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

## TL;DR

This paper introduces a seaweed-based emulsion gel that improves the delivery and stability of fucoxanthin, a compound with limited solubility and bioavailability.

## Contribution

The study presents a novel fucoxanthin delivery system using cellulose nanofibrils from seaweed, which has not been previously reported.

## Key findings

- Cellulose nanofibrils (CNFs) effectively stabilize emulsions and enhance fucoxanthin delivery.
- Optimal emulsion conditions achieved high stability and preserved antioxidant activity under various stresses.
- Fucoxanthin release increased under specific pH, salinity, and temperature conditions.

## Abstract

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.