BSA-Coated Metal–Phenolic Complex Assembly of 8-Shogaol Nanoparticles: Characterization, Stability, and Slow-Release Properties

This study reports a self-assembled ternary delivery system composed of bovine serum albumin (BSA), Fe(III), and 8-Shogaol (BSA-Fe(III)-8S) to enhance the stability of this labile ginger-derived bioactive compound. Optimized nanoparticles prepared via one-pot coprecipitation exhibited a particle size of 115.14 nm, polydispersity index (PDI) of 0.084, zeta potential of +52.23 mV, encapsulation efficiency of 94.93%, and loading capacity of 23.73%. Spectroscopic analyses (FT-IR, UV–Vis, XPS) and fluorescence quenching confirmed the formation of a core–shell metal–phenolic network, where Fe(III) coordinates with 8-Shogaol and BSA forms the outer protein shell. Compared to free 8-Shogaol, the BSA-Fe(III)-8S MPN nanoparticles demonstrated significantly enhanced thermal, UV, and storage stability. During simulated gastrointestinal digestion, the nanoparticles retained 64.04% of 8-Shogaol, compared to only 51.38% for the free compound. Cytotoxicity assays on HEK293 cells confirmed the biocompatibility of the nanoparticles. This BSA-Fe(III)-8S delivery system offers a promising strategy for protecting bioactive phenolic compounds, with potential applications in functional foods and nutraceutical formulations.