pH-driven plant protein nanoparticles modulated by flaxseed gum oligosaccharides for apigenin delivery

Polysaccharide-modulated plant protein nanoparticles offer a promising strategy for polyphenol delivery. In this study, flaxseed gum oligosaccharides (FGOS) were used to modify apigenin (Ap)-loaded nanoparticles assembled from perilla (PPI), flaxseed (FPI), and sesame (SPI) protein isolates via a pH-driven method, forming FGOS/PPI@Ap, FGOS/FPI@Ap, and FGOS/SPI@Ap. FGOS coating reduced particle size and increased surface charge, enhancing encapsulation efficiency, antioxidant activity, and stability. In these three nanoparticles, FGOS/PPI@Ap exhibited superior performance in encapsulation, in vitro sustained release, and significantly improved bioaccessibility and oral bioavailability. Fluorescence quenching, molecular docking, and molecular dynamics simulations revealed stronger Ap-PPI interactions mediated by hydrogen bonding, hydrophobic, and electrostatic forces. Pharmacokinetic results further validated the in vivo delivery advantages of FGOS/PPI@Ap. This work provides insight into FGOS-protein-polyphenol ternary systems and identifies FGOS as a stabilizing agent and PPI as an efficient protein-based carrier for enhancing polyphenol delivery in functional foods.