed to the loss of water by the lactose.