## 3 Results
### Nanemulsion Stability During Storage
#### 3.3.2 Bioaccessibility Study of Nanoemulsions
The values reported are in agreement with the literature, though differences may be attributed to variations in emulsifiers, homogenization conditions, or the amount of oil used in the lipid phase of the emulsions. Particularly, [PERSON] et al. [56] supported that using olive oil in emulsions with sodium alginate improved lycopene bioaccessibility (61.5%) compared to corn oil (52.2%). [PERSON] et al. [31] observed up to 85% lycopene bioaccessibility in olive oil emulsions, highlighting the role of emulsifier type and homogenization conditions in carotenoid release. Moreover, the composition of the fatty acids of the oils used in the lipid phase of nanemulsions is reported to have a significant impact on carotenoid bioaccessibility [60]. Oils with long-chain fatty acids can improve bioaccessibility by forming mixed micelles with high solubility for lipophilic compounds, while also stimulating the formation of chylomicrons in the epithelial cells, facilitating absorption and reducing first-pass metabolism [61]. In vivo studies with animal subjects have shown that monounsaturated fatty acids (MUFAs) and n-6 polyunsaturated fatty acids (PUFAs) enhance carotenoid absorption through the postprandial lipemic response, whereas long-chain n-3 PUFAs show a lower increase in blood fat levels [63; 64]. This indicates that oils rich in MUFAs, such as olive pomace and canola oil, can improve carotenoid bioavailability, while PUFAs in fish oil are expected to show lower values. Furthermore, oils with a high concentration of PUFAs, such as fish and corn oil, can form larger mixed micelles, which may reduce their diffusion through the unstirred water layer, thereby decreasing their uptake in the intestine. PUFAs are also more prone to oxidation, which can lead to lycopene oxidation in the intestinal chrome, resulting in lower bioaccessibility [54]. The bioaccessibility of phenolic compounds was found to be high, with values exceeding 100%, indicating effective release and solubilization during digestion. These results are in agreement with the existing literature, as many researchers have reported similar results where TPC was higher after simulated digestion [31; 65; 66]. This phenomenon may be attributed to the hydrolysis of polymerized polyphenols into monomers and aglycones as they pass through the gastrointestinal tract, leading to an increase in free phenolic components [67]. The lipid phase did not have a significant effect on TPC bioaccessibility (\(p\) > 0.05), indicating that the intestinal absorption of olive pomace polyphenols is independent of the oil composition. This contrasts with the results observed for lycopene  
Figure 5: Lycopene and total phenolic compound (TPC) bioaccessibility (%) in different nanoemulsions containing olive pomace oil (OPO), canola oil (CLA), sunflower oil (SFO), corn oil (CO), and fish oil (FO). Superscript letters a and b represent significant differences (\(p\) < 0.05) in lycopene between lipid phases. Superscript letters x for TPC represent no significant differences (\(p\) > 0.05) between lipid phases. Data are described as mean value \(\pm\) standard deviation (n = 3). bioaccessibility. Consequently, the selection of the appropriate lipid phase was primarily focused on enhancing lycopene bioaccessibility rather than TPC. The nanoemulsion containing olive pomace oil was chosen for incorporation into the apple juice beverage due to its higher lycopene bioaccessibility and other favorable characteristics, such as stability during storage. In this sample, the DPPH assay was used to evaluate antioxidant activity, which was reduced to 63.6 \(\pm\) 2.3% after digestion. This result contrasts with the TPC of the same sample, which increased to 109.0 \(\pm\) 2.5%, indicating that the observed antioxidant activity was primarily attributed to the added ascorbic acid rather than the olive pomace polyphenols.