Development and Characterization of Bigel Based on Chitosan/Sodium Caseinate Hydrogel and Soy Lecithin/Beeswax Oleogel as Carriers for Ferulic Acid

ABSTRACT

Bigels (BGs) composed of chitosan (CS)/sodium caseinate (Na‐Cas) hydrogel (HG) and soy lecithin (L)/beeswax (BW) oleogel (OG) were developed as carriers for ferulic acid (FA). The effects of BW concentration and CS: Na‐Cas ratio on FA delivery were investigated. Increasing BW reduced swelling, with the CS‐dominant sample (BG4, 7% BW, 100:0 CS: Na‐Cas) showing the lowest swelling due to its hydrophobic network. Rheological tests suggested shear‐thinning and gel‐like behavior ( G ′ >  G ″, tanδ < 1), enhanced by higher BW and CS. Also, FTIR spectra revealed synergistic interactions between HG and OG phases, while SEM showed dense, homogeneous morphology in CS/BW‐rich BGs. In addition, release studies indicated that BW limited FA release. In the gastric phase, CS concentration correlated positively with release, whereas Na‐Cas showed a negative correlation. In contrast, in the intestinal phase, higher CS reduced release, while Na‐Cas enhanced it. These findings demonstrate BGs' structural tunability for controlled FA delivery in food matrices.