Effect of gum arabic-modified alginate on physicochemical properties, release kinetics, and storage stability of liquid-core hydrogel beads

Different weight ratios of alginate/gum arabic (GA) solutions were prepared to serve as the wall material of liquid-core hydrogel beads (LHB) that were formulated to protect the total phenolic compounds (TP) of radish by-product juice from degradation during storage and release in simulated gastrointestinal fluid. The diameter of LHB ranged from 4.63 to 5.66 mm with a sphericity lower than 0.05. LHB formulated with 25% GA (AGB0.25) exhibited the highest hardness (26.63 N), and those formulated with 50% GA (AGB0.50) exhibited the highest loading efficiency (86.67%). AGB0.25 was effective in preventing TP from degrading during storage with a decay rate (k) of 6.10 × 10−3 day−1 and a half-life (t1/2) of 113.63 days, it showed the slowest release of TP in simulated gastric fluid (k = 2.25 × 10−6), and the release mechanism followed Fickian diffusion. The results suggest that GA is effective in improving the physicochemical properties of alginate.