## 3 Results and Discussion
### Release Test  
The release experiments on both SGF and SIF were performed for experiment 6, which contained mangiferin co-precipitates and experiment 8, which contained quercetin co-precipitates. These two experiments were chosen because the products contained the highest amounts of antioxidant in the analyzed samples (Table 2). The release tests for the deposition of co-precipitates on silica particles were compared with release tests carried out on the antioxidant processed by SAS, co-precipitate CAP/Q and CAP/MNG in a 2:1 ratio and also with raw quercetin and mangiferin.  
The release of composites with quercetin in both SGF and SIF is represented in Figures 7 and 8. It can be observed that in both diagrams the dissolution rate in the gastric fluid is lower than in the intestinal fluid for the deposition tests. This finding is due to the fact that quercetin is more soluble in the intestinal fluid [40]. It can be observed that the deposition of co-precipitate on silica using the SAS2 configuration increased the efficiency of the protection of the quercetin in SGF when compared to the co-precipitate with the same ratio but without silica [31], delaying the release during the first hour. However, it is very interesting to note that the deposition experiment showed a higher and burst release in the SIF when compared with the co-precipitation experiment without silica in the first 15 min. Finally, quercetin had a higher dissolution rate in all experiments, with the amount released reaching 100% in the first 15 min for processed Q and deposited composite, 30 min for the co-precipitate, and almost 4 h for raw Q. This demonstrates the effectiveness of the SAS method for micronizing and increasing the dissolution rate of this type of compound while providing protection for the active principle, in this case, the antioxidant in the gastric fluid.  
Figure 7: Release test of Q from composites in SGF corresponding to experiment 8 (180 bar, 323 K, 30 g/min CO\({}_{2}\) flow rate, SAS2).  
In the case of mangiferin deposition, the same trend as for quercetin was found (Figures 9 and 10). A higher dissolution rate was observed in the intestinal fluid than in the gastric fluids. The protective effect of the polymer and silica with the MNG was evident. In SFG fluid, the antioxidant released after 8 h for the co-precipitate and deposited composites were around 50%, while the raw MNG was 80% and MNG processed by the SAS process was almost completely dissolved. In this case, the deposition experiment carried out in this work did not show any difference when compared with the co-precipitated experiment at the same ratio but without silica, which was carried out in a previous study [34] in SGF fluid. It can be observed, as in the case of Q, that in SIF the deposition experiment showed a burst release in the first 15 min--in contrast to the co-precipitation experiment. This fact could be associated with higher efficiency of the controlled release of the antioxidant in co-precipitate experiments in the absence of silica particles.  
Figure 8: Release test of Q from composites in SIF corresponding to experiment 8 (180 bar, 323 K, 30 g/min CO\({}_{2}\) flow rate, SAS2).  
Figure 9: Release test of MNG from composites in SGF corresponding to experiment 6 (180 bar, 323 K, 30 g/min CO\({}_{2}\) flow rate, SAS1).  
If the target is protecting the MNG in the gastric fluids due to its beneficial properties, this must be released and absorbed in the intestinal fluids. The experiments were successful because, in the SIF, the deposition experiment carried out with the SAS1 configuration made it possible to create composites of many compounds with a result as good as with the co-precipitate, i.e., increasing the solubility to almost 100% in the SIF. Finally, SAS1 and SAS2 gave similar results, although the versatility offered by the SAS2 configuration is advantageous in the use of different co-solvents for the polymer and the active principle.