## 3 Results and Discussion  
### Physical Properties of Prepared Linsed Oil Emulsions  
Emulsions (size \(<\) 200 nm) solve the problem of the solubility of hydrophobic materials and enable their use in aqueous food systems with improved bioavailability and targeted delivery [31]. In many applications, the dry emulsion (the powder produced from the emulsion after drying) should be able to reconstitute the primary emulsion after rehydration [32]. Therefore, the particle size distributions in fresh emulsions (E) and those reconstituted from the obtained powder in water (ER) were compared. The results are shown in Figure 1, while their compositions were presented in Material and Methods. As a result of the comparative analysis, it was shown that emulsions reconstituted from powder have a slightly different microstructure than fresh emulsions. Although all samples were monodispersed, none of the emulsion samples reconstituted from powder were able to fully reproduce the particle size distribution profile of the original emulsion. In the case of samples Nos. 1, 2, and 4, the particle size distribution of the reconstituted emulsion was wider than that of the original emulsion. The polydispersity index (PDI) for samples Nos. 1, 2 and 4 had values of 0.11, 0.12, and 0.14 for E and 0.19, 0.21, and 0.19 for ER, respectively, with the average particle size (Z-average) being 175.02 nm, 167.70 nm, and 170.34 nm for E and 199.24 nm, 199.68 nm, and 204.59 nm for ER (Table 2). In the case of emulsion samples Nos. 5 and 6 (containing 10% and 15% SDF I), changes in the structure caused by drying and redispersion were not as visible as in the previous ones. The PDI values for samples Nos. 5 and 6 were 0.14 and 0.13 for E and 0.18 and 0.17 for ER, respectively, with an average particle size (Z-average) of 177.38 nm and 197.31 nm for E, and 195.02 nm and 223.19 nm for ER. The best reproduction of the particle size distribution profile for the emulsion reconstituted from powder relative to the original emulsion was obtained in the case of sample No. 3 (coating: 15% SDF N + 5% OSA-starch). The value of the PDI was 0.10 for E and 0.12 for ER, while the average particle size was 166.60 nm for E and 174.28 nm for ER. The PDI in the emulsions is the standard deviation of the particle diameter distribution divided by the mean particle diameter and is related to several factors, such as the homogenizing process, the use of emulsifiers, and the concentration and properties of the wall material. When values are close to 1, this indicates heterogeneity, whereas values less than 0.5 indicate more uniformity and homogeneity of particle dispersion [33]. According to [PERSON] et al. [34],a mean particle size of <200 nm and a PDI < 0.5 are usually preferred for the emulsion. Only in samples Nos. 4 and 6 for the reconstituted emulsions values above 200 nm were obtained. The obtained results are consistent with those reported by [PERSON] et al. [35]. In their study, high-pressure homogenization at 172.3 MPa (in our study 150 MPa) led to the formation of an emulsion with nano-size droplets, whose diameter varied from 154 to 162 nm. Also, [PERSON] et al. [31] using a microfluidic at 100 MPa pressure obtained an emulsion with droplets in the range of 100-558 nm, and the particle size increased with the increase in starch concentration. On the other hand, [PERSON] et al. [32] reported that an increase in water hardness resulted in a significant increase in the size of the smaller particles, especially in the emulsion reconstituted from spray-dried powders with a lower content of the oil phase. Figure 1: Fresh (E) and reconstituted emulsion (R) droplet size distribution. Nos. **1**–**6** according to description in Table 1.  
Dynamic shear rheometers, such as the Brookfield rotational rheometer, are popular devices for simple measurements of the viscosity of emulsions at a single speed.