## 3 Results and Discussion
The stability factor values determined after 31 days of storage for the E4-E9 systems were in the range of 5.0-13.0, which classified these systems into categories C or D, i.e., systems with poor or unsatisfactory stability (Figure 3). Figure 3: TSI values for E1–E15 systems when stored for 31 days at 25 \({}^{\circ}\)C. a–k—different letters indicate statistically significant differences between the averages for TSI values (\(p\leq 0.05\)). Figure 2: Profiles of changes in backscattered light intensity as a function of sample height for E1–E15 emulsions when stored for 31 days at 25 \({}^{\circ}\)C.  
Among HPMC-stabilized emulsions, the least-advanced destabilization processes were observed for systems E1-E3 (Figure 2). The course of \(\Delta\)BS curves from successive scans did not coincide in the parts of the graphs corresponding to the lower or upper part of the measurement vessels. This indicated an early stage in the process of migration of dispersed phase droplets into the upper parts of the vials. The average \(\Delta\)BS values of those recorded in the middle part of the graphs did not exceed 2.0%. This confirmed that flocculation and coalescence processes did not occur for these systems [30]. Analyzing the obtained stability index values for the aforementioned systems, it was found that two emulsions (E1 and E2) qualified for category B, indicating their satisfactory stability (Figure 3). The calculated TSI coefficient values for these systems (<2.0), statistically, were not significantly different from each other (\(p\) > 0.05), although they were significantly lower (\(p\)\(\leq\) 0.05) than the values obtained for the other systems. On the other hand, the TSI value determined for emulsion E3, which contained the highest HPMC concentration analyzed (1.0 % \(w\)/\(w\)), was 5.0, indicating a significantly lower stability of this system (category C) compared to systems E16 and E17. Analyzing the discussed results of stability evaluation of the presented fifteen emulsion systems, a clear dependence of the advancement of destabilization changes on the type of fat phase used was observed. As the hemp seed oil content in the esterified fat phase increased, a decrease in the stability of the emulsion systems was noted (E1-E3 > E4-E6 > E7-E9 > E10-E12 > E13-E15). On the other hand, in the case of the next variable used--HPMC concentration--no single, consistent relationship was noted for all systems. Based on the TSI values obtained, in the case of systems E1-E3 and E7-E9, it can be concluded that the use of lower HPMC concentrations (0.6 and 0.8% \(w\)/\(w\)) was correlated with a statistically significantly (\(p\)\(\leq\) 0.05) increased stability of these systems. However, in the case of emulsions E4-E6 and E10-E12, only the lowest concentration used (0.6% \(w\)/\(w\)) of this texture modifier was associated with statistically significantly (\(p\)\(\leq\) 0.05) reduced values of the TSI parameter. The above-presented results are consistent with those obtained by [PERSON] et al. (2016) [16], who showed that HPMC is an ineffective viscosity modifier due to the fact that it forms a network that poorly stabilizes the dispersed phase droplets of an emulsion. On the other hand, the results obtained from the evaluation of the stability of systems produced on the basis of modified fats show that the effectiveness of this thickener depends on both the composition of the fat phase and the type of emulsifier used. The \(\Delta\)BS results for the E1 and E2 systems indicate that it is possible to produce emulsion systems containing HPMC that show good stability for at least 31 days. Performing a visual assessment of the changes occurring in the emulsions, no destabilizing changes were observed for the E1-E9 systems. These changes, especially for emulsions E7-E9, invisible to the naked eye, were registered by measuring the intensity of backscattered light (category D). On the other hand, from the image of emulsions E10-E12, the appearance of a clear layer in the lower part of the vials was clearly visible (Figure 4).