Sodium caseinate‑sodium alginate binary complex stabilized W₁/O/W₂ emulsion gels loaded with proanthocyanidins from...

This study developed a W₁/O/W₂ emulsion gel encapsulating proanthocyanidins from Aronia melanocarpa (Michx.) Elliott (APC) using polyglycerol ricinoleate (PGPR) as the lipophilic emulsifier and sodium caseinate (NaCN)-alginate (Alg) as the hydrophilic emulsifier. The optimal preparation process was established based on particle size, zeta potential, phase separation, centrifugal stability, and microscopic morphology: 4.5 % PGPR concentration, a W₁:O phase mass ratio of 3:7, 0.6 % NaCN concentration, and a W₁/O:W₂ mass ratio of 3:7. The influence of varying Alg concentrations on the microstructure, gel properties, stability, and in vitro digestibility of the emulsion gels was then investigated. Results indicated that NaCN-Alg emulsion gels with 0.8 % Alg exhibited uniform structure distribution, excellent elasticity, and deformation resistance, with an APC encapsulation efficiency of (98.09 ± 0.11)%. The addition of Alg enhanced the thermal and storage stability of the emulsion gel. After 28 days of storage, the gel with 0.8 % Alg demonstrated superior water retention and pH stability. During in vitro digestion, Alg slowed the hydrolysis of NaCN and oil droplets, improving the bioaccessibility and bioavailability of APC. These findings provide a foundation for applying NaCN-Alg emulsion gels in low-fat food products.