## 3 Results and Discussion
### Powder Characterization: Macroscopic Analysis and Morphology  
The transformation of the lyophilized extract (Figure 5a) into a micro-particulate powder form (Figure 5b) was verified by a macroscopic and microscopic analysis of the pre- and post-processing materials. Figure 5a shows the lyophilized sample consisting of reddish, dark material, in flakes of different shapes. The material was made up of solid micro-scales crystalline material even larger than 20 um (Table 7, the higher is the span value the higher the polydispersity index), with a non-homogeneous distribution, as established by the LLS curve, which is almost bidimensional (Figure 5c) and confirmed by SEM analysis (Figure 5e).  
Conversely, Figure 5b shows the post-processing material via spray-drying: a fine and slightly pinkish homogeneous powder with a reduced color compared to the starting extract. This outcome highlights the improvement in the resulting powder confirming the success of the technological intervention adopted. Moreover, under the microscope (Figure 5f), such transformation is highlighted by the formation of trendy spherical, small microparticle structures (particle size about 2 um), well-formed and completely amorphous. The dimensional distribution of 6.17 um (Figure 5d, Table 7) could be due to the presence of few aggregates on partially collapsed microparticles surface, as also shown by the SEM image. The collapses are probably due to the rapid evaporation of the solvent during the atomization process which causes a slight depression of the internal volume with consequent contraction of the particle surface. This contraction, also due to the presence of  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & **M/P** & **AGL-28** & **Yield** & **TEC \({}^{\text{a}}\)** & **TAC \({}^{\text{b}}\)** & **AEC \({}^{\text{c}}\)** & **AAC \({}^{\text{d}}\)** & **EE \({}^{\text{e}}\)** & **d\({}_{\text{SO}}\)**um** \\  & **g/100 mL** & **g/100 mL** & **\%** & **\%** & **\%** & **\%** & **\%** & **\%** & **(Span) \({}^{\text{f}}\)** \\ \hline \hline \multicolumn{1}{c}{AGL-28} & - & - & - & - & - & - & 10.4 \(\pm\) 1.5 \({}^{\text{d}}\) & & 20.22 (8.13) \\ \hline \hline \multicolumn{1}{c}{MP\({}_{0}\)} & 10/0.1 & - & 61.84 \(\pm\) 2.14 & - & - & - & - & - & n.d. \\ \hline \multicolumn{1}{c}{MP\({}_{1}\)} & 10/0.2 & - & 62.43 \(\pm\) 3.36 & - & - & - & & n.d. \\ \hline \multicolumn{1}{c}{MP\({}_{2}\)} & 10/0.3 & - & 69.84 \(\pm\) 2.14 & & & & & \\ \hline \multicolumn{1}{c}{MP\({}_{3}\)} & 10/0.4 & - & 77.88 \(\pm\) 0.17 & - & - & - & - & 6.46 (1.74) \\ \hline \multicolumn{1}{c}{MP\({}_{4}\)} & 10/0.5 & - & 78.04 \(\pm\) 1.21 & - & - & - & - & - & 5.34 (1.99) \\ \hline \multicolumn{1}{c}{MPA} & 10/0.4 & 0.5 & 83.26 \(\pm\) 0.34 & 4.8 \(\pm\) 0.31 \({}^{\text{f}}\) & 0.48 \(\pm\) 0.05 \({}^{\text{f}}\) & 4.51 \(\pm\) 0.63 & 0.45 \(\pm\) 0.08 & 93.96 & 6.17 (2.02) \\ \hline \multicolumn{1}{c}{MPA\({}_{/1}\)} & 10/0.5 & 0.5 & 77.57 \(\pm\) 2.06 & n.d. \({}^{\text{g}}\) & n.d. & n.d. & n.d. & 5.27 (1.47) \\ \hline \hline \end{tabular}  
* M: maltodextrin; P: pectin; AGL-28: ‘Aglianico’ raw extract,\({}^{\text{a}}\) theoretical extract content;\({}^{\text{b}}\) theoretical active content;\({}^{\text{c}}\) actual extract content;
* actual extract content;\({}^{\text{e}}\) encapsulation efficiency;\({}^{\text{f}}\) span value calculated as (d\({}_{\text{SO}}-{}_{\text{LO}}\))/d\({}_{\text{SO}}\);\({}^{\text{g}}\) not determined.  
\end{table}
Table 7: Composition and characteristics of raw materials and spray-drying powders.  
the hydrocolloid pectin which confers plasticity to the wall, does not cause fractures that can destabilize the integrity of the particle structure.