Influence of Gum Arabic and Maltodextrin on the Performance of Biopolymer Microencapsulation for Tithonia diversifolia Extract: Efficiency and Release Kinetics

Sustainable biopolymer-based carriers are increasingly utilized to protect phytochemicals and control their release. This study compares gum Arabic (GA) and maltodextrin (MD) as wall materials for spray-dried microencapsulation of Tithonia diversifolia leaf extract. Optimal conditions differed for each polymer: GA microcapsules at 4% w/v (90 min stirring time at pH 5) with %EE 80.3% and MD microcapsules at 0.8% w/v (90 min stirring time at pH 5) with %EE 73.9%. This efficiency was mirrored in antioxidant retention, where GA microcapsules exhibited a lower DPPH IC₅₀ value (117.4 μg/mL) compared to MD (138.1 μg/mL). In vitro release tests demonstrated distinct pH-responsive kinetics, GA showed higher cumulative release in both simulated gastric (43%) and intestinal (96%) compared to MD in simulated gastric (30%) and intestinal (80%). SEM analysis revealed oval, slightly corrugated GA microcapsules, whereas MD microcapsules displayed semi-spherical morphologies with surface fissures. FTIR spectra confirmed stronger matrix-core interactions in GA microcapsules than in MD. These findings demonstrate that biopolymer wall material selection critically influences encapsulation efficiency, antioxidant stability, and pH-responsive release behavior. GA microcapsules is identified as the more effective and pH-responsive matrix for developing functional food or phytopharmaceutical delivery systems.