Temperature-mediated assembly of quinoa protein-κ-carrageenan soluble complexes for stabilizing high internal phase emulsions to improve the intestinal targeted delivery of curcumin.

Lutein-loaded Pickering high internal phase emulsions stabilized by protein-polyphenol-polysaccharide self-assembled particles: Interfacial behavior, in vitro/in vivo stability and release.

This study aimed to encapsulate lutein in high internal phase emulsions (HIPEs) stabilized by quinoa protein isolate (QPI), tannic acid (TA), and high-methoxy pectin (HMP) particles at varying concentrations to address its low delivery efficiency and bioavailability. High concentrations (3%-4%) of QPI-TA-HMP particles demonstrated strong interfacial adsorption, forming thick viscoelastic films around oil droplets. These interfacial properties imparted controllable rheological behaviors, textural characteristics, and stable 3D-printing scaffolds to the lutein-loaded HIPEs, achieving an encapsulation efficiency of 81.65 ± 2.36%. In vitro tests indicated that HIPEs enhanced lutein's resistance to storage, heat, and UV exposure while facilitating sustained intestinal release, resulting in a lutein bioaccessibility of 43.73 ± 1.44%. In vivo experiments further demonstrated that the HIPEs delivery system maintained high lutein concentrations in the small intestine, cecum, and colon, thereby significantly enhancing lutein accumulation in systemic circulation. These findings provide new insights into enhancing lutein's stability, delivery performance, and bioavailability.

Response surface methodology-guided design of oil-in-water emulsions coated with complex coacervates for precision intestinal delivery of sulforaphane.

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.

Pickering emulsions for intelligent curcumin delivery: Synergistic stabilization by starch nanocrystals and soy β-conglycinin or glycinin.

Starch nanocrystals (SNCs) derived from rice starch were complexed with soybean β-conglycinin (7S) or glycinin (11S) to develop food-grade Pickering emulsifiers for curcumin delivery. The effects of the SNC-to-protein mass ratio on particle structure, interfacial properties, emulsion stability, and gastrointestinal digestion were systematically evaluated. At an SNC-to-protein mass ratio of 1:1, the SNCs-7S and SNCs-11S complexes exhibited the smallest particle sizes of 110 ± 4 and 234 ± 6 nm, respectively. Their three-phase contact angles approached 90°, indicating favorable interfacial wettability. SNCs induced concentration-dependent fluorescence quenching of 7S and 11S, with maximum quenching efficiencies of 61.02 ± 1.41% and 37.51 ± 1.09%, respectively. Raman spectroscopy and molecular docking analyses indicated that complex formation involved rearrangements of the protein secondary structure and hydrogen bonding. All calculated binding energies were below -6.0 kcal/mol, with the lowest value of -6.5 kcal/mol observed for SNCs-11S. Pickering emulsions containing 60% soybean oil exhibited shear-thinning and predominantly elastic behavior (G' > G″). The 1:1 composite systems formed the strongest network structures and exhibited no evident creaming, flocculation, or oiling-off after storage at 4 °C for 30 days. The SNCs-7S emulsion achieved a curcumin encapsulation efficiency (EE) and loading capacity of 90% and 7.5%, respectively, exceeding the corresponding values of 86% and 6.0% obtained for the SNCs-11S emulsion. After intestinal digestion, free fatty acid release from the SNCs-7S and SNCs-11S emulsions reached 46.31 ± 2.71% and 40.68 ± 0.71%, respectively. Overall, the 1:1 SNCs-7S system exhibited the most favorable interfacial assembly, storage stability, curcumin encapsulation, and lipid digestibility.

β-Cyclodextrin/tea saponin complex-stabilized eugenol emulsion functionalized composite films with antibacterial and sustained-release properties for fruit preservation.

Addressing the severe postharvest losses of perishable fruits and environmental concerns caused by plastic packaging, this study developed a multifunctional composite film. Specifically, a composite of β-cyclodextrin and tea saponin-a byproduct of camellia oil processing-was synthesized and served as a stabilizer for the eugenol emulsion. This composite exhibited favorable surface activity, endowing the emulsion with excellent storage stability. Further, incorporating the emulsion into a κ-carrageenan/cationic guar gum film-forming matrix, the obtained film exhibited favorable mechanical properties (tensile strength: 22.62 MPa, elongation at break: 33.16%), outstanding antioxidant activity (scavenging rates of 60.77% for DPPH and 94.03% for ABTS radicals), and excellent sustained-release effect. Strawberry preservation experiment further confirmed that the composite film can inhibit microbial growth and reduce water loss, thereby extending the shelf life of fruits. This study provides valuable insights for advancing green packaging technologies and promoting the sustainable utilization of food processing byproducts.

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

Soy Protein Isolate-Chitosan Maillard Graft-Stabilized Curcumin-Loaded Emulsions for Encapsulation and Sustained Release

Hydrophobic bioactive compounds are difficult to deliver because of poor water solubility, limited stability, and uncontrolled release. In this study, chitosan-soy protein isolate (CS-SPI) conjugates were prepared by dry-heat Maillard reaction and used as natural polymeric emulsifiers for curcumin-loaded emulsions. The highest grafting degree of 15.3% was obtained at 70 °C, 74.50% relative humidity, 96 h, and a CS:SPI mass ratio of 1:3. Compared with chitosan and CS-SPI non-covalent complex-stabilized emulsions, the CS-SPI conjugate-stabilized emulsion showed the smallest droplets (7.23 μιη) and a more uniform distribution. It maintained high encapsulation efficiency after 6 days of storage (94.28%) and suppressed burst release during simulated gastric digestion, extending curcumin release to about 72 h. These results suggest that CS-SPI conjugates improve emulsion stability and sustained-release performance.