Pickering emulsion gels stabilized by novel complex particles of high-pressure-induced WPI gel and chitosan: Fabrication, characterization and encapsulation

Encapsulation of lycopene in Pickering emulsion stabilized by complexes of whey protein isolate fibrils and sodium alginate: Physicochemical property, structural characterization and in vitro digestion property

In present study, whey protein isolate fibrils and sodium alginate complexes (WPIFs-SA) were prepared and further used to stabilize Pickering emulsions for lycopene delivery. The optimal interaction between WPIFs and SA occurred at pH 3.0, with a mass ratio of 2:1. Increasing the oil fractions and the content of WPIFs-SA complexes significantly improved Pickering emulsions' stability, concurrently reducing droplet size and increasing viscoelasticity. Meanwhile, it facilitated the formation of a thicker protective layer and a compact network structure around the oil droplets, offering better protection for lycopene against thermal and photo degradation. In vitro digestion studies revealed that as the oil fractions and complex contents increased, the lipolysis degree decreased. The engineered WPIFs-SA Pickering emulsion could be used as an innovative delivery system for the protection and delivery of lycopene.

Soy protein isolate-xanthan gum complexes to stabilize Pickering emulsions for quercetin delivery

This study aimed to prepare soy protein isolate-xanthan gum complexes (SPI-XG) at pH 7.0 and as emulsifiers to prepare Pickering emulsions for delivering quercetin (Que). The results showed that SPI-XG exhibited a gel network structure in which protein particles were embedded. Fourier transform infrared spectroscopy (FTIR) and molecular docking elucidated that SPI-XG formed through hydrogen bonding, hydrophobic, and electrostatic interactions. Three-phase contact angle (θo/w) of SPI-XG approached 90° with biphasic wettability. SPI-XG adsorbed at the oil-water interface to form an interfacial layer with a gel network structure, which prevented droplet aggregation. Following in vitro simulated digestion, Que displayed higher bioaccessibility in SPI-XG stabilized Pickering emulsions (SPI-XG PEs) than SPI stabilized Pickering emulsions. In conclusion, SPI-XG PEs were a promising system for Que delivery.

Antioxidant amyloid fibril derived from rice protein hydrolysate as stabilizer towards preparing high-stable emulsion

An antioxidant amyloid fibril was prepared as an emulsifier by fibrillating limited enzymatic hydrolysis-modified rice protein (HRP). The purpose of this study was to investigate the feasibility of using fibrillated HRP to stabilize oil-in-water emulsion. A free radical scavenging assay revealed that the antioxidant activity of fibrillated HRP was 2.09 times higher than that of native rice protein. Fibrillated HRP demonstrated a marked reduction in interfacial tension, increased surface hydrophobicity and contact angle (> 80°), and rapid adsorption to the interface, with 35.34 ± 2.43% interfacial adsorbed protein content. The fibrillated HRP barriers resisted environment stresses such as NaCl, pH variations, long-term storage, while reducing lipid oxidation degree. Additionally, fibrillated HRP-based emulsion was more effective in protecting β-carotene from degradation compared to other samples. These findings provide theoretical support for the development of rice protein-based antioxidant emulsifiers and modification of emulsifying properties of plant proteins.

The double-layer emulsions loaded with bitter melon (Momordica charantia L.) seed oil protect against dextran sulfate sodium-induced ulcerative colitis in mice

In this study, a whey protein isolate (WPI)-chitooligosaccharide (COS) stabilized bitter melon (Momordica charantia L.) seed oil emulsions (WC-BSOE) were prepared using the electrostatic layer-by-layer self-assembly technique, and their modulating effects on ulcerative colitis (UC) were investigated in dextran sulfate sodium (DSS)-induced UC mice model. The stability and releasing ability of WC-BSOE under simulated gastrointestinal digestion condition and their acute toxicity were also investigated. The results showed that WC-BSOE was stable to droplet aggregation in the simulated gastric and intestinal fluids and exhibited sustained release profile during gastrointestinal transit, evidenced by the measurement of particle size, polydispersity index, zeta-potential and released free fatty acids contents. Moreover, WC-BSOE had no toxic effects on BALB/c mice within the dose range of 40,000 mg/kg body weight (BW), and treatment with WC-BSOE at a dosage of 15 mg/kg BW effectively relieved DSS-induced UC symptoms in mice. Furthermore, WC-BSOE could improve the IL-4 and IgA contents in serum, as well as up-regulate the occludin and ZO-1 expressions and down-regulate MPO, MDA and ROS levels in colon tissues of colitis mice, and it also elevated the diversity and relative abundances of Firmicutes, Bacteroides, and Lactobacillus in the intestinal microbiota. These findings indicated that WC-BSOE exerted protective effects in UC through decreasing proinflammatory cytokines, increasing tight junction proteins, suppressing oxidative stress, and regulating intestinal microbiota. Collectively, this study suggested WC-BSOE might be developed as a promising dietary supplement for UC protection.

Improved light and ultraviolet stability of curcumin encapsulated in emulsion gels prepared with corn starch, OSA-starch and whey protein isolate

The objective of this study was to enhance the bioavailability and stability of curcumin (Cur) by encapsulating it in corn starch (CS)/octenylsuccinic acid modified (OSA)-starch-whey protein isolate (WPI) emulsion gels (EGs). As the volume fraction of the oil phase increased, the droplet size and ζ- potential of the EGs decreased. The encapsulation efficiency and bioavailability of Cur in CS/OSA-starch-WPI EGs with a 60% oil ratio were 96.0% and 67.3%, respectively. The release rate of free fatty acid and the bioavailability of Cur from the EGs after digestion were significantly higher compared to Cur dissolved in oil. EGs with an oil phase volume fraction of 75% and 80% demonstrated greater protection against light irradiation but were less effective against UV irradiation compared to EGs with a 60% oil phase volume fraction. Encapsulation in EGs proved to be an effective method for enhancing the bioavailability and stability of Cur.

Novel Pickering bigels stabilized by whey protein microgels: Interfacial properties, oral sensation and gastrointestinal digestive profiles

In the ongoing quest to formulate sensory-rich, low-fat products that maintain structural integrity, this work investigated the potential of bigels, especially those created using innovative Pickering techniques. By harnessing the unique properties of whey protein isolate (WPI) and whey protein microgel (WPM) as interfacial stabilizers, WPM-based Pickering bigels exhibited a remarkable particle localization at the interface due to specific intermolecular interactions. The rise in protein concentration not only intensified particle coverage and interface stabilization but also amplified attributes like storage modulus, yield stress, and adhesiveness, owing to enhanced intermolecular forces and a compact gel matrix. Impressively, WPM-based Pickering bigels outshone in practical applications, showcasing exceptional oil retention during freeze-thaw cycles and extended flavor release-a promising indication for frozen food product applications. Furthermore, these bigels underwent a sensory evolution from a lubricious texture at lower concentrations to a stable plateau at higher ones, offering an enriched consumer experience. In a comparative digestibility assessment, WPM-based Pickering bigels demonstrated superior prowess in decelerating the release of free fatty acids, indicating slowed lipid digestion. This study demonstrates the potential to fine-tune oral sensations and digestive profiles in bigels by modulating Pickering particle concentrations.

Construction of emulsion gel based on the interaction of anionic polysaccharide and soy protein isolate: Focusing on structural, emulsification and functional properties

In this study, the effects on the structures and emulsion gels of carrageenan (CA) and gum arabic (GA) with soybean protein isolate (SPI) were investigated. The results showed that CA and GA exposed hydrophobic groups to SPI, and formed complexes through non-covalent interactions to improve the stability of the complexes. Furthermore, the emulsion gels based on the emulsions exhibited that CA formed emulsion-filled gels with higher elasticity, stronger gel strength, and thermal reversibility, whereas GA formed emulsion-aggregated gels with higher viscosity, and a weak-gel network. The results of digestion showed that, CA was more helpful to slow down the release of free fatty acids and protect vitamin E during digestion. Compared with SPI-GA emulsion gel, SPI-CA emulsion gel had better physicochemical properties and stronger network structure. The results of this study may be useful in the development of anionic polysaccharides that interact with SPI, and they may provide new insights on the preparation of emulsion gels that slowly release fat-soluble nutrients.

Insight into oil-water interfacial adsorption of protein particles towards regulating Pickering emulsions: A review

Over the past decade, Pickering emulsions (PEs) stabilized by protein particles have been the focus of researches. The characteristics of protein particles at the oil-water interface are crucial for stabilizing PEs. The unique adsorption behaviors of protein particles and various modification methods enable oil-water interface to exhibit controllable regulation strategies. However, from the perspective of the interface, studies on the regulation of PEs by the adsorption behaviors of protein particles at oil-water interface are limited. Therefore, this review provides an in-depth study on oil-water interfacial adsorption of protein particles and their regulation on PEs. Specifically, the formation of interfacial layer and effects of their interfacial characteristics on PEs stabilized by protein particles are elaborated. Particularly, complicated behaviors, including adsorption, arrangement and deformation of protein particles at the oil-water interface are the premise of affecting the formation of interfacial layer. Moreover, the particle size, surface charge, shape and wettability greatly affect interfacial adsorption behaviors of protein particles. Importantly, stabilities of protein particles-based PEs also depend on properties of interfacial layers, including interfacial layer thickness and interfacial rheology. This review provides useful insights for the development of PEs stabilized by protein particles based on interfacial design.

Nutraceutical delivery systems to improve the bioaccessibility and bioavailability of lycopene: A review

Lycopene is a promising biological functional component with various biological activities and excellent pharmacological activities. However, its low water solubility and stability lead to low oral bioavailability, which limits its edible and medicinal research. Then, it is necessary to explore effective methods to protect lycopene from destruction and further exploit its potential benefits. The absorption of lycopene in vivo is affected by solubility, stability, isomer type, emulsifying ability, difficulty in forming micelles in vivo, and interaction with food components. Emulsions, pickering emulsions, micelles, liposomes, bigels, beasds, solid dispersions, microcapsules, nanoparticles, electrospinning and other drug delivery systems can be used as good strategies to improve the stability and bioavailability of lycopene. In this paper, the absorption process of lycopene in vivo and the factors affecting its bioavailability were discussed, and the preparation strategies for improving the stability, bioavailability, and health benefits of lycopene were reviewed, to provide some clues and references for the full utilization of lycopene in the field of health. However, there are still various unresolved mysteries regarding the metabolism of lycopene. The safety and in vivo studies of various preparations should be further explored, and the above technologies also face the challenge of industrial production.

Transforming Medicinal Oil into Advanced Gel: An Update on Advancements

The present study delves into the evolution of traditional Ayurvedic oil preparations through innovative strategies to develop advanced gel formulations, aiming at amplifying their therapeutic efficacy. Ayurvedic oils have a rich historical context in healing practices, yet their conversion into contemporary gel-based formulations represents a revolutionary approach to augment their medicinal potential. The primary objective of this transformation is to leverage scientific advancements and modern pharmaceutical techniques to enhance the application, absorption, and overall therapeutic impact of these traditional remedies. By encapsulating the essential constituents of Ayurvedic oils within gel matrices, these novel strategies endeavor to improve their stability, bioavailability, and targeted delivery mechanisms. This review highlights the fusion of traditional Ayurvedic wisdom with cutting-edge pharmaceutical technology, paving the way for more effective and accessible utilization of these revered remedies in modern healthcare.

Design, characterization and digestibility of β-carotene-loaded emulsion system stabilized by whey protein with chitosan and potato starch addition

The physicochemical properties and gastrointestinal fate of β-carotene-loaded emulsions and emulsion gels were examined. The emulsion was emulsified by whey protein isolate and incorporated with chitosan, then the emulsion gels were produced by gelatinizing potato starch in the aqueous phase. The rheology properties, water distribution, and microstructure of emulsions and emulsion gels were modulated by chitosan combination. A standardized INFOGEST method was employed to track the gastrointestinal fate of emulsion systems. Significant changes in droplet size, zeta-potential, and aggregation state were detected during in vitro digestion, including simulated oral, stomach, and small intestine phases. The presence of chitosan led to a significantly reduced free fatty acids release in emulsion, whereas a slightly increasing released amount in the emulsion gel. β-carotene bioaccessibility was significantly improved by hydrogel formation and chitosan addition. These results could be used to formulate advanced emulsion systems to improve the gastrointestinal fate of hydrophobic nutraceuticals.

The evaluation of mixed-layer emulsions stabilized by myofibrillar protein-chitosan complex for delivering astaxanthin: Fabrication, characterization, stability and in vitro digestibility

Muscle protein based functional foods have been attracted great interests in novel food designing. Herein, myofibrillar protein (MP)-chitosan (CH) electrostatic complexes were employed to fabricate mixed-layer emulsions to protect and deliver astaxanthin. The MP/CH complex fabricated mixed-layer emulsions displayed higher stability against pH and temperature changes, exhibiting smaller droplet and homogenous distributions. After UV-light irradiation for 8 h, the mixed-layer emulsions had higher astaxanthin retention (69.11 %, 1:1 group). During storage, a lower degree of lipid oxidation, protein oxidation and higher astaxanthin retention were obtained, indicating desirable protections of mixed-layer emulsions. The vitro digestion reveled the mixed-layer emulsions could decrease the release of free fatty acids. Meanwhile, the bioaccessibility of astaxanthin was higher (30.43 %, 2:1 group) than monolayer emulsion. In all, the MP/CH prepared mixed-layer emulsions could protect and deliver fat-soluble bioactive compounds, and contributed to develop muscle protein based functional foods to meet the needs of slow and controlled release.

Preparation and Characterization of Fish Oil Pickering Emulsions Stabilized by Resveratrol-Loaded Gliadin/Chitin Nanocrystal Composite Nanoparticles

Unsaturated fatty acids present in fish oil offer various physiological benefits to the human body. However, their susceptibility to oxidation severely limits their potential applications. The purpose of this study was to develop Pickering emulsions stabilized from a composite of resveratrol-loaded gliadin nanoparticles and oxidized chitin nanocrystals (GR/OC) to protect fish oil from oxidation. The effects of the GR/OC composite on the characterizations of fish oil Pickering emulsions were investigated, including the microstructure, physicochemical properties (stability and rheological behavior), and digestion properties in vitro. The results revealed that an increased concentration of the GR/OC composite significantly reduced the droplet size and improved the ambient stability of the emulsions (in terms of pH, ionic strength, temperature, and storage time). Confocal laser scanning microscopy images depicted that the GR/OC nanoparticles were uniformly dispersed at the interface between water and fish oil (W-O interface). This distribution formed a protective envelope around the droplets. Remarkably, the addition of 2% GR/OC nanoparticles stabilized the Pickering emulsions and showed the most positive effect on the antioxidant capacity compared to that of the control group. These stabilized emulsions maintained lower peroxide values and acid values, which were 1.5 times less than those of the blank control during the 14 day accelerated oxidation experiment. Furthermore, the Pickering emulsions stabilized by GR/OC nanoparticles exhibited the ability to protect fish oil from contamination by gastric juices and facilitate the intestinal absorption of omega-3 polyunsaturated fatty acids. The findings suggest that these GR/OC-stabilized Pickering emulsions offer a promising alternative for delivering fish oils in various industries, including the food industry.

The formation mechanism and textural properties of a complex gel based on soybean glycinin-chitosan complex coacervates: Effects of pH, heat treatment temperature and centrifugation

The soybean glycinin (11S)-chitosan (CS) complex gels with various textural properties were successfully constructed. The process involved the initial formation of 11S-CS coacervates through electrostatic interactions, followed by a heating treatment to obtain the final complex gels. The impacts of pH, heating temperature, and centrifugation on 11S-CS complex gel properties were investigated. The results indicated that the pore arrangement of the gel formed at pH 7.3 was more tightly and uniformly packed than those formed at pH 6.8 and 7.8. Centrifugation facilitated denser and more ordered gel structures at the three pH values, while increasing the heating temperature exhibited the opposite trend at pH 6.8 and 7.8. These structural differences were also reflected in the rheological and textural properties of the gel. The 11S-CS complex gels exhibited an elasticity-based gel property. The textural properties of gels formed at pH 6.8 were stronger compared to those formed at pH 7.3 and 7.8. However, when the 11S-CS coacervates were heated without centrifugation, the resulting gels were weak. This study emphasizes the potential of using protein/polysaccharide associative interactions during gel formation to alter the microstructure of the gel, meeting various production requirements.

Riboflavin-loaded soy protein isolate cold gel treated with combination of high intensity ultrasound and high hydrostatic pressure: Gel structure, physicochemical properties and gastrointestinal digestion fate

Transglutaminase (TGase) was added to soy protein isolate (SPI) dispersion after the combination treatment of high intensity ultrasound (HIU) and high hydrostatic pressure (HHP) to catalyze the formation of cold gel, which was used to encapsulate riboflavin. The structure, physicochemical properties and in vitro digestion characteristics of riboflavin-loaded SPI cold gel were investigated. HIU-HHP combined treatment enhanced the strength, water retention, elastic property, thermal stability and protein denaturation degree of riboflavin-loaded SPI cold gels, and improved the gel network structure, resulting in a higher encapsulation efficiency of riboflavin and its chemical stability under heat and light treatment. HIU-HHP combined treatment reduced the erosion and swelling of SPI cold gel in simulated gastrointestinal fluid, and improved the sustained release effect of SPI gel on riboflavin by changing the digestion mode and rate of gel. In addition, HIU-HHP combined treated gels promoted the directional release of riboflavin in the simulated intestinal fluid, thereby improving its bioaccessibility, which was related to the secondary structure orderliness, tertiary conformation tightness and aggregation degree of protein during the gastrointestinal digestion. Therefore, HIU-HHP combined treatment technology had potential application value in improving the protection, sustained/controlled release and delivery of SPI cold gels for sensitive bioactive compounds.

Pickering emulsions stabilized by cellulose nanocrystals extracted from hazelnut shells: Production and stability under different harsh conditions

Cellulose nanocrystals (CNCs) are biodegradable particles that have emerged as promising stabilizers for Pickering emulsions. This study investigated the effectiveness of CNCs in forming the Pickering emulsion from hazelnut shells (HS), an agricultural waste. Following the alkaline and bleaching treatments applied to HS, CNCs were obtained from treated hazelnut shell with acid hydrolysis. The physicochemical characteristics of CNCs were investigated using dynamic light scattering, XRD, FTIR, SEM, and TEM. A high crystalline (69.6 %) CNCs with a spherical shape were obtained. Contact angle and interfacial tension tests were conducted and showed that CNCs had amphiphilic nature. Pickering emulsions were investigated for their size, zeta potential, and stability under varying CNC concentrations. The results showed that when CNCs concentration increased from 0.5 to 2.0 wt%, droplet diameter decreased approximately 1.8 times and zeta potential increased. Creaming was not observed during 28 days of storage in a concentration of 2.0 wt% CNCs. The CNC stabilized emulsions exhibited high stability within a range of pH, temperatures, and salt concentrations. This study demonstrated that CNCs extracted from HS as environmentally friendly and cost-effective materials, could serve as a new stabilizer for Pickering emulsions especially for high temperature and low pH sensitive products such as mayonnaise.

Microvesicle-Embedded Solid-liquid Composite Coating for the Tribological Behavior Regulation and Long-Acting Lubrication

Friction interfaces in liquid-embedded composite lubrication coatings commonly comprise a combination of discontinuous fluid films and rough solid contact surfaces, which together ensure easy shearing and a prolonged wear life. However, achieving high efficacy in mixed lubrication poses a challenge due to the conflicting nature of enhanced migration freedom for the liquid lubricant and increased mechanical strength of the solid matrix. Recent efforts have focused on incorporating reinforcing fillers to develop multicomponent, multiphase composites that can address this paradox. Here, we describe a modified attapulgite (APT) with strong biphasic wettability via the oil decompressive osmosis treatment on APT nanocontainers grafted with long nonpolar alkyl chains. This modified APT enables control over the size, distribution, and mobility of lubricant droplets by constructing a Pickering emulsion and toughens the solid-phase matrix through dispersion strengthening. Additionally, the introduction of APT induces the formation of a solid tribofilm during friction, which possesses a higher oil adsorption capacity, as verified through first-principles calculations based on density functional theory (DFT). Consequently, the fluid films can be replenished by the fracture of nanocontainers and adsorption from the bulk phase; further comprehensive and effective regulation of the friction interface leads to low friction and wear.

Eco-friendly microalgae harvesting using lipid-cored particles with a comparative life-cycle assessment

This study proposed an innovative approach using lipid-cored particles (LCPs) aimed at addressing the efficiency, cost, and environmental impact challenges in microalgae harvesting. Cetyltrimethylammonium bromide (CTAB) and chitosan (CS) were used to modify LCPs and to optimize efficiency and investigate the mechanisms of harvesting with Chlorella vulgaris. Results showed that a maximum harvesting efficiency of 97.14 % was achieved using CS-LCPs. Zeta potential and microscopic images revealed the presence of embedded CS-LCPs within microalgal flocs. Fractal dimension data suggested looser aggregates of CS-LCPs and Chlorella vulgaris, corroborated by Excitation-emission matrices (EEM) analysis further confirmation the presence of bridging networks. Moreover, life cycle assessment of five harvesting methods pointed freshwater ecotoxicity potential (FEP) and terrestrial ecotoxicity potential (TEP) as major environmental impacts, mainly from flocculant use, carrier production, and electricity consumption. Notably, LCPs showed the lowest global warming potential (GWP) at 1.54 kg CO2 eq, offering a viable, low-carbon, cost-effective harvesting alternative.

Development of Emulsion Gels Stabilized by Chitosan and Octenyl Succinic Anhydride-Modified β-Cyclodextrin Complexes for β-Carotene Digestion and 3D Printing

β-cyclodextrin (β-CD)-based emulsion gels encapsulated with nutrition for three-dimensional (3D) printing are promising, while obstacles such as low bioaccessibility of bioactive compounds and the molding process in food manufacturing hinder their application. This study intended to develop stable composite emulsion gels using the complexes of chitosan (CS) and octenyl succinic anhydride (OSA)-modified β-CD (OCD) to conquer these challenges. The esterification of OSA generated more negatively charged OCD and ester groups, which aided in the combination of OCD and CS through enhanced electrostatic and hydrogen bonding interactions. The addition of CS improved the emulsification properties of the complexes and acted as a bridge link in the aqueous phase, thereby increasing the gel strength of the composite emulsion gels. Moreover, the encapsulation of β-carotene destabilized the strength of the emulsion gels by lowering the interfacial tension. The emulsion gel stabilized by OCD3/CS-0.75% at an initial pH not only successfully encapsulated β-carotene and presented the highest bioaccessibility of 41.88 ± 0.87% in the in vitro digestion but also showed excellent 3D printability. These results provided a promising strategy to enhance the viscoelasticity of β-CD-based emulsion gels and accelerate their application in bioactive compound delivery systems and 3D food printing.

Soy Protein Isolate-Chitosan Nanoparticle-Stabilized Pickering Emulsions: Stability and In Vitro Digestion for DHA

The purpose of the study was to investigate the stability and oral delivery of DHA-encapsulated Pickering emulsions stabilized by soy protein isolate-chitosan (SPI-CS) nanoparticles (SPI-CS Pickering emulsions) under various conditions and in the simulated gastrointestinal (GIT) model. The stability of DHA was characterized by the retention rate under storage, ionic strength, and thermal conditions. The oral delivery efficiency was characterized by the retention and release rate of DHA in the GIT model and cell viability and uptake in the Caco-2 model. The results showed that the content of DHA was above 90% in various conditions. The retention rate of DHA in Pickering emulsions containing various nanoparticle concentrations (1.5 and 3.5%) decreased to 80%, while passing through the mouth to the stomach, and DHA was released 26% in 1.5% Pickering emulsions, which was faster than that of 3.5% in the small intestine. After digestion, DHA Pickering emulsions proved to be nontoxic and effectively absorbed by cells. These findings helped to develop a novel delivery system for DHA.

Hydroxypropyl methyl cellulose/soybean protein isolate nanoparticles incorporated broccoli leaf polyphenol to effectively improve the stability of Pickering emulsions

This study prepared SPI-Pol-HPMC (SPH) nanoparticles from soybean protein isolate (SPI), hydroxypropyl methyl cellulose (HPMC), and broccoli leaf polyphenol (Pol) and used them as a stabilizer for the Pickering emulsion. The SPH (2:1) nanoparticles have the best ability to encapsulate broccoli leaf polyphenols, with uniform particle size distribution, and a more dense and stable structure. The chemical and hydrogen bonding forces between the SPH nanoparticle components were enhanced. Additionally, the 1.5 % SPH nanoparticle-stabilized emulsions exhibited good physical stability, manifesting as small particle droplets with good rheological properties and uniform dispersion. The volume fraction of the emulsified phase of the 1.5 % SPH nanoparticle-stabilized emulsions was the greatest after 21 days of storage. Interestingly, SPH nanoparticles also improved the oxidative stability of the emulsions, as evidenced through their lower peroxide values and thiobarbituric acid active substances. The aforementioned results suggest that SPH nanoparticles may be used as food-grade emulsifiers that stabilize emulsions and inhibit their lipid oxidation.

Panax Notoginseng polysaccharide stabilized gel-like Pickering emulsions: Stability and mechanism

In this work, the polysaccharide from Panax Notoginseng (SPNP), a traditional herb in China, was used as an outstanding Pickering stabilizer to fabricate Pickering emulsions. The SPNP was characterized to be a porous network structure with a rough surface surrounded by some nanoparticles. Rheological measurement of the obtained Pickering emulsions demonstrated the formation of emulsion gels. Moreover, the emulsions exhibited excellent storage (14 days), pH (1.0-11.0), ionic strength (0-500 mM), and temperature (4-50 °C) stabilities. In addition, the Pickering emulsions showed a freeze-thaw stability, which is beneficial in food, cosmetic or biomedical applications when they may require freezing for storage and melting before use. Confocal laser scanning microscope (CLSM) and cryo-scanning electron microscopy (cryo-SEM) results showed that SPNPs effectively adsorbed at the oil-water interface by forming a compact three-dimensional (3D) network structure and multilayer anchoring on the surface of the emulsion droplets, thus inhibiting the droplet coalescence and flocculation. This study provides a kind of Pickering emulsions applicable in food, biomedical and cosmetic industries.

High internal phase Pickering emulsions stabilised by ultrasound-induced soy protein-β-glucan-catechin complex nanoparticles to enhance the stability and bioaccessibility of curcumin

AIMS

To evaluate the potential applications of soy protein-glucan-catechin (SGC) complexes prepared with different ultrasound times in stabilising high internal phase Pickering emulsion (HIPPE) and delivering curcumin.

METHODS

The SGC complexes were characterised by particle size, morphology, zeta potential, Fourier transform infra-red, and fluorescence spectroscopy. Formation and stability of curcumin emulsions were monitored by droplet size, microstructure, rheological property, lipid oxidation, and in vitro digestion.

RESULTS

Short-time ultrasound-induced complexes (SGC-U15) exhibited a small size and wettability of ∼82.5°. The chemical stability and bioaccessibility of curcumin was greatly improved by SGC-U15-stabilised HIPPEs, even after 70 days of storage, heating at 100 °C for 30 min, ultraviolet irradiation for 120 min, and in vitro digestion, owing to the formation of elastic gel-like structure at the oil/water interfaces.

CONCLUSION

Our findings may contribute to the design of emulsion-based delivery systems using ultrasound-induced protein-polysaccharide-polyphenol complexes.

Development of protein-polyphenol particles to stabilize high internal phase Pickering emulsions by polyphenols' structure

Protein-polyphenol colloidal particles are promising stabilizers for high internal phase Pickering emulsions (HIPPEs). However, the relationship between the structure of the polyphenols and its ability to stabilize HIPPEs has not been studied thus far. In this study, bovine serum albumin (BSA)-polyphenols (B-P) complexes were prepared, and their ability to stabilize HIPPEs was investigated. The polyphenols were bound to BSA via non-covalent interactions. Optically isomeric polyphenols formed similar bonds with BSA, whereas a greater number of trihydroxybenzoyl groups or hydroxyl groups in the dihydroxyphenyl moieties of polyphenols increased the B-P interactions. Polyphenols also reduced the interfacial tension and enhanced the wettability at the oil-water interface. The HIPPE stabilized by BSA-tannic acid complex exhibited the highest stability among the B-P complexes and resisted demixing and aggregation during centrifugation. This study promotes the potential applications of polyphenol-protein colloidal particles-stabilized HIPPEs in the food industry.

Soluble dietary fibres decrease α-glucosidase inhibition of epigallocatechin gallate through affecting polyphenol-enzyme binding interactions

The effects of soluble dietary fibres (SDFs) on α-glucosidase inhibition of EGCG were studied. Three arabinoxylans and polygalacturonic acid (PGA) significantly decreased inhibitory activity of EGCG against α-glucosidase, while two β-glucans hardly affected the inhibition. Although arabinoxylans and PGA weakened the competitive inhibition character of EGCG, they maintained the fluorescence quenching effect of EGCG. Then, arabinoxylans and PGA significantly decreased the particle size and turbidity of EGCG-enzyme complex. These results suggest that there formed SDFs-EGCG-enzyme ternary complexes. The stronger decreasing-effects of arabinoxylans and PGA on α-glucosidase inhibition of EGCG than β-glucans resulted from the stronger non-covalent interactions of arabinoxylans and PGA with EGCG. This is considered to arise from the short-branches of arabinoxylans that provided more opportunity for capturing EGCG, and from the strong polarity of PGA carboxyl that promoted hydrogen bondings with EGCG. Conclusively, SDFs should be considered as an impact factor when evaluating α-glucosidase inhibition of dietary polyphenols.

Antioxidant and antimicrobial collagen films incorporating Pickering emulsions of cinnamon essential oil for pork preservation

Cinnamon essential oil (CEO)-based Pickering emulsions were prepared using chitosan (CS) and soy protein isolate (SPI) colloid particles as stabilizers and genipin as cross-linker. Pickering emulsions have smaller particle sizes, higher stability, and encapsulation efficiency at a CS:SPI ratio of 1:4. The Pickering emulsion-modified collagen films showed enhanced thermal stability, UV-blocking properties, and water resistance. In addition, the antioxidant (DPPH scavenging activity, 18.35%-50.59%) and antimicrobial activities (inhibition zone, Escherichia coli, 0-1.85 cm; Staphylococcus aureus, 0-1.57 cm; Pseudomonas fluorescens, 0-1.34 cm) of the films were improved due to the sustained release of CEO, with the release kinetics following the Fickian diffusion of the Ritger-Peppas model. When the functionalized film was used for pork preservation, a four-day extension of shelf life was observed. Collectively, our findings suggest that Pickering emulsions provide great potential for the application of collagen film in pork preservation.

Whey Protein Isolate-Mesona chinensis Polysaccharide Conjugate: Characterization and Its Applications in O/W Emulsions

Mesona chinensis polysaccharide (MCP), a common thickener, stabilizer and gelling agent in food and pharmaceuticals, also has antioxidant, immunomodulatory and hypoglycemic properties. Whey protein isolate (WPI)-MCP conjugate was prepared and used as a stabilizer for O/W emulsion in this study. FT-IR and surface hydrophobicity results showed there could exist interactions between -COO- in MCP and -NH³⁺ in WPI, and hydrogen bonding may be involved in the covalent binding process. The red-shifted peaks in the FT-IR spectra suggested the formation of WPI-MCP conjugate, and MCP may be bound to the hydrophobic area of WPI with decreasing surface hydrophobicity. According to chemical bond measurement, hydrophobic interaction, hydrogen bond and disulfide bond played the main role in the formation process of WPI-MCP conjugate. According to morphological analysis, the O/W emulsion formed by WPI-MCP had a larger size than the emulsion formed by WPI. The conjugation of MCP with WPI improved the apparent viscosity and gel structure of emulsions, which was concentration-dependent. The oxidative stability of the WPI-MCP emulsion was higher than that of the WPI emulsion. However, the protection effect of WPI-MCP emulsion on β-carotene still needs to be further improved.

Recent progress in emulsion gels: from fundamentals to applications

Emulsion gels, also known as gelled emulsions or emulgels, have garnered great attention both in fundamental research and practical applications due to their superior stability, tunable morphology and microstructure, and promising mechanical and functional properties. From an application perspective, attention in this area has been, historically, mainly focused on food industries, e.g., engineering emulsion gels as fat substitutes or delivery systems for bioactive food ingredients. However, a growing body of studies has, in recent years, begun to demonstrate the full potential of emulsion gels as soft templates for designing advanced functional materials widely applied in a variety of fields, spanning chemical engineering, pharmaceutics, and materials science. Herein, a concise and comprehensive overview of emulsion gels is presented, from fundamentals to applications, highlighting significant recent progress and open questions, to scout for and deepen their potential applications in more fields.

Effects of environmental stimuli on the physicochemical and rheological properties of chitosan-macroalgal polyphenol stabilized Pickering emulsion

In this study, Pickering emulsions stabilized by chitosan (CS), chitosan-Laminaria japonica polyphenols (CP) and chitosan-Ascophyllum nodosum polyphenols (CB) were fabricated. This study also evaluated the stability of CS, CP, and CB under different environmental factors including pH (2-9), NaCl concentrations (0-500 mM), heat treatments (50-100 °C) and storage period (0-8 weeks). The characterization on interfacial layer of emulsion droplets demonstrated that macroalgal polyphenols could combined with the amorphous regions of chitosan particles through hydrogen bond and electrostatic interactions, providing stronger dual wettability with enhanced ability of interfacial layer in stabilizing Pickering emulsions. All three emulsions showed best droplet distribution, highest emulsion stability and specific surface area at pH 6 and 0 mM NaCl concentration as fresh emulsion. Moreover, CS, CP, and CB exhibited the rheological behaviour of pseudoplastic fluids at different pH and NaCl concentration. It should be noted that CP and CB exhibited higher emulsion stability than CS under a variety of environmental stresses. Overall, this research proved that chitosan-macroalgal polyphenol co-stabilized Pickering emulsion had enhanced stability against various environmental stimuli, which could be utilized as potential delivery and protection system for hydrophobic bioactive compounds.

Formation, stability and the application of Pickering emulsions stabilized with OSA starch/chitosan complexes

We demonstrated the formation, structure and stability of Pickering emulsions stabilized by octenyl succinic anhydride starch (OSA-S)/chitosan (CS) complexes and explored their potential as templates for porous materials. Sufficient oil fraction (Φ > 50 %) was decisive for stable emulsions, whereas the complex concentration (c) significantly affected the gel network of emulsions. An increase in Φ or c led to tighter droplet arrangement and enhanced network, which improved the self-supporting characteristics and the stability of emulsions. The stacking of OSA-S/CS complexes at the oil-water interface influenced the emulsion properties, forming typical microstructure with small droplets embedded in interstices of large droplets, and bridging flocculation occurred. Porous materials prepared using emulsions (Φ > 75 %) as templates exhibited semi-open structures with pore size and network varying with different Φ or c. There was no structure collapse due to the interconnectivity of complexes. Our work provides comprehensive information on OSA-S/CS complex-stabilized Pickering emulsions.

Naturally occurring protein/polysaccharide hybrid nanoparticles for stabilizing oil-in-water Pickering emulsions and the formation mechanism

In this study, we reported for the first time that the natural protein/polysaccharide hybrid nanoparticles (PPH NPs) with a diameter of ∼ 129 nm, originating from Lactobacillus plantarum fermented cheese whey, could act as green-based NPs for stabilizing Pickering emulsions. Characterizations of PPH NPs showed that the negative-charged PPH NPs were composed of ∼ 37.7% total protein and ∼ 7.3% polysaccharide bearing several functional groups, such as -OH, -NH, -COOH, etc.; and displayed excellent emulsifying capacity in preparing oil-in-water Pickering emulsions. The obtained emulsions exhibited gel-like behavior with excellent stability against the variation of pH, ionic strength, and temperature. Confocal observations showed that PPH NPs effectively adsorbed and anchored at the oil-water interface, thus creating the steric hindrance to inhibit droplet coalescence. This research is of importance in developing novel and biocompatible Pickering stabilizers with outstanding performance, as well as enable a versatile design of stable Pickering emulsions suitable for food industries.

Fabrication and Characterization of the Egg-White Protein Chitosan Double-Layer Emulsion

Egg-white protein has an abundance of hydrophobic amino acids and could be a potential emulsifier after modification. Here, egg-white protein was modified via ultrasonic and transglutaminase treatments to destroy the globular structure. The egg-white protein gel particles (EWP-GPs) were prepared and then a novel highly stable EWP-chitosan double-layer emulsion was constructed. When ultrasonic treatment was applied at 240 W and TGase (20 U/g EWP) treatment, the EWP-GPs had a low particle size and good emulsification performance. The particle size of EWP-GPs was a minimum of 287 nm, and the polymer dispersity index (PDI) was 0.41. The three-phase contact angle (θ_o/w) of EWP-GPs was 79.6° (lower than 90°), performing with good wettability. Based on these results, the EWP-chitosan double-layer emulsion was prepared through the EWP-GPs being treated with 240 W ultrasound, TGase, and chitosan in this study. When the double-layer emulsion had 0.6% (v/v) chitosan, the zeta potential of the double-layer emulsion was -1.1 mV and the double-layer emulsion had a small particle size (56.87 µm). The creaming index of double-layer emulsion at 0.6% (v/v) chitosan was 16.3% and the droplets were dispersed uniformly. According to the rheological results, the storage modulus (G') was larger than the loss modulus (G″) in the whole frequency, indicating the formation of an elastic gel network structure in the emulsion. It is hoped to develop a novel food-grade stabilizer and a stable double-layer emulsion, providing new environment-friendly processing in hen egg products and delivery systems.

Construction of lipid-biomacromolecular compounds for loading and delivery of carotenoids: Preparation methods, structural properties, and absorption-enhancing mechanisms

Due to the unstable chemical properties and poor water solubility of carotenoids, their processing adaptation and oral bioavailability are poor, limiting their application in hydrophilic food systems. Lipid-biomacromolecular compounds can be excellent carriers for carotenoid delivery by taking full advantage of the solubilization of lipids to non-polar nutrients and the water dispersion and gastrointestinal controlled release properties of biomacromolecules. This paper reviewed the research progress of lipid-biomacromolecular compounds as encapsulation and delivery carriers of carotenoids and summarized the material selection and preparation methods for biomacromolecular compounds. By considering the interaction between the two, this paper briefly discussed the effect of these compounds on carotenoid water solubility, stability, and bioavailability, emphasizing their delivery effect on carotenoids. Finally, various challenges and future trends of lipid-biomacromolecular compounds as carotenoid delivery carriers were discussed, providing new insight into efficient loading and delivery of carotenoids.