Encapsulation of seabass oil in chitosan-tripolyphosphate nanoparticles: Physicochemical characterization and oxidative stability during storage

This study investigated encapsulating seabass oil in chitosan-tripolyphosphate nanoparticles (CSNP) via a dual-step emulsification and ionic cross-linking process to enhance oxidative stability. Varying the core-to-wall ratio significantly influenced the system's physicochemical properties, yielding encapsulation efficiencies of 33.38–63.42%, loading capacities of 19.18–26.68%, particle diameters of 144.50–317.73 nm, polydispersity index of 0.15-0.24, and zeta potentials of +4.03 to +41.07 mV. Fourier transform infrared (FTIR) spectra indicated molecular interactions between seabass oil and the chitosan-TPP matrix. Scanning electron micrographs (SEM) revealed that CSNP are spherical in shape. Additionally, differential scanning calorimetry (DSC) showed altered thermal transition behavior in the lipid-loaded nanoparticles. During an 8-week storage period, nanoencapsulated oil demonstrated markedly superior oxidative stability compared to the unencapsulated control (p < 0.05). Furthermore, polyunsaturated fatty acids (PUFAs) were significantly better retained in the encapsulated samples (p < 0.05), validating the efficacy in preventing nutritional degradation. Ultimately, CSNP encapsulation represents a highly practical strategy for mitigating lipid oxidation and preserving the nutritional integrity of marine oils.