Food-grade Pickering emulsions for encapsulation and delivery of bioactives

Characterization and stability of lycopene-loaded high internal phase emulsion stabilized by ovalbumin-chitosan complexes

Lycopene, a carotenoid with numerous physiological benefits, particularly in its Z-isomer form, faces challenges in its application due to low chemical stability. To address this limitation, high internal phase emulsion was successfully synthesized using ovalbumin-chitosan complexes. The aim was to enhance the stability of lycopene including Z-lycopene. The solubility, particle size, ζ-potential and uniformity of the mixture were dependent on pH value and biopolymer proportion. Notably, optimal ovalbumin-chitosan complex formation occurred at pH 2.5 with a ratio of 4:1 resulting in the highest solubility and optimal uniformity which contributed to its superior emulsification properties. Evaluation of encapsulating efficiency and loading amount revealed 98.19% and 1.7661 mg/g respectively for lycopene in ovalbumin-chitosan stabilized emulsions, inhibiting the transformation from Z-lycopene to (all-E)-lycopene. The encapsulated lycopene possessed UV stability where retention rate remained high at 81.86%. The retention rate was up to 65.37% and 41.82% at 45 °C and 80 °C, respectively.

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.

Controlled assembly of superparamagnetic iron oxide nanoparticle into nanoliposome for Pickering emulsion preparation

There has been a surge in effort in the development of various solid nanoparticles as Pickering emulsion stabilizers in the past decades. Regardless, the exploration of stabilizers that simultaneously stabilize and deliver bioactive has been limited. For this, liposomes with amphiphilic nature have been introduced as Pickering emulsion stabilizers but these nano-sized vesicles lack targeting specificity. Therefore in this study, superparamagnetic iron oxide nanoparticles (SPION) encapsulated within liposomes (MLP) were used as Pickering emulsion stabilizers to prepare pH and magnetic-responsive Pickering emulsions. A stable MLP-stabilized Pickering emulsion formulation was established by varying the MLP pH, concentration, and oil loading during the emulsification process. The primary stabilization mechanism of the emulsion under pH variation was identified to be largely associated with the MLP phosphate group deprotonation. When subjected to sequential pH adjustment to imitate the gastrointestinal digestion pH environment, a recovery in Pickering emulsion integrity was observed as the pH changes from acidic to alkaline. By incorporating SPION, the Pickering emulsion can be guided to the targeted site under the influence of a magnetic field without compromising emulsion stability. Overall, the results demonstrated the potential of MLP-stabilized Pickering emulsion as a dual pH- and magnetic-responsive drug delivery carrier with the ability to co-encapsulate hydrophobic and hydrophilic bioactive.

Pickering emulsion co-delivery system: Stimuli-responsive biomineralized particles act as particulate emulsifiers and bioactive carriers

Pickering emulsions provide a promising platform for the efficient delivery of bioactive. However, co-delivery of fragile bioactives with different physicochemical properties for comprehensive effects still faces practical challenges due to the limited protection for bioactives and the lack of stimuli-responsive property for on-demand release. Herein, a stimuli-responsive co-delivery system is developed based on biomineralized particles stabilized Pickering emulsions. In this tailor co-delivery system, hydrophilic bioactive (pepsin) with the fragile structure is encapsulated and immobilized by biomineralization, the obtained biomineralized particles (PPS@CaCO3) are further utilized as emulsifiers to form O/W Pickering emulsions, in which the hydrophobic oxidizable bioactive (curcumin) is stably trapped into the dispersed phase. The results show that two bioactives are successfully co-encapsulated in Pickering emulsions, and benefiting from the protection capacities of biomineralization and Pickering emulsions, the activity of pepsin and curcumin shows a 7.33-fold and 144.83-fold enhancement compared to the free state, respectively. Moreover, In vitro study demonstrates that Pickering emulsions enable to co-release of two bioactives with high activity retention by the acid-induced hydrolyzation of biomineralized particles. This work provides a powerful stimuli-responsive platform for the co-delivery of multiple bioactive compounds, enabling high activity of bioactives for the comprehensive health effects.

Current Challenges in Microcapsule Designs and Microencapsulation Processes: A Review

Microencapsulation is an advanced methodology for the protection, preservation, and/or delivery of active materials in a wide range of industrial sectors, such as pharmaceuticals, cosmetics, fragrances, paints, coatings, detergents, food products, and agrochemicals. Polymeric materials have been extensively used as microcapsule shells to provide appropriate barrier properties to achieve controlled release of the encapsulated active ingredient. However, significant limitations are associated with such capsules, including undesired leaching and the nonbiodegradable nature of the typically used polymers. In addition, the energy cost of manufacturing microcapsules is an important factor to be considered when designing microcapsule systems and the corresponding production processes. Recent factors linked to UN sustainability goals are modifying how such microencapsulation systems should be designed in pursuit of "ideal" microcapsules that are efficient, safe, cost-effective and environmentally friendly. This review provides an overview of advances in microencapsulation, with emphasis on sustainable microcapsule designs. The key evaluation techniques to assess the biodegradability of microcapsules, in compliance with recently evolving European Union requirements, are also described. Moreover, the most common methodologies for the fabrication of microcapsules are presented within the framework of their energy demand. Recent promising microcapsule designs are also highlighted for their suitability toward meeting current design requirements and stringent regulations, tackling the ongoing challenges, limitations, and opportunities.

3D printing of Pickering emulsions, Pickering foams and capillary suspensions - A review of stabilization, rheology and applications

Pickering emulsions and foams as well as capillary suspensions are becoming increasingly more popular as inks for 3D printing. However, a lack of understanding of the bulk rheological properties needed for their application in 3D printing is potentially stifling growth in the area, hence the timeliness of this review. Herein, we review the stability and bulk rheology of these materials as well as the applications of their 3D-printed products. By highlighting how the bulk rheology is tuned, and specifically the inks storage modulus, yield stress and critical balance between the two, we present a rheological performance map showing regions where good prints and slumps are observed thus providing clear guidance for future ink formulations. To further advance this field, we also suggest standard experimental protocols for characterizing the bulk rheology of the three types of ink: capillary suspension, Pickering emulsion and Pickering foam for 3D printing by direct ink writing.

W/O/W Pickering emulsions stabilized by complex modified phycocyanin

BACKGROUND

A water-in-oil-in-water (W/O/W) double emulsion can simultaneously load hydrophilic and hydrophobic substances due to its unique two-membrane, three-phase structure. However, thermodynamic instability greatly limits the application of double emulsions in food processing. Further development of Pickering emulsions based on proteins, etc., can improve the stability and loading capacity. It is of great significance to promote their practical application.

RESULTS

Herein, we prepared ultrasound pretreatment complex glycation-modified phycocyanin (UMPC) to stabilize a W/O/W Pickering emulsion for the codelivery of vitamin B12 (VB12) and vitamin E (VE). First, an inner water phase and oil phase containing polyglycerin polyricinoleate were homogenized to prepare a W/O emulsion. Subsequently, the W/O emulsion was homogenized with an outer water phase containing UMPC to obtain a W/O/W Pickering emulsion. A gel-like inner phase emulsion with excellent storage and thermal stabilities was obtained under the condition that the W/O emulsion volume ratio was 80% and the UMPC was stabilized by 10 g kg-1. The double emulsion after loading VB12 and VE showed good encapsulation effect during the storage period, the encapsulation rate could reach more than 90%, it also showed excellent protection effect under long-time storage and UV irradiation and the retention rate increased by more than 65%. In addition, the bioavailability of VB12 and VE significantly increased during simulated gastrointestinal digestion and reached 46.02% and 52.43%, respectively.

CONCLUSION

These results indicate that the UMPC-stabilized W/O/W Pickering emulsion is an effective carrier for the codelivery of hydrophilic and hydrophobic bioactive molecules and also provides a means for useful exploration of an efficient and stable emulsion system stabilized by biological macromolecules. © 2024 Society of Chemical Industry.

A Review of Whey Protein-Based Bioactive Delivery Systems: Design, Fabrication, and Application

The efficacy of many edible bioactive agents is limited by their low water dispersibility and chemical instability in foods, as well as by their poor bioaccessibility, low absorption, and metabolism within the human gastrointestinal tract. Whey proteins are amphiphilic molecules that can be used to construct a variety of edible carrier systems that can improve the performance of bioactive ingredients. These carrier systems are being used by the food and biomedical industries to encapsulate, protect, and deliver a variety of bioactive agents. In this article, we begin by providing an overview of the molecular and functional characteristics of whey proteins, and then discuss their interactions with various kinds of bioactive agents. The ability of whey proteins to be used as building blocks to assemble different kinds of carrier systems is then discussed, including nanoparticles, hydrogels, oleogels, bigels, nanofibers, nanotubes, and nanoemulsions. Moreover, applications of these carrier systems are highlighted. Different kinds of whey protein-based carriers can be used to encapsulate, protect, and deliver bioactive agents. Each kind of carrier has its own characteristics, which make them suitable for different application needs in foods and other products. Previous studies suggest that whey protein-based carriers are particularly suitable for protecting chemically labile bioactive agents and for prolonging their release profiles. In the future, it is likely that the applications of whey protein-based carriers in the food and pharmaceutical fields will expand.

Enhancing cellulose-stabilized multiphase/Pickering emulsions systems: A molecular dynamics perspective

Cellulose stabilized multiphase systems (CSMS) have garnered significant attention due to their ultra-stabilization mechanism and vast potential across different fields. CSMS have found valuable applications in scientific disciplines, including Food Science, Pharmaceutical Science, Material Science, and related fields, owing to their beneficial attributes such as sustainability, safety, renewability, and non-toxicity. Furthermore, MPS exhibit novel characteristics that enable multiple mechanisms to produce HIPEs, aerogels, and oleogels revealing undiscovered information. Therefore, to explore the undiscovered phenomena of MPS, molecular level insights using advanced simulation/computational approaches are essential. The molecular dynamics simulation (MDS), play a valuable role in analyzing the interactions of ternary interphase. The MDS have successfully quantified the interactions of MPS by generating, visualizing, and analyzing trajectories. Through MDS, researchers have explored CSMS at the molecular level and advanced their applications in 3D printing, packaging, preparation, drug delivery, encapsulation, biosensors, electronic devices, biomaterials, and energy conservation. This review highlights the remarkable advancements in CSMS over the past five years, along with contributions of MDS in evaluating the relationships that dictate the functionality and properties of CSMS. By integrating experimental and computational methods, we underscore the potential to innovate and optimize these multiphase systems for groundbreaking applications.

Sustained-release mechanism of β-Cyclodextrin/cationic cellulose-stabilized Pickering emulsions loaded with citrus essential oil

Citrus oil (CO) is a commonly used natural flavor with high volatility, which is not conducive to sustained release under food environmental stress. This study constructed novel β-cyclodextrin/cationic cellulose nanocrystal (β-CD/C-CNC) complexes via noncovalent interaction, which were used to stabilize CO-loaded Pickering emulsions (PEβ-CD/C-CNC). The C-CNC greatly improved the physical stability, droplet dispersion and viscoelasticity of PEβ-CD/C-CNC by forming a tight network structure, as verified by rheological behavior. Moreover, C-CNC improved the wettability of β-CD/C-CNC complexes and enhanced the interaction between adjacent β-CD/C-CNC complexes. C-CNC also contributed to the interfacial viscoelasticity, hydrated mass, and layer thickness via the interfacial dilational modulus and QCM-D. β-CD/C-CNC complexes adsorbed on the oil-water interface gave rise to a dense filling layer as a physical barrier, enhancing the sustained-release performance of PEβ-CD/C-CNC by limiting diffusion of citrus essential oil into the headspace. This study provides new technical approaches for aroma retention in the food industry.

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.

Zein and tannic acid hybrid particles improving physical stability, controlled release properties, and antimicrobial activity of cinnamon essential oil loaded Pickering emulsions

Pickering emulsion loading essential oil has demonstrated a promising strategy as delivery system in food preservation, but localization in stability and antimicrobial activity limits application. In this study, Pickering emulsions co-loaded with tannic acid and cinnamon essential oil (ZTC) have been developed based on zein and tannic acid complexes (ZT) mediated interfacial engineering. Fourier transform infrared, fluorescence spectroscopy, and molecular docking results indicated tannic acid altered the structural of zein. Interfacial tension results indicated that tannic acid accelerated the adsorbed speed of zein particles by decreased interfacial tension (11.99-9.96 mN/m). ZT5 formed a viscoelastic and dense layer in oil-water interface than that for other ZTs, which improved stability and control release performance of ZTC. Furthermore, the ZTC showed an effective antimicrobial activity against spoilage organisms Pseudomonad paralactis MN10 and Lactobacillus sakei VMR17. These findings provide new insight for developing co-loaded multiple antimicrobial agents within Pickering emulsion as a delivery system.

Bioaccessibility of chlorogenic acid and curcumin co-encapsulated in double emulsions with the inner interface stabilized by functionalized silica nanoparticles

The aim of this study was to evaluate the bioaccessibility of chlorogenic acid (CA) and curcumin co-encapsulated in Pickering double emulsions (DEs) with the inner interface stabilized by hydrophobically modified silica nanoparticles with myristic acid (SNPs-C14) or tocopherol succinate (SNPs-TS). Both SNPs-C14 and SNPs-TS showed contact angles > 90°. Pickering W1/O emulsions were formulated with 4 % of both types of SNPs. Pickering DEs showed higher creaming stability (5-7 %, day 42) and higher CA encapsulation efficiency (EE; 80 %) than control DE. The EE of curcumin was > 98 % in all the DEs. CA was steadily released from Pickering DEs during digestion, achieving bioaccessibility values of 58-60 %. Curcumin was released during the intestinal phase (∼80 % bioaccessibility in all DEs). Co-loaded DEs showed similar bioaccessibility for CA and curcumin than single-loaded. SNPs-C14 and SNPs-TS were suitable to stabilize the W1:O interface of DEs as co-delivery systems of bioactive compounds with health-promoting properties.

Multiple Pickering emulsions stabilized by food-grade particles as innovative delivery systems for bioactive compounds

The most common carrier for encapsulation of bioactive components is still simple emulsion. Recently, bio-based novel emulsion systems such as multiple emulsions (MEs) and Pickering emulsions (PEs) have been introduced as innovative colloidal delivery systems for encapsulation and controlled release of bioactive compounds. Multiple PEs (MPEs), which carries both benefit of MEs and PEs could be fabricated by relatively scalable and simple operations. In comparison with costly synthetic surfactants and inorganic particles which are widely used for stabilization of both MEs and PEs, MPEs stabilized by food-grade particles, while having health-promoting aspects, are able to host the "clean label" and "green label" attributes. Nevertheless, in achieving qualified techno-functional attributes and encapsulation properties, the selection of suitable materials is a crucial step in the construction of such complex systems. Current review takes a cue from both MEs and PEs emulsification techniques to grant a robust background for designing various MPEs. Herein, various fabrication methods of MEs and PEs are described comprehensively in a physical viewpoint in order to find key conception of successful formulation of MPEs. This review also highlights the link between the underlying aspects and exemplified specimens of evidence which grant insights into the rational design of MPEs through food-based ingredients to introduces MPEs as novel colloidal/functional materials. Their utilization for encapsulation of bioactive compounds is discussed as well. In the last part, instability behavior of MPEs under various conditions will be discussed. In sum, this review aims to gain researchers who work with food-based components, basics of innovative design of MPEs.

Encapsulation of phenolic acids within food-grade carriers systems: a systematic review

Phenolic acids are natural compounds with potential therapeutic effects against various diseases. However, their incorporation into food and pharmaceutical products is limited by challenges such as instability, low solubility, and reduced bioavailability. This systematic review summarizes recent advances in phenolic acid encapsulation using food-grade carrier systems, focusing on proteins, lipids, and polysaccharides. Encapsulation efficiency, release behavior, and bioavailability are examined, as well as the potential health benefits of encapsulated phenolic acids in food products. Strategies to address limitations of current encapsulation systems are also proposed. Encapsulation has emerged as a promising method to enhance the stability and bioavailability of phenolic acids in food products, and various encapsulation technologies have been developed for this purpose. The use of proteins, lipids, and carbohydrates as carriers in food-grade encapsulation systems remains a common approach, but it is associated with certain limitations. Future research on phenolic acid encapsulation should focus on developing environmentally friendly, organic solvent-free, low-energy, scalable, and stable encapsulation systems, as well as co-encapsulation methods that combine multiple phenolic acids or phenolic acids with other bioactive substances to produce synergistic effects.

Plant gums in Pickering emulsions: A review of sources, properties, applications, and future perspectives

Recently, there has been an increasing research interest in the development of Pickering emulsions stabilized with naturally derived biopolymeric particles. In this regard, plant gums, obtained as plant exudates or from plant seeds, are considered promising candidates for the development of non-toxic, biocompatible, biodegradable and eco-friendly Pickering stabilizers. The main objective of this review article is to provide a detailed overview and assess the latest advances in the formulation of Pickering emulsions stabilized with plant gum-based particles. The plant gum sources, types and properties are outlined. Besides, the current methodologies used in the production of plant gum particles formed solely of plant gums, or through interactions of plant gums with proteins or other polysaccharides are highlighted and discussed. Furthermore, the work compiles and assesses the innovative applications of plant gum-based Pickering emulsions in areas such as encapsulation and delivery of drugs and active agents, along with the utilization of these Pickering emulsions in the development of active packaging films, plant-based products and low-fat food formulations. The last part of the review presents potential future research trends that are expected to motivate and direct research to areas related to other novel food applications, as well as tissue engineering and environmental applications.

Modified Amber Particles as a Stabilizer to Construct Oil-in-Water Pickering Emulsions for Improved Thermal Stability of Acorus tatarinowii Essential Oil

Lingzhu Pulvis is a classic formulation for treating febrile convulsions in children. However, Acorus tatarinowii essential oil (AT-EO) in this prescription is prone to volatilization and oxidation, compromising the efficacy and quality control of this formulation. Herein, based on the concept of "combination of medicine and adjuvant", Pickering emulsion technology was applied to enhance the stability of AT-EO using modified amber as a stabilizer. Amber was a resinous medicinal powder in Lingzhu Pulvis and was modified into a suitable stabilizer for Pickering emulsion through surface modification. A thermal stability study indicated that Pickering emulsion, stabilized by modified amber, exhibited a higher retention rate of AT-EO and lower levels of peroxide value and malondialdehyde content compared to those of the pure AT-EO group after heat treatment at 40 °C for 1, 3, and 8 h. Additionally, component analysis in content and composition revealed that the volatile components of AT-EO in the Pickering emulsion were more stable during the thermal treatment process. This study convincingly illustrates the potential of a Pickering emulsion stabilized with modified medicinal powders to improve the thermal stability of the essential oil.

General approaches to biopolymer-based Pickering emulsions

Pickering emulsion is a type of emulsion that uses solid particles or colloidal particles as emulsifiers rather than surfactants to adhere at oil-water interface. Pickering emulsions have gathered significant research attention recently due to their excellent stability and wide range of potential uses compared to traditional emulsions. Major advancements have been made in development of innovative Pickering emulsions using different colloidal particles by various techniques including homogenization, emulsification and ultrasonication. Use of biopolymer particles gives Pickering emulsions a more escalating possibilities. In this review paper, we seek to present a critical overview of development in food-grade particles that have been utilized to create Pickering emulsions with a focus on techniques and application of Pickering emulsions. Particularly, we have evaluated protein, lipid, polysaccharide-based particles and microalgal proteins that have emerged in recent years with respect to their potential to stabilize and add novel functionalities to Pickering emulsions. Some preparation methods of Pickering emulsions in brief, applications of Pickering emulsions are also highlighted. Encapsulation and delivery of bioactive compounds, fat substitutes, film formation and catalysis are potential applications of Pickering emulsions. Pickering double emulsions, nutraceutical and bioactive co-delivery, and preparation of porous materials are among research trends of food-grade Pickering emulsions.

Catalytic and biomedical applications of nanocelluloses: A review of recent developments

Nanocelluloses exhibit immense potential in catalytic and biomedical applications. Their unique properties, biocompatibility, and versatility make them valuable in various industries, contributing to advancements in environmental sustainability, catalysis, energy conversion, drug delivery, tissue engineering, biosensing/imaging, and wound healing/dressings. Nanocellulose-based catalysts can efficiently remove pollutants from contaminated environments, contributing to sustainable and cleaner ecosystems. These materials can also be utilized as drug carriers, enabling targeted and controlled drug release. Their high surface area allows for efficient loading of therapeutic agents, while their biodegradability ensures safer and gradual release within the body. These targeted drug delivery systems enhance the efficacy of treatments and minimizes side effects. Moreover, nanocelluloses can serve as scaffolds in tissue engineering due to their structural integrity and biocompatibility. They provide a three-dimensional framework for cell growth and tissue regeneration, promoting the development of functional and biologically relevant tissues. Nanocellulose-based dressings have shown great promise in wound healing and dressings. Their ability to absorb exudates, maintain a moist environment, and promote cell proliferation and migration accelerates the wound healing process. Herein, the recent advancements pertaining to the catalytic and biomedical applications of nanocelluloses and their composites are deliberated, focusing on important challenges, advantages, limitations, and future prospects.

Self-constructed water-in-oil Pickering emulsions as a tool for increasing bioaccessibility of betulin

Self-constructed water-in-oil emulsions can be stabilized by a natural pentacyclic triterpenoid, betulin. A higher betulin concentration (3%) results in smaller emulsion droplet sizes. Microscopy, confocal laser scanning microscopy and rheology indicate that the stabilizing mechanism is attributed to betulin crystals on the emulsion interface and within the continuous phase, thereby enabling excellent freeze/thaw and thermal stability. The betulin Pickering emulsion (1%) significantly increased betulin bioaccessibility (22.4%) compared to betulin alone (0.2%) and betulin-oil physical mixture (7.9%). A higher level of betulin at 3% leads to smaller emulsion particle size, potentially resulting in a greater surface area. This, in return, promotes a higher release of free fatty acids (FFA), contributing to the release and solubilization of betulin from emulsions. Additionally, it leads to the formation of micelles, further increasing betulin bioaccessibility (29.3%). This study demonstrates Pickering emulsions solely stabilized by phytochemical betulin provides an innovative way to improve its bioaccessibility.

Antioxidant properties of bovine liver protein hydrolysates and their practical application in biphasic systems

BACKGROUND

The influence of protein hydrolysate produced from bovine liver protein hydrolysate (LPH) by enzymatic hydrolysis, using Alcalase/Protamex (1:1), on lipid dispersions was investigated. LPH production was optimized to maximize the antioxidant activity (at 45, 50, and 55 °C for 12, 18, and 24 h). Different concentrations of LPHs (1, 3, and 5 mg/g) were added to emulsions and to liposomes. Lipid oxidation level and particle size of the lipid dispersions were monitored for 14 days of storage at 25 °C.

RESULTS

Radical scavenging activity and reducing power were the highest at 45 °C after 24 h of hydrolysis. Electrophoresis pattern showed that the antioxidant activity was arising from the peptides with molecular weight around 10 kDa. Lipid oxidation occurred more rapidly in samples without LPH during storage. In emulsions, lower thiobarbituric acid-reactive substance and conjugated diene values were measured with increasing concentrations of LPH at day 14. Accordingly, particle size of the samples containing 5 mg/g of LPH was smaller than those of other groups. Phase separation was observed only in lecithin emulsion without LPH at day 14. The use of LPH in liposome limited the lipid oxidation and maintained the size of the particles independently from the concentration.

CONCLUSION

This study highlights the potential applications of animal by-products as natural antioxidants in complex food systems. The results demonstrate that LPH, particularly when hydrolyzed at optimized conditions, can effectively inhibit lipid oxidation. The findings suggest that biphasic systems incorporating LPH have promising prospects for enhancing the stability and quality of food products. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Proteinaceous Microsphere-Based Water-in-Oil Pickering Emulsions for Preservation of Chlorella Cells

Microalgae are highly regarded as ideal materials for the creation of liquid biofuels and have substantial potential for growth and utilization. However, traditional storage and culture methods for microalgae are plagued by challenges such as uncontrolled growth, bacterial contamination, and self-shading among algae. These issues severely impede the photosynthetic process and the efficient extraction of biomass energy. This study tackles these problems by utilizing magnetic hydrophobic protein particles to stabilize water-in-oil Pickering emulsions. This allows for the micro-compartment storage and magnetic transfer of algae. Additionally, the successful encapsulation of Chlorella cells in high-internal-phase water-in-oil Pickering emulsions effectively mitigates the settling problem of Chlorella cells in the liquid phase, thereby enabling the potential use of Pickering emulsions for the confined cultivation of microalgae.

From Nature-Sourced Polysaccharide Particles to Advanced Functional Materials

Polysaccharides constitute over 90% of the carbohydrate mass in nature, which makes them a promising feedstock for manufacturing sustainable materials. Polysaccharide particles (PSPs) are used as effective scavengers, carriers of chemical and biological cargos, and building blocks for the fabrication of macroscopic materials. The biocompatibility and degradability of PSPs are advantageous for their uses as biomaterials with more environmental friendliness. This review highlights the progresses in PSP applications as advanced functional materials, by describing PSP extraction, preparation, and surface functionalization with a variety of functional groups, polymers, nanoparticles, and biologically active species. This review also outlines the fabrication of PSP-derived macroscopic materials, as well as their applications in soft robotics, sensing, scavenging, water harvesting, drug delivery, and bioengineering. The paper is concluded with an outlook providing perspectives in the development and applications of PSP-derived materials.

Progress of Drug Nanocrystal Self-Stabilized Pickering Emulsions: Construction, Characteristics In Vitro, and Fate In Vivo

A drug nanocrystal self-stabilized Pickering emulsion (DNSPE) is a novel Pickering emulsion with drug nanocrystals as the stabilizer. As a promising drug delivery system, DNSPEs have attracted increasing attention in recent years due to their high drug loading capacity and ability to reduce potential safety hazards posed by surfactants or specific solid particles. This paper comprehensively reviews the progress of research on DNSPEs, with an emphasis on the main factors influencing their construction, characteristics and measurement methods in vitro, and fate in vivo, and puts forward issues that need to be studied further. The review contributes to the advancement of DNSPE research and the promotion of their application in the field of drug delivery.

Chitosan-based food-grade Pickering emulsion loading with Rosa roxburghii extract against precancerous lesions of gastric carcinoma

Precancerous lesions of gastric carcinoma (PLGC) are the most important stage in the development of gastric cancer, accompanied by significant oxidative stress and inflammatory response. Rosa roxburghii extract (RRE) has unique advantages in anti-PLGC due to its multi-component, high antioxidant and anti-inflammatory activities. However, the astringency and instability of RRE in the digestive tract seriously hinder its clinical application. Herein, we report a chitosan-based food-grade Pickering emulsion (PE) for loading RRE to block unpleasant taste, improve stability, and promote the entry of RRE into gastric epithelial cells through the gastric adhesion of chitosan, thereby enhancing preventive and therapeutic effects against PLGC. This Pickering emulsion is constructed as a water-in-oil (W/O) emulsion stabilized by the food-grade nanoparticles composed of soybean protein isolate (SPI) and chitosan (CS) through electrostatic interaction (defined as RRE@PE). The experimental results showed that RRE@PE performed better efficacy against PLGC than RRE by scavenging or inhibiting reactive oxygen species generation and reducing inflammatory cytokines. This Pickering emulsion enhances the application potential of RRE and is expected to be used for the treatment of clinical patients with PLGC.

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

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

Salt-Promoted Fibrillation of Legume Proteins Enhanced Interfacial Modulus for Stabilization of HIPEs Encapsulating Carotenoids with Improved Nutritional Performance

The thermal acidic-treatment-induced fibrillation of legume proteins isolated from cowpea and mung bean was demonstrated to be promoted by salt. Worm-like thin prefibrilar intermediates were formed in low salt concentrations (0-75 mM), which twisted to be the thick and mature amyloid-like fibrils with multistrands as the salt content was elevated (150-300 mM). Absorption of the fibrils fabricated in high salt concentrations to the oil/water interface constructed the protein layer with a significantly higher interfacial modulus compared with the one formed by the fibrils fabricated in low salt concentrations. Consequently, they showed the superiority in stabilizing high internal phase emulsions (HIPEs) with oil volume fraction ratios higher than 74%. HIPEs stabilized by the high salt-concentration-induced legume protein fibrils had stronger capabilities not only in encapsulating liposoluble carotenoids but also in protecting their stability against heating, ultraviolet, and iron ion stimulus, compared with the one stabilized by the low-salt-concentration-induced legume protein fibrils. Bioaccessibilities of the carotenoids in simulating gastrointestinal (GI) digestion were significantly improved after encapsulation by the HIPEs, which were interestingly increased with the elevation of salt concentrations utilized for preparing the legume protein fibrils. Furthermore, the carotenoids-loading-HIPEs were injectable and showed in vivo nutritional functions of mitigating colitis.

Nanoscale Pickering emulsion food preservative films/coatings: Compositions, preparations, influencing factors, and applications

Pickering emulsion (PE) technology effectively addresses the issues of poor compatibility and low retention of hydrophobic active ingredients in food packaging. Nonetheless, it is important to recognize that each stage of the preparation process for PE films/coatings (PEFCs) can significantly influence their functional properties. With the fundamental considerations of environmental friendliness and human safety, this review extensively explores the potential of raw materials for PEFC and introduces the preparation methods of nanoparticles, emulsification technology, and film-forming techniques. The critical factors that impact the performance of PEFC during the preparation process are analyzed to enhance food preservation effectiveness. Moreover, the latest advancements in PE packaging across diverse food applications are summarized, along with prospects for innovative food packaging materials. Finally, the preservation mechanism and application safety have been systematically elucidated. The study revealed that the PEFCs provide structural flexibility, where designable nanoparticles offer unique functional properties for intelligent control over active ingredient release. The selection of the dispersed and continuous phases, along with component proportions, can be customized for specific food characteristics and storage conditions. By employing suitable preparation and emulsification techniques, the stability of the emulsion can be improved, thereby enhancing the effectiveness of the films/coatings in preserving food. Including additional substances broadens the functionality of degradable materials. The PE packaging technology provides a safe and innovative solution for extending the shelf life and enhancing the quality of food products by protecting and releasing active components.

Survivability of probiotics in Pickering emulsion gels stabilized by salmon by-product protein / sodium alginate soluble complexes at neutral pH

Adequate amounts of live probiotics reaching the gut are necessary to maintain host health. However, the harsh environment during processing, the low pH of human gastric acid, and the high concentration of bile salts in the gut can significantly reduce survivability of probiotics. In this work, we propose a simple Pickering emulsion gels strategy to encapsulate Lactobacillus plantarum Lp90 into oil droplets filled in calcium alginate gels to improve its viability under pasteurization and gastrointestinal conditions. The emulsion gels were stabilized by the soluble complexes of salmon by-product protein (SP) and sodium alginate (ALG), and the aqueous phase was solidified by the addition of calcium. The interaction between SP and ALG and the effect of ALG concentration on emulsifying ability and emulsion stability were studied. The results from optical imaging, nuclear magnetic resonance, and rheological properties showed that the stability and viscosity of the emulsions gradually increased with the increased ALG concentration, while the droplet size of the emulsions and the content of free water in the system decreased significantly. Especially when the concentration of ALG was 1 %, the emulsion system was stable under the environment of high temperature and high ionic strength, and the water holding capacity was the highest. Through pasteurization and gastrointestinal digestion experiments, it was found that the survival rate of probiotics encapsulated in emulsion gels was significantly higher than that encapsulated in emulsions or hydrogels, which benefited from the dual action of oil droplets and calcium alginate gels network. These results provide a new strategy for the processing of probiotics and the high-value utilization of marine fish by-products.

Noncovalent interactions between biomolecules facilitated their application in food emulsions' construction: A review

The use of biomolecules, such as proteins, polysaccharides, saponins, and phospholipids, instead of synthetic emulsifiers in food emulsion creation has generated significant interest among food scientists due to their advantages of being nontoxic, harmless, edible, and biocompatible. However, using a single biomolecule may not always meet practical needs for food emulsion applications. Therefore, biomolecules often require modification to achieve ideal interfacial properties. Among them, noncovalent interactions between biomolecules represent a promising physical modification method to modulate their interfacial properties without causing the health risks associated with forming new chemical bonds. Electrostatic interactions, hydrophobic interactions, and hydrogen bonding are examples of noncovalent interactions that facilitate biomolecules' effective applications in food emulsions. These interactions positively impact the physical stability, oxidative stability, digestibility, delivery characteristics, response sensitivity, and printability of biomolecule-based food emulsions. Nevertheless, using noncovalent interactions between biomolecules to facilitate their application in food emulsions still has limitations that need further improvement. This review introduced common biomolecule emulsifiers, the promotion effect of noncovalent interactions between biomolecules on the construction of emulsions with different biomolecules, their positive impact on the performance of emulsions, as well as their limitations and prospects in the construction of biomolecule-based emulsions. In conclusion, the future design and development of food emulsions will increasingly rely on noncovalent interactions between biomolecules. However, further improvements are necessary to fully exploit these interactions for constructing biomolecule-based emulsions.

Media-milled agar particles as a novel emulsifier for food Pickering emulsion

Pickering emulsions was successfully fabricated using ball-milled agar particles with sizes and sulfate content around 7 μm and 0.62 %, respectively. These particles were obtained through a simple media-milling process using agar powders initially sized at 120 μm. The lamellated agar is aggregated into a mass after the milling process. The surface charge and hydrophobicity of the ball-milled agar particles were characterized through zeta potential and contact angle measurements, respectively. The droplet size of Pickering emulsions was related to oil fraction and particle concentration, ranging from approximately 45 μm to 80 μm. Ball-milled agar stabilized emulsions were sensitive to pH and salt conditions. The results of confocal laser scanning microscopy and cryo-SEM showed that at low particle concentrations and oil fractions, ball-milled agar stabilized the emulsions by dispersing particles on the surface of the oil droplets through electrostatic repulsion. Conversely, ball-milled agar stabilized the emulsions under high particle concentrations and oil fractions by forming a gel network structure to bind the oil droplets. In this research, this developed method provides the basis for the high-value application of agar and a new idea for preparing stable food-grade Pickering emulsion-based functional foods using raw-food material without surface wettability.

Formation Mechanism of Starch-Based Double Emulsions from the Interfacial Perspective

Double emulsions are of significant practical value in protecting the core material owing to their multicomponent structure and have thus been applied in various fields, such as food, cosmetics, and drugs. However, the mechanism of double emulsion formation by native starch is not well established. Herein, we demonstrate a facile route to develop type-A, type-B, and type-C double emulsions using native starch and develop an innovative design for a carrier. Interfacial interaction, enthalpy changes of starch, and interfacial properties are key factors governing the formation of double emulsions and controlling the type of double emulsions formed. Therefore, the results of this study provide a better understanding of how and what type of starch-based double emulsions are formed.

Co-Delivery System of Vitamin B12 and Vitamin E Using a Binary W/O/W Emulsion Based on Soybean Isolate Protein-Xanthan Gum/Carrageenan: Emulsification Properties, Rheological Properties, Structure, Stability, and Digestive Characteristics

In this study, the soybean protein isolate (SPI)-xanthan gum (XG) or carrageenan (CA) W/O/W emulsions for the co-delivery of vitamin B12 and vitamin E were prepared. The effects of XG and CA concentrations on the physicochemical properties and digestive characteristics of the emulsions were also investigated. The addition of XG and CA improved the SPI aggregation and increased its electrostatic repulsion so that more SPI was adsorbed at the phase interface. The emulsifying activity index and emulsifying stability index increased to 24.09 (XG 0.4%) and 14.00 (CA 0.5%) and 151.08 (XG 0.4%) and 135.34 (CA 0.5%), respectively. The adsorbed protein content increased to 88.90% (XG 0.4%) and 88.23% (CA 0.5%), respectively. Moreover, the encapsulation efficiencies of vitamin B12 and vitamin E were increased to 86.72% (XG 0.4%) and 86.47 (CA 0.5%) and 86.31% (XG 0.4%) and 85.78% (CA 0.5%), respectively. The bioaccessibility of vitamin B12 and vitamin E increased to 73.53% (XG 0.4%) and 71.32% (CA 0.5%) and 68.86% (XG 0.4%) and 68.74% (CA 0.5%). The best properties of the emulsions were obtained at a 0.4% concentration of XG and 0.5% of CA. This study offers a novel system for delivering bioactive substances, which is favorable for the advancement of food with delivery capability in food processing.

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.

Intestine-targeted high internal phase Pickering emulsion formulated using silkworm pupa protein via ultrasonic treatment

High internal phase Pickering emulsions (HIPPEs) stabilized by food grade particles have received much attention as deliver vehicles for bioactives in recent years. In this study, ultrasonic treatment was conducted to regulate the size of silkworm pupa protein (SPP) particles, fabricating oil-in-water (O/W) HIPPEs with intestinal releasability. Briefly, the pretreated SPP and SPP-stabilized HIPPEs were characterized, and the targeting release was investigated using in vitro gastrointestinal simulations and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Results revealed ultrasonic treatment time was the key factor regulating emulsification performance and stability of HIPPEs. Optimized SPP particles were obtained based on their size and zeta potential of 152.67 nm and 26.77 mV, respectively. With ultrasonic treatment, the hydrophobic groups in the secondary structure of SPP were exposed, facilitating the formation of a stable oil-water interface for HIPPEs. Additionally, SPP-stabilized HIPPE showed high stable against the gastric digestion. The SPP with 70 kDa molecular weight, which was the major interfacial proteins of the HIPPE, can be hydrolyzed by intestinal digestive enzymes, enabling the intestine-targeted release of the emulsion. Overall, in the present study, a facile method was developed to stabilize HIPPEs using solo SPP with ultrasonic treatment to protect and deliver hydrophobic bioactive ingredients.

Alginate-based materials for enzyme encapsulation

Enzymes are widely used in industry due to their high efficiency and selectivity. However, their low stability during certain industrial processes can result in a significant loss of catalytic activity. Encapsulation is a promising technique that can stabilize enzymes by protecting them from environmental stresses such as extreme temperature and pH, mechanical force, organic solvents, and proteases. Alginate and alginate-based materials have emerged as effective carriers for enzyme encapsulation due to their biocompatibility, biodegradability, and ability to form gel beads through ionic gelation. This review presents various alginate-based encapsulation systems for enzyme stabilization and explores their applications in different industries. We discuss the preparation methods of alginate encapsulated enzymes and analyze the release mechanisms of enzymes from alginate materials. Additionally, we summarize the characterization techniques used for enzyme-alginate composites. This review provides insights into the use of alginate encapsulation as a means of stabilizing enzymes and highlights the potential benefits for various industrial applications.

Starch-based Janus particle: Fabrication, characterization and interfacial properties in stabilizing Pickering emulsion

Janus particles (J-OSPs) based on the composite of chitosan nanoparticles (CSNPs) and octadecenyl succinic anhydride starch (OSPs) were tailor-made by Pickering emulsion method and electrostatic interaction. With different positions of OSPs embedded in the oil phase of Pickering emulsion template and the diversified shapes of starch particles, J-OSPs exhibited various asymmetric structures, which was verified by scanning electron microscope (SEM) and confocal laser microscope (CLSM). By characterizing the interfacial characteristics of J-OSPs, directional distribution of CSNPs was found to enhance the hydrophobicity of J-OSPs and changed its surface charges from positive to negative as pH increased. When J-OSPs were taken as stabilizers, the formed Pickering emulsion had the highest emulsion index and viscosity compared with OSPs and OSPs fully covered by CSNPs (F-OSPs), which was attributed to the self-assembly property of Janus particles that enabled them to form larger aggregates to hinder the collapse of droplets. This study provides a new idea for the construction of plant-derived Janus particles, and its superiority in stabilizing the Pickering emulsion will broaden the application of Janus particles in the field of storage and delivery of active substances.

Formulation and Characterization of Emulgel-Based Jelly Candy: A Preliminary Study on Nutraceutical Delivery

The development of consumer-friendly nutraceutical dosage forms is highly important for greater acceptance. In this work, such dosage forms were prepared based on structured emulsions (emulgels), where the olive oil phase was filled within the pectin-based jelly candy. The emulgel-based candies were designed as bi-modal carriers, where oil-soluble curcumin and water-soluble riboflavin were incorporated as the model nutraceuticals. Initially, emulsions were prepared by homogenizing varied concentrations (10% to 30% (w/w)) of olive oil in a 5% (w/w) pectin solution that contained sucrose and citric acid. Herein, pectin acted as a structuring agent-cum-stabilizer. Physico-chemical properties of the developed formulations were thoroughly analyzed. These studies revealed that olive oil interferes with the formation of polymer networks of pectin and the crystallization properties of sugar in candies. This was confirmed by performing FTIR spectroscopy and DSC studies. In vitro disintegration studies showed an insignificant difference in the disintegration behavior of candies, although olive oil concentration was varied. Riboflavin and curcumin were then incorporated into the jelly candy formulations to analyze whether the developed formulations could deliver both hydrophilic and hydrophobic nutraceutical agents. We found that the developed jelly candy formulations were capable of delivering both types of nutraceutical agents. The outcome of the present study may open new directions for designing and developing oral nutraceutical dosage forms.

A Bioactive Compound-Loaded Zinc-Aminoclay Encapsulated, Pickering Emulsion System for Treating Acne-Inducing Microbes

Acne is a common skin condition caused by the growth of certain bacteria. Many plant extracts have been investigated for their potential to combat acne-inducing microbes, and one such plant extract is microwave-assisted Opuntia humifusa extract (MA-OHE). The MA-OHE was loaded onto zinc-aminoclay (ZnAC) and encapsulated in a Pickering emulsion system (MA-OHE/ZnAC PE) to evaluate its therapeutic potential against acne-inducing microbes. Dynamic light scattering and scanning electron microscopy were used to characterize MA-OHE/ZnAC PE with a mean particle diameter of 353.97 nm and a PDI of 0.629. The antimicrobial effect of MA-OHE/ZnAC was evaluated against Staphylococcus aureus (S. aureus) and Cutibacterium acnes (C. acnes), which contribute to acne inflammation. The antibacterial activity of MA-OHE/ZnAC was 0.1 and 0.025 mg/mL to S. aureus and C. acnes, respectively, which were close to naturally derived antibiotics. Additionally, the cytotoxicity of MA-OHE, ZnAC, and MA-OHE/ZnAC was tested, and the results showed that they had no cytotoxic effects on cultured human keratinocytes in a range of 10-100 μg/mL. Thus, MA-OHE/ZnAC is suggested to be a promising antimicrobial agent for treating acne-inducing microbes, while MA-OHE/ZnAC PE is a potentially advantageous dermal delivery system.

Properties of Pickering emulsions stabilized by cellulose nanocrystals extracted from litchi peels

The development of Pickering emulsions which are applicable to the food industry still remains challenges due to the limited availability for biocompatible, edible and natural emulsifiers. The purpose of this study was to extract cellulose nanocrystals from litchi peels (LP-CNCs), and evaluate their emulsifying properties. The results showed that the LP-CNCs were needle-like and they possessed high crystallinity (72.34 %) and aspect ratio. When the concentrations of LP-CNCs were >0.7 wt% or the contents of oil were no >0.5, stable Pickering emulsions were obtained. The microstructures of emulsions confirmed that LP-CNCs formed dense interfacial layers on the surface of oil droplets, which functioned as barriers to prevent aggregation and flocculation among droplets. Rheological results showed that the emulsions exhibited typical shear thinning behavior. The elastic of emulsions was dominant, and their gel strength could be enhanced by regulating the contents of emulsifiers or oil. Additionally, the Pickering emulsions stabilized by LP-CNCs showed extremely high pH, ionic strength, and temperature tolerance. This strategy provides an innovative alternative to tackle the dilemma of preparing highly stable Pickering emulsions using natural particles in food products.

Pickering emulsion stabilized by casein-caffeic acid covalent nanoparticles to enhance the bioavailability of curcumin in vitro and in vivo

BACKGROUND

In recent years, the design of food-grade Pickering emulsion delivery systems has become an effective strategy for improving the low bioavailability of bioactive substances. Protein-based Pickering emulsions have received extensive attention because of a high biocompatibility and loading capacity. The bioavailability of active substances is mainly evaluated by simulating in vitro gastrointestinal digestion. As a model organism for antioxidation and anti-aging, Caenorhabditis elegans can provide additional biological information for the in vivo utilization of active substances.

RESULTS

After the introduction of caffeic acid, the average particle size and Zeta potential of the casein-caffeic acid covalent complex nanoparticles (CCP) were 171.11 nm and - 37.73 mV, respectively. The three-phase contact angle was also increased to 89.8°. By using CCP to stabilize Pickering emulsion (CCE), the retention quantity of the embedded curcumin increased by 2.19-fold after 28 days. In the simulated gastric digestion, curcumin degradation in CCE was reduced by 61.84%, released slowly in the intestinal environment, and the final bioaccessibility was increased by 1.90-fold. In C. elegans, CCE significantly reduced ROS accumulation, increased SOD activity by 2.01-fold and CAT activity by 2.30-fold, decreased MDA content by 36.76%, prolonging the lifespan of nematodes by 13.33% under H₂ O₂ stimulation and improving bioavailability in vivo.

CONCLUSION

The results indictae that CCP-stabilized Pickering emulsion can efficiently implement the physiological activities of bioactive compounds in vitro digestion and C. elegans, and thus it can be regarded as a reliable delivery system for food and medicine. © 2023 Society of Chemical Industry.

Cellulose nanocrystalline from biomass wastes: An overview of extraction, functionalization and applications in drug delivery

Cellulose nanocrystals (CNC) have been extensively used in various fields due to their renewability, excellent biocompatibility, large specific surface area, and high tensile strength. Most biomass wastes contain significant amounts of cellulose, which forms the basis of CNC. Biomass wastes are generally made up of agricultural waste, and forest residues, etc. CNC can be produced from biomass wastes by removing the non-cellulosic components through acid hydrolysis, enzymatic hydrolysis, oxidation hydrolysis, and other mechanical methods. However, biomass wastes are generally disposed of or burned in a random manner, resulting in adverse environmental consequences. Hence, using biomass wastes to develop CNC-based carrier materials is an effective strategy to promote the high value-added application of biomass wastes. This review summarizes the advantages of CNC applications, the extraction process, and recent advances in CNC-based composites, such as aerogels, hydrogels, films, and metal complexes. Furthermore, the drug release characteristics of CNC-based material are discussed in detail. Additionally, we discuss some gaps in our understanding of the current state of knowledge and potential future directions of CNC-based materials.

Food-Grade Oil-in-Water (O/W) Pickering Emulsions Stabilized by Agri-Food Byproduct Particles

In recent years, emulsions stabilized by solid particles (known as Pickering emulsions) have gained considerable attention due to their excellent stability and for being environmentally friendly compared to the emulsions stabilized by synthetic surfactants. In this context, edible Pickering stabilizers from agri-food byproducts have attracted much interest because of their noteworthy benefits, such as easy preparation, excellent biocompatibility, and unique interfacial properties. Consequently, different food-grade particles have been reported in recent publications with distinct raw materials and preparation methods. Moreover, emulsions stabilized by solid particles can be applied in a wide range of industrial fields, such as food, biomedicine, cosmetics, and fine chemical synthesis. Therefore, this review aims to provide a comprehensive overview of Pickering emulsions stabilized by a diverse range of edible solid particles, specifically agri-food byproducts, including legumes, oil seeds, and fruit byproducts. Moreover, this review summarizes some aspects related to the factors that influence the stabilization and physicochemical properties of Pickering emulsions. In addition, the current research trends in applications of edible Pickering emulsions are documented. Consequently, this review will detail the latest progress and new trends in the field of edible Pickering emulsions for readers.

Dual (pH and thermal) stimuli-responsive Pickering emulsion stabilized by chitosan-carrageenan composite microgels

Formulation of water-in-oil (W/O) Pickering emulsion (PE) for food applications has been largely restricted by the limited choices of food-grade Pickering emulsifiers. In this study, composite microgels made of chitosan and carrageenan were explored as a dual (pH and thermal) stimuli-responsive Pickering emulsifier for the stabilization of W/O PE. The chitosan-carrageenan (CS-CRG) composite microgels not only exhibited pH- and thermo-responsiveness, but also displayed enhanced lipophilicity as compared to the discrete polymers. The stability of the CS-CRG-stabilized W/O PE system (CS-CRG PE) was governed by CS:CRG mass ratio and oil fractions used. The CS-CRG PE remained stable at acidic pH and at temperatures below 40 °C. The instability of CS-CRG composite microgels at alkaline pH and at temperatures above 40 °C rendered the demulsification of CS-CRG PE. This stimuli-responsive W/O PE could unlock new opportunities for the development of stimuli-responsive W/O PE using food-grade materials.

Polysaccharide Nanofiber-Stabilized Pickering Emulsion Microparticles Induce Pyroptotic Cell Death in Hepatocytes and Kupffer Cells

The intracellular uptake and interaction behavior of emulsion microparticles in liver cells critical to host defense and inflammation is significant to understanding their potential cytotoxicity and biomedical applications. In this study, the cell death responses of fibroblastic, hepatocyte, and Kupffer cells (KCs) induced by four types of emulsion particles that are stabilized by polysaccharide nanofibers (cellulose or chitin), an inorganic nanoparticle (β-tricalcium phosphate), or surfactants are compared. Pickering emulsion (PE) microparticles stabilized by polysaccharide nanofibers or inorganic nanoparticles have a droplet size of 1-3 µm, while the surfactant-stabilized emulsion has a diameter of ≈190 nm. Polysaccharide nanofiber-stabilized PEs (PPEs) markedly induce lactate dehydrogenase release in all cell types. Additionally, characteristic pyroptotic cell death, which is accompanied by cell swelling, membrane blebbing, and caspase-1 activation, occurs in hepatocytes and KCs. These PE microparticles are co-cultured with lipopolysaccharide-primed KCs associated with cytokine interleukin-1β release, and the PPEs demonstrate biological activity as a mediator of the inflammation response. Well-designed PPE microparticles induce pyroptosis of liver cells, which may provide new insight into regulating inflammation-related diseases for designing potent anticancer drugs and vaccine adjuvants.

Preparation and Characterization of a Novel Natural Quercetin Self-Stabilizing Pickering Emulsion

In contrast to their well-known physiological properties, phytochemicals, such as flavonoids, have been less frequently examined for their physiochemical properties (e.g., surface activity). A natural quercetin self-stabilizing Pickering emulsion was fabricated and characterized in the present study. The antisolvent precipitation method was used to modify quercetin (in dihydrate form), and the obtained particles were characterized by light microscope, atom force microscope, XRD, and contact angle. The antisolvent treatment was found to reduce the particle size, crystallinity, and surface hydrophobicity of quercetin. We then examined the effects of the antisolvent ratio, particle concentration, and oil fraction on the properties of the quercetin particle-stabilized emulsions. In addition, increasing the antisolvent ratio (1:1~1:10) effectively improved the emulsification performance of the quercetin particles. The emulsion showed good storage stability, and the particle size of the emulsion decreased with the rising particle concentration and increased with the rising oil phase ratio. The findings indicate that natural quercetin treated with antisolvent method has a good ability to stabilize Pickering emulsion, and this emulsion may have good prospective application potential for the development of novel and functional emulsion foods.

Pickering emulsions stabilized by Chlorella pyrenoidosa protein-chitosan complex for lutein encapsulation

Lutein has many physiological functions like antioxidation, anti-cancer, and anti-inflammation, which presents good potential in the development of functional food for eye protection. However, the hydrophobicity and harsh environment factors during digestive absorption process will greatly reduce lutein bioavailability. In this study, Chlorella pyrenoidosa protein-chitosan complex stabilized Pickering emulsions were prepared, and lutein was encapsulated into corn oil droplets to increase its stability and bioavailability in gastrointestinal digestion. The interaction between Chlorella pyrenoidosa protein (CP) and chitosan (CS), and the effect of chitosan concentration on the emulsifying ability of the complex and emulsion stability were studied. With the increase of CS concentration from 0% to 0.8%, the emulsion droplet size obviously decreased, and the emulsion stability and viscosity increased significantly. In particular, when the concentration was 0.8%, the emulsion system was stable at 80 °C and 400 mM sodium chloride. After ultraviolet irradiation for 48 h, the retention rate of lutein encapsulated in Pickering emulsions was 54.33%, which was significantly higher than that (30.67%) of lutein dissolved in corn oil. The retention rate of lutein in Pickering emulsions stabilized by CP-CS complex was significantly higher than that in Pickering emulsions stabilized by CP only and corn oil after heating at 90 °C for 8 h. The results of simulated gastrointestinal digestion showed that the bioavailability of lutein encapsulated in Pickering emulsions stabilized by CP-CS complex reached 44.83%. These results explored the high-value utilization of Chlorella pyrenoidosa and provided new insights into the preparation of Pickering emulsions and the protection for lutein.

A comprehensive review of protein-based carriers with simple structures for the co-encapsulation of bioactive agents

The rational design and fabrication of edible codelivery carriers are important to develop functional foods fortified with a plurality of bioactive agents, which may produce synergistic effects in increasing bioactivity and functionality to target specific health benefits. Food proteins possess considerable functional attributes that make them suitable for the delivery of a single bioactive agent in a wide range of platforms. Among the different types of protein-based carriers, protein-ligand nanocomplexes, micro/nanoparticles, and oil-in-water (O/W) emulsions have increasingly attracted attention in the codelivery of multiple bioactive agents, due to the simple and convenient preparation procedure, high stability, matrix compatibility, and dosage flexibility. However, the successful codelivery of bioactive agents with diverse physicochemical properties by using these simple-structure carriers is a daunting task. In this review, some effective strategies such as combined functional properties of proteins, self-assembly, composite, layer-by-layer, and interfacial engineering are introduced to redesign the carrier structure and explore the encapsulation of multiple bioactive agents. It then highlights success stories and challenges in the co-encapsulation of multiple bioactive agents within protein-based carriers with a simple structure. The partition, protection, and release of bioactive agents in these protein-based codelivery carriers are considered and discussed. Finally, safety and application as well as challenges of co-encapsulated bioactive agents in the food industry are also discussed. This work provides a state-of-the-art overview of protein-based particles and O/W emulsions in co-encapsulating bioactive agents, which is essential for the design and development of novel functional foods containing multiple bioactive agents.

Chitosan-based Pickering emulsion: A comprehensive review on their stabilizers, bioavailability, applications and regulations

BACKGROUND

Chitosan-based particles are one of the most promising Pickering emulsions stabilizers due to its cationic properties, cost-effective, biocompatibility, biodegradability. However, there are currently no comprehensive reviews analyzing the role of chitosan to develop Pickering emulsions, and the bioavailability and multiple uses of these emulsions.

SCOPE AND APPROACH

This review firstly summarizes the types, preparation and functional properties of chitosan-based Pickering emulsion stabilizers, followed by in vivo and in vitro bioavailability, main regulations, and future application and trends.

KEY FINDINGS AND CONCLUSIONS

Stabilizers used in chitosan-based Pickering emulsions include 6 categories: chitosan self-aggregating particles and 5 types of composites (chitosan-protein, chitosan-polysaccharide, chitosan-fatty acid, chitosan-polyphenol, and chitosan-inorganic). Chitosan-based Pickering emulsions improved the bioavailability of different compounds compared to traditional emulsions. Current applications include hydrogels, microcapsules, food ingredients, bio-based films, cosmeceuticals, porous scaffolds, environmental protection agents, and interfacial catalysis systems. However, due to current limitations, more research and development are needed to be extensively explored to meet consumer demand, industrial manufacturing, and regulatory requirements. Thus, optimization of stabilizers, bioavailability studies, 3D4D printing, fat substitutes, and double emulsions are the main potential development trends or research gaps in the field which would contribute to increase adoption of these promising emulsions at industrial level.

Gastrointestinal pH-Sensitive Pickering Emulsions Stabilized by Zein Nanoparticles Coated with Bioactive Glycyrrhizic Acid for Improving Oral Bioaccessibility of Curcumin

Pickering emulsions have received considerable attention for their stability and functionality. Environmentally responsive Pickering emulsions could be used as vehicles for oral administration. However, challenges still exist, such as nonbiocompatibility of emulsifier and mismatched response behavior in the gastrointestinal environment. In this study, a strategy was proposed that bioactive saponin glycyrrhizic acid (GA) was used as a pH-responsive substance to functionalize zein nanoparticles, and tannic acid (TA) was used as a primer for cross-linking GA and zein nanoparticles. The Pickering emulsions fabricated by zein/TA/GA nanoparticles (ZTGs) exhibited excellent stability at acid conditions while slowly demulsifying at neutral conditions, which can be further used as an intestine-targeted delivery system. Curcumin was encapsulated into ZTG-stabilized Pickering emulsions, and the encapsulation efficiency results suggested that the presence of GA coating remarkably facilitated the encapsulation of curcumin. An in vitro digestion study suggested that ZTGs provided protection for emulsions from pepsin hydrolysis and exhibited higher free fatty acid release as well as higher bioaccessibility of curcumin during simulated intestine digestion. This study provides an effective strategy to prepare pH-responsive Pickering emulsions for improving the oral bioaccessibility of hydrophobic nutraceuticals.