This experiment aimed to show the effectiveness of gelatin coating to inhibit the penetration of gallic acid inside the beads. The results are shown in Fig. 3. The images depicting the cross section of the beads (Fig. 3C) showed that with the double coated bead the dark colour (indicating gallic acid) was not able to pass into of the core of the bead as much as into the uncoated bead, suggesting an increased protection in the former case