Synergistic stabilization of DHA algal oil via amyloid fibril-anchored Haematococcus pluvialis protein/PVA core-shell nanofibers

Bio-based nanofibers use H. pluvialis protein and amyloid fibrils as emulsifiers. • Conductivity-viscosity balance induced hollow core-shell structures at 30% oil load. • Molecular-level hydrogen bonding between the lipid core and polymer shell underpins enhanced thermal stability. • Synergistic physical and chemical protection reduced DHA oxidation products effectively. The application of docosahexaenoic acid (DHA) in functional foods is severely restricted by its susceptibility to oxidative degradation. To overcome this, a novel bioactive delivery vehicle was engineered using Haematococcus pluvialis protein (HPP) and glycosylated soy protein amyloid fibrils (AFS) via emulsion electrospinning. This study investigated the physicochemical properties and oxidation stability of core-shell nanofibers fabricated from spinning solution with varying oil contents (0–4%). The spinning solutions exhibited shear-thinning non-Newtonian fluid behavior. The incorporation of oil increased the hydrophobicity of the nanofiber films, with the water contact angle rising from 46.8° (0% oil) to 86.4° (40% oil) due to physical cross-linking. Transmission electron microscopy (TEM) revealed that the 30% oil content group (E 3 ) formed a distinct, uniform hollow core-shell structure, driven by the optimal balance between conductivity and viscosity. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) suggested the presence of hydrogen bonding interactions between the lipid core and the polymer shell significantly enhanced thermal stability. Crucially, accelerated oxidation tests demonstrated a synergistic protective mechanism combining the physical barrier of the nanofiber shell with the chemical antioxidant activity of HPP. After 7 days, the E 3 nanofibers exhibited the lowest accumulation of primary and secondary oxidation products (POV: 238.66 ± 2.72 mmol/kg oil; TBARS: 49.26 ± 3.91 mg/kg oil), representing a 63.6% reduction in POV and 33.3% reduction in TBARs compared to the unencapsulated control (POV: 656.07 ± 2.14 mmol/kg oil; TBARS: 73.88 ± 0.27 mg/kg oil). This study supports the potential use of amyloid-fibril-stabilized natural interfaces for the efficient preservation of functional lipids, highlighting the superior synergistic protective effect of the HPP-AFS composite system. A PVA nanofiber membrane system was constructed by electrospinning to load the aqueous solution of proteins from Haematococcus pluvialis , algae oil, and chitosan soybean protein isolate, forming an AFS. This achieved the goal of protecting food from various forms of oxidation, including lipid oxidation, in practical applications. Download: Download high-res image (136KB) Download: Download full-size image