Thermodynamic compatibility and conformational adaptability enable the matrix-adaptive protection of glycated pea protein isolate-curcumin nanoparticles in frying oils.
The solvent effects exerted by continuous lipid matrices on nanocarrier antioxidant efficacy remain insufficiently defined. Herein, glycated pea protein isolate-curcumin nanoparticles (gPPI-CUR NPs) were engineered to elucidate their matrix-adaptive kinetic responses across frying oils with distinct saturation profiles. Protective efficacy correlated positively with lipid unsaturation, demonstrating 55.1% relative peroxide inhibition in highly unsaturated soybean oil versus 31.7% in saturated palm oil. Concurrently, the system suppressed cytotoxic aldehydes accumulation, mitigated viscosity increments, and inhibited thermal cis-to-trans isomerization. Molecular dynamics simulations elucidated this structural adaptability. The protein shell underwent conformational expansion driven by thermodynamic compatibility with linoleic acid, while the internal core maintained hydrophobic retention for ligand stability. This structural equilibrium maximized solvent-accessible surface area, increasing interfacial collision probability for in situ lipid radical scavenging. These findings generalize the dynamic balance between interfacial flexibility and core retention as a fundamental design principle for targeted lipid protection in high-stress processing.
This study investigates how electrostatic interactions between whey protein isolate (WPI) and polysaccharides (konjac glucomannan, guar gum, pectin, sodium alginate, chitosan) affect the stability and encapsulation of high-internal-phase emulsions (HIPEs, oil fraction >74%), revealing charge-driven structural and network stabilization mechanisms. The findings demonstrate that anionic WPI (pH 7.0) alone was more effective than cationic WPI (pH 4.0) in stabilizing oil-in-water HIPEs. Neutral polysaccharides enhanced emulsifying performance through viscosity-induced stabilization. While electrostatic repulsion increased ζ-potential of the complexes, thereby synergistically strengthening hydrophobic interaction-driven emulsifying activity. In contrast, excessive attraction (pectin, ζ-potential -17.0 mV) destabilized structural network through bridging or depletion flocculation, whereas moderate attraction (sodium alginate, ζ-potential -11.5 mV), facilitated the formation of stable emulsion systems. Notably, sodium alginate-WPI systems demonstrated robust stability (for 4 months) across all electrostatic conditions and offered excellent biocompatibility (<5%) and probiotic protection (>9.05 log CFU/mL). Collectively, these findings elucidate the mechanism of electrostatic tuning in stabilization of HIPEs, providing a promising approach for probiotics delivery.
Temperature is a key factor regulating the assembly and functional properties of protein-polysaccharide complexes. In this study, curcumin-loaded high internal phase emulsions (HIPEs) were fabricated using quinoa protein-κ-carrageenan (QPI-κC) soluble complexes treated at temperatures ranging from 45 to 75 °C as stabilizers. Results indicated that oil phase screening showed rapeseed oil had the best curcumin solubility, while HIPEs prepared with soybean oil displayed uniform fine droplets and optimal stability. Moreover, moderate heat treatment (55 °C) endowed curcumin-loaded HIPEs with superior shear-thinning behavior, an elasticity-dominated gel structure, and the highest creep resistance and structural tolerance. Stability tests confirmed that after 35 days of storage, the HIPEs of the QPI-κC-55 °C group achieved the highest curcumin retention rate and degradation half-life at 25 °C (W = 59.73%, t = 32.89 days) and 4 °C (W = 72.40%, t = 44.12 days). Meanwhile, these HIPEs remarkably prolonged the degradation half-life of curcumin under high-temperature (t = 5.24 h) and ultraviolet irradiation (t = 5.75 h) conditions. During in vitro digestion, the intact interfacial barrier enables controlled lipolysis, yielding the highest free fatty acid release and curcumin bioaccessibility (59.73%). Thus, appropriately heat-treated QPI-κC complexes offer a synergistic plant-based platform for the encapsulation, protection, and intestinal delivery of hydrophobic bioactives.
Jiangling Zhang, Guangfan Qu, Feiyan Yang et al.· International Journal of Bio...· 0 citations
Omega-3 polyunsaturated fatty acids are highly susceptible to oxidation, limiting the shelf life and sensory quality of omega-3-fortified foods. Herein, wheat gluten peptide nanoparticles (WGPNs) with coupled emulsifying and antioxidant functions were produced by sequential pepsin-trypsin hydrolysis. LC-MS/MS showed a peptide pool (1-4 kDa) enriched in Gln/Pro, featuring hydrophobic motifs and C-terminal Lys/Arg residues that confer surfactant-like behavior. WGPNs formed spontaneously in aqueous media, mainly driven by hydrophobic association and hydrogen bonding, with concentration-dependent β-sheet formation and a critical aggregation concentration of ∼0.17 mg/mL. Above this threshold, WGPNs exhibited enhanced radical-scavenging activity and colloidal stability across a wide ionic-strength range. Interfacial measurements demonstrated rapid adsorption of WGPNs at the oil-water interface, reduced interfacial tension, and formation of a stable interfacial layer. Consequently, WGPNs effectively stabilized fish oil emulsions and markedly retarded lipid oxidation. This work establishes WGPNs as a clean-label, dual-function platform for protecting oxidation-sensitive lipids in food systems.
Guangxin Feng, Weiting Feng, Xiaowen Feng et al.· Journal of Agricultural and...· 0 citations
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
This study establishes that combined ultrasonication and pH-shifting treatment effectively valorizes wheat gluten, leading to improved enzymatic hydrolysis and antioxidant peptide release. The treatment triggers a molecular restructuring, characterized by weakened hydrophobic interactions and intensified covalent bonds, and shifting from β-sheets to β-turns. These structural modifications lead to significant functional improvements: solubility increased from 3.9% to 11.2%, while dispersion stability was enhanced. Process optimization revealed treatment at pH 9 maximized enzymatic hydrolysis efficiency (protein recovery increased from 83.82% to 88.49%) and DPPH radical scavenging capacity (89.32% to 92.36%), whereas pH 12 combined with 200 W ultrasonication yielded superior ABTS radical scavenging activity (54.73%). Mechanistically, structural unfolding exposed hydrophobic and aromatic amino acids (e.g., Trp), facilitating the release of bioactive peptides. Notably, the identified peptide LWAWW exhibited strong Keap1 binding affinity (-9.5 kcal/mol). This work provides an efficient, sustainable strategy for transforming wheat gluten into high-value, functional food ingredients.
Peng Cheng, Xueying Song, Yihan Mu et al.· Food Chemistry· 0 citations
Proteins are effective carriers for polyphenols, yet whether structural differences between plant- and animal-derived proteins influence the delivery and functionality of polyphenols in their nanocomplexes remains unclear. In this study, soy protein isolate-curcumin (SPI-CUR) and myofibrillar protein-curcumin (MP-CUR) nanocomplexes were fabricated via a pH-driven method, and their physicochemical properties, interaction mechanisms, and cryoprotective effects on surimi were investigated. Both nanocomplexes achieved high encapsulation efficiencies (90.63% for SPI-CUR and 83.29% for MP-CUR) and thus exhibited enhanced antioxidant activity. CUR loading induced conformational changes in the protein carriers, as evidenced by increased α-helix content and decreased β-sheet content, suggesting the formation of a more compact structure. Meanwhile, this conformational change was accompanied by a marked reduction in particle size, with SPI-CUR reaching 66.13 nm. Molecular docking further revealed that hydrophobic interactions and hydrogen bonding were the primary forces stabilizing both nanocomplexes. During freeze-thaw cycles of surimi, both SC and MC nanocomplexes were superior to commercial cryoprotectants in preserving product quality, evidenced by improved water-holding capacity, enhanced gel properties, and inhibited protein oxidation. Notably, the two nanocomplexes exhibited distinct protective profiles depending on the protein source. MP-CUR demonstrated superior preservation of gel texture by minimizing thawing loss to 0.53% and maintaining high hardness (425.50 ± 34.85 g) and springiness (0.81 ± 0.03), which facilitated the formation of a denser gel network. In contrast, SPI-CUR demonstrated superior viscoelasticity and yielded the highest storage modulus (G'). This study establishes a foundation for the rational design of natural and efficient surimi cryoprotectants derived from protein-polyphenol complexes.
Xiaoyun Liu, Yang Meng, Zhikun Yang et al.· Journal of Food Science· 0 citations