Peanut protein-fortified alginate hydrogel beads for EGCG encapsulation: Fabrication, characterization, and in vitro digestive behavior

EGCG was encapsulated within composite hydrogel beads reinforced with PPI. • An 81.91% encapsulation efficiency was achieved at a 5:5 PPI-to-SA mass ratio. • PPI incorporation delayed EGCG release kinetics. • PPI addition densified the hydrogel network microstructure. Epigallocatechin-3-gallate (EGCG) is a potent bioactive compound with notable physiological benefits. However, its poor stability and susceptibility to degradation in the gastric environment limit its bioavailability. In this study, composite hydrogel beads were developed as a controlled-release delivery system for EGCG. Composite hydrogel beads were fabricated via ionic gelation through the incorporation of peanut protein isolate (PPI) into a sodium alginate (SA) matrix, with varying SA: PPI mass ratios (8:2 to 4:6). As the content of PPI increased, the internal network structure of the hydrogel beads became more compact, and the encapsulation efficiency increased from 33.79% to 81.91%; During simulated in vitro digestion, the beads exhibited pH-responsive swelling behavior. Moreover, compared to the control group (i.e., pure SA beads), the EGCG release rate decreased from 43.27% to 20.38% after 2 h of simulated gastric digestion, demonstrating the composite hydrogel beads' efficacy in controlling EGCG release. Download: Download high-res image (330KB) Download: Download full-size image