The Development and Properties of alginate/κ‐carrageenan Hydrogel: Beeswax Oleogel Bigels

ABSTRACT

This study developed a bigel composite material, based on alginate/κ‐carrageenan (AG/κ‐CG) hydrogel and beeswax/palm oil (BW/PO) oleogel, and investigated the influence of hydrogel composition, oleogel concentration, and hydrogel‐to‐oleogel ratio on material properties. The bigel beads were characterized using rheological measurements, confocal microscopy, hardness testing, Fourier transform infrared spectroscopy, and x‐ray diffraction analysis. Oleogel oil retention efficiency reached up to 90.32% and was influenced by emulsion stability, AG:κ CG ratio, oleogelator concentration, and the hydrogel and oleogel volume fractions. Confocal microscopy revealed compact microstructures. The beads exhibited high sphericity (> 0.93), and increasing oleogel content reduced shrinkage (44.90%–57.64%) and hardness (1.280–3.178 N) of the bigel. Swelling studies demonstrated structural resilience under acidic conditions (pH 1.2), with swelling ratios up to 0.36, and substantially increased swelling under alkaline conditions (pH 7.2), with ratios up to 3.30. This work characterizes bigels composed of an AG/κ‐CG hydrogel phase and a BW/PO oleogel phase, and demonstrates how formulation variables influence oleogel retention, microstructure, and mechanical behavior, highlighting their potential for controlled release applications in food and pharmaceutical systems.