## 3 Results and Discussion
### Oxidation Tests
#### 3.2.2 Storage Stability of Extract-Loaded Emulsions  
C11-BODIPY581/591 fluorescence changes after 320 min of oxidation as a function of storage time are presented in Figure 4. During storage, only in the case of acetone and methanolic extracts was a significant improvement observed in the oxidative stability of the emulsion. In turn, for water and ethanolic extracts, no significant changes in the oxidation behavior of LA emulsion were observed. On the other hand, clear acceleration of the oxidation process with storage time was observed in the presence of Toc. The presence of GA in the emulsion does not change this trend, with the exception of water and acetone extracts, for which, after 14 days of storage, clearly increased the emulsion oxidation rate by about 10% (similar results were obtained for GA alone). Notably, in an emulsion containing both GA and Toc, the oxidation process was slower compared with the rate of oxidation  
Figure 3: C11-BODIPY581/591 fluorescence intensity changes as a function of time (excitation 505 nm; emission 520 nm). Legend: reference, non-doped emulsion; GA, gallic acid; Toc,tocopherol; E, ethanolic extract; A, acetone extract; W, water extract; M, methanolic extract. in the presence of Toc alone. We can therefore conclude that, during storage, a synergistic effect between Toc and GA was observed. The abovementioned dominant pro-antioxidant effect of GA seems to be correct in the case of water and ethanolic extracts, for which the oxidation rate of the emulsion in the presence of GA exceeded the values for the reference sample after 14 days of storage. On the other hand, methanolic and acetone extracts showed an improvement in antioxidant properties with time of storage, although the course of oxidation for both extracts in the presence of GA during storage demonstrated opposite behavior. For the methanolic extract, the protection against oxidation increased both for the extract itself and in the presence of GA, while for the acetone extract in the presence of GA, the protection slightly decreased. Interestingly, in the case of acetone extract after 7 days of storage, the degree of protection of LA against oxidation was comparable to that of Toc and a sample containing GA. This significant improvement in oxidation stability was not reflected in the DLS measurements. These results have shown that other mechanisms may also take place during the oxidation processes of freshly prepared LA emulsion and during storage. In order to explain this observation, we performed an experiment where acetone extract was added to the prepared emulsion immediately after its preparation and to the emulsion after 7 days of storage (Figure 5). For a freshly prepared emulsion, acetone extract demonstrated approximately 40% protection against oxidation. After 7 days of storage, its protection increased to approximately 67%, a similar value as obtained for Toc (Figure 4). When acetone extract was added to the emulsion after 7 days, its protective properties only showed approximately 30% effectiveness. Moreover, the addition of GA did not improve these properties, as was observed in the case of the \"fresh\" emulsion. Figure 4: C11-BODIPY581/591 fluorescence intensity at 520 nm after 320 min of oxidation as a function of storage time (excitation 505 nm; emission 520 nm). Legend: reference, non-doped emulsion; GA, gallic acid; Toc,tocopherol; E, ethanolic extract; A, acetone extract; W, water extract; M, methanolic extract. The same experiments were also performed for Toc. In this case, the emulsion oxidation process was even faster than for the acetone extract, and in the presence of GA, it was accelerated even more. This effect is in contrast to the synergistic effect observed with Toc and GA present in the emulsion from the beginning. The above results show that in the case of acetone extract, the aging of the emulsion may affect how components of the extract interact with LA.