Development of stable high internal phase emulsions by pickering stabilization: Utilization of zein-propylene glycol alginate-rhamnolipid complex particles as colloidal emulsifiers

Recent progress in protein-based high internal-phase Pickering emulsions: Composition, stabilization, applications, and future trends

Protein-based high internal-phase Pickering emulsions (HIPPEs) have attracted widespread attention in recent years because they exhibit unique advantages for 3D printing and dysphagia food, including moist, soft, and creamy texture, good swallowing behavior, and excellent 3D printing effect. HIPPEs stability vastly influences its 3D printing accuracy, texture, and swallowing behavior. This review aims to comprehensively explore crucial factors influencing the formation and stability of HIPPEs, presenting reasonable strategies to enhance HIPPEs stability. Our emphasis lies in uncovering the relationship between protein-based particles' interfacial behavior, HIPPEs stability, and the application of HIPPEs on 3D printing and dysphagia food. Furthermore, the convergence of 3D printing and dysphagia foods expected to deepen, facilitating development of HIPPEs-based dysphagia food. Although application prospect of HIPPEs is very wide, looking ahead, there are many areas where further research is still required: (1) exploring more sources of protein fibrils, microalgae and insect proteins as Pickering particles to stabilize HIPPEs; (2) constructing mathematical model that unraveling the relationship between particles' interfacial behavior and HIPPEs stability; (3) combining dual-nozzle 3D printing with infill structure to modify the texture behavior and obtain more attractive appearance of HIPPEs-based dysphagia foods; (4) linking rheological behavior with oral processing and swallowing will be a research trend for exploring the texture and mouthfeel of dysphagia foods at different stages of oral processing; (5) developing evaluation system connected with oral processing behavior of dysphagia foods; (6) exploring the nutrition retention and texture behavior of dysphagia foods during 3D printing, post-processing, and chewing/swallowing process.

Stabilization of high internal phase emulsions by combination of polysaccharide and protein: Synergistic efficiency, mechanism, and application

This review presents recent advances in the combined use of protein and polysaccharide for synergistic stabilization of high internal phase emulsions (HIPEs). Four types of protein-polysaccharide systems that can be used as stabilizes for HIPEs are discussed, including non-covalent complexes, covalent conjugates, core-shell nanoparticles, and ternary complexes. These binary/ternary systems exhibit favorable performance in the construction of stable HIPEs, protection and controlled delivery of bioactive compounds. We discuss various material sources, formation mechanism, and physicochemical characteristic of each system. The challenges associated with the appropriate selection of wall materials, interaction with digestive systems, and in vivo biological fate of HIPEs are also highlighted. This review could help comprehensively understand the synergistic efficiencies of protein and polysaccharide on HIPEs for the functional food applications.

Preparation, characterization and slow-release behavior during in vitro digestion of rice porous starch-based microencapsulated camellia oil

Microcapsules laden with camellia oil (CO), utilizing rice porous starch (PS) as the core material carrier, were successfully prepared through spray drying, employing whey protein isolate (WPI) and maltodextrin (MD) as composite wall materials. This study delved into the rheological characteristics, zeta potential, and physical stability of the CO emulsions. The results indicated a notable reduction in the apparent viscosity of the CO emulsions upon the incorporation of MD. During the WPI and MD compounding process, the W7M3 emulsions system exhibited optimal particle interactions, deformation resistance, and physical stability. Furthermore, the formation process, structural properties, and in vitro simulated digestion and release behaviors of various PS-based CO microcapsules were characterized. The encapsulation efficacy and physicochemical attributes of CO were closely associated with the characteristics of the PS carriers. FT-IR analyses confirmed the encapsulation of the essential oil in microcapsule form. PS-based microcapsules possessed a higher thermal stability. During the in vitro simulated digestion and release process, the gastric release of PS-based CO microcapsules was delayed, while the intestinal release was relatively gradual, exhibiting a superior sustained release effect. The final release amount of CO ranged between 82.60 % and 91.18 %.

Curcumin-loaded Pickering emulsions stabilized by Spanish mackerel protein-pectin for ameliorating ulcerative colitis through barrier repair and anti-inflammatory effects

Curcumin (Cur) has gained considerable recognition because of its anti-inflammatory and antioxidant effects as a bioactive compound, but its water insolubility and low bioaccessibility limit its application in food industry. In this study, Pickering emulsion stabilized by Spanish mackerel protein and pectin complex (SMP/PEC) was prepared to deliver curcumin, and its alleviating effects on DSS-induced ulcerative colitis (UC) were investigated. The emulsions stabilized by SMP/PEC 1:1 inhibited phase separation, had good rheological properties and the emulsions were stable at high temperatures, centrifugation, salt ions, and pH conditions. Meanwhile, the bioaccessibility of Cur loaded in the emulsion was 2.6 times higher than that of free Cur in corn oil. Furthermore, in vivo experiments have demonstrated that Cur loaded Pickering emulsion stabilized by SMP/PEC could enhance the proliferation of goblet cells and the expression of tight junction proteins, and restore the structural integrity of colonic tissues. Additionally, it has been shown to downregulate pro-inflammatory cytokines, such as serum IL-6 and TNF-α, and reduce the levels of MPO, NO, and other biomarkers in colonic tissues. Concurrently, gut microbiota demonstrated that emulsion stabilized by SMP/PEC could regulate the relative abundance of intestinal microorganisms, facilitating the increase of beneficial bacteria and reducing the level of harmful bacteria in the gut. In conclusion, the findings of this study indicated that SPECPE might be a potentially beneficial dietary supplement for the prevention of ulcerative colitis.

Fabrication of Rubus chingii Hu ellagitannins-loaded W/O and O/W emulsion gels: Structure, stability, in vitro digestion and in vivo metabolism

Tannin is the main naturally occurring phytochemicals in Rubus chingii Hu with poor digestive stability and low bioavailability. In this study, oil-in-water (O/W) and water-in-oil (W/O) emulsion gels encapsulating Rubus chingii Hu ellagitannins (RCHT) were fabricated and their structure, rheology, stability, in vitro digestion and in vivo metabolism were characterized. The W/O emulsion gel showed smaller particle size, better pH stability, thermal stability, centrifugal stability and storage stability. Regarding rheology, two emulsion gels exhibited characteristics of non-Newtonian fluids. The encapsulation efficiency of W/O emulsion gel was higher, reaching 95.46 %. The lower release rate and higher bioaccessibility of RCHT were also observed in the W/O emulsion gel. In vitro fermentation results indicated that W/O emulsion gel could promote the growth of intestinal beneficial bacteria and inhibit the growth of harmful bacteria. Metabolic kinetics in rats showed that the embedding of W/O emulsion gel greatly promoted the absorption and transformation of ellagitannins to urolithins in vivo. Thus, the W/O emulsion gel was quite suitable for the delivery of RCHT.

Modification of Inca peanut albumin-polyphenol conjugates by chitosan through laccase catalysis: Structural, interfacial, and functional properties

As a green method, enzyme crosslinking can catalyze chitosan (CS) to improve further the structural, interfacial, and functional properties of Inca peanut albumin (IPA)-polyphenols. However, the structural impact of laccase-catalyzed CS on different IPA-polyphenol conjugates has not been reported. Results revealed that enzymatic cross-linking of IPA-gallic acid (GA) and IPA- (-)-epigallocatechin-3-gallate (EGCG) with CS resulted in a decrease in α-helices, an increase in β-helices, and a more ordered structure. The contact angles of IPA-GA-CS and IPA-EGCG-CS decreased from 99.4° and 101.2° to 89.9° and 95.4°, respectively, indicating reduced hydrophobicity and enhanced interfacial adsorption. Furthermore, using copolymers as emulsifiers significantly improved the emulsification and antioxidant properties of high internal phase Pickering emulsions (HIPEs). In particular, the apparent viscosity and viscoelasticity of HIPEs constructed with IPA-GA-CS notably improved, and the EGCG-induced copolymers exhibited superior lipid antioxidation. The method of laccase-mediated crosslinking for the preparation of protein-polyphenol-polysaccharide polymers enhances the functional properties and anti-pH sensitivity of IPA, representing a novel protein modification strategy.

High internal-phase Pickering emulsions constructed using myofibrillar proteins from large yellow croaker: Effect of glycerol

Exploring the emulsification of myofibrillar protein (MP) from large yellow croaker (Larimichthys crocea) could meet the demand for high-value development and utilization of fish proteins. Therefore, MPs as the emulsifier to form stable high internal-phase Pickering emulsions (HIPPEs) with the addition of glycerol and the effects of different glycerol addition ratios of HIPPEs were investigated. HIPPEs could be constructed by MPs with the glycerol addition at a ratio of 15 %-30 % (v/v) compared to those without the addition of glycerol. With the increase in glycerol ratios, the absolute value of Zeta potential increased and reached 22.57 ± 0.29 mV at the glycerol ratio of 30 %. All the HIPPEs stabilized by MPs with the addition of glycerol possessed storage stability. Besides, the centrifugal stability constant (Ke), backscattered light intensity and reflected light stability index confirmed that the addition of glycerol was beneficial for the formation of stable HIPPEs prepared by MPs. Additionally, HIPPEs stabilized by MPs with the addition of glycerol possessed small emulsion droplets and viscoelastic behavior. These findings could be helpful for the development and utilization of MPs of large yellow croaker in the food industry.

Recent advances in the plant protein-polyphenol interactions for the stabilization of emulsions

Proteins from plant sources including legumes, cereals and oilseeds are gaining attention due to their suitability for sustainable production, functionality, and positive consumer perception. On the other hand, polyphenols (PPs) are receiving considerable attention as natural ingredients in the human diet due to their potent antioxidant and anti-inflammatory properties. Recent studies indicate that the emulsifying properties of plant proteins (PLPs) can be improved after modification through covalent and/or non-covalent interactions with PPs due to the changes in the conformation and/or the surface chemistry of the proteins. Complexes formed between PLPs-PPs can serve as innovative ingredients for developing novel food products with modified textural properties. Also, Pickering emulsions, multiple emulsions, multilayer emulsions, nanoemulsions, and high internal phase emulsions can be stabilized by such systems to deliver bioactive compounds. This paper reviews the most recent research on the PLP-PP interactions and their role in the stabilization of various emulsion-based systems. A special emphasis is given to modifying the structure and functionality of PLPs and PPs. The challenges and opportunities of applying PLP-PP interactions in emulsion-based systems are also highlighted.

Preparation and characterization of lactoferrin-polyphenol conjugate with stabilizing effects on fish oil high internal phase Pickering emulsions

The combination of protein and polyphenol is an effective approach to improve the stability of protein emulsions. The lactoferrin (LF)-(-)-epigallocatechin-3-gallate (EGCG) covalent complex (LF-EGCG) was first prepared by alkali-induced reaction, then the structure and physicochemical properties between LF-EGCG and non-covalent complex (LF + EGCG) were compared, and finally the stability of complexes to fish oil high internal Pickering emulsions (HIPPEs) was tested. Results showed that LF-EGCG had stronger antioxidant activity, higher thermal stability, and better surface wettability than LF + EGCG. Meanwhile, the complexes showed no cytotoxicity within the tested concentration range (12.5-200 μg/mL). The HIPPEs stabilized with LF-EGCG possessed smaller droplet size, higher ζ-potential, and more uniform oil/water proton distribution. Covalent treatment also enhanced the storage, thermal, freeze-thaw and physical stability of LF HIPPEs. Furthermore, due to the higher antioxidant activity and denser microstructure, LF-EGCG HIPPE can more effectively inhibit the oxidation of fish oil.

Relationship between the interfacial properties of lactoferrin-(-)-epigallocatechin-3-gallate covalent complex and the macroscopic properties of emulsions

This study explored the relationship between the interfacial behavior of lactoferrin-(-)-epigallocatechin-3-gallate covalent complex (LF-EGCG) and the stability of high internal phase Pickering emulsions (HIPPEs). The formation of covalent bond between lactoferrin and polyphenol was verified by the increase in molecular weight. In LF-EGCG group, the surface hydrophobicity, interfacial pressure, and adsorption rate were decreased, while the molecular flexibility, interfacial film viscoelasticity, and interfacial protein content were increased. Meanwhile, LF-EGCG HIPPE possessed reduced droplet size, increased ζ-potential and stability. Rheology showed the viscoelasticity, structural recovery and gel strength of LF-EGCG HIPPE were improved, giving HIPPE inks better 3D printing integrity and clarity. Moreover, the free fatty acids (FFA) release of LF-EGCG HIPPE (62.6%) was higher than that of the oil group (50.1%). Therefore, covalent treatment effectively improved the interfacial properties of protein particles and the stability of HIPPEs. The macroscopic properties of HIPPEs were positively regulated by the interfacial properties of protein particles. The result suggested that the stability of emulsions can be improved by regulating the interfacial properties of particles.

Pickering emulsions stabilized by prolamin-based proteins as innovative carriers of bioactive compounds

Pickering emulsions (PEs) can be used as efficient carriers for encapsulation and controlled release of different bioactive compounds. Recent research has revealed the potential of prolamins in development of nanoparticle- and emulsion-based carriers which can improve the stability and bioavailability of bioactive compounds. Prolamin-based particles have been effectively used as stabilizers of various PEs including single PEs, high internal phase PEs, multiple PEs, novel triphasic PEs, and PE gels due to their tunable self-assembly behaviors. Prolamin particles can be fabricated via different techniques including anti-solvent precipitation, dissolution followed by pH adjustment, heating, and ion induced aggregation. Particles fabricated from prolamins alone or in combination with other hydrocolloids or polyphenols have also been used for stabilization of different PEs which were shown to be effective carriers for food bioactives, providing improved stability and functionality. This article covers the recent advances in various PEs stabilized by prolamin particles as innovative carriers for bioactive ingredients. Strategies applied for fabrication of prolamin particles and prolamin-based carriers are discussed. Emerging techno-functional applications of prolamin-based PEs and possible challenges are also highlighted.

High internal phase pickering emulsions stabilized by zein/whey protein nanofibril complexes: Preparation and lycopene loading

High internal phase Pickering emulsions (HIPPEs) prepared from natural polymers have attracted much attention in the food manufactures. However, single zein-stabilized HIPPEs are poorly stable and prone to flocculation near the isoelectric point. To address this issue, in this study, zein and whey protein nanofibrils (WPN) complex nanoparticles (ZWNPs) were successfully prepared using a pH-driven method, and ZWNPs were further used as HIPPEs stabilizers. The results showed that zein and WPN were combined together through hydrogen bonding and hydrophobic interaction to form ZWNPs, and the HIPPEs stabilized by ZWNPs had excellent stability, which could effectively protect the internally encapsulated lycopene and improve the bioaccessibility of lycopene. In conclusion, this study provides a new strategy for the preparation of stable hydrophobic protein-based HIPPEs, represented by zein.

Preparation of a Porous Protein-Based Composite Material by In Situ Polymerization of Pickering High Internal Phase Emulsion for Adsorption of Lead Ions

The preparation of complex porous materials using a small molecular surfactant as the stabilizer of a high internal phase emulsion can result in harm to the environment. In this study, porous composites based on soy protein isolate with poly(acrylic acid) were prepared by in situ polymerization of a high internal phase monomer emulsion with an internal phase volume fraction of 80%. The material was prepared from acrylic acid and an N,N-methyl diacrylic acid monomer solution as the continuous phase, peanut oil as the dispersed phase, and soy protein isolate as the composite stabilizer. Scanning electron microscopy showed that porous composites exhibited a concave/convex three-dimensional interpenetrating pore structure. Fourier-transform infrared spectra revealed the existence of many active groups such as carboxyl, amino, hydroxyl, and sulfhydryl. The composite had a high adsorption capacity for lead ions, even at low concentration, with a removal rate of up to 95.7%. The adsorption process conformed to a two-stage model involving internal diffusion and Langmuir isothermal adsorption. The maximum saturated adsorption capacity was 36.71 mg/g when the initial solution concentration was 150 mg/L, the adsorbent concentration was 7.0 g/L, and the adsorption mechanism involved chemical interactions between the lead ions and the composite groups -COOH, -OH, and -SH.

Complex bio-nanoparticles assembled by a pH-driven method: environmental stress stability and oil-water interfacial behavior

BACKGROUND

Protein-based nanoparticles have gained considerable interest in recent years due to their biodegradability, biocompatibility, and functional properties. However, nanoparticles formed from hydrophobic proteins are prone to instability under environmental stress, which restricts their potential applications. It is therefore of great importance to develop green approaches for the fabrication of hydrophobic protein-based nanoparticles and to improve their physicochemical performance.

RESULTS

Gliadin/shellac complex nanoparticles (168.87 ~ 403.67 nm) with various gliadin/shellac mass ratios (10:0 ~ 5:5) were prepared using a pH-driven approach. In comparison with gliadin nanoparticles, complex nanoparticles have shown enhanced stability against neutral pH, ions, and boiling. They remained stable under neutral conditions at NaCl concentrations ranging from 0 to 100 mmol L-1 and even when boiled at 100 °C for 90 min. These nanoparticles were capable of effectively reducing oil-water interfacial tension (5 ~ 11 mNm-1 ) but a higher amount of shellac in the nanoparticles compromised their ability to lower interfacial tension. Moreover, the wettability of the nanoparticles changed as the gliadin/shellac mass ratio changed, leading to a range of three-phase contact angles from 52.41° to 84.85°. Notably, complex nanoparticles with a gliadin/shellac mass ratio of 8:2 (G/S 8:2) showed a contact angle of 84.85°, which is considered suitable for the Pickering stabilization mechanism. Moreover, these nanoparticles exhibited the highest emulsifying activity of 52.42 m2 g-1 and emulsifying stability of 65.33%.

CONCLUSIONS

The findings of the study revealed that gliadin/shellac complex nanoparticles exhibited excellent resistance to environmental stress and demonstrated superior oil-water interfacial behavior. They have strong potential for further development as food emulsifiers or as nano-delivery systems for nutraceuticals. © 2023 Society of Chemical Industry.

A smart thermoresponsive macroporous 4D structure by 4D printing of Pickering-high internal phase emulsions stabilized by plasma-functionalized starch nanomaterials for a possible delivery system

Hierarchically porous structures combine microporosity, mesoporosity, and microporosity to enhance pore accessibility and transport, which are crucial to develop high performance materials for biofabrication, food, and pharmaceutical applications. This work aimed to develop a 4D-printed smart hierarchical macroporous structure through 3D printing of Pickering-type high internal phase emulsions (Pickering-HIPEs). The key was the utilization of surface-active (hydroxybutylated) starch nanomaterials, including starch nanocrystals (SNCs) (from waxy maize starch through acid hydrolysis) or starch nanoparticles (SNPs) (obtained through an ultrasound treatment). An innovative procedure to fabricate the functionalized starch nanomaterials was accomplished by grafting 1,2-butene oxide using a cold plasma technique to enhance their surface hydrophobicity, improving their aggregation, and thus attaining a colloidally stabilized Pickering-HIPEs with a low concentration of each surface-active starch nanomaterial. A flocculation of droplets in Pickering-HIPEs was developed after the addition of modified SNCs or SNPs, leading to the formation of a gel-like structure. The 3D printing of these Pickering-HIPEs developed a highly interconnected large pore structure, possessing a self-assembly property with thermoresponsive behavior. As a potential drug delivery system, this thermoresponsive macroporous 3D structure offered a lower critical solution temperature (LCST)-type phase transition at body temperature, which can be used in the field of smart releasing of bioactive compounds.

Effect of NaCl concentration on the formation of high internal phase emulsion based on whey protein isolate microgel particles

At present, the effect of structural modification of microgel particles on high internal phase emulsions (HIPEs) is less studied. In this study, the structural modification effect of NaCl on whey protein isolate microgels (WPIMPs) was comprehensively characterized and applied to the construction of HIPEs. WPIMPs were prepared with NaCl (0-150 mM) and the structural changes were analyzed by measuring the particle size, Zeta-potential, and endogenous fluorescence spectra. The results showed that inducing WPIMPs by NaCl enhanced the surface hydrophobicity, decreased the Zeta potential, and elevated the degree of cross-linking. The interfacial behavior of WPIMPs was characterized by measuring interfacial tensions and adsorbed layer properties. The results showed that NaCl induction decreased the interfacial tension, increased the thickness of the adsorbed layer, and improved the viscoelasticity. The HIPEs were analyzed for micromorphology and particle sizes. The results indicated that NaCl-induced WPIMPs favored the formation of HIPEs with small particle sizes and provided HIPEs with superior environmental stability. This study provides a new idea for the structural modification of microgels and a new theoretical basis for the construction conditions of HIPE.

A review of high internal phase Pickering emulsions: Stabilization, rheology, and 3D printing application

High internal phase Pickering emulsion (HIPPE) is renowned for its exceptionally high-volume fraction of internal phase, leading to flocculated yet deformed emulsion droplets and unique rheological behaviors such as shear-thinning property, viscoelasticity, and thixotropic recovery. Alongside the inherent features of regular emulsion systems, such as large interfacial area and well-mixture of two immiscible liquids, the HIPPEs have been emerging as building blocks to construct three-dimensional (3D) scaffolds with customized structures and programmable functions using an extrusion-based 3D printing technique, making 3D-printed HIPPE-based scaffolds attract widespread interest from various fields such as food science, biotechnology, environmental science, and energy transfer. Herein, the recent advances in preparing suitable HIPPEs as 3D printing inks for various applied fields are reviewed. This work begins with the stabilization mechanism of HIPPEs, followed by introducing the origin of their distinctive rheological behaviors and strategies to adjust the rheological behaviors to prepare more eligible HIPPEs as printing inks. Then, the compatibility between extrusion-based 3D printing and HIPPEs as building blocks was discussed, followed by a summary of the potential applications using 3D-printed HIPPE-based scaffolds. Finally, limitations and future perspectives on preparing HIPPE-based materials using extrusion-based 3D printing were presented.

Composite formation of whey protein isolate and OSA starch for fabricating high internal phase emulsion: A comparative study at different pH and their application in biscuits

The composites formed by whey protein isolate (WPI) and octenyl succinate anhydride (OSA)-modified starch were characterized with a focus on the effect of pH, and their potential in fabricating high internal phase emulsions (HIPEs) as fat substitutes was evaluated. The particles obtained at pH 3.0, 6.0, 7.0, and 8.0 presented a nanosized distribution (122.04 ± 0.84 nm-163.24 ± 4.12 nm) while those prepared at pH 4.0 and 5.0 were remarkably larger. Results from the shielding agent reaction and Fourier transform infrared spectroscopy (FT-IR) showed that the interaction between WPI and OSA starch was mainly hydrophobic at pH 3.0-5.0, while there was a strong electrostatic repulsion at pH 6.0-8.0. A quartz crystal microbalance with dissipation (QCM-D) study showed that remarkably higher ΔD and lower Δf/n were observed at pH 3.0-5.0 after successive deposition of WPI and OSA starch, whereas slight changes were noted for those made at higher pH values. The WPI-OSA starch (W-O) composite-based HIPEs made at pH 3.0 and 6.0-8.0 were physically stable after long-term storage, thermal treatment, or centrifugation. Incorporation of HIPE into the biscuit formula yielded products with a desirable sensory quality.

The role of polysaccharides in improving the functionality of zein coated nanocarriers: Implications for colloidal stability under environmental stresses

Zein has gained popularity over the past few years as an incredible food and bio-based materials. The potential functions and health benefits of zein microcapsules or micro-/nanoparticles in bioactive components delivery, structured emulsion, etc., have received great attention. However, the development has been limited by colloidal destabilization, especially when thermal processing is involved. There is a recent trend in developing zein-polysaccharide complexes (ZPCs), which has tremendously improved the performance of zein-based colloidal carrier systems or emulsions. Increasing our understanding of zein interactions and their contribution to the structure of various macromolecules can help us to develop novel biomaterials that can be used in food, agriculture, biomedicine, and cosmetics. In addition, these nanocarriers are suitable for the encapsulation and delivery of bioactive compounds which have positive perspective in food industry. Therefore, this article aimed to review recent advances in the ZPCs that can be applied to functional or health-promoting foods, with a focus on the characteristics of different ZPCs, factors and mechanisms affecting the stability (especially thermal stability) of these complexes, and their application in food industry as a carrier for BCs. Further, the stability of ZPCs based emulsions under processing and physiological environments, as well some typical effective methods are introduced. Also, the principal challenges and prospects were enumerated and discussed.

Rhamnolipids: A biosurfactant for the development of lipid-based nanosystems for food applications

Biosurfactants (surfactants synthesized by microorganisms) are produced by microorganisms and are suitable for use in different areas. Among biosurfactants, rhamnolipids are the most studied and popular, attracting scientists, and industries' interest. Due to their unique characteristics, the rhamnolipids have been used as synthetic surfactants' alternatives and explored in food applications. Besides the production challenges that need to be tackled to guarantee efficient production and low cost, their properties need to be adjusted to the final application, where the pH instability needs to be considered. Moreover, regulatory approval is needed to start being used in commercial applications. One characteristic of interest is their capacity to form oil-in-water nanosystems. Some of the most explored have been nanoemulsions, solid-lipid nanoparticles and nanostructured lipid carriers. This review presents an overview of the main properties of rhamnolipids, asserts the potential and efficiency of rhamnolipids to replace the synthetic surfactants in the development of nanosystems, and describes the rhamnolipids-based nanosystems used in food applications. It also discusses the main characteristics and methodologies used for their characterization and in the end, some of the main challenges are highlighted.

Tunable rheological properties of high internal phase emulsions stabilized by phosphorylated walnut protein/pectin complexes: The effects of pH conditions, mass ratios, and concentrations

The current study reported high internal phase emulsions (HIPEs) stabilized by phosphorylated walnut protein/pectin complexes (PWPI/Pec) and elucidated how their rheological properties were modulated by pH conditions, mass ratios, and concentrations of the complexes. At pH 3.0, the HIPEs stabilized by PWPI/Pec exhibited smaller oil droplet sizes, as well as higher storage modulus (G') and flow stress, in comparison to those stabilized by the complexes formed at pH 4.0-6.0. These observations can be directly linked to pH-dependent changes in particle size, surface hydrophobicity, and wettability of the PWPI/Pec complexes. Rheological analysis revealed that all generated HIPEs displayed weak strain overshoot behavior, irrespective of pH conditions. Notably, HIPEs stabilized by PWPI/Pec at mass ratios of 2:1 and 4:1 showed enlarged oil droplet sizes, lower G' and flow stress but higher flow strain with unaffected loss factor compared to those stabilized by PWPI/Pec 1:1. However, reducing the concentration of PWPI/Pec led to a simultaneous decrease in G', flow stress, and flow strain, along with a significant increase in the loss factor of the HIPEs. Furthermore, the HIPEs formed with 1% PWPI/Pec 1:1 at pH 3.0 demonstrated excellent stability against heat treatment and long-term storage. These results provide valuable insights into the modulation of rheological characteristics of HIPEs and offer guidance for the application of walnut protein-based stabilizers in HIPE systems.

Rheological study of nanoemulsions with repulsive and attractive interdroplet interactions

Nanoemulsions have adjustable transparency, tunable rheology, high stability, and low sensitivity to changes in pH and temperature, which make them interesting for applications such as low-fat and low-calorie foods. In this research, we study model concentrated nanoemulsions which are stabilized by sodium dodecyl sulfate (SDS). To prepare samples in different structural states, semi-dilute nanoemulsions are prepared at 25% droplet volume fraction (φ), after which evaporating the continuous phase at room temperature leads to concentrated nanoemulsions up to 60% volume fraction. Surfactant concentration is also tuned to induce different interdroplet interactions so that concentrated nanoemulsions in repulsive glass, attractive glass, and gel states are achieved. Rheological properties of nanoemulsions with different structural states are comprehensively studied over a volume fraction range. Utilizing the existing predictive models for (nano)emulsion rheology reveals a more satisfactory prediction for repulsive systems than systems with attractive interactions. In addition, a master curve is constructed for storage and loss moduli of nanoemulsions with different interdroplet interactions. The present work offers control over physicochemical properties of nanoemulsions for design of new food products with enhanced quality and functionality.

Ultrasonic and homogenization: An overview of the preparation of an edible protein-polysaccharide complex emulsion

Emulsion systems are extensively utilized in the food industry, including dairy products, such as ice cream and salad dressing, as well as meat products, beverages, sauces, and mayonnaise. Meanwhile, diverse advanced technologies have been developed for emulsion preparation. Compared with other techniques, high-intensity ultrasound (HIUS) and high-pressure homogenization (HPH) are two emerging emulsification methods that are cost-effective, green, and environmentally friendly and have gained significant attention. HIUS-induced acoustic cavitation helps in efficiently disrupting the oil droplets, which effectively produces a stable emulsion. HPH-induced shear stress, turbulence, and cavitation lead to droplet disruption, altering protein structure and functional aspects of food. The key distinctions among emulsification devices are covered in this review, as are the mechanisms of the HIUS and HPH emulsification processes. Furthermore, the preparation of emulsions including natural polymers (e.g., proteins-polysaccharides, and their complexes), has also been discussed in this review. Moreover, the review put forward to the future HIUS and HPH emulsification trends and challenges. HIUS and HPH can prepare much emulsifier-stable food emulsions, (e.g., proteins, polysaccharides, and protein-polysaccharide complexes). Appropriate HIUS and HPH treatment can improve emulsions' rheological and emulsifying properties and reduce the emulsions droplets' size. HIUS and HPH are suitable methods for developing protein-polysaccharide forming stable emulsions. Despite the numerous studies conducted on ultrasonic and homogenization-induced emulsifying properties available in recent literature, this review specifically focuses on summarizing the significant progress made in utilizing biopolymer-based protein-polysaccharide complex particles, which can provide valuable insights for designing new, sustainable, clean-label, and improved eco-friendly colloidal systems for food emulsion. PRACTICAL APPLICATION: Utilizing complex particle-stabilized emulsions is a promising approach towards developing safer, healthier, and more sustainable food products that meet legal requirements and industrial standards. Moreover, the is an increasing need of concentrated emulsions stabilized by biopolymer complex particles, which have been increasingly recognized for their potential health benefits in protecting against lifestyle-related diseases by the scientific community, industries, and consumers.

Optimization of food-grade colloidal delivery systems for thermal processing applications: a review

Colloidal delivery systems are widely used in the food industry to enhance the dispersibility, stability, efficacy, or bioavailability. However, when exposed to the high temperature, delivery systems are often prone to degradation, which limits its application in thermal processing. In this paper, the effects of thermal processing on the performance of traditional protein-based or starch-based delivery systems are firstly described, including the molecular structure changes of proteins, starches or lipids, and the degradation of embedded substances. These effects are unfavorable to the application of the delivery system in thermal processing. Then, strategies of improving the heat resistance of food grade colloid delivery system and their use in frying, baking and cooking food are mainly introduced. The heat resistance of the delivery system can be improved by a variety of strategies, including the development of new heat-resistant materials, the addition of heat-resistant coatings to the surface of delivery systems, the cross-linking of proteins or starches using cross-linking agents, the design of particle structures, the use of physical means such as ultrasound, or the optimization of the ingredient formula. These strategies will help to expand the application of heat-resistant delivery systems so that they can be used in real thermal processing.

Regulation mechanism of ionic strength on the ultra-high freeze-thaw stability of myofibrillar protein microgel emulsions

The regulation mechanism of ionic strength (0-1000 mM) on the freeze-thaw (FT) stability of emulsions stabilized by myofibrillar protein microgel particles (MMP) was systematically investigated. High ionic strength emulsions (300-1000 mM) exhibited stability after five FT cycles. With ionic strength increasing, the repulsive force between particles gradually reduced, the flocculation degree (20.72 ∼ 75.60%) and apparent viscosity of emulsions gradually rose (69 ∼ 170 mPa·s), promoting the formation of protein network structures in the continuous phase. Concurrently, the interfacial proteins rearranged (18.8 ∼ 104.2 s^-1) and aggregated rapidly, facilitating the formation of a stable interface network structure, ultimately improving its stability. Besides, scanning electron microscopy (SEM) images revealed that the interfacial proteins gradually aggregated, further forming a network with the MMP in the continuous phase, allowing MMP emulsions with enhanced FT stability at high ionic strength (300-1000 mM). This study was beneficial to produce emulsion-based sauces with ultra-high FT stability.

Low oil Pickering emulsion gels stabilized by bacterial cellulose nanofiber/soybean protein isolate: An excellent fat replacer for ice cream

Food-grade Pickering emulsion gels with different oil phase fractions stabilized by Bacterial cellulose nanofibers/Soy protein isolate complex colloidal particles were prepared by one-step method. The properties of Pickering emulsion gels with different oil phase fractions (5 %, 10 %, 20 %, 40 %, 60 %, 75 %, v/v) and their applications in ice cream were investigated in the present study. The microstructural results showed that Pickering emulsion gels with the low oil phase fractions (5 %-20 %) were an emulsion droplet-filled gel, where the oil droplets were embedded in the network structure of cross-linked polymer, while Pickering emulsion gels with higher oil phase fractions (40 %-75 %) were an emulsion droplet-aggregated gel, which formed a network structure by flocculated oil droplets. The rheology result showed that the low oil Pickering emulsion gels had the same excellent performance as the high oil Pickering emulsion gels. Furthermore, the low oil Pickering emulsion gels showed good environmental stability under harsh conditions. Consequently, Pickering emulsion gels with 5 % oil phase fraction were used as fat replacers in ice cream and ice cream with different fat replacement rates (30 %, 60 % and 90 %, w/w) was prepared in this work. The results showed the appearance and texture of the ice cream with low oil Pickering emulsion gels as fat replacers was similar to that of the ice cream with no fat replacers, and the melting rate of the ice cream with low oil Pickering emulsion gels as fat replacers showed the lowest value of 21.08 % during the 45 min of melting experiment, as the fat replacer rate in the ice cream reached to 90 %. Therefore, this study demonstrated that low oil Pickering emulsion gels were excellent fat replacers and had great potential application in low calorie food production.

Tuning interfacial microstructure of alginate-based amphiphile by dynamic bonding for stabilizing Pickering emulsion

Polysaccharide-based soft colloidal particles mediated by the dynamic bonding-engineered interfacial self-assembly can regulate the properties of oil-water interfacial films, availing the stability of emulsions under a wide pH range. The amphiphilic phenylboronic alginate soft colloidal particles (Alg-PBA) were designed to stabilize pH-responsive Pickering emulsions (PEs). Combining stability analysis with quartz crystal microbalance and dissipation monitoring (QCM-D), the microstructure and viscoelasticity of Alg-PBA at the oil-water interface were determined. The results showed that PEs stabilized by Alg-PBA due to a thicker and stronger viscoelastic interface film induced by BO bonds and hydrogen bonds. The structure-function relationship of the Alg-PBA emulsifier driven by dynamic bonds was further elaborated at multiple scales by laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Meanwhile, the microstructure of aerogels templated by emulsion could be tuned by adjusting dynamic bonds, which provides a new idea for polysaccharide soft material engineering.

Investigation and Characterization of Pickering Emulsion Stabilized by Alkali-Treated Zein (AZ)/Sodium Alginate (SA) Composite Particles

Pickering emulsions stabilized by food-grade colloidal particles have attracted increasing attention in recent years due to their "surfactant-free" nature. In this study, the alkali-treated zein (AZ) was prepared via restricted alkali deamidation and then combined with sodium alginate (SA) in different ratios to obtain AZ/SA composite particles (ZS), which were used to stabilize Pickering emulsion. The degree of deamidation (DD) and degree of hydrolysis (DH) of AZ were 12.74% and 6.58% respectively, indicating the deamidation occurred mainly in glutamine on the side chain of the protein. After the treatment with alkali, AZ particle size decreased significantly. Moreover, the particle size of ZS with different ratios was all less than 80 nm. when the AZ/SA ratio was 2:1(Z2S1) and 3:1(Z3S1), the three-phase contact angle (θ_o/w) were close to 90°, which was favorable for stabilizing the Pickering emulsion. Furthermore, at a high oil phase fraction (75%), Z3S1-stabilized Pickering emulsions showed the best long-term storage stability within 60 days. Confocal laser scanning microscope (CLSM) observations showed that the water-oil interface was wrapped by a dense layer of Z3S1 particles with non-agglomeration between independent oil droplets. At constant particle concentration, the apparent viscosity of the Pickering emulsions stabilized by Z3S1 gradually decreased with increasing oil phase fraction, and the oil-droplet size and the Turbiscan stability index (TSI) also gradually decreased, exhibiting solid-like behavior. This study provides new ideas for the fabrication of food-grade Pickering emulsions and will extend the future applications of zein-based Pickering emulsions as bioactive ingredient delivery systems.

Stability of protein particle based Pickering emulsions in various environments: review on strategies to inhibit coalescence and oxidation

The emerging research interests in fabrication of protein particles as soft-particle emulsifiers show the prospective potential of using protein particles in novel poly-phase dispersing food systems. This review first provides a comprehensive summary and analysis on the dominant role of key physicochemical properties of protein particles including wettability, morphology, surface charge and protein concentration on their emulsifying abilities to construct Pickering emulsions. It was found that the constructed emulsions showed high sensitivity to changes in pH, ionic strength and temperature (thermal and freeze-thaw treatment). Moreover, oxidation remains as a challenge for protein particle based Pickering emulsions during prolonged storage, reducing their acceptance in food products. Current strategies for improving the stability of these emulsions to variable aqueous conditions and variable temperatures, and restricting oxidation event are summarized. In summary, an "ideal" protein particle-based Pickering emulsion system is proposed, encompassing aspects of interfacial property, emulsion network and texture, and antioxidant enrichment, thus promoting industrial translation into novel food and nutraceutical products.

Biopolymer-based pickering high internal phase emulsions: Intrinsic composition of matrix components, fundamental characteristics and perspective

Pickering HIPEs have received tremendous attention in recent years due to their superior stability and unique solid-like and rheological properties. Biopolymer-based colloidal particles derived from proteins, polysaccharides and polyphenols have been demonstrated to be safety stabilizers for the construction of Pickering HIPEs, which can meet the demands of consumers for "all-natural" products and provide "clean-label" foods. Furthermore, the functionality of these biopolymers can be further extended by forming composite, conjugated and multi-component colloidal particles, which can be used to modulate the properties of the interfacial layer, thereby adjusting the performance and stability of Pickering HIPEs. In this review, the factors affecting the interfacial behavior and adsorption characteristics of colloidal particles are discussed. The intrinsic composition of matrix components and fundamental characteristics of Pickering HIPEs are emphatically summarized, and the emerging applications of Pickering HIPEs in the food industry are reviewed. Inspired by these findings, future perspectives concerning this field are also put forward, including (1) the exploration of the interactions between biopolymers used to produce Pickering HIPEs and target food ingredients, and the influence of the added biopolymers on the flavor and mouthfeel of the products, (2) the investigation of the digestion properties of Pickering HIPEs under oral administration, and (3) the fabrication of stimulus-responsive or transparent Pickering HIPEs. This review will give a reference for exploring more natural biopolymers for Pickering HIPEs application development.

Modified whey protein isolate gel prepared by thermal aggregation combined with transglutaminase crosslinking achieves Casein-like slow digestion in vitro and in vivo

Our study aimed to fabricate a modified slow-digestive whey protein isolate (WPI), which can supply enough branched-chain amino acids (BCAAs) during long-term fasting. The WPI aqueous solution (10 % w/v) was treated by heat (80 ℃) to unfold the protein tertiary structure, and subsequently treated with transglutaminase to form a gel via cross-linking. The powder of the WPI gel was obtained by spray drying, which can dissolve in water easily and self-assemble into gels again. This modified WPI contained protein aggregates with high molecular weight, and kept a stable gel-like structure under simulated gastric digestion conditions (pH = 3, 37 ℃). A dense honeycomb internal microstructure of the freeze-dried gel was observed. Further, we found that the WPI gel successfully achieved a casein-like digestible ratio (37.37 %) and released more BCAAs (0.18 mg/mL) than casein during the 4 h of in vitro simulated digestion based on the INFOGEST method. Finally, our results showed that the C57BL/6 mice oral administrated with the modified WPI gel had consistently higher BCAAs concentration (0.052 mg/mL) in their blood serum than the mice with normal WPI intake during the 6 h of in vivo digestion.

Heteropolysaccharides in sustainable corrosion inhibition: 4E (Energy, Economy, Ecology, and Effectivity) dimensions

Carbohydrate polymers (polysaccharides) and their derivatives are widely utilized in sustainable corrosion inhibition (SCI) because of their various fascinating properties including multiple adsorption sites, high solubility and high efficiency. Contrary to traditional synthetic polymer-based corrosion inhibitors, polysaccharides are related to the 4E dimension, which stands for Energy, Economy, Ecology, and Effectivity. Furthermore, they are relatively more environmentally benign, biodegradable, and non-bioaccumulative. The current review describes the SCI features of various heteropolysaccharides, including gum Arabic (GA), glycosaminoglycans (chondroitin-4-sulfate (CS), hyaluronic acid (HA), heparin, etc.), pectin, alginates, and agar for the first time. They demonstrate impressive anticorrosive activity for different metals and alloys in a variety of corrosive electrolytes. Through their adsorption at the metal/electrolyte interface, heteropolysaccharides function by producing a corrosion-protective film. In general, their adsorption follows the Langmuir isotherm model. In their molecular structures, heteropolysaccharides contain several polar functional groups like -OH, -NH₂, -COCH₃, -CH₂OH, cyclic and bridging O, -CH₂SO₃H, -SO₃OH, -COOH, -NHCOCH₃, -OHOR, etc. that serve as adsorption centers when they bind to metallic surfaces.

Protein-Based High Internal Phase Pickering Emulsions: A Review of Their Fabrication, Composition and Future Perspectives in the Food Industry

Protein-based high internal phase Pickering emulsions (HIPEs) are emulsions using protein particles as a stabilizer in which the volume fraction of the dispersed phase exceeds 74%. Stabilizers are irreversibly adsorbed at the interface of the oil phase and water phase to maintain the droplet structure. Protein-based HIPEs have shown great potential for a variety of fields, including foods, due to the wide range of materials, simple preparation, and good biocompatibility. This review introduces the preparation routes of protein-based HIPEs and summarizes and classifies the preparation methods of protein stabilizers according to their formation mechanism. Further outlined are the types and properties of protein stabilizers used in the present studies, the composition of the oil phase, the encapsulating substances, and the properties of the constituted protein-based HIPEs. Finally, future development of protein-based HIPEs was explored, such as the development of protein-based stabilizers, the improvement of emulsification technology, and the quality control of stabilizers and protein-based HIPEs.

Stability and digestibility of encapsulated lycopene in different emulsion systems stabilized by acid-modified soybean lipophilic protein

BACKGROUND

Owing to the harsh acidic environment of the stomach, acid-resistant emulsion products have wide-ranging applications in the food industry. Herein, natural soybean lipophilic protein (LP) was used to establish coarse emulsions, nanoemulsions, emulsion gels, and high internal phase Pickering emulsions (HIPPE) under acidic conditions. Furthermore, the carrying characteristics of the acid-resistant emulsion system with lycopene were explored.

RESULTS

Comparisons of particle sizes, potentials, microstructures, and rheology of the four carrier systems revealed that HIPPE has a single particle-size distribution, the largest zeta potential, and an elastic gel-like network structure. Comparison of encapsulation rates indicated that HIPPE had the best effect on encapsulating lycopene, reaching approximately 90%. The pH stability, storage stability, and simulated in vitro digestion experiments showed that the four emulsions that were stable under acidic conditions had good acid resistance. Among them, the acid-induced LP-stabilized HIPPE had the best storage stability and superior compatibility with the harsh acidic environment of the stomach, which not only achieved the purpose of delaying the release of lipids but also conferred better protection to lycopene in the gastric tract; moreover, it achieved the best bioavailability.

CONCLUSION

LP-stabilized HIPPE has the best stability and can yield better absorption and utilization of lycopene by the body. The results of this study are helpful for the development of acid-resistant functional emulsion foods that are conducive to the absorption of lycopene. © 2022 Society of Chemical Industry.

Recent advances in self-assembly behaviors of prolamins and their applications as functional delivery vehicles

Prolamins are a group of storage proteins (zeins, kafirins, hordeins, secalins, gliadins, glutenins, and avenins) found in the endosperm of cereal grains and characterized by high glutamine and proline content. With the high proportion of nonpolar amino acids (40-80%) and peculiar solubility (alcohol (60-90%), acetic acid, and alkaline solutions), prolamins exhibit tunable self-assembly behaviors. In recent years, research practices of utilizing prolamins as green building materials of functional delivery vehicles to improve the health benefits of bioactive compounds have surged due to their attractive advantages (e.g. sustainability, biocompatibility, fabrication potential, and cost-competitiveness). This article covers the recent advances in self-assembly behaviors leading to the fabrication of nanoparticles, fibers, and films in the bulk water phase, at the air-liquid interface, and under the electrostatic field. Different fabrication methods, including antisolvent precipitation, evaporation induced self-assembly, thermal treatment, pH-modulation, electrospinning, and solvent casting for assembling nanoarchitectures as functional delivery vehicles are highlighted. Emerging industrial applications by mapping patents, including encapsulation and delivery of bioactive compounds and probiotics, active packaging, Pickering emulsions, and as functional additives to develop safer, healthier, and sustainable food products are discussed. A future perspective concerning the fabrication of prolamins as advanced materials to promote their commercial food applications is proposed.

pH-driven self-assembly of alcohol-free curcumin-loaded zein-propylene glycol alginate complex nanoparticles

This study aimed to prepare alcohol-free curcumin-loaded zein-propylene glycol alginate (zein-PGA-Cur) nanoparticles using the pH-driven method to enhance the bioavailability and physicochemical stability of curcumin. The prepared zein-PGA-Cur nanoparticles exhibited a small size (360 nm) and negative zeta-potential (-5.8 mV), as well as excellent physical stability, under storage conditions of pH 4.0 and temperature at 4 °C for 30 days. In addition, the Fourier transform infrared spectroscopy results demonstrated that the main interactions of pH-driven for the formation of zein-PGA-Cur nanoparticles were hydrogen bonding, hydrophobic, and electrostatic interactions. Fluorescence spectroscopy revealed that the curcumin-induced fluorescence quenching of zein was static. Circular Dichroism spectroscopy demonstrated that the pH-driven method mainly decreased the β-sheet structure of zein from 3.9 % to 1.4 %. Furthermore, the HT-29 colorectal adenocarcinoma cells viability experiments revealed that the prepared zein-PGA-Cur nanoparticles exhibited excellent biocompatibility. In vivo rat experiments also demonstrated that the prepared nanoparticles resulted in a higher plasma concentration of curcumin, representing a 7.2-fold enhancement in bioavailability compared with pure curcumin crystals. The findings of this study will provide a green and energy-saving method for the development of insoluble drug self-assembly systems and promote their wider applications in drug delivery.

Self-assembly of gelatin and phycocyanin for stabilizing thixotropic emulsions and its effect on 3D printing

Nutritional phycocyanin (PC) may be non-covalently bound to gelatin (GE) and form the self-assembly complex proteins, which could stabilize high internal phase emulsions (HIPEs) by one-pot homogenization. The effects of PC on physicochemical, structural, extrudable, thixotropic properties and practical printability of HIPEs were investigated. The electrostatic interaction and hydrogen bonds between GE and PC facilitated the compact structure, promoted the interfacial adsorption behavior at oil-water interface, enhanced emulsion stability, and reduced creaming index of HIPEs. Shearing-thinning property and proper yield stress proved the excellent extrudability of HIPEs. Moreover, thixotropy results indicated that low-content PC resulted in high hysteresis area and large recovery rate of HIPEs, suggesting the outstanding structure rebuilding capacity and structure maintainability. 3D printing of HIPEs illustrated the high printing definition and shape retention conforming to the original models. Overall, this study provides reference for developing functional thixotropic emulsions with high potential in customizing special three-dimensional food.

Fabrication and characterization of Pickering high internal phase emulsions stabilized by debranched starch-capric acid complex nanoparticles

High internal phase emulsions (HIPEs) stabilized by debranched starch-capric acid (DBS-CA) complex nanoparticles were fabricated and their performance was evaluated. DBS-CA was prepared through enzymatic debranching and solid encapsulation methods, and displayed V-type crystalline structure. Contact angle measurements show enhanced hydrophobicity of DBS-CA compared to native starch. The DBS-CA nanoparticles have an average size of 463.77 nm and tended to be aggregating as analyzed by scanning electron microscope and dynamic light scattering particle size analysis. When used as a particulate emulsifier, DBS-CA could stabilize HIPEs with oil volume fraction as high as 80%. The HIPEs showed pH-dependent properties; good storage stability and mechanical strength were achieved within pH range from 3 to 11, especially under alkaline conditions. It was proposed that smaller particle size and higher surface charging were responsible for the more tightly connected gel structure and thus their performance. This study demonstrates a novel approach to fabricate food-grade Pickering HIPEs, which may have many promising potential applications in the food industry.

Fabrication of food-grade Pickering high internal phase emulsions (HIPEs) stabilized by a dihydromyricetin and lysozyme mixture

This study evaluated the feasibility of fabricating food-grade HIPEs using a dihydromyricetin and lysozyme mixture. The effects of the oil phase volume fraction (φ), composition (lysozyme:dihydromyricetin, k), and addition amount (w) of the mixture on the formation and properties of the HIPEs were analyzed. Then, the interactions of dihydromyricetin and lysozyme were investigated. The results indicated that when w was 0.4%, HIPEs with φ value of 90% could be obtained. Furthermore, the k also affected the microstructure, mechanical properties, oil oxidation, and lutein protection ability of the HIPEs. However, the presence of dihydromyricetin did not affect lysozyme activity. Both isothermal titration calorimetry and molecular simulations proved that they did not form a typical host-guest complex. But, dihydromyricetin could absorb on the lysozyme surface. Therefore, we speculated that lysozyme and dihydromyricetin particles could overlap and form a 3D network structure to stabilize the HIPEs, which was consistent with the microstructure observations.