Collagen peptides induce hollow vesicle formation during intestinal digestion to enhance curcumin bioaccessibility in whey protein concentrate-stabilized emulsions

Stigmasterol-Stabilized Nanoliposomes Enhance Oral Delivery of Collagen Peptides Through Improved Systemic Exposure of Hydroxyproline-Containing Peptides

Collagen peptides (CPs) possess diverse biological activities, yet their oral efficacy is limited by gastrointestinal degradation and restricted systemic exposure of intact bioactive peptide species. Herein, a stable cholesterol-free nanoliposome system was developed using soybean phospholipids and stigmasterol through high-pressure microfluidization, followed by tangential flow filtration and spray drying to obtain a stable dry formulation. The optimized nanoliposomes exhibited a particle size below 100 nm, high peptide loading, excellent redispersibility, and remarkable physicochemical stability during refrigerated storage and under different pH and thermal conditions. During simulated gastrointestinal digestion, the stigmasterol-stabilized phospholipid bilayer effectively preserved encapsulated CPs throughout the gastric phase while facilitating peptide release under intestinal conditions. Oral administration in rats significantly enhanced collagen peptide bioavailability, increasing the plasma exposure (iAUC0–8 h) of total hydroxyproline by 3.84-fold compared with free CPs. Peptide-bound hydroxyproline exposure increased 9.3-fold and accounted for approximately 94% of total absorbed hydroxyproline. UHPLC–HRMS analysis confirmed substantially enhanced systemic exposure of multiple characteristic hydroxyproline-containing dipeptides and tripeptides following nanoliposomal delivery. These findings indicate that stigmasterol-containing nanoliposomes improve the gastrointestinal stability and systemic delivery performance of collagen peptides, providing a promising strategy for enhancing the oral delivery potential of food-derived bioactive peptides.

Development Of Protease-Encapsulated Microcapsules For Improved Digestion In Pancreatic Insufficiency

Overall, the developed solid-in-oil spray-dried ethylcellulose microcapsules represent a promising oral enzyme delivery platform with potential applications in enzyme replacement therapy for exocrine pancreatic insufficiency, phenylketonuria, and related metabolic disorders.

Enzymatic Construction of Whey Protein-Arabinoxylan Conjugate Particles and Their Regulation on the Stability and Curcumin Delivery Property of High Internal Phase Pickering Emulsions

Self-Assembled Wheat Gluten Peptide Nanoparticles as Dual-Functional Stabilizers for the Protection of Omega-3 Polyunsaturated Fatty Acids.

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.

Comparative Effects of Soybean Protein Isolate- and Myofibrillar Protein-Based Curcumin Nanocomplexes on the Freeze-Thaw Stability of Surimi.

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.

Interfacial chemistry modulates lipophilic nutraceuticals supersaturation and digestion profile in food-grade microemulsions.

Supersaturation improves the apparent solubility of lipophilic nutraceuticals but is constrained by crystallization and limited stability. This study elucidates how interfacial molecular organization in microemulsions governs curcumin supersaturation stabilization. An optimal supersaturation degree (50-200-fold) was identified, within which over 80% of the initial supersaturation was preserved during storage and upon gastrointestinal dilution, whereas excessive loading (300-fold) triggered crystallization and loss of metastability. 1H NMR analysis revealed progressive upfield shifts of Tween 80 α1-CH2/α2-CH2 protons, accompanied by perturbations in curcumin aromatic and olefinic signals, indicating preferential localization within the spatially confined interfacial layer. This interfacial partitioning likely restricts molecular mobility and suppresses nucleation. Functionally, microemulsions enhanced intestinal transport and bioavailability of curcumin. Bioavailability increased within the 50-200-fold range but declined at higher supersaturation due to aggregation during digestion. This work establishes a structure-function relationship between interfacial organization and supersaturation stability, providing a rational basis for designing high-performance delivery systems for lipophilic bioactives.