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This study aims to investigate the effects of interfacial layer composition and structure on the formation, physicochemical properties and stability of Pickering emulsions. Interfacial layers were formed using pea protein isolate (PPI), PPI microgel particles (PPIMP), a mixture of PPIMP and sodium alginate (PPIMP-SA), or PPIMP-SA conjugate. The encapsulation and protective effects on different hydrophobic bioactives were then evaluated within these Pickering emulsions. The results demonstrated that the PPIMP-SA conjugate formed thick and robust interfacial layers around the oil droplet surfaces, which increased the resistance of the emulsion to coalescence, creaming, and environmental stresses, including heating, light exposure, and freezing-thawing cycle. Additionally, the emulsion stabilized by the PPIMP-SA conjugate significantly improved the photothermal stability of hydrophobic bioactives, retaining a higher percentage of their original content compared to those in non-encapsulated forms. Overall, the novel protein microgels and the conjugate developed in this study have great potential for improving the physicochemical stability of emulsified foods., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

For some food applications, it is desirable to control the flavor release profiles of volatile flavor compounds. In this study, the effects of crosslinking method and protein composition on the flavor release properties of emulsion-filled protein hydrogels were explored, using peppermint essential oil as a model volatile compound. Emulsion-filled protein gels with different properties were prepared using different crosslinking methods and gelatin concentrations. Flavor release from the emulsion gels was then monitored using an electronic nose, gas chromatography-mass spectrometry (GC-MS), and sensory evaluation. Enzyme-crosslinked gels had greater hardness and storage modulus than heat-crosslinked ones. The hardness and storage modulus of the gels increased with increasing gelatin concentration. For similar gel compositions, flavor release and sensory perception were faster from the heat-crosslinked gels than the enzyme-crosslinked ones. For the same crosslinking method, flavor release and perception decreased with increasing gelatin concentration, which was attributed to retardation of flavor diffusion through the hydrogel matrix. Overall, this study shows that the release of hydrophobic aromatic substances can be modulated by controlling the composition and crosslinking of protein hydrogels, which may be useful for certain food applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The application of many hydrophilic and hydrophobic nutraceuticals is limited by their poor solubility, chemical stability, and/or bioaccessibility. In this study, a novel Pickering high internal phase double emulsion co-stabilized by modified pea protein isolate (PPI) and sodium alginate (SA) was developed for the co-encapsulation of model hydrophilic (riboflavin) and hydrophobic (β-carotene) nutraceuticals. Initially, the effect of emulsifier type in the external water phase on emulsion formation and stability was examined, including commercial PPI (C-PPI), C-PPI-SA complex, homogenized and ultrasonicated PPI (HU-PPI), and HU-PPI-SA complex. The encapsulation and protective effects of these double emulsions on hydrophilic riboflavin and hydrophobic β-carotene were then evaluated. The results demonstrated that the thermal and storage stabilities of the double emulsion formulated from HU-PPI-SA were high, which was attributed to the formation of a thick biopolymer coating around the oil droplets, as well as thickening of the aqueous phase. Encapsulation significantly improved the photostability of the two nutraceuticals. The double emulsion formulated from HU-PPI-SA significantly improved the in vitro bioaccessibility of β-carotene, which was mainly attributed to inhibition of its chemical degradation under simulated acidic gastric conditions. The novel delivery system may therefore be used for the development of functional foods containing multiple nutraceuticals., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Lycopene is claimed to have numerous physiological benefits, but its poor water solubility, chemical instability, and low bioavailability limit its application in functional foods and health care products. In this study, lycopene-loaded emulsions containing oil droplets with different interfacial structures were prepared and then cross-linked using transglutaminase (TG) and/or calcium ions (Ca 2+ ) to form emulsion gels. The oil droplets were first coated by interfacial layers comprised of whey protein isolate (WPI) and sodium alginate (SA). During emulsion preparation, the SA was added either before or after homogenization to create complex or layer-by-layer coatings, respectively. Subsequently, TG and Ca 2+ were used to cross-link WPI and SA to form emulsion gels. The results show that double-crosslinking increased the gel strength and viscosity of the emulsion gels. The layer-by-layer emulsion gels were stronger and more viscous than the complex ones. The photochemical and gastrointestinal stability of lycopene encapsulated within the emulsion gels was higher than that of free lycopene. An MTT toxicity test showed that the emulsion gels exhibited no cytotoxicity to Caco-2 cells. The lycopene-loaded emulsion gels exhibited stronger anti-inflammatory activity on the Caco-2 cells than the control. In addition, the absorption of lycopene by the Caco-2 cells increased after encapsulation. This study provides a new approach of preparing edible soft materials to enhance the application of hydrophobic bioactives (like lycopene) in functional foods., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Astaxanthin (AST) has been shown to have neuroprotective effects; however, its bioavailability in vivo is low due to its hydrophobic properties. In this study, lactoferrin (LF) was prepared by heat-treatment at different temperatures, and on this basis, a layer-by-layer self-assembly method was used to construct double-layer emulsions with LF as the inner layer and polysaccharide (beet pectin, BP or carboxymethyl chitosan, CMCS) as the outer layer. Then AST was encapsulated in the emulsions and their physiochemical properties and function were investigated. The results indicated that high temperature heated LF (95 °C) showed a more stable structure than the lower temperature one, and the exposed internal nonpolar groups of LF could give the emulsion an enhanced stability. The rheology results showed that compared with CMCS, the double-layer emulsion formed by BP had a higher viscosity. In addition, the 95 °C LF-AST-BP emulsion showed the best stability among all the bilayer emulsions. The best emulsion was then used as a model drug to investigate its effects on lipopolysaccharide (LPS)-induced neuroinflammation and learning-memory loss in C57BL/6J mice. Through animal behavioral experiments, it was found that dietary supplementation with the AST emulsion could effectively improve the brain cognitive and learning memory impairment caused by inflammation. Transmission electron microscopy, mRNA and western blotting results also illustrated that the AST emulsion could alleviate neuroinflammation caused by LPS. This study provides a feasible scheme for exploring an AST loaded system and may be suitable for food and drug applications.

Proteins and polysaccharides are widely used as ingredients in food emulsions due to their high biocompatibility, good biodegradability, and a broad range of techno-functionalities. In particular, they are used as emulsifiers, texture modifiers, and stabilizers in many emulsion-based foods. Moreover, the functionality of these biopolymers can be extended by forming protein-polysaccharide complexes that can be used to modulate the characteristics of the oil-water interface, thereby altering the stability and performance of food emulsions. This review highlights a number of approaches to modulate the interfacial properties of oil-in-water emulsions based on the utilization of protein-polysaccharide complexes: direct mixing, layer-by-layer assembly, and conjugation. Besides, the impact of altering the interfacial properties on emulsion performance is highlighted, including their formation, stability, and functional attributes. Interfacial engineering approaches can be used to tailor the properties of food emulsions to particular applications. For instance, they can be used to create emulsion-based delivery systems for bioactive agents, such as vitamins, nutraceuticals, antimicrobials, colors, flavors, and antioxidants. Moreover, they can be used to create emulsion-based foods with lower calorie contents and enhanced satiety responses. Nevertheless, it is important to account for various factors when developing successful interfacial engineering technologies, including safety concerns, production costs, environmental impact, sustainability, government regulations, and labeling issues., (© 2020 Institute of Food Technologists®.)

The purpose of this study was to fabricate biopolymer conjugates from lactoferrin (LF) and hyaluronic acid (HA) and then to investigate their potential as emulsifiers for forming sesamol-loaded emulsions. Initially, LF-HA covalent conjugates were formed using the carbodiimide coupling method in aqueous solutions at pH = 4.5, and then the nature of the conjugates was investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy, and fluorescence spectroscopy. The results demonstrated the formation of an amide link between the amine groups of LF and the carboxyl groups of HA. Sesamol emulsions were prepared using the LF-HA conjugates as emulsifiers and their stability was determined. The conjugates improved both the physical and chemical stability of the emulsions during storage. Optimum stability of the emulsion was obtained at a LF-to-HA molar ratio of 2:1. Our results suggest that LF-HA conjugates may be effective emulsifiers for use in food stuffs and other applications.

BACKGROUND: Capsaicin, as a major pungent ingredient of peppers, has many health benefits. However, the strong irritation effect of capsaicin inhibits its application in the food industry. Emulsions can be an effective approach to alleviate the irritation. RESULTS: In this study, we used tocopheryl polyethylene glycol 1000 succinate (TPGS) as an emulsifier to prepare capsaicin emulsions through high‐pressure homogenization. Capsaicin emulsions with a particle size of about 100 nm, −36.4 mV zeta potential, and 91.9% encapsulation efficiency were prepared successfully and showed better environmental stability and higher antioxidant activity. Emulsions reduced the cumulative release of capsaicin and had no toxic effect on buffalo rat liver (BRL‐3A) cells. Moreover, the gastrointestinal injury model of rats showed that emulsions reduced the strong irritation of capsaicin. CONCLUSION: This work provides a theoretical basis for the application of irritant ingredients in food industry. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The 3D printing of foods has grown in interest recently due to its ability to create customized or personalized food products. This study focused on the creation of stable high internal phase Pickering emulsions (HIPPEs) for application as edible inks in 3D food printing. These concentrated oil-in-water emulsions were innovatively prepared using modified pea protein isolate (PPI) and sodium alginate (SA) complexes as stabilizers. Pea protein isolate was used in its commercial form (C-PPI) or in a high-pressure homogenized and ultrasonically modified form (HU-PPI). Four types of stabilizers were used to formulate the HIPPEs: C-PPI, HU-PPI, C-PPI-SA, and HU-PPI-SA. The particle size, microstructure, rheology, stability, and 3D printability of the resulting emulsions were characterized. HIPPEs formed using HU-PPI-SA complexes had the smallest particle diameters (<50 μm), as well as a more compact microstructure than those formed using the C-PPI-SA. Rheologically, the HU-PPI-SA stabilized HIPPEs had a higher storage modulus (500 Pa) and apparent shear viscosity (1000 mPa·s), which enhanced their 3D printability. Shapes printed with these emulsions maintained their structural integrity for up to 24 h, indicating the potential of HU-PPI-SA stabilized HIPPEs as edible inks for 3D food printing applications because of their enhanced stability, printability and rheological properties. This study provides new information that could facilitate the development of edible inks that combine good printability and nutritional value to achieve customized nutrition and efficient industrial food production. [Display omitted] • High internal phase Pickering emulsions (HIPPEs) were used as edible inks. • Modified pea protein enhanced the stability of the 3D printed edible inks. • Sodium alginate markedly improved the printability of the 3D printed edible inks. • Printing performance of HIPPE-based edible inks was improved using these biopolymers. [ABSTRACT FROM AUTHOR]

Globular proteins can form fibrillar structures, for example, by heating them above their thermal denaturation temperature under suitable pH (usually highly acidic) and ionic strength (usually relatively low) conditions. These fibrils can then be used as functional ingredients in foods. In this study, we investigated the potential of whey protein isolate fibrils (WPIFs) to act as stabilizers to create pH-responsive emulsions. Initially, changes in the properties of the WPIFs were measured when the system was changed from pH 2.5 to 10.0 and then back to pH 2.5. WPIF-based emulsions were then prepared and subjected to the same pH regime. For comparison, WPI-emulsions stabilized by the molecular form of native whey protein were subjected to the same treatment. The pH-dependence of the properties of the WPIF-emulsions was different from that of the WPI-ones. Insights into the molecular origin of these effects were obtained by measuring the interfacial properties, circular dichroism spectra, and surface hydrophobicities of the WPIFs and WPI. These results indicated the relative importance of electrostatic, hydrogen bonding, and hydrophobic interactions at the oil-water interface and/or continuous phase in stabilizing the emulsions. WPIF-emulsions were more resistant to coalescence than WPI-emulsions, which was attributed to the formation of a more robust interfacial coating around the oil droplets and a strong viscoelastic network in the aqueous phase. This research shows that the functional performance of food proteins can be extended by creating fibril structures. [Display omitted] • Whey protein isolate fibrils (WPIFs) were formed by controlled heating. • The morphology and aggregation state of the WPIFs depended on pH. • WPIF-emulsions exhibited pH-responsive behavior. • WPIF-emulsions were more resistant to coalescence than WPI-emulsions. [ABSTRACT FROM AUTHOR]

Protein complexes have great potential for forming and stabilizing high internal phase emulsions (HIPEs) loaded with bioactive compounds. In this study, we investigated the potential of three types of complexes, namely pea protein isolate (PPI), PPI-epigallocatechin gallate (EGCG) and PPI-EGCG-Fe3+, to form and stabilize HIPEs with a 75% oil phase volume fraction. Initially, the impact of pH and emulsifier type on emulsions performance was investigated. Confocal laser scanning microscopy (CLSM) and particle size analysis showed that all three complexes could form HIPEs that remained stable under acidic and neutral conditions. These emulsions contained uniform oil droplets coated by a layer of the complexes. Notably, the PPI-EGCG-Fe3+ complexes formed HIPEs with the highest thermal and storage stability, which was attributed to the denser and thicker interfacial coatings. These emulsions also protected encapsulated β-carotene from degradation when exposed to light and thermal stress conditions. Furthermore, we measured lipid digestion and β-carotene bioaccessibility in the emulsions using an in vitro digestion model. The PPI-EGCG-Fe3+ stabilized emulsions not only exhibited slow fatty acid release but also enhanced β-carotene bioaccessibility (46.5%) under simulated small intestine conditions. This study demonstrates the potential of using protein-polyphenol-Fe3+ complexes to form and stabilize HIPEs, which may then be used to enhance the bioaccessibility and bioactivity of hydrophobic nutraceuticals. [Display omitted] • Ternary complexes were assembled from pea protein isolate (PPI), EGCG and iron. • These complexes were utilized to stabilize high internal phase emulsions (HIPEs). • The PPI-EGCG-Fe3+ complexes enhanced thermal and storage stability of HIPEs. • Encapsulation of β-carotene in HIPEs improved its stability and bioaccessibility. [ABSTRACT FROM AUTHOR]

Pickering emulsions prepared using food-grade colloidal particles can be designed to have high physical stability, tunable textural attributes, and good loading/release properties. Protein-based colloidal particles are particularly suitable for this purpose because they are widely available, inexpensive, have good emulsifying properties, and nutritional benefits. This paper reviews the stabilization mechanisms of Pickering emulsions, then summarizes the preparation, properties, and applications of protein-stabilized Pickering emulsions, focusing on protein nanoparticles, microgels, and fibrils. The challenges of utilizing protein-based Pickering emulsions in the food industry are also discussed. At present, there are three main types of mechanisms responsible for stabilizing Pickering emulsion using proteins: (i) formation of a solid particle coating at the interface; (ii) formation of a three-dimensional viscoelastic particle network in the continuous phase; (iii) depletion stabilization. Each of these mechanisms has its own advantages and disadvantages, and selecting the most appropriate one (or combination) depends on the application requirements of the Pickering emulsion. Currently, the most common applications of protein-stabilized Pickering emulsions in the food industry are: formulation of spread-like products (like margarine); encapsulation of bioactive components; and, protection of lipids against oxidation. Image 1 • Stabilization mechanisms of Pickering emulsion and the impact factors were summarized. • Several methods to improve the stability of protein-based Pickering emulsions were proposed. • Different configurational proteins particles stabilized Pickering emulsions were highlighted. • The application of protein-based Pickering emulsions in food was discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • A water-in-oleic acid-in-water multiple emulsion was successfully formulated. • The emulsion was stabilized by phosphatidylcholines and PPI-saccharide conjugates. • The phosphatidylcholine concentration was crucial for emulsion stability. • The conjugate enhanced the co-delivery efficiency of bioactive ingredients. Hydrophobic β-carotene and hydrophilic riboflavin offer a wide range of health benefits, but their limited stability and bioaccessibility pose challenges to their use in the food industry. This study developed a water-in-oleic acid-in-water (W/OA/W) emulsion. The effects of internal/external water phase emulsifiers were investigated on their microstructure, encapsulation efficiency, and stability. Only 0.05 wt% soybean-derived phosphatidylcholine was required as a lipophilic emulsifier to produce W/OA/W emulsions that can encapsulate both hydrophobic β-carotene and hydrophilic riboflavin. Compared to the commercial pea protein isolate (PPI), the PPI-xylooligosaccharide conjugate demonstrated superior performance as hydrophilic emulsifiers in stabilizing W/OA/W emulsions. The W/OA/W emulsion co-delivery system improved the thermal stability, light stability, and bioaccessibility of β-carotene, as well as the light stability of riboflavin. Overall, the W/OA/W emulsion holds great promise for application in natural food and for co-delivering hydrophobic and hydrophilic bioactive ingredients. [ABSTRACT FROM AUTHOR]

High internal phase Pickering emulsions (HIPPEs) stabilized by protein nanoparticles have been widely reported, but the use of enzymatic methods for preparing these nanoparticles remains underexplored. Our hypothesis is that enzymatically crosslinked α-lactalbumin (ALA) nanoparticles (ALATGs) prepared using transglutaminase will demonstrate improved properties as stabilizers for HIPPEs. In this study, we investigated the physicochemical properties and microstructures of ALATGs, finding that enzymatic crosslinking could be enhanced by removing Ca2+ ions from ALA and preheating the proteins (85 °C, 15 min). The electrical charge, secondary structure, and surface hydrophobicity of ALATGs were found to depend on crosslinking conditions. HIPPEs formed with an ALA concentration of 10 mg/mL and an enzyme activity of 120 U/g exhibited the highest apparent viscosity and mechanical strength, as well as significantly improved loading capacity and photostability for the encapsulated lycopene. Overall, our results support the hypothesis that ALATG-nanoparticles show superior performance as emulsifiers compared to ALA-nanoparticles. [ABSTRACT FROM AUTHOR]

High internal phase emulsions (HIPEs) are soft materials that can be designed to contain nutrients and active agents. As a result, they are being explored for their potential application as edible inks in 3D food printing applications. However, the rheological characteristics of HIPEs are often unsuitable for this purpose, resulting in unsatisfactory precision and resolution performance during 3D printing. This study aims to overcome these problems by creating HIPEs with improved rheological properties by using pea protein-inulin glycosylation products as plant-based emulsifiers. These conjugates were prepared from pea protein isolate (PPI) and inulin by glycosylation using a combined ultrasound/pH-shift method. The oil phase of these emulsions consists of omega-3 rich algal oil and lemon oil. We showed that stable HIPEs could be formed at an oil phase content of 80%. At this oil content, the oil droplets were uniform and stable, and the emulsions exhibited higher storage modulus. Compared to PPI alone or physical mixture of PPI and inulin, PPI-inulin conjugates formed oil droplets with smaller diameters and better uniformity, as well as thicker and denser biopolymer coatings. Compared with protein alone, the rheological analysis demonstrated that the HIPEs formulated with PPI-inulin conjugates had a higher viscosity, higher elasticity, higher recovery rate, and better thixotropy, indicating that they had physiochemical characteristics suitable for edible inks applications. This was confirmed by using the HIPEs as edible inks to 3D print model food objects. In conclusion, the pea protein-inulin conjugates fabricated in this study can be used as plant-based emulsifiers to form edible inks based on HIPEs. In principle, a range of nutrients and other bioactive agents could be incorporated into these inks for personalized nutrition applications. [Display omitted] • Conjugates were prepared from pea protein isolate (PPI and inulin). • These conjugates were used to form and stabilize high internal phase emulsions (HIPEs). • The conjugates formed thicker and denser coatings around the oil droplets than protein alone. • The rheological properties of the HIPEs could be manipulated by introducing inulin into the system. • PPI-inulin conjugates improved the accuracy and stability of 3D printed objects formed from HIPEs. [ABSTRACT FROM AUTHOR]

Background Lactoferrin (LF) is an iron-binding glycoprotein that exhibits a variety of potentially beneficial biological activities and has favorable safety and biocompatibility characteristics. For these reasons, LF has been widely used as a functional component in the medical, food, and cosmetic industries. Applications of LF-based materials, such as complexes, nanoparticles, hydrogels and emulsions, to encapsulate, protect and deliver bioactive compounds is gaining increasing attention. Scope and approach This review highlights the considerable potential of LF-based encapsulation and delivery systems by summarizing research progress on the structure, physicochemical properties, and biological activities of LF. In particular, it highlights advances in utilizing LF-based nanocarriers as natural vehicles for nutraceutical delivery and release, as well as strategies for encapsulating LF as a functional ingredient. Key findings and conclusions Functional LF-biopolymer complexes can be formed by heat treatment, covalent conjugation or electrostatic assembly under appropriate fabrication conditions. These complexes have been shown to be highly effective for the oral delivery of nutraceuticals and drugs. LF can also be utilized to fabricate emulsions, nanoparticles, or microgels to improve the stability and bioaccessibility of bioactive components. However, there are still a number of challenges associated with optimizing the performance of LF-based delivery systems so that they can be used in commercial applications. [ABSTRACT FROM AUTHOR]

• Water-in-oil-in-water (W/O/W) emulsions were used to encapsulate probiotics. • Stable W/O/W emulsions were formed using soy protein-alginate as an emulsifier. • Fish oil improved probiotic survival and adhesion in a simulated digestive tract. • W/O/W emulsions may protect probiotics in the human gastrointestinal tract. Aqueous probiotic suspensions were dispersed in an oil phase consisting of fish oil and medium chain triglycerides to form W 1 /O emulsions. These emulsions were then homogenized with an aqueous solution containing soybean protein isolate and sodium alginate to form W 1 /O/W 2 emulsions. Fish oil was used to promote the growth of the probiotics and increase their ability to adhere to the intestinal mucosa. Sodium alginate increased the viscosity, stability, and probiotic encapsulation efficiency of the double emulsions, which was mainly attributed to its interactions with adsorbed soy proteins. The encapsulation efficiency of the probiotics in the double emulsions was relatively high (>96%). In vitro simulated digestion experiments showed that the double emulsions significantly increased the number of viable probiotics remaining after passing through the entire gastrointestinal tract. This study suggests that encapsulation of probiotics in double emulsions may increase their viability under gastrointestinal conditions, thereby enhancing their efficacy in functional foods. [ABSTRACT FROM AUTHOR]

Hydrophobic curcumin and hydrophilic epigallocatechin gallate (EGCG) are reported to exhibit a variety of biological activities and may exhibit synergistic effects when used in combination. A co-encapsulation system was developed to improve their applicability and bioavailability. This delivery system consisted of a water-in-oil-in-water (W 1 /O/W 2) double emulsion stabilized by whey protein isolate fibrils (WPIFs) and cellulose nanocrystals (CNCs). Double emulsions were fabricated using a two-step emulsification method using either WPIF-CNC complexes or WPIF alone. The physicochemical stability, encapsulation performance, and digestive properties of the delivery systems were then investigated. The double emulsions stabilized by the WPIF-CNC complexes were more resistant to heat and salt stress, exhibited greater encapsulation stability, and had a higher bioaccessibility for curcumin (67.8%) and EGCG (68.9%) than those stabilized by WPIFs. This research shows that the stability and bioaccessibility of curcumin and EGCG can be enhanced by co-encapsulating them in emulsion-based delivery systems using nanostructured protein-polysaccharide complexes. [Display omitted] • Double emulsions (DEs) were prepared using whey protein fibril-cellulose (WPIF-CNC) complexes. • WPIF-CNC DEs were more resistant to heat and salt stress than WPIF-ones. • WPIF-CNC DEs efficiently co-encapsulated curcumin and EGCG. • The bioaccessibility of curcumin and EGCG was improved. [ABSTRACT FROM AUTHOR]

Edible proteins can self-assemble into fibrils, which can improve their performance as emulsifiers. However, they are limited in some food applications. We prepared whey protein isolate fibril-cellulose nanocrystal complexes (WPIF-CNC) by electrostatic complexation. The stabilities of emulsions prepared using either WPIF or WPIF-CNC were compared to evaluate the effect of complexation on emulsion formation and properties. Moreover, the potential of the emulsions to act as delivery systems for curcumin was investigated. WPIF and CNC were found to complex by hydrogen bonding, hydrophobic, and electrostatic interactions. The complexes formed were good Pickering stabilizers in oil-in-water emulsions. Emulsions formulated using the complexes were more resistant to creaming than those stabilized by WPIF. The complexes were able to form self-supporting gelled emulsions at 70 % oil concentration, which protected curcumin from photo- and thermal-degradation. Consequently, dual-fibrous complexes may have application in the food industry as novel emulsifiers for the creation of nutraceutical delivery systems. [Display omitted] • Whey protein isolate fibril-cellulose nanocrystal (WPIF-CNC) complexes were prepared. • WPIF-CNC complexes were used as Pickering emulsifiers. • WPIF-CNC emulsions were more resistant to coalescence than WPIF emulsions. • WPIF-CNC emulsions protected curcumin from UV-light and heat degradation. [ABSTRACT FROM AUTHOR]

This study investigated the effects of different interfacial structures on the performance of oil-in-water emulsions including their physicochemical stability, lipid digestion profiles, and nutraceutical bioaccessibilities. Emulsions containing oil droplets coated by lactoferrin (LF) and/or hyaluronic acid (HA) were prepared with different structural organizations: (i) LF only; (ii) LF + HA mixtures; (iii) LF + HA bilayers; and (iv) LF-HA covalent conjugates. The bilayers were formed by depositing HA onto LF-coated lipid droplets after homogenization, while the conjugates were formed by covalent attachment of HA to LF before homogenization. The interfacial pressure, adsorption kinetics, interfacial thickness, and surface load were characterized. The physicochemical properties and stability of the four types of emulsions were also measured and compared. The covalent attachment of HA to LF reduced the surface activity of the protein, which was attributed to a reduction in diffusion rate and surface hydrophobicity. The emulsifying activity and emulsion stability index of the LF were enhanced, and the salt stability and freeze-thaw stability of LF-stabilized emulsion were improved when HA was covalently attached to it. This effect was attributed to the formation of a relatively thick (161 nm) and strongly charged (−45.8 mV) interfacial layer that increased the steric and electrostatic repulsion between the oil droplets. Emulsions with mixed, bilayer, or conjugated LF-HA interfaces gave better photostability and bioaccessibility of two encapsulated nutraceuticals (curcumin and resveratrol) than LF interfaces. Overall, however, the LF-HA conjugates were the most effective at improving the performance of the emulsions. These results suggest that interfacial engineering technologies can be utilized to enhance the performance of emulsions. [Display omitted] • Lactoferrin (LF) and hyaluronic acid (HA) were selected to construct different interfacial structures of O/W emulsions. • LF-HA mixture promoted LF to reduce the interfacial tension while the LF-HA conjugate had a lower diffusion rate. • Oil droplets coated by the conjugate were more stable to environmental stresses. • Emulsions with LF and HA interfaces gave better photostability and bioaccessibility of curcumin and resveratrol. [ABSTRACT FROM AUTHOR]

[Display omitted] • Lactoferrin (LF) − EGCG conjugates were prepared using an ultrasound-assisted method. • The antioxidant properties of the conjugates were better than that of pure LF. • The conjugates were used to stabilize algae oil-in-water emulsions. • The oxidative stability of the emulsions was enhanced using the conjugates. The aim of this study was to prepare lactoferrin-epigallocatechin-3-gallate (LF–EGCG) conjugates and to determine their ability to protect emulsified algal oil against aggregation and oxidation. LF–EGCG conjugates were formed using an ultrasound-assisted alkaline treatment. The ultrasonic treatment significantly improved the grafting efficiency of LF and EGCG and shortened the reaction time from 24 h to 40 min. Fourier transform infrared spectroscopy and circular dichroism spectroscopy analyses showed that the covalent/non-covalent complexes could be formed between LF and EGCG, with the C O and C N groups playing an important role. The formation of the conjugates reduced the α-helix content and increased the random coil content of the LF. Moreover, the antioxidant activity of LF was significantly enhanced after conjugation with EGCG. LF–EGCG conjugates as emulsifiers were better at inhibiting oil droplet aggregation and oxidation than LF alone. This study demonstrates that ultrasound-assisted formation of protein–polyphenol conjugates can enhance the functional properties of the proteins, thereby extending their application as functional ingredients in nutritionally fortified foods. [ABSTRACT FROM AUTHOR]

The processing instability and strong pungent smell limit the use of allicin. To overcome these shortcomings, emulsion gels loaded with allicin were constructed using soybean protein isolate (SPI) and gum Arabic (GA) through ultrasound treatment and transglutaminase (TG) induction. The effect of ultrasonic modification and GA concentration on the physical properties of emulsion gels was investigated, and the protective effect of emulsion gel on allicin was evaluated. The results showed that ultrasonic pretreatment of SPI can significantly improve the water holding capacity, hardness, viscosity, and elasticity modulus of emulsion gels, forming denser homogeneous network structure, and these properties were best when GA concentration was 0.3%. In the process of gel formation, ultrasound can change the spatial structure of protein, the introduction of polysaccharide can enhance the hydrogen bond between molecules, and TG can promote the intramolecular crosslinking, the three worked together to form a gel network. The encapsulation efficiency of the ultrasonic SPI-GA emulsion gel can reach 70.84%, while it was only 26.63% for the SPI emulsion gel. The degradation of allicin was inhibited under strong light and high temperature. This study provides a new idea for the development of functional food rich in allicin. [Display omitted] • A new allicin delivering method by emulsion gels was designed. • Emulsion gels were prepared by transglutaminase induction. • The formation mechanism of the emulsion gels was explored. • The emulsion gels effectively protect allicin against degradation. [ABSTRACT FROM AUTHOR]

• Native and heated lactoferrin were complexed with carboxymethyl chitosan. • The two different complexes could stabilize the high internal phase emulsions (HIPEs). • The two HIPEs had different structures and stabilization mechanisms. • The HIPEs could deliver curcumin and improve its photo-stability. While the high internal phase emulsions (HIPEs) have been formed by food-grade biopolymers and granules have been widely reported, it is not known which components are more effective. In this work, we first used heat-treated lactoferrin (LF)-carboxymethyl chitosan (CMCTS) granules and native LF-CMCTS physical mixtures as emulsifiers to form HIPEs. The results showed that the interfacial behavior and emulsifying properties of the two complexes were controlled by the ratio of LF-CMCTS and the optimal ratio of LF to CMCTS was 1:1. Heated LF-CMCTS granules anchored to the water–oil interface and formed an elastic shell to stabilize HIPEs, while unheated LF-CMCTS complexes formed a thick film layer to stabilize HIPEs. Both HIPEs could act as delivery systems loaded with curcumin, and they showed better protection of curcumin than Tween-80 under light. This study provides a new basis for the design of LF-based HIPEs systems loaded with lipophilic food functional ingredients. [ABSTRACT FROM AUTHOR]

Organic particles are increasingly being utilized instead of inorganic ones to form and stabilize Pickering emulsions for food applications. In particular, polysaccharide-based particles are being used for this purpose because they can be assembled from low-cost, abundant, and sustainable ingredients. However, the functional performance of individual natural polysaccharides is often limited. Consequently, there has been interest in extending their performance by using physical or chemical modification methods. In this paper, we review recent advances in using natural polysaccharides, modified polysaccharides, and polysaccharide complexes as particles to form and stabilize Pickering emulsions. In particular, we focus on the impact of particle properties, emulsion composition, and environmental conditions (pH, ionic strength, and temperature) on the stabilization and properties of polysaccharide-based Pickering emulsions. In addition, we examine a number of potential applications of these emulsions: to encapsulate and deliver bioactive ingredients; to control the digestion of emulsified lipids; and, to create fat substitutes. [Display omitted] • Modified polysaccharides can effectively stabilize Pickering emulsions. • Polysaccharide complexes can form and stabilize Pickering emulsions. • Polysaccharide-based Pickering emulsions have good environmental tolerance. • The emulsions are good encapsulation carriers and healthy food ingredients. [ABSTRACT FROM AUTHOR]

In this study, a double-cross-linked emulsion gel was formed using a Pickering emulsion as a template and two food-grade biopolymers, zein and sodium alginate (SA), as gelling agents. First, the zein was crosslinked with transglutaminase (TG) and then the alginate was crosslinked with calcium ions. The structure, interactions, and functional properties of the composite systems were then characterized using microscopy, infrared spectroscopy, and rheology measurements. These methods provided valuable insights into the formation mechanism of the double-cross-linked emulsion gels. The effects of single/double cross-linked emulsion gels on the photostability and bioaccessibility of co-loaded polyphenols (curcumin and resveratrol) were also compared. Our results show that SA concentration and TG activity impact emulsion gels stability and rheology. Single-cross-linked emulsion gels could be formed by only crosslinking SA (0.5 wt%) with calcium ions, but not by only crosslinking zein with TG. Double-cross-linked emulsion gels with dense network microstructures and high viscoelasticity were formed by using 60 U/g TG and 1.25 mM Ca2+ to crosslink the protein and polysaccharide, respectively. The single cross-linked emulsion gels improved the light stability and bioaccessibility of the two polyphenols, with the Ca2+-crosslinked system being more effective than the TG-crosslinked one. The double-cross-linked emulsion gels gave higher light stability and bioaccessibility than the single-cross-linked ones. Overall, this study shows that using a combination of TG and Ca2+ to crosslink the two biopolymers leads to edible composite materials with improved functional performance. Image 1 • Zein nanoparticles and/or alginate in Pickering emulsions were crosslinked. • Crosslinking performed using transglutaminase (zein) and calcium (alginate). • Emulsion gels were formed using calcium or calcium and transglutaminase. • Double crosslinking increased nutraceutical stability and bioaccessibility. [ABSTRACT FROM AUTHOR]

This article focused on the formation, physicochemical properties, and functionality of whey protein isolate (WPI) emulsion gels induced by crosslinking with transglutaminase and/or Ca2+ ions. The emulsion gels were fabricated using the combination of high-energy homogenization and cold-gelation. The microstructure, rheology and processing characteristics of the emulsion gels were then evaluated. Cross-linking with transglutaminase led to the formation of emulsion gels containing small particle aggregates, whereas cross-linking with Ca2+ led to the formation of larger particle aggregates. As expected, the apparent viscosity, strength, water holding capacity and hardness of the emulsion gels increased after crosslinking, especially when transglutaminase and Ca2+ ions were added together. Moreover, WPI hydrogels had higher gel strength in the presence of oil droplets than in their absence, suggesting that the droplets reinforced the gel structure. FTIR confirmed that the crosslinking agents promoted the aggregation of the proteins, thus forming an emulsion gel network. The results of this study may facilitate the design of new food materials with novel or improved textural and sensory characteristics. Image 1 • WPI hydrogel and emulsion gel were prepared by homogenization and cold-gelation. • Double crosslinkers promoted the aggregation of the proteins to form emulsion gel networks. • Emulsion gel exhibited a stronger gel network structure than hydrogel. • Emulsion gel with transglutaminase and calcium ions led to improved functional attributes. [ABSTRACT FROM AUTHOR]