## 3 Results and Discussion
### Comparison of Microcapsules by Scanning Electron Microscopy (SEM)  
Scanning electron microscopy images of the freshly produced CMs and CMAQP, CMFDP, and CMWLAG are shown in (Figure 3A-D). The SEM image of control CMs (Figure 3A1a,A2a) reveals the typical morphology of spray-dried casein micelles composed of spherical particles with a shrunken and essentially smooth surface. As controlled casein micelles have been spray dried after rehydration, the micrographs of controlled casein micelles (Figure 3A1a,A2a) depicting the short bridges and direct inter-micellar contacts that act together to maintain a casein micelles network, hence, resist disruption into individual caseins after spray-drying [53]. These micrographs were also consistent with previously reported CM structures after spray-drying [11]. Some holes and roughness on the surface of casein micelles were visible with a wrinkled and deflated morphology with open voids, as described previously [54; 55]. The wrinkled particles were related to the low diffusion coefficients of caseins. As the droplets dried before casein molecules diffused evenly, dimpled particles were formed. Figure 3B1b,B2b showed the morphology of CMAQP having wrinkled and non-spherical shapes. It can be explained that anthraquinones should have been bound to casein and embedded in the hydrophobic location of casein micelles after encapsulation. \(\kappa\)-caseins and \(\beta\)-casein quickly separated from a micellar structure at lower pH (5.5) and lower temperature, respectively. However, as the temperature rises during spray-drying, \(\beta\)-caseins reincorporate. This suggests that the structure was entirely open at pH 5.5, allowing for the incorporation of anthraquinones while displacing water molecules and retained inside the casein micelles during spray-drying, giving non-spherical casein micelles with irregular and rough surfaces. The incorporation of AQ into casein micelles ([PERSON] et al., 2015) was supported by Figure 3B2b, which depicted fibril-like casein micelles adhering to one another (as depicted by 20 \(\upmu\)m image) with non-micellar material serving as glue. According to our previous study, this non-micellar substance might be \(\beta\)-caseins separated from casein micelles in solution [14], which has been attached to the surface of the powder. Additionally, the solvent evaporation and molecular diffusion ratios when anthraquinones are added to CMs change the shape of CMAQP. The particle size of CMAQP (2.39 \(\pm\) 1.1 \(\upmu\)m) microcapsules was less than the control casein micelles (2.65 \(\pm\) 0.93 \(\upmu\)m; [11]), showing encapsulation of AQ within casein micelles' hydrophobic core by displacing water molecules from the interior of casein micelles. It can also be confirmed by low moisture contents, higher encapsulation efficiency and through SEM images, where CM shape and appearance changed from spherical to non-spherical and irregular objects with tiny dimples, which might lead to the incorporation of anthraquinones into the interior of casein micelles. These results are consistent with shapes already given in literature while making coffee-casein complexes and spray-dried emodin-casein microcapsules [56; 57]. Figure 3C1c,C2c shows the morphology of CMFDP having rough, fractal surfaces. A change in protein to minerals ratio causes the loosening and swelling of casein micelles [58; 59]. As before spray-drying, the measured pH of the solution was 4.9, where  
solubilization of some colloidal calcium phosphate takes place. Casein micelles would eventually aggregate during spray-drying due to the breakage of hydrogen bonding that held anthraquinones inside and outside the micelles. Moreover, at this pH, the mean intra-particle distance increases and the probability of finding a next-neighbor particle at a specific distance decrease. So, the obtained CMs were fractal with a rough surface and the production of a cluster after spray-drying for CMFDP was larger than the reassembled CMs.