## 3 Results
### Powders--Morphology, Particle Size Distribution and other Physicochemical Properties  
Morphology, particle size distribution, and physicochemical properties of encapsulated powders are related to processing parameters, including feeding rate, initial concentration of the solid material, inlet and outlet temperatures, surface tension, and other intrinsic properties of the drying material [40]. The SEM images of SD and FD powders are shown in Figure 4. Powders obtained by the SD technique were characterized by a spherical shape, while the particles of powders obtained by FD had broken glasslike surfaces, similar to flakes. The images showed that regardless of the used core and wall ingredients, the powders were similar to each other for drying technique. Similarly, no differences were observed between microcapsules containing linseed oil and its esters. All SD samples had particles that varied in size, some being quite small and others being large. Most of the particles did not have a smooth surface, and dents were visible. Additionally, agglomeration of the same particles was observed. Similar observations were presented by [PERSON] et al. [41] in powders containing high concentrations of maltodextrin. The authors reported that it can be related to a slow rate of crust formation and less elasticity of the wall matrix to resist structural collapse of the droplets during the spray-drying process [41]. Our results are in agreement with the findings of [PERSON] et al. [42]. In their study, powders containing maltodextrin and gum arabic had many dents and were remarkably shrunk. In turn, FD powders had a large, rather smooth surface. The image of LMG powder also showed the cross-section of powder particles (circled with a blue loop). Generally, FD powders had many pores on the surface as a result of the water sublimation during freeze-drying [16; 43], but in the present study, it was shown that the particles did not have a porous structure. [PERSON] et al. [16] also observed a smooth surface of FD powders containing, depending on the variant, different proportions of maltodextrin, low-methoxylated pectin, or sunflower wax. Nevertheless, by analyzing the structure of the products obtained as a result of freeze-drying, it should be taken into account that particle morphology reflects the result of grinding. Table 2 presents the selected physicochemical properties of powders. Powders produced by FD were characterized by a slightly lower moisture content (1.23-1.57%) compared to powders produced by SD (2.09-2.84%). Similar moisture values of the obtained microcapsules with both drying techniques were previously stated by [PERSON] et al. [44] and [PERSON] et al. [45]. The influence of coating ingredients on the moisture of powders was also observed, which was lower in the case of samples containing gum arabic. The determined variation of a powder's moisture made with WPC and gum arabic seems to be a general rule, since in a study conducted by [PERSON] et al. [46] powders made of a mixture of gum arabic and maltodextrin had a moisture content in the range of 1.6-2.0%, while in a study conducted by [PERSON] et al. [28], the moisture content was in the range of 3.83-5.35% for the powders made with WPC and maltodextrin. Overall, the drying process parameters used in the current study resulted in powders with the desired moisture level, which should not exceed the 4% allowed by the food industry [16; 44]. Encapsulation efficiency is one of the most important parameters in powder production, as well as surface oil presence. The type of wall material and the drying method simultaneously showed a significant impact on the lipid content on the surface. Regardless of whether linseed oil or its ethyl esters were encapsulated, powders in which the coating material was gum arabic and maltodextrin that were dried by the FD technique were characterized by the lowest surface oil content of 4.42 and 5.52%, respectively.