Abstract: This study innovatively constructed a quaternized cellulose nanofiber (QCNF)/zein core-shell delivery system. By precisely controlling the concentration of QCNF (0.05–0.25 g/100 mL), the regulatory mechanisms of this system on the steady-state performance and targeted delivery of fucoxanthin (FUC) were elucidated. Fourier transform infrared (FTIR) spectroscopy revealed that electrostatic interactions between zein and nanofibers led to the formation of a stable interface. Transmission electron microscopy (TEM) images demonstrated that at a QCNF concentration of 0.2 g/100 mL, a distinct layer-by-layer self-assembled core-shell structure was formed, and the encapsulation efficiency of FUC was (95.64 ± 0.06) %. Moreover, 0.2 g/100 mL QCNF/zein@FUC was more stable to heat, light, pH and ions during storage at 4 ℃ compared with the control group (zein@FUC). Furthermore, the addition of QCNF as a coating on the zein surface was found to trigger passive targeted release of the encapsulated fucoxanthin, thereby enhancing its intestinal bioaccessibility. During in vitro simulated digestion, the cumulative release of 0.2 g/100 mL QCNF/zein@FUC was (85.32 ± 0.46) % with a bioaccessibility of (58.77 ± 3.84) %, indicating programmed and sustained release of fucoxanthin. The findings of this study offer theoretical support for exploring the formation mechanism and the steady-state targeted release performance of natural bio-based self-assembled nanodelivery carriers.

Key words: fucoxanthin, quaternized cellulose nanofibers, zein, core-shell nanoparticles, steady-state delivery