## 3 Results and Discussion
### Content and Retention Efficiency of Bioactive Compounds and Antioxidant Capacity in Microcapsules
[PERSON] et al. [39] obtained similar AA content (466 \(\mu\)g AA/gdw) in the spray drying of Mexican plum juice, using maltodextrin 10 DE as wall material. As can be seen in Figure 3b, in both drying methods, DHA content was higher than the AA content. This can be due to the high temperatures used in the drying process (170 \({}^{\circ}\)C for SD and 160\({}^{\circ}\) for SFB) which could enhance oxidation of AA, and therefore produced an increase in DHA content [40]. Figure 3c shows the antioxidant capacity retention and the AC values. For both the ABTS and DPPH methods, the microcapsules obtained by SFB have the higher antioxidant capacity values and retention, and as can be seen, in all cases, the AC by ABTS was higher than DPPH because the ABTS method can determinate the AC of hydrophilic and lipophilic compounds, while the DPPH method only determines the AC from hydrophobic compounds [41]. [PERSON] et al. [16] encapsulated Mexican plum extract by SFB and obtained a lower AC value than in this study; this could be due to the different extraction conditions (temperature, time, solvent, among others). Furthermore, in this study, both pulp and peel of Mexican plum were used and the peel has the major bioactive compounds content and, therefore, the major antioxidant capacity. Recovery and Bioaccessibility Indices of Bioactive Compounds and Antioxidant Capacity of Microcaps Obtained by Spray Dried and Spout-Fluid Bed  
In order to avoid overestimation of the results, due to the presence of GA as wall material, the PC and AC in the blank (empty microcapsules) after the gastric and intestinal phase were also quantified and deducted from PC and AC in the microcapsules. As an easier and more economical alternative method of bioactive compound preservation, bioactive compound recovery and bioaccessibility in the dehydrated Mexican plum powder after in vitro digestion were compared to those obtained in the microcapsules by SD and SFB. Recovery and bioaccessibility indices of phenolic compounds are shown in Figure 4a. The values for the extract alone and the dehydrated Mexican plum powder as an alternative method of preservation are shown as reference. The extract showed the lower RI and BI (31.31% and 24.51%, respectively), while the microcapsules by SD and the dehydrated Mexican plum powder showed the highest RI (86.16% and 84.45%, respectively), but at the end of the in vitro digestion, the higher BI was obtained for the SFB and SD microcapsules (63.61% and 61.35%, respectively). No significant difference in RI was found between dehydrated Mexican plum powder and microcapsules by SD; however, at the end of the intestinal phase, the BI of the Mexican plum powder had a significant decrease. According to [PERSON] et al. [42], the instability of the PC in the intestinal phase is due to enzymatic hydrolysis of phenolic and aromatic molecules, therefore, the phenolic compounds could change into their derivates (such as chalcones or quinones), which are unstable at high pH values. Recovery and bioaccessibility indices for AA, DHA and total vitamin C are shown in Figure 4b-d, respectively. Recovery Index of AA, DHA and total vitamin C (AA+DHA) in the extract was significantly (\(p\leq 0.05\)) higher (49.64%, 82.09% and 88.81%, respectively) in comparison to that obtained after intestinal digestion (BI) for all compounds (40.21% for AA, 18.26% for DHA and 20.01 for total vitamin C). Research works have reported losses of ascorbic acid after digestion with pepsin [15]. Studies have reported that ascorbic acid was not able to increase the pH value of the acid. Figure 4: Recovery and Bioaccessibility indices of bioactive compounds and antioxidant capacity of microcapsules obtained by spray dried and sprout-fluid bed. (**a**) Phenolic compounds (PC); (**b**) ascorbic acid (AA); (**c**) dehydro-roscorbic acid (DHA); (**d**) total vitamin C (AA+DHA); (**e**) antioxidant capacity by ABTS; (**f**) antioxidant capacity by DPPH. Data are expressed as the mean \(\pm\) standard deviation of the analysis in triplicate.