High-Pressure Homogenized Seaweed Cellulose Nanofibrils-Based Emulsion Gel: An Innovative Platform for Fucoxanthin Encapsulation and Stability Improvement

Poor solubility and bioavailability have limited the application of fucoxanthin and functional food processing. In order to encapsulate fucoxanthin in delivery systems, cellulose nanofibril-stabilized emulsion gels (CNFs) derived from industrial brown seaweed residue were developed to enhance fucoxanthin delivery. Cellulose nanofibrils (CNFs) were isolated using high-pressure homogenization at 105 MPa through 5, 10, and 15 cycles (denoted as C5, C10, and C15) and yielding reduced crystallinity down to 52.91 ± 2.13% (C15). The minimum particle size of the present CNFs is approximately 37 nm (C15). Moreover, single-factor and orthogonal experiments optimized the stability of the present emulsion. A 17.5 mg/mL CNFs 50% oil phase with coconut oil, 0.5 mg/mL fucoxanthin, and homogenization for 60 s were identified to be the optimal conditions for such emulsion gel. The present emulsions demonstrated a high storage stability at 4 °C versus 25 °C, which maintained minimal phase separation over 8 days. The release kinetics showed significant dependencies with fucoxanthin release increasing to 9.22 ± 0.62% at pH 8.0, 9.52 ± 0.58% under 1000 mM NaCl, and 8.25 ± 0.62% at 100 °C. In addition, the CNFs effectively preserved the antioxidant activity of the fucoxanthin under different pH values, salinities, and temperatures. The results establish seaweed-derived CNFs as effective stabilizers for fucoxanthin encapsulation, enhancing stability while preserving functionality against food-processing stresses. To our knowledge, no prior research has been reported on a fucoxanthin delivery system utilizing an emulsion gel stabilized by cellulose nanofibrils (CNFs). Such emulsions might provide a sustainable strategy for valorizing seaweed waste and advance functional food applications of marine bioactives.