Improving emulsion stability based on ovalbumin-carboxymethyl cellulose complexes with thermal treatment near ovalbumin isoelectric point

Changes of structure properties and potential allergenicity of ovalbumin under high hydrostatic pressures

Egg proteins, notably ovalbumin (OVA), contribute to a prevalent form of food allergy, particularly in children. This study aims to investigate the impact of high hydrostatic pressure (HHP) treatment at varying levels (300, 400, 500, and 600 MPa) on the molecular structure and allergenicity of OVA. The structure of HHP-treated OVA was assessed through fluorescence spectroscopy, circular dichroism spectroscopy, and molecular dynamics (MD) simulation. HHP treatment (600 MPa) altered OVA structures, such as α-helix content decreased from 28.07 % to 19.47 %, and exogenous fluorescence intensity increased by 8.8 times compared to that of the native OVA. The free sulfhydryl groups and zeta potential value were also increased with HHP treatment (600 MPa). ELISA analysis and MD simulation unveiled a noteworthy reduction in the allergenicity of OVA when subjected to 600 MPa for 10 min. Overall, this study suggests that the conformational changes in HHP-treated OVA contribute to its altered allergenicity.

Emulsification properties of ovalbumin-fucoidan (OVA-FUC) binary complexes

The poor thermal stability and emulsifying properties of ovalbumin (OVA) limit its functional performance, but these limitations may be overcome by forming binary complexes. We prepared binary complexes of OVA and fucoidan (FUC) through electrostatic self-assembly and investigated the emulsifying properties of the complex by measuring the particle size, interfacial membrane thickness, zeta potential, and stability of the emulsion prepared with camellia oil and the complex. The OVA-FUC emulsions have a thicker interfacial membrane, lower mobility, higher viscosity, and better stability compared with the OVA emulsions. The emulsion prepared with 1.5 % OVA-FUC remained stable and homogeneous during storage. They tended to become unstable with freeze-thaw, but the oil encapsulated did not leak after coalescence occurred. With the addition of Ca2+, the OVA-FUC emulsion will be converted into a gel state. These findings indicate that OVA-FUC binary complexes can be used to prepare high-performance emulsions with great potential for development.

Effects of rice bran rancidity on the interfacial adsorption properties of rice bran protein fibril aggregates and stability of high internal phase Pickering emulsions

The effects of rice bran rancidity-induced protein oxidation and heating time on the stability of rice bran protein fibril aggregates (RBPFA)-high internal phase Pickering emulsions (HIPPEs) were investigated. The optimal conditions for RBPFA-HIPPEs were 8 mg/mL RBPFA with an oil phase volume fraction of 75 %. Moderate oxidation (rice bran stored for 3 d) and moderate heating (8 h) enhanced the wettability, flexibility, diffusion rate, and adsorption rate of RBPFA, meanwhile, the rheological properties of RBPFA-HIPPEs increased. RBPFA-HIPPEs could be stably stored for 50 d at 25 °C. Moderate oxidized and moderate heated RBPFA-stabilized HIPPEs could remain stable after heat treatment and could be re-prepared after freeze-thaw (3 cycles). Additionally, the stability of RBPFA-HIPPEs was significantly related to the structural characteristics and interfacial properties of RBPFA. Overall, moderate oxidation and moderate heating enhanced the storage, thermal, and freeze-thaw stability of RBPFA-HIPPEs by improving the interfacial properties of RBPFA.

Enhancing Stability and Antioxidant Activity of Resveratrol-Loaded Emulsions by Ovalbumin-Dextran Conjugates

A reliable strategy for improving the stability and shelf life of protein-stabilized systems is by covalently attaching the protein onto a polysaccharide. In this study, ovalbumin (OVA) was modified with dextran (DEX) of different molecular weights by the Maillard reaction, and was used to enhance the stability of emulsions loaded with resveratrol. The surface hydrophobicity, thermal stability, and FT-IR spectroscopy of the OVA-DEX conjugates were evaluated. The results showed that the surface hydrophobicity of OVA decreased, while the thermal stability of OVA was significantly improved after DEX covalent modification. The OVA-DEX1k-stabilized emulsion exhibited high encapsulation efficiency of resveratrol, with the value of 89.0%. In addition, OVA-DEX was considerably more effective in droplet stabilization against different environmental stresses (heat, pH, and ionic strength). After 28 days of storage at 25 °C, the OVA-stabilized emulsion showed faster decomposition of resveratrol, whereas the OVA-DEX-conjugate-stabilized emulsion had approximately 73% retention of resveratrol. Moreover, the antioxidant activity of resveratrol-loaded emulsions stabilized by OVA-DEX was higher during storage under different temperatures. These results proved that the OVA-DEX conjugates had the potential to form stable, food-grade emulsion-based delivery systems against environmental stresses, which strongly supports their potential in the field of food and biomedical applications.

Comparison of ovalbumin glycation induced by high-temperature steaming and high-temperature baking: A study combining conventional spectroscopy with high-resolution mass spectrometry

High-temperature steaming (HTS) and high-temperature baking (HTB)-induced ovalbumin (OVA)-glucose glycation (140 °C, 1-3 min) were compared, and the different mechanisms were evaluated by changes in protein conformation, glycation sites and average degree of substitution per peptide molecule (DSP) values as well as the antioxidant activity of glycated OVA. Conventional spectroscopic results suggested that in comparison with HTB, HTS promoted protein expansion, increased β-sheet content and made OVA structure more orderly. Liquid chromatography-high resolution mass spectrometry (LC-HRMS) analysis showed that 10 glycation sites were found under HTB, while 4 new glycation sites R111, R200, R219 and K323 appeared under HTS, and 2 of them (R219 and K323) were located in internal β-sheet chains. The antioxidant activities of glycated OVA increased with increasing treatment time, and HTS showed stronger enhancement effect than HTB. Furthermore, the DSP values were generally higher under HTS than HTB. Compared with HTB, HTS with high penetrability could enhance the change of OVA primary structure and spatial conformation, making the protein structure more unfolded and stable, leading to more protein-sugar collisions occurred in inner OVA molecular and significantly promoted glycation. In conclusion, HTS is a promising method for high-temperature short-time glycation reaction, with drastically increasing the protein antioxidant activities.

Polymer-lipid hybrid nanoparticles as potential lipophilic anticancer drug carriers

Nanocarrier systems are widely used for drug delivery applications, but limitations such as the use of synthetic surfactants, leakage of toxic drugs, and a poor encapsulation capacity remain as challenges. We present a new hybrid nanocarrier system that utilizes natural materials to overcome these limitations and improve the safety and efficacy of drug delivery. The system comprises a biopolymeric shell and a lipid core, encapsulating the lipophilic anticancer drug paclitaxel. Bovine serum albumin and dextran, in various molecular weights, are covalently conjugated via Maillard reaction to form the shell which serves as a stabilizer to maintain nanoparticle integrity. The properties of the system, such as Maillard conjugate concentration, protein/polysaccharide molar ratio, and polysaccharide molecular weight, are optimized to enhance nanoparticle size and stability. The system shows high stability at different pH conditions, high drug loading capacity, and effective in vitro drug release through the trigger of enzymes and passive diffusion. Serine proteases are used to digest the protein portion of the nanoparticle shell to enhance the drug release. This nanocarrier system represents a significant advancement in the field of nanomedicine, offering a safe and effective alternative for the delivery of lipophilic drugs.

Fabrication, characterization of carboxymethyl konjac glucomannan/ovalbumin-naringin nanoparticles with improving in vitro bioaccessibility

Naringin is potential functional and therapeutic ingredient, has low bioavailability because of poor aqueous solubility. In this study, an ovalbumin (OVA)-carboxymethyl konjac glucomannan (CKGM) nano-delivery system was developed to enhance the bioavailability of naringin. The effects of proportion (OVA: CKGM), pH and naringin concentration were studied on the formation, encapsulation efficiency (EE) and bioaccessibility of OVA/CKGM-Naringin nanoparticles (OVA/CKGM-Naringin NPs). Its morphology and size were viewed by Scanning Electron Microscope (SEM) and Transmission Electron Microscopy (TEM). The cross-linkage between OVA and CKGM was verified by Fourier Transform Infrared Spectroscopy (FTIR) and Fluorescence Intensity analysis. The size of OVA/CKGM-Naringin NPs were 463.83 ± 18.50 nm (Polydispersity Index-PDI, 0.42 ± 0.05). It indicated that 2:1 of OVA: CKGM, pH 3 and 7 mg/mL of naringin concentration were optimized processing parameters of OVA/CKGM-Naringin NPs with EE (97.90 ± 2.97 %) and remarkably improved bioaccessibility (85.01 ± 2.52 %). The OVA/CKGM-Naringin NPs was energy efficiently prepared and verified as an ideal carrier of naringin.

Microfluidic Systems For Manufacturing of Microparticle-Based Drug-Delivery Systems: Design, Construction, and Operation

Particles synthesized from biodegradable polymers hold great potential as controlled drug delivery systems. Continuous flow platforms based on microfluidics offer attractive advantages over conventional batch-emulsification techniques for the scalable fabrication of drug-loaded particles with controlled physicochemical properties. However, widespread utilization of microfluidic technologies for the manufacturing of drug-loaded particles has been hindered largely by the lack of practical guidelines toward cost-effective development and reliable operation of microfluidic systems. Here, we present a framework for rational design and construction of microfluidic systems using commercially available components for high-throughput production of uniform biodegradable particles encapsulating drugs. We also demonstrate successful implementation of this framework to devise a robust microfluidic system that is capable of producing drug-carrying particles with desired characteristics. The guidelines provided in this study will likely help broaden the applicability of microfluidic technologies for the synthesis of high-quality, drug-loaded biodegradable particles.

Polysaccharides improved the viscoelasticity, microstructure, and physical stability of ovalbumin-ferulic acid complex stabilized emulsion

This study explored the mechanism underlying the interactions between polysaccharides and ovalbumin-ferulic acid (OVA-FA) and the effect of polysaccharides on OVA-FA-stabilized emulsions. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to study the polysaccharide OVA-FA interactions mechanism and to resolve the changes in the protein secondary structure and crystal structure. OVA-FA-polysaccharide-stabilized emulsions were studied using confocal laser scanning microscopy (CLSM), and their rheological properties and stability were determined. The results showed that the non-covalent interactions between polysaccharides and OVA-FA led to an increase in the β-sheet content of OVA and a decrease in the α-helix and random coil contents. The stability of the OVA-FA-polysaccharide-stabilized emulsions was better compared with that of the OVA-FA-stabilized emulsions. By comparing the different OVA-FA-polysaccharide-stabilized emulsions, we observed that OVA-FA-agar did not stabilize the emulsion well, while the OVA-FA-SA- and OVA-FA-KC-stabilized emulsions had good elasticity, and the microstructure and storage stability of the OVA-FA-KC-stabilized emulsion were better. Our findings provide a new perspective for the application of OVA-FA-KC in complex food emulsions.

Influence of Proteins on the Absorption of Lipophilic Vitamins, Carotenoids and Curcumin - A Review

While proteins have been widely used to encapsulate, protect, and regulate the release of bioactive food compounds, little is known about the influence of co-consumed proteins on the absorption of lipophilic constituents following digestion, such as vitamins (A, D, E, K), carotenoids, and curcumin. Their bioavailability is often low and very variable, depending on the food matrix and host factors. Some proteins can act as emulsifiers during digestion. Their liberated peptides have amphiphilic properties that can facilitate the absorption of microconstituents, by improving their transition from lipid droplets into mixed micelles. Contrarily, the less well digested proteins could negatively impinge on enzymatic accessibility to the lipid droplets, slowing down their processing into mixed micelles and entrapping apolar food compounds. Interactions with mixed micelles and proteins are also plausible, as shown earlier for drugs. This review focuses on the ability of proteins to act as effective emulsifiers of lipophilic vitamins, carotenoids, and curcumin during digestion. The functional properties of proteins, their chemical interactions with enzymes and food constituents during gastro-intestinal digestion, potentials and limitations for their use as emulsifiers are emphasized and data from human, animal, and in vitro trials are summarized.

Study of Different Chitosan/Sodium Carboxymethyl Cellulose Proportions in the Development of Polyelectrolyte Complexes for the Sustained Release of Clarithromycin from Matrix Tablets

This study investigated the combination of different proportions of cationic chitosan and anionic carboxymethyl cellulose (CMC) for the development of polyelectrolyte complexes to be used as a carrier in a sustained-release system. Analysis via scanning electron microscopy (SEM) Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) confirmed ionic interactions occur between the chitosan and carboxymethyl cellulose chains, which increases drug entrapment. The results of the dissolution study in acetate buffer (pH 4.2) showed significant increases in the kinetic profiles of clarithromycin for low proportions of chitosan/carboxymethyl cellulose tablets, while the tablets containing only chitosan had high relaxation of chitosan chains and disintegrated rapidly. The Korsmeyer–Peppas kinetic model for the different interpolymer complexes demonstrated that the clarithromycin transport mechanism was controlled by Fickian diffusion. These results suggest that the matrix tablets with different proportions of chitosan/carboxymethyl cellulose enhanced the ionic interaction and enabled the prolonged release of clarithromycin.

Spray-drying encapsulation of microwave-assisted extracted polyphenols from Moringa oleifera: Influence of tragacanth, locust bean, and carboxymethyl-cellulose formulations

In this work, polyphenols from Moringa oleifera (Mor) leaves were extracted by microwave-assisted extraction (MAE) and encapsulated by spray-drying (SD). Particularly, we explored the influence of tragacanth gum (TG), locust bean gum (LBG), and carboxymethyl-cellulose (CMC) as wall-materials on the physicochemical behavior of encapsulated Mor. Single or combined wall-material treatments (100:00 and 50:50 ratios, and total solid content 1%) were tested. The results showed the wall-material had a significant effect on the process yield (55.7-68.3%), encapsulation efficiency (24.28-35.74%), color (yellow or pale-yellow), total phenolic content (25.17-27.49 mg GAE g^-1 of particles), total flavonoid content (23.20-26.87 mg QE g^-1 of particles), antioxidant activity (DPPH^• = 5.96-6.95 mg GAE g^-1; ABTS^•+ = 5.61-6.18 mg TE g^-1 of particles), and particle size distribution (D₅₀ = 112-1946 nm) of the encapsulated Mor. On the other hand, SEM analysis showed smooth and spherical particles, while TGA and DSC analyses confirmed the encapsulation of bioactive compounds based on the changes in thermal peaks. Finally, XRD analysis showed that the particles have an amorphous behavior. The encapsulated Mor produced with individual TG or CMC demonstrated better properties than those obtained from mixed gums. Thus, TG or CMC might be feasible wall materials for manufacturing encapsulated Mor that conserve the phenolic content and antioxidant activity.

Egg White Protein Carrier-Assisted Development of Solid Dispersion for Improved Aqueous Solubility and Permeability of Poorly Water Soluble Hydrochlorothiazide

Hydrochlorothiazide (HTZ) is a first-line drug used in the treatment of hypertension suffered from low oral bioavailability due to poor aqueous solubility and permeability. Hence, lyophilized egg white protein-based solid dispersion (HTZ-EWP SD) was developed to explore its feasibility as a solid dispersion carrier for enhanced aqueous solubility and permeability of HTZ. The HTZ-EWP SD was prepared using the kneading method. HTZ-EWP SD was characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transforms infrared spectroscopy (FT-IR), powder X-ray diffractometer (PXRD), solubility, in vitro dissolution, and ex vivo permeation studies. The physico-chemical evaluation suggested the formation of the solid dispersion. Optimized HTZ-EWP SD4 drastically enhanced (~32-fold) aqueous solubility (~16.12 ± 0.08 mg/mL) over to pure HTZ (~ 0.51 ± 0.03 mg/mL). The dissolution study in phosphate buffer media (pH 6.8) revealed that HTZ-EWP SD4 significantly enhanced the release rate of HTZ (~ 87 %) over to HTZ (~ 25 %). The permeation rate of HTZ from optimized HTZ-EWP SD4 was enhanced significantly (~ 84 %) compared to pure HTZ (~ 24 %). Optimized HTZ-EWP-SD4 enhanced the rate of HTZ dissolution (~ 86 %) in FeSSIF (fed state simulated intestinal fluid), compared to a low dissolution rate (~ 72 %) in FaSSIF (fasted state simulated intestinal fluid) state after 2-h study. Obtained results conclude that lyophilized egg white protein can be utilized as an alternative solid dispersion carrier for enhancing the solubility and permeability of HTZ.

Microstructures of encapsulates and their relations with encapsulation efficiency and controlled release of bioactive constituents: A review

Vitamins, peptides, essential oils, and probiotics are examples of health beneficial constituents, which are nevertheless heat-sensitive and possess poor chemical stability. Various encapsulation methods have been applied to protect these constituents against thermal and chemical degradations. Encapsulates prepared by different methods and/or at different conditions exhibit different microstructures, which in turn differently influence the encapsulation efficiency as well as retention of encapsulated core materials. This review provides a summary of various microstructures resulted from the use of selected encapsulation methods or systems, namely, spray coating; co-extrusion; emulsion-, micelle-, and liposome-based; coacervation; and ionic gelation encapsulation, at different conditions. Subsequent effects of the different microstructures on encapsulation efficiency and retention of encapsulated core materials are mentioned and discussed. Encapsulates having compact microstructures resulted from the use of low-surface tension and low-viscosity encapsulants, high-stability encapsulation systems, lower loads of core materials to total solids of encapsulants and appropriate solidification conditions have proved to exhibit higher encapsulation efficiencies and better retention of encapsulated core materials. Encapsulates with hollow, dent, shrunken microstructures or thinner walls resulted from inappropriate solidification conditions and higher loads of core materials, on the other hand, possess lower encapsulation efficiencies and protection capabilities. Encapsulates having crack, blow-hole or porous microstructures resulted from the use of high-viscosity encapsulants and inappropriate solidification conditions exhibit the lowest encapsulation efficiencies and poorest protection capabilities. Compact microstructures and structures formed between ionic biopolymers could be used to regulate the release of encapsulated cores.