Gallic acid-mediated interfacial engineering of flaxseed oil bodies via emulsion electrospinning: Enhanced oxidative stability and lipid bioaccessibility

Flaxseed oil bodies (FOBs) are natural lipid assemblies rich in α-linolenic acid (ALA), but their high degree of unsaturation makes them susceptible to oxidation. To address this, the present study employed gallic acid (GA)-mediated interfacial engineering to reinforce the FOBs surface, providing a molecular shield against pro-oxidants. The GA-modified FOBs emulsions were subsequently incorporated with pullulan to fabricate core-shell nanofibrous delivery systems via emulsion electrospinning. Results showed that GA-engineered interface of FOBs not only fortified the oxidative barrier but also imparted a favorable rheological profile to the emulsions, thereby facilitating the stable production of uniform nanofibers. Structural characterization confirmed that GA interacted with FOBs membrane proteins via hydrogen bonding and hydrophobic interactions, inducing conformational rearrangements that anchored the antioxidant at the interface. This dual-protective strategy, combining interfacial reinforcement with core-shell matrix encapsulation, resulted in a 49.2% reduction in peroxide value (POV) and a 66.3% decrease in TBARS values during 7 days of storage. In vitro digestion studies demonstrated that the core-shell structure of the nanofibers effectively regulated lipid release via Fickian diffusion, as confirmed by the Ritger-Peppas model (R² ≥ 0.94), with bioaccessibility reaching 62.8% after 120 min. These findings indicate that the combined strategy of GA-mediated interfacial engineering and emulsion electrospinning offers an effective strategy to enhance the oxidative stability and digestive performance of ALA-rich oil body delivery systems.