Novel Pickering emulsion gels stabilized solely by phenylalanine amidated pectin: Characterization, stability and curcumin bioaccessibility

Ultrasound-assisted oligochitosan/casein complexes stabilized Pickering emulsion: Characterization, stability and its application for lutein delivery

Lutein is a natural pigment with various beneficial biological activities, but its poor water solubility, chemical instability, and low bioavailability limit its application in food processing. In this study, modified casein (CAS-OCS NPs)-based Pickering emulsions were constructed under the combined effect of TGase-type glycation and ultrasound treatment as delivery systems for lutein fortification. Pickering emulsions based on CAS-OCS NPs enhanced the encapsulation efficiency of lutein (87.04 ± 0.30 %). The modification treatments improved the emulsifying properties, environmental stability, and digestive stability, as well as the delivery capability of lutein and antioxidant activity in simulated in vitro gastrointestinal digestion. After glycation modification, the lutein release rate of CAS-OCS NPs-based Pickering emulsions after in vitro digestion was higher than that of untreated casein-based Pickering emulsions, and the maximum release rate was 55.44 ± 0.50 %. Moreover, the CAS-OCS NPs-based Pickering emulsions showed improved lutein bioaccessibility, reaching the maximum value of 58.52 ± 0.52 %. These findings demonstrated the suitability of TGase-type glycation and ultrasound treatment for the preparation of Pickering emulsions to deliver bioactive compounds.

Physicochemical and rheological characterization of plant-based proteins, pectin, and chitin nanofibers for developing high internal phase Pickering emulsions as potential fat alternatives

This study evaluated the properties of lentil protein, pea protein, quinoa protein, and soy protein as natural nanoparticle stabilizers and their interactions with pectin and chitin nanofiber in preparing high internal phase Pickering emulsions (HIPPEs). The globular plant proteins interact with polysaccharides through hydrogen bonding and electrostatic interactions, transforming the structure into complex morphologies, including fibrous and elliptical shapes. These complex nanoparticles exhibited enhanced thermal decomposition stability, and the HIPPEs constructed by them demonstrated significantly improved apparent viscosity and elastic modulus, with a yield stress of 931.9 Pa, showing gel-like viscoelastic characteristics. The complex system not only reduced droplet size but also formed a compact network structure, which enabled the emulsion to maintain excellent stability under heat treatment, long-term storage and high-speed centrifugation. Our findings revealed the promising potential of utilizing plant-based proteins with polysaccharides to prepare HIPPEs for developing fat alternatives.

Preparation of soybean oil-based emulsions stabilized by shiitake mushroom chitosan modified in both enzymatic and non-enzymatic systems and their application in β-carotene delivery

This study investigates the laccase-catalyzed grafting of gallic acid (GA) onto shiitake mushroom chitosan to enhance its emulsifying properties and improve β-carotene delivery. Structural characterization using FTIR, XPS, and 1H NMR revealed that laccase catalysis promoted the formation of amide bonds, disrupted the crystalline structure of chitosan, and enhanced both its hydration and interfacial activity. The modified chitosan emulsions exhibited significantly improved emulsification capacity and stability, with GA-grafted chitosan achieving emulsification activity of 3.34 L/g·cm and stability of 97.6 %. The β-carotene encapsulation efficiency increased to 82.1 %, with enhanced resistance to UV light and H₂O₂-induced degradation. In vitro digestion experiments demonstrated that the modified chitosan emulsion improved β-carotene bioaccessibility (75.8 %) and cellular uptake (55.3 %), significantly improving delivery efficiency. This study provides a novel approach for the development of functional emulsion carriers and lays the foundation for their application in food and drug delivery systems.

Tuning the amphiphilicity of agarose by grafting phenolic acids: A versatile approach for developing lutein-loaded emulsion gels

In this study, three phenolic acids, namely 3,4-Dihydroxybenzoic acid (DBA), 3,4-Dihydroxyphenylacetic acid (DPA), and 3,4-Dihydroxyphenylpropanoic acid (DPPA), were grafted onto agarose molecules to improve the physicochemical and biological properties of agarose. DBA-grafted agarose (DBA-AG), DPA-grafted agarose (DPA-AG), and DPPA-grafted agarose (DPPA-AG) were prepared and used as encapsulation materials to construct a lutein-loaded emulsion gel delivery system. The results confirmed that phenolic acids were successfully grafted onto the agarose backbone via ester bonds, with a grafting degree of approximately 8 %. As the length of the phenolic acid side chain increased (DBA < DPA < DPPA), the agarose gel exhibited decreased strength, thermal stability, and transparency while displaying increased hydrophobicity and emulsifying activity. Phenolic acid grafting significantly enhanced the radical scavenging ability of agarose and improved its inhibitory activity against Staphylococcus aureus (100 %) and Escherichia coli (78.44 %-100 %). DPPA-AG exhibited the highest antioxidant activity, while DBA-AG showed the best antibacterial effect. Moreover, phenolic acid grafting transformed agarose from a hydrophilic gel to an amphiphilic emulsion gel, greatly increasing lutein's encapsulation efficiency (87.3 %-94.2 %), chemical stability, and bioavailability. DPPA-AG demonstrated the optimal emulsifying activity and lutein encapsulation performance. In vitro hemolysis experiments indicated good prospects for applications in food, pharmaceutical, and cosmetic industries.

Caffeic Acid-Modified Mushroom Chitosan as a Natural Emulsifier for Soybean Oil-Based Emulsions and Its Application in β-Carotene Delivery

In this study, we developed a soybean oil-based emulsion system stabilized by caffeic acid-modified mushroom-derived chitosan, significantly enhancing its functional properties. The modification increased the grafting ratio from 5.02% to 8.26%, which greatly improved antioxidant activity and antimicrobial efficacy against Escherichia coli and Staphylococcus aureus. The modified chitosan exhibited superior rheological properties, including increased viscosity and elasticity, contributing to improved emulsification performance. Emulsions stabilized with caffeic acid-modified chitosan showed smaller and more uniform droplet sizes, along with greater stability, as indicated by a higher zeta potential (55.63 mV). These modifications resulted in enhanced β-carotene encapsulation efficiency (up to 87.46%) and improved bioaccessibility (up to 52.13%), highlighting the system's potential as an efficient food-grade carrier for hydrophobic bioactive compounds. In conclusion, caffeic acid-modified mushroom chitosan is an effective natural emulsifier, enhancing stability, antioxidant activity, and nutrient delivery, and has promising applications in functional foods and nutraceuticals.

Recent advances in the development and application of curcumin-loaded micro/nanocarriers in food research

The application of curcumin in food science is challenged by its poor water solubility, easy degradation under processing and within the gastrointestinal tract, and poor bioavailability. Micro/nanocarrier is an emerging and efficient platform to overcome these drawbacks. This review focuses on the recent advances in the development and application of curcumin-loaded micro/nanocarriers in food research. The recent development advances of curcumin-loaded micro/nanocarriers could be classified into ten basic systems: emulsions, micelles, dendrimers, hydrogel polymeric particles, polymer nanofibers, polymer inclusion complexes, liposomes, solid lipid particles, structured lipid carriers, and extracellular vesicles. The application advances of curcumin-loaded micro/nanocarriers for food research could be classified into four types: coloring agents, functional active agents, preservation agents, and quality sensors. This review demonstrated that micro/nanocarriers were excellent carriers for the fat-soluble curcumin and the obtained curcumin-loaded micro/nanocarriers had promising application prospects in the field of food science.

Pickering emulsions embedded in Bletilla striata polysaccharide based nanogel for enhancing skin-whitening effect of essential oils

To improve the retention time and skin-whitening efficacy of Atractylodes macrocephale essential oil (AMO), a novel Pickering emulsion based nanogel loaded with AMO (AMO-PEG) was successfully developed. This formulation employed nano-pearl powder (NPP) as the particle stabilizer for the Pickering emulsion and Bletilla striata polysaccharide (BSP) as the gel matrix. The pH, rheological properties, hardness, and elasticity of AMO-PEG were affected by the ratio of AMO-Pickering emulsion (AMO-PE) to BSP gel matrix. The results showed that AMO-PEG exhibited solid-like behavior and was capable of forming nanogels when the ratio of AMO-PE to BSP was 1:1. AMO-PE and AMO-PEG are two different dosage forms in the preparation of AMO. The effects of varying dosage forms on AMO were evaluated by in vitro transdermal release, skin irritation test, and skin-whitening effect. AMO-PEG conforms to the zero-order kinetic equation (R2 = 0.9189). The skin retention rate of AMO-PEG was 1.37 times higher than that of AMO-PE, indicating that AMO-PEG could continuously and slowly exert the whitening effect of the drugs. Compared with AMO-PE, AMO-PEG significantly increased the inhibition of tyrosinase activity and melanogenesis in B16F10 cells. AMO-PEG can promote the inhibition of B16F10 cells and improve the whitening effect of AMO and BSP. In conclusion, the Pickering emulsion based nanogel appears to be a promising strategy for enhancing the skin-whitening efficacy of both AMO and BSP.

Hawthorn (Crataegus pinnatifida) berries ripeness induced pectin diversity: A comparative study in physicochemical properties, structure, function and fresh-keeping potential

The effect of hawthorn berries ripeness on the physicochemical, structural and functional properties of hawthorn pectin (HP) and its potential in sweet cherry preservation were investigated. With the advanced ripeness of hawthorn berries, the galacturonic acid (GalA) content decreased from 59.70 mol% to 52.16 mol%, the molecular weight (Mw) reduced from 368.6 kDa to 284.3 kDa, the microstructure exhibited variable appearance from thick lamella towards porous cross-linked fragment, emulsifying activity and emulsions stability, antioxidant activities, α-amylase and pancreatic lipid inhibitory capacities significantly increased. The heated emulsion stored for 30 d presented higher creaming index and more ordered oil droplets compared to the unheated emulsion. With the extended berries ripeness, the firmness of HP gels remarkably decreased from 225.69 g to 73.39 g, while the springiness increased from 0.78 to 1.16, HP exhibited a superior inhibitory effect in water loss, browning, softening, and bacterial infection in sweet cherries preservation.

Physicochemical properties and in vitro digestive behavior of astaxanthin loaded Pickering emulsion gel regulated by konjac glucomannan and κ-carrageenan

This study aimed to elaborate the combination effect of polysaccharides on physicochemical properties and in vitro digestive behavior of astaxanthin (AST)-loaded Pickering emulsion gel. AST-loaded Pickering emulsion gel was prepared by heating Pickering emulsion with konjac glucomannan (KGM) and κ-carrageenan (CRG). The microstructure revealed that adding the two polysaccharides resulted in Pickering emulsion forming a network structure. It exhibited a denser and more uniform network structure, enhancing its mechanical properties four times and increasing its water-holding capacity by 20 %. In vitro digestion experiments demonstrated that the release of free fatty acids from the Pickering emulsion gel (4.25 %) was notably lower than that from conventional Pickering emulsion (17.19 %), whereas AST bioaccessibility was remarkably low at 0.003 %. It provided a feasible strategy to regulate the bioaccessibility in Pickering emulsion, which has theoretical significance to guide the current eutrophic diet people.

Modified Cinnabaris-stabilized Pickering emulsions loaded with the essential oil of Acorus tatarinowii Schott: preparation, characterization and in vitro evaluation

Essential oil of Acorus tatarinowii Schott (ATEO) have significant biological activity, but their physical and chemical properties are unstable and susceptible to interference by external factors, resulting in oxidation, decomposition, and isomerization of essential oils (EOs), ultimately diminishing the quality of EOs and escalating clinical risks. In this research, based on the concept of " combination of medicine and adjuvant, " the unsuitable stabilizer Cinnabaris in Lingzhu powder prescription was modified with a SiO2 surface to become a stabilizer suitable for Pickering emulsion. The modified Cinnabaris was synthesized, with a focus on exploring the surface modification of Cinnabaris to facilitate its role as a stabilizer in Pickering emulsion. Thermal stability studies showed that modified Cinnabaris-stabilized emulsion had higher EOs retention and lower peroxide value and hydrogen peroxide content. GC-MS analysis showed that the volatile components in the emulsion were more stable than the EOs. In vitro dissolution experiments showed that in the dissolution medium of artificial gastric juice and artificial intestinal juice, compared with the ATEO, the release in Pickering emulsion was faster within 48 h, indicating that the ATEO had been encapsulated in Pickering emulsion, which could improve the in vitro dissolution rate of EOs. This study convincingly demonstrates the potential of modified Cinnabaris-stabilized Pickering emulsion to improve the thermal stability and in vitro dissolution rate of EOs.

Enhanced bioaccessibility of interfacial delivered oleanolic acid through self-constructed Pickering emulsion: Effects of oil types

Pentacyclic triterpenes have attracted much attention because of their many bioactivities, but their bioaccessibility is low. Oleanolic acid (OA) was used in this study as a typical edible pentacyclic triterpene. In this work, we proposed an OA interfacial delivery model based on W/O Pickering emulsion, and investigated the effects of different oil types on the emulsion properties and OA bioaccessibility of the OA W/O Pickering emulsion interfacial delivery system (EIDS). Medium chain triglyceride (MCT), long chain triglycerides (LCT) and MCT/LCT (1:1, w/w) were selected as carrier oils for the preparation of emulsions, respectively. The results showed that the emulsions formed from LCT had smaller particle sizes, which increased the deformation resistance of the emulsions and exhibited good stability during the simulated in vitro digestion. The extent of free fatty acid (FFA) release during oil digestion was MCT (103.32 ± 3.74 %) > M/L (97.89 ± 2.89 %) > LCT (71.41 ± 6.64 %). Of interest, the bioaccessibility of OA was influenced by the carrier oil: LCT (59.34 ± 2.55 %) > M/L (47.35 ± 6.25 %) > MCT (13.11 ± 1.40 %) ＞ PBS (7.11 ± 1.74 %), and such a difference was mainly attributed to the greater solubilisation of OA in mixed micelles consisting of long-chain fatty acids. In summary, the size of hydrophobic domains in the mixed micelles produced a greater effect than the effect of FFA release on OA bioaccessibility. This study provides a theoretical basis for the interfacial delivery of OA and the enhancement of OA bioaccessibility based on W/O Pickering emulsions with different oil types.

The present state and future outlook of pectin-based nanoparticles in the stabilization of Pickering emulsions

The stabilization of Pickering emulsions using micro/nanoparticles has gained significant attention due to their wide range of potential applications in industries such as cosmetics, food, catalysis, tissue engineering, and drug delivery. There is a growing demand for the development of environmentally friendly micro/nanoparticles to create stable Pickering emulsions. Naturally occurring polysaccharides like pectin offer promising options as they can assemble at oil/water interfaces. This polysaccharide is considered a green candidate because of its biodegradability and renewable nature. The physicochemical properties of micro/nanoparticles, influenced by fabrication methods and post-modification techniques, greatly impact the characteristics and applications of the resulting Pickering emulsions. This review focuses on recent advancements in Pickering emulsions stabilized by pectin-based micro/nanoparticles, as well as the application of functional materials in delivery systems, bio-based films and 3D printing using these emulsions as templates. The effects of micro/nanoparticle properties on the characteristics of Pickering emulsions and their applications are discussed. Additionally, the obstacles that currently hinder the practical implementation of pectin-based micro/nanoparticles and Pickering emulsions, along with future prospects for their development, are addressed.

Exploring the emulsification potential of chitosan modified with phenolic acids: Emulsifying properties, functional activities, and application in curcumin encapsulation

This study successfully grafted caffeic acid and 3,4-dihydroxybenzoic acid into chitosan through a coupling reaction, yielding grafting ratio of 8.93 % for caffeic acid grafted chitosan (CA-GC) and 9.15 % for 3,4-dihydroxybenzoic acid grafted chitosan (DHB-GC) at an optimal concentration of 4 mmol phenolic acids. The characterization of modified chitosans through ultraviolet visible spectrometer (UV-vis), Fourier transform infrared spectrometer (FTIR), proton nuclear magnetic resonance (1H NMR), and x-ray photoelectron spectrometer (XPS) confirmed the successful grafting of phenolic acids. In the subsequent step of emulsion preparation, confocal laser scanning microscope images confirmed the formation of O/W (oil-in-water) emulsions. The phenolic acid-grafted chitosans exhibited better emulsification properties compared to native chitosan, such as reduced droplet size, more uniform emulsion droplet distribution, increased ζ-potential, and enhanced emulsifying activity and stability. Moreover, the modified chitosans demonstrated increased antioxidant activities (evidenced by DPPH and β-carotene assays) and displayed greater antimicrobial effects against E. coli and S. aureus. Its efficacy in curcumin encapsulation was also notable, with improved encapsulation efficiency, sustained release rates, and enhanced storage and photostability. These findings hint at the potential of modified chitosans as an effective emulsifier.

Tailoring the oral sensation and digestive behavior of konjac glucomannan-gelatin binary hydrogel based bigel: Effects of composition and ratio

In the food industry, there is a growing demand for bigels that offer both adaptable oral sensations and versatile delivery properties. Herein, we developed bigels using a binary hydrogel of konjac glucomannan (KGM) and gelatin (G) combined with a stearic acid oleogel. We closely examined how the oleogel/hydrogel volume ratio (φ) and the KGM/G mass ratio (γ) influenced various characteristics of the bigels, including their microstructure, texture, rheological properties, thermal-sensitivity, oral tribology, digestive stability, and nutraceutical delivery efficiency. A noteworthy observation was the structural evolution of the bigels with increasing φ values: transitioning from oleogel-in-hydrogel to a bicontinuous structure, and eventually to hydrogel-in-oleogel. Lower γ values yielded a softer, thermally-responsive bigel, whereas higher γ values imparted enhanced viscosity, stickiness, and spreadability to the bigel. Oral tribology assessments demonstrated that φ primarily influenced the friction sensations at lower chewing intensities. In contrast, γ played a significant role in augmenting oral friction perceptions during more intense chewing. Additionally, φ dictated the controlled release and bioaccessibility of curcumin, while γ determined digestive stability. This study provides valuable insights, emphasizing that through meticulous selection and adjustment of the hydrogel matrix composition, bigels can be custom-fabricated to achieve specific oral sensations and regulated digestive behaviors.

Edible polysaccharide-based oleogels and novel emulsion gels as fat analogues: A review

Polysaccharide-based oleogels and emulsion gels have become novel strategies to replace solid fats due to safe and plentiful raw material, healthier fatty acid composition, controllable viscoelasticity, and more varied nutrition/flavor embedding. Recently, various oleogelation techniques and novel emulsion gels have been reported further to enrich the potential of polysaccharides in oil structuring, in which a crucial step is to promote the formation of polysaccharide networks determining gel properties through different media. Meanwhile, polysaccharide-based oleogels and emulsion gels have good oil holding, nutrient/flavor embedding, and 3D food printability, and their applications as fat substitutes have been explored in foods. This paper comprehensively reviews the types, preparation methods, and mechanisms of various polysaccharide-based oleogels and emulsion gels; meanwhile, the food applications and new trends of polysaccharide-based gels are discussed. Moreover, some viewpoints about potential developments and application challenges of polysaccharide-based gels are mentioned. In the future, polysaccharide-based gels may be flexible materials for customized nutritional foods and molecular gastronomy. However, it is still a challenge to select the appropriate oleogels or emulsion gels to meet the requirements of the products. Once this issue is addressed, oleogels and emulsion gels are anticipated to be used widely.

Mechanism for improving coconut milk emulsions viscosity by modifying coconut protein structure and coconut milk properties with monosodium glutamate

In this study, monosodium glutamate (MSG) was used to improve the viscosity of coconut milk and the underlying mechanism was explored by investigating the changes in structures of coconut milk protein and physicochemical properties of coconut milk. Firstly, the effect of MSG on the properties of coconut milk was studied. The results showed that MSG increased the pH and zeta potential, reduced the particle size, thus enhancing the droplet interaction and increasing the viscosity of coconut milk. Subsequently, the effects of MSG on the structure and properties of coconut proteins (CP) were investigated. FTIR spectroscopy and circular dichroism spectroscopy showed that MSG was able to change the secondary structure of CP. The results of SDS-PAGE showed that MSG was able to bind to CP to form a larger molecular weight protein, thus improving the viscosity of coconut milk. Moreover, MSG was also able to increase the water-binding capacity of CP. In addition, molecular docking and driving force analysis revealed that hydrogen bonds, electrostatic forces, disulfide bonds, and hydrophobic interactions are the main interactions between MSG and CP. Studying the effect of MSG on the viscosity of coconut milk provides theoretical support to improve the viscosity of other plant protein emulsions.