Interfacial engineering of quinoa protein-guar gum complexes for 3D printable Pickering emulsions: Rheological modulation, structural fidelity, and lipophilic bioactive delivery.
Oct 2026· Carbohydrate Polymers· Vol 389, pp.
125696
· 0 citations· 79 references
Medicine
Abstract
The development of food-grade bio-inks combining 3D printability with bioactive protection is important for personalized nutrition applications. This work presents a quinoa protein isolate-guar gum (QPI-GG) Pickering emulsion system for encapsulating lipophilic bioactives and enabling 3D printing. Particle size, ζ-potential and wettability analyses showed the formation of stable complexes with a unimodal distribution near 200 μm, a ζ-potential of -37.9 mV and intermediate wettability. FTIR, XRD, SEM and CD analyses, together with dynamic interfacial tension, AFM, molecular docking and molecular dynamics simulations, showed that GG associated with surface-accessible regions of 11S globulin through persistent hydrogen bonding, electrostatic interactions and van der Waals forces. This association altered QPI secondary structure, redirected heat-induced aggregation toward interconnected and conformationally adaptable assemblies, and enhanced interfacial adsorption and steric stabilization. The resulting emulsions formed elastic, shear-thinning networks with enhanced deformation recovery, enabling support-free printing with a collapse rate of 1.11% and water-holding capacity of 99.78%. The optimized formulation encapsulated CoQ10 with 96.81% efficiency, restricted gastric release to 20.9%, and achieved 51.7% cumulative release after intestinal digestion. This study demonstrates QPI-GG Pickering emulsions as a clean-label bioink platform integrating interfacial engineering and additive manufacturing for nutraceutical delivery.
This work evaluated how ferulic acid (FA) impacted the conformational properties of whey protein isolate (WPI) and altered the environmental tolerance of oleogel/water (Og/W) emulsions formulated with Ganoderma lucidum spore oil (GLSO). Molecular dynamics simulation analyses revealed that FA interacted with α-lactalbumin via hydrogen bonding and hydrophobic interactions, whereas it bound into the hydrophobic cavity of β-lactoglobulin through a “lock-and-key” mode driven primarily by hydrophobic forces. Fourier transform infrared spectroscopy analysis verified that such non-covalent forces triggered the dissociation and structural extension of WPI, which was manifested as a significant loss of α-helix and β-sheet architectures along with a corresponding rise in random coils. FA addition increased the positive charge, mean droplet size, interfacial contact angle and antioxidant stability of WPI-FA nanoparticles when the WPI-to-FA ratio exceeded 1:2 (i.e., WPI was in excess relative to FA). The GLSO-based Og/W emulsions exhibited a weak gel structure with predominantly elastic characteristics. Furthermore, WPI-FA nanoparticles fabricated at a 2:1 ratio minimized emulsion droplet size and imparted optimal stability to the Og/W emulsions, demonstrating superior freeze–thaw and salt resistance, alongside suppressed GLSO flavor release. This work provides critical insights into tailoring protein-polyphenol interactions to stabilize GLSO-based Og/W emulsion delivery systems for food applications.
Wenjia Yan, Yuting Bao, Hao Wang et al.· Gels· 0 citations
Protein nanofibers (PNFs) derived from lysozyme and bovine serum albumin (BSA) were employed as stabilizers for oil-in-water Pickering emulsions. Emulsions containing up to 50 wt % canola oil were prepared and remained stable for ∼6 months, demonstrating highly competitive performance relative to previously reported biobased Pickering stabilizers. Formulation and processing variables were systematically analyzed to determine mechanistic impacts on emulsion formation and stability. Scanning electron microscopy and fluorescence microscopy were used to evaluate protein nanofiber adsorption at the oil–water interface. Both lysozyme and BSA nanofibers produced emulsions with monomodal droplet size distributions, reversible creaming behavior, and resistance to centrifugal stress (10,000 × g); however, lysozyme nanofibers provided superior stabilization compared to BSA nanofibers. This is consistent with the higher surface charge of lysozyme PNFs, which may contribute to increased electrostatic repulsion between droplets, as well as their increased rigidity, leading to more effective interfacial coverage. Taken together, our results demonstrate the potential of protein nanofibers as sustainable and effective Pickering stabilizers with strong potential for the development of biobased products.
C. Ordoñez, Nihal Ahmed, Joshua J. Buzolic et al.· Langmuir· 0 citations
Succinylated xanthan gum (SA-XG) was developed to overcome native XG's poor emulsion-stabilizing capacity caused by inherent high hydrophilicity, yielding a biocompatible emulsion stabilizer for food, cosmetic, and pharmaceutical applications. Under optimized conditions (SA-XG degree of substitution (DS) 0.03, 0.5% w/v concentration, and oil fraction (φ) 0.5), the introduction of carboxyl groups via succinylation significantly enhanced the hydrophilicity and swelling capacity of XG (water contact angle reduced from 68.19 ± 0.08° to 32.72 ± 0.05°, swelling ratio increased by 6% versus native XG). Cryo-scanning electron microscopy (cryo-SEM) showed swollen SA-XG formed a honeycomb-like 3D viscoelastic network, which, coupled with strong electrostatic repulsion (absolute zeta potential >40 mV), endowed the oil-in-water (O/W) emulsion with exceptional 60-day long-term stability (no phase separation) and uniform 40.5 ± 0.07 μm droplets. Notably, this structural basis also conferred the emulsion pH-responsive stability that adapts to gastrointestinal pH fluctuations, the dominant factor governing in vitro digestion performance. The emulsion achieved a luteolin encapsulation efficiency (EE) of 92.2 ± 1.2%, digestive stability of 61.7 ± 0.4%, and bioaccessibility of 45.6 ± 0.5%, representing a 119% improvement in bioaccessibility compared to the native XG emulsion evaluated under identical experimental conditions. MD simulations confirmed this pH-responsive delivery. While maintaining macroscopic colloidal stability, the microscopic SA-XG network exhibited dense hydrogen bonding in gastric fluid (pH 2.5) to inhibit premature release, whereas deprotonation-driven network swelling in intestinal fluid (pH 7.4) facilitated sustained luteolin release. This work proposed a synergistic stabilization framework driven by enhanced hydrophilicity, viscosity, and electrostatic repulsion based on experimental observations, offering a scalable strategy for advanced emulsion delivery systems.
Qin Yin, Xingtao Zhang, Na Li et al.· International Journal of Bio...· 0 citations
Chemically modified protein-based nanocomplexes are widely used as food-grade carriers, but their molecular mechanisms remain unclear. This study developed Pickering emulsions (PEs) composed of phosphorylated (PLF) or succinylated (SLF) lactoferrin (LF) complexed with luteolin (LUT) via a pH-driven method, integrating experimental and computational approaches. SLF-LUT PEs showed superior physicochemical properties, including smaller droplet sizes, encapsulation efficiency up to 80% under neutral conditions, and enhanced storage stability at pH 8 over 30 days. SLF-LUT also significantly inhibited lipid oxidation, with reduced primary and secondary oxidation products. Multi-ligand docking and 100 ns molecular dynamics simulations revealed that LUT binds multiple flaxseed oil fatty acids within lactoferrin's hydrophobic pocket, positioning it for radical scavenging at the oil-water interface. The LF-LUT complex remained stable in a lipid-rich environment, with key residues (LEU320, PRO251, SER252) critical for stabilization. Network pharmacology further linked these interactions to antioxidant pathways (KEAP1/NRF2, FoxO, AGE-RAGE). These findings highlight the potential of nanocomplex-based oil-in-water PEs for delivering hydrophobic bioactives in food and pharmaceutical applications.
Tianzhu Guan, Ning Li, Yining Feng et al.· npj Science of Food· 0 citations
Interpenetrating network emulsion gels were fabricated from pea protein isolate (PPI) and polysaccharides with different charges: anionic Artemisia sphaerocephala Krasch gum (ASKG) or neutral curdlan (CURD). Microstructure, molecular interactions, rheology, texture, water holding capacity (WHC), cooking properties, and freeze-thaw stability were characterized. PPI-ASKG reduced oil droplet size compared to PPI-CURD. Polysaccharides modulated protein secondary structure, with hydrophobic attraction and hydrogen bonding as dominant intermolecular forces. The PPI-ASKG gels formed a thicker oil-water interfacial layer, contributing to superior viscoelasticity, WHC, and cooking performance. A preferred formulation with 0.3 wt% ASKG (A3) displayed the highest Q fator (23.62), thixotropic recovery rate (90.50%), strain-stiffening/thickening indices, and lowest freeze-thaw syneresis (22.4%), well-preserved texture and a reduced freezing point of -19.05 °C. All emulsion gels with 0.2-0.4 wt% polysaccharides met International Dysphagia Diet Standardization Initiative Level 5 criteria. This work provides a scientific basis for developing plant-based dysphagia-targeted foods with excellent freeze-thaw stability.
Sulforaphane (SFN) is structurally unstable and sensitive to pH variations. This study developed O/W emulsions coated with complex coacervate (ECC) composed of mung bean protein isolate (MPI) and ι-carrageenan. The SFN-loaded ECC (SFN-ECC) was fabricated to enhance stability and targeted delivery. A two-stage response surface methodology was applied to sequentially optimize the formulation, targeting emulsion stability and size first, then coacervate coating yield and encapsulation efficiency. The optimal parameters were identified as 8793 rpm, 54% oil, 0.6% ι-carrageenan, 1.17% MPI, and pH 3.71. The resulting SFN-ECC exhibited a compact core-shell morphology and improved thermal stability due to strong protein-polysaccharide interactions. In vitro digestion models demonstrated that SFN-ECC minimized gastric release to 6.9% while enhancing controlled intestinal delivery to 45.1%. This dual-layer encapsulation suppresses premature release under gastric conditions and enables controlled release at the intestinal stage, offering a strategy to improve the bioavailability of unstable lipophilic bioactives in functional foods.
Su Min Park, J. Han, Keun-Koo Kang et al.· Food Chemistry· 0 citations