Polysaccharide-based Pickering emulsions: Formation, stabilization and applications

Ultrasound combined mechanical wall-breaking extraction of new Ganoderma leucocontextum polysaccharides and their application as a structural and functional improver in set fat-free goat yogurt production

Herein, we investigate the yield, micro-structures, rheological properties and bioactivities of new Ganoderma leucocontextum polysaccharide (GLPUBE) obtained from Kangding via ultrasound combined mechanical wall-breaking extraction (UBE), and examine the effect of GLPUBE as a structural and functional improver on the physicochemical, sensory, aromatic, water-holding capacity (WHC), textural, rheological, micro-structural and protein structural properties, and bioactivities of set fat-free goat yogurt (set-FGY). Through response surface optimisation, the extracted GLPUBE achieved a maximum yield of 2.18 %, showing good apparent viscosity and elastic behaviour in 3 % aqueous solution as well as good micro-structure and significant anti-oxidant and anti-diabetic activities. The presence of 0.12 % GLPUBE significantly improved the WHC, pH, acidity, textural and rheological properties, protein concentration and secondary structure, but had no effect on the protein primary structure in set-FGY production. The addition of 0.12 % GLPUBE had an excellent ability in promoting sensory acceptance; total solid, and total polyphenol contents, WHC, pH, acidity, texture, free amino acid contents, viscosity, rheology and aroma properties; enhancing anti-oxidant and anti-diabetic abilities; inhibiting protein degradation; and maintaining the micro-structure and stability of the primary and secondary structures of protein complex of set-FGY during 21 days of storage. Therefore, GLPUBE can be used as an innovative structural and functional improver in set fat-free yogurt industry.

Insights into the Pickering emulsions stabilized by yeast dietary fiber: Interfacial adsorption kinetics, rheological characteristics, and stabilization mechanisms

This study developed Pickering emulsions based on yeast dietary fiber (YDF) and investigated the interfacial adsorption kinetics of YDF, rheological properties and stabilization mechanisms of emulsions. Results indicated that increasing YDF concentration enhanced its diffusion and rearrangement at the oil-water interface. At a concentration of 8 %, YDF exhibited the highest diffusion rate (0.1406 mN·m-1·s-0.5) and rearrangement rate (18.8 s-1). The emulsion stabilized at this concentration had the smallest droplet size (1.55 μm) and the slowest droplet migration rate (0.34 mm/h), effectively suppressing droplet aggregation due to collisions and thereby improving the overall emulsion stability. Confocal laser scanning microscopy results confirmed that emulsion stability relied on the co-adsorption of proteins and polysaccharides from YDF at the interface, with proteins primarily adsorbed at the oil-water interface and polysaccharides responsible for the continuous phase network formation. This study demonstrates YDF's potential as an emulsion stabilizer and elucidates the stabilization mechanism of YDF-induced emulsion.

Emulsifying properties of cellulose nanocrystals with different structures and morphologies from various solanaceous vegetable residues

The stems of solanaceous vegetables with attractive source of cellulose, have caused severe environmental problems as agricultural residues. For the reutilization of the residues, this study isolated cellulose nanocrystals (CNs) from the stems of tomato, eggplant, and pepper to explore their applications in Pickering emulsions. Detailed analyses of the crystalline structure and morphology revealed differences in their emulsifying properties. Tomato stem CNs had higher crystallinity of 82.1 % and a short, straight rod-like shape with a low aspect ratio of 8.0, while eggplant and pepper CNs were long, curved whisker-like fibers with lower crystallinities of 75.3 % and 75.4 %, respectively. Tomato stem CNs exhibited the best emulsifying properties, attributed to their relatively higher crystallinity and larger crystal brick size enhancing amphiphilicity, along with their lower aspect ratio improving interface coverage, which resulted in stable emulsions across different temperatures, pH levels, and ionic strengths. This study enhances our understanding of how the structure and morphology of CNs influence their emulsifying properties, thereby contributing to the promotion of agricultural waste reutilization.

A novel emulsifier for Pickering emulsion composed of whey protein and OSA-pectin loaded with Monascus pigments

Protein-polysaccharide complex carrier can solve the problem of insufficient stability of Monascus pigments (MPs), a kind of natural pigments, against heat and light. It also has the function to stabilize Pickering emulsion (PE) that can be used as fat replacer in meat products. In this study, heat denatured whey protein (HWP) and pectin modified by octenyl succinic anhydride (OSA-pectin) were prepared into complex by adding Ca2+ loaded with MPs. The complex carrier significantly enhanced the light and heat stabilities of MPs and exhibited excellent wettability. It was then used to prepare PE (HOCM-PE) as a fat replacer to improve the color performance of meat patties. The microstructure and rheological properties of HOCM-PE clarified that the main stable mechanism was to form network structure wrapped around oil droplets in the continuous phase. This structure conferred excellent viscoelasticity and stability to the emulsion. The key quality parameters of meat patties showed that HOCM-PE as a fat substitute was able to maintain the textural properties of the meat patties while providing bright red color. The research provided an ideal dual-functional emulsion for the development of low-fat and low-nitrite meat products.

Cellulose nanocrystals-based Pickering emulsion with enhanced foliar adhesion and pH responsiveness for intelligent delivery of pesticides

Pickering emulsions stabilized by functionalized natural macromolecules have emerged with promising responsiveness for pesticide encapsulation and release. This study developed Pickering emulsions using amine-modified cellulose nanocrystals (ACNCs) as stabilizers. The resultant O/W ACNCs-Pickering emulsions (ACNCs-Pickering) exhibited long-term storage stability and showed increasing emulsion stability depending on the concentration of ACNCs. Imidacloprid (IMI) was subsequently loaded onto the ACNCs-Pickering to form the IMI@ACNCs-Pickering via the in-situ loading route. The release rate of IMI demonstrated a notable pH responsiveness. Moreover, the IMI@ACNCs-Pickering prepared with an ACNCs concentration of 3 wt% showed optimal performances. Its foliar adhesion on Chinese cabbage (Brassica rapa L.ssp.pekinensis) was significantly higher than that of the commercial IMI formulation (70 WS, Bayer®, LS200032) (DG). In detail, the pesticide residue for the IMI@ACNCs-Pickering was 3.8 folds to that for DG after spraying and washing for 10 min. Also, the green peach aphid mortality rate was 98.33 %, which was 1.1 folds higher than that of the DG group. The present work developed a Pickering emulsion-based fat-soluble pesticide formulation with excellent foliar adhesion, resistance to rainfall washout, and insecticidal effect. It provided a new option to ensure the sustainable development of green agriculture.

Cold atmospheric plasma-induced alterations in the multiscale structural and functional properties of guar gum

The use of guar gum in the food industry faces challenges owing to its large molecular weight and high viscosity. Cold atmospheric plasma (CAP) is a novel technique that utilizes the reactive species produced by high voltage discharge to modify food ingredients. In this study, guar gum was treated with CAP at different powers and duration, and its rheological properties, molecular structure, thermal stability, emulsifying activity, and stability were evaluated. CAP reduced the molecular weight of guar gum and altered its M/G ratio, leading to a decrease in the apparent viscosity of guar gum and an enhancement in its thermal stability and emulsifying function for soy protein isolate emulsions. Molecular structure analysis revealed the CAP treatment did not destroy the basic structure of guar gum, but caused alterations in the linkages between its glycosidic bonds and/or carbohydrate units. Scanning electron microscopy showed guar gum changed from a dense surface structure to a porous and loose structure after CAP treatment. Therefore, CAP effectively modifies guar gum, enhancing its potential in food and other industries.

Interfacial mechanisms, environmental influences, and applications of polysaccharide-based emulsions: A review

To develop stable polysaccharide-based emulsions, many studies have focused on the interfacial behavior of adsorbed polysaccharides. This review first discussed the mechanism of polysaccharides self-assembly at the oil-water interface. It can be concluded that polysaccharides can form a thick and strong interfacial membrane that stabilizes emulsions through steric hindrance and electrostatic interactions. In particular, we also investigated the influence of various conditions (i.e., mechanical stress, heating, pH, enzymatic treatment, and ionic strength) on the architecture and properties of polysaccharide-based emulsions. Additionally, the interactions of polysaccharides with other molecules in the emulsion system were summarized, revealing that co-adsorption further changes their properties. Furthermore, current approaches for monitoring the behavior of adsorbed polysaccharides at the oil/water interface were reviewed, highlighting their advantages and limitations. Lastly, we emphasized the potential of polysaccharides for producing environmental-friendly emulsions in the food industry.

Tannic acid coordination assembly enhances the interfacial properties of salted egg white gel particles

Tannic acid (TA) has attracted the attention of researchers as a promising organic ligand capable of forming metal-organic coordination networks with various metal ions at interfaces to impact surface properties. In this study, we innovatively reported a self-assembly method for surface decoration by depositing TA/Fe3+ coatings on the surface of desalted duck egg white nanoparticles (DEWN), further studying the oil/water interfacial properties of the modified particles. The results showed that the ratio and concentration of TA to Fe3+ could modulate interfacial properties. The modified DEWN has low interfacial tension, with TFe2 having near-neutral wettability (θo/w ∼ 90°) and stabilizing emulsions for over 60 days. Moreover, the emulsions stabilized by TFe1 and TFe2 formed stronger gel structures with better thixotropic recovery (98.82 % and 89.26 %). After further increasing the oil phase ratio, the increased layer assembly concentration improved the stability of the oil phase and formed a dense gel mesh structure. The effects of temperature and salt ion concentration on the emulsion were investigated under optimum conditions, both of which showed good stability. Overall, our research not only highlighted straightforward strategies for preparing emulsions with higher stability using green and sustainable raw materials, but also broadened the range of applications for metal-phenol decoration.

Fabrication and characterization of novel TGase-mediated glycosylated whey protein isolate nanoparticles for curcumin delivery

The aim of this study was to fabricate novel transglutaminase (TGase)-mediated glycosylated whey protein isolate (WPI) nanoparticles for the encapsulation and delivery of curcumin. The influences of glycosylation on the physiochemical properties, stability, bioavailability, and antioxidant properties of WPI nanoparticles loaded with curcumin were investigated. Composite nanoparticles exhibited uniform distribution and small particle sizes. The main driving forces for the formation of curcumin nanoparticles were electrostatic interactions, hydrogen bonding, and hydrophobic interactions. The encapsulation and loading efficiency of curcumin after TGase-type glycosylation were significantly increased in comparison to WPI-curcumin nanoparticles. Glycosylated WPI-curcumin nanoparticles had stronger antioxidant properties and stability to resist external environmental changes than WPI-curcumin nanoparticles. In addition, glycosylated WPI-curcumin nanoparticles showed a controlled release and enhanced curcumin bioavailability in vitro gastrointestinal digestion. This study provides novel insights for self-assembled glycosylated protein nanoparticles as delivery systems for protecting hydrophobic nutrients.

Strong self-association of chitosan microgels at interface mediated high stabilities in Pickering emulsion

The spontaneous self-organization of naturally-occurring polysaccharide particles into a thick and robust gel network at interface in Pickering emulsion is challenging. Inspired by the phenomenon that chitosan microgels (CSMs) with a certain size could self-associate into a solidified gel phase upon freezing, here we tentatively used CSMs to construct a highly-stable Pickering emulsion. CSMs can form a stable Langmuir's layer at the water/oil interface through the network deformation and re-arrangement of dangling chains, while the subsequent negative polymer coating can avoid the bridging resulting from the cross-association for CSMs on different emulsion droplets upon freezing. The experimental results indicated that the emulsion showed excellent features, including the wide pH range stability (3-12), long-term storage stability (> 3 months), thermal stability (121 °C, 30 min). Moreover, CSMs could self-associate into a reliable gel layer around the oil droplet in freezing, leading to the better freeze-thaw stability (1-3 cycles). The negative coating not only facilitates the formation of interfacial gel network around each emulsion droplet, but also produces huge steric hindrance and electrostatic repulsion to suppress the coalescence. This work provides a different way to modulate the interfacial structure, thus developing a more stable polysaccharide-based Pickering emulsion.

Study on the stability and magnetically induced demulsification performance of Pickering emulsions based on arginine-modified lignin/Fe3O4 nanoparticles

In this study, four different arginine-modified lignin composites (Lig-Arg-x) were synthesized via the Mannich reaction, followed by the preparation of Lig-Arg-x/Fe3O4 magnetic nanoparticles (NPs) using hydrothermal reduction. The magnetic particles were characterized, and their emulsification properties were investigated. The highest grafting degree was achieved at a 1:1 M ratio of arginine to lignin. Pickering emulsions were formulated and Lig-Arg-x/Fe3O4 NPs as the emulsifier. The study examined the impact of arginine grafting degree, oil-to-water volume ratio, and nanoparticle concentration on emulsion stability and demulsification performance. Optimal emulsion stability, characterized by the smallest droplet size of 20.57 μm, was achieved with a 1:1 M ratio of lignin to arginine, a 7:3 oil-to-water volume ratio, and a nanoparticle concentration of 1.0 w/v%. Magnetic induction experiments demonstrated significant phase separation in the stable emulsion under a magnetic field, confirming the magnetic-induced demulsification capability of the composite particles. Oil displacement experiments demonstrated that Lig-Arg-x/Fe3O4 NPs modulate oil droplet diffusion via the Marangoni effect, indicating their potential for oil recovery applications. After three cycles, Lig-Arg-1/Fe3O4 NPs retained 80 % of their saturation magnetization, demonstrating strong reusability. This study showcases lignin-magnetite nanocomposites' versatility in stabilizing emulsions and exhibiting magnetic responsiveness, advancing demulsification and oil spill recovery technologies.

Enhancing Starch Film Properties Using Bacterial Nanocellulose-Stabilized Pickering Emulsions

This study aimed to address issues related to hydrophilicity, barrier properties, and mechanical performance in starch-based films by incorporating Pickering emulsions stabilized with nano-fibrillated bacterial cellulose (BC). Emulsions were added to the film-forming suspension at varying concentrations (1.0%, 2.5%, 5.0%, and 7.5% v/v) for comparison. The films were evaluated using water vapor permeability (WVP), contact angle, Fourier Transform Infrared Spectroscopy (FTIR), and tensile tests. The results showed a significant reduction in film hydrophilicity, with the contact angle increasing from 49.7° ± 1.5 to 71.0° ± 1.4, and improved water vapor barrier properties, with WVP decreasing from 0.085 ± 0.04 to 0.016 ± 0.01 g·mm/h·m2·kPa. FTIR analysis confirmed the successful incorporation of the emulsion into the starch matrix. Among the tested concentrations, 2.5% provided an optimal balance, increasing hydrophobicity while maintaining mechanical strength. These findings demonstrate that Pickering emulsions are an effective strategy for enhancing the functional properties of starch films.

The latest research progress on polysaccharides-based biosensors for food packaging: A review

In recent years, polysaccharide-based biosensors have emerged as promising technologies for intelligent food packaging, offering innovative solutions to enhance food quality and safety. This review highlights advancements in designing, developing, and applying these biosensors, particularly those utilizing polysaccharides such as chitosan, cellulose and alginate. Engineered with nanomaterials like ZnO, silver, and carbon nano-tubes demonstrated high sensitivity in real-time monitoring of food spoilage indicators, including pH changes, volatile nitrogen compounds and microbial activity. We discuss the electrochemical properties of these biosensors, highlighting how the integration of electrochemical methods significantly improves their detection capabilities within packaging environments, leading to sensor sensitivity enhancement, greater accuracy, and spoilage detection, ultimately extending the shelf life of perishable food products. Additionally, the review addresses the practical challenges of industrial implementation and explores future research directions for optimizing sensor functionality and scalability. The findings underscore the potential of polysaccharide-based intelligent packaging as a sustainable and effective alternative to conventional methods, paving the way for broader commercial adoption.

Ultrasound-assisted fabrication of chitosan-hydroxypropyl methylcellulose nanoemulsions loaded with thymol and cinnamaldehyde: Physicochemical properties, stability, and antifungal activity

This study investigated the influence of chitosan (CH) and hydroxypropyl methylcellulose (H), along with ultrasound power, on the physicochemical properties, antifungal activity, and stability of oil-in-water (O/W) nanoemulsions containing thymol and cinnamaldehyde in a 7:3 (v/v) ratio. Eight O/W formulations were prepared using CH, H, and a 1:1 (v/v) blend of CH and H, both with and without ultrasonication (U). Compared to untreated samples, U-treated nanoemulsions had lower droplet sizes (433-301 nm), polydispersity index (0.42-0.47), and zeta potential (-0.42-0.77 mV). The U treatment decreased L* and b* values, increased a* color attribute values, and increased apparent viscosity (0.26-2.17) at the same shear rate. After 28 days, microbiological testing of nanoemulsions treated with U showed counts below the detection limits (< 2 log CFU mL-1). The U-treated nanoemulsions exhibited stronger antifungal effects against R. stolonifer, with the NE/CH-U and NE/CH-H-U formulations demonstrating the lowest minimum inhibitory and fungicidal concentrations, measured at 0.12 and 0.24 μL/mL, respectively. On day 28, U-treated nanoemulsions demonstrated higher ionic, thermal, and physical stability than untreated samples. These findings suggest that the stability and antifungal efficacy of polysaccharide-based nanoemulsions may be improved by ultrasonic treatment. This study paves the way for innovative, highly stable nanoemulsions.

Structural and functional properties of polysaccharides extracted from three Dioscorea species

Dioscorea has a history spanning over 2000 years for both medicinal and edible purposes in China. It contains rich polysaccharides, which are frequently utilized as thickening and stabilizing agents in the food industry. However, there has been relatively little focus on polysaccharides from common Dioscorea species besides D. opposita, such as D. alata and D. esculenta. In this study, non-starch crude polysaccharides were isolated from D. opposita (BD), D. alata (WC), and D. esculenta (GZ). Their structures, physicochemical compositions, and functional properties were characterized and compared. The results indicated three polysaccharides all exhibited characteristic peaks of polysaccharides and possessed triple-helix structures. The Glc (36.78-83.90 %), Man (6.71-26.68 %), and GalA (8.54-10.22 %) were identified as the primary monosaccharide components. In terms of functionality, three polysaccharide solutions demonstrated non-Newtonian flow characteristics and displayed commendable thermal stability. It is worth noting that the antioxidant and emulsifying properties of polysaccharides isolated from D. opposita (BD) and D. alata (WC) were superior to those of D. esculenta (GZ), making them more suitable for use as antioxidants and stabilizers. By comparing polysaccharides derived from different Dioscorea species, this study provides valuable insights into the food, cosmetic, and pharmaceutical industries based on the unique properties of these different polysaccharides.

Water chestnut starch nanoparticle Pickering emulsion for enhanced apricot seed oil stability: A sustainable functionality approach

The usage of starch nanoparticles for Pickering emulsion stabilization has become more popular for various benefits. This work investigated the potential of nano reduced starch as stabilizer in Pickering emulsions. Two different concentrations of starch nanoparticles (2.5 % and 5 %) were used for stabilization of apricot seed oil-in-water Pickering emulsion. Emulsion stabilized by 5 % starch nanoparticles (PE (5 %)) displayed zeta potential of -46.92 mV and emulsions stabilized by 2.5 % starch nanoparticles (PE (2.5 %)) exhibited zeta potential of -15.33 mV. In PE (2.5 %) after 24 h, creaming index (CI) was 12 %. CI remained zero in PE (5 %) after 30 days of storage period.PE (2.5 %) and apricot oil (AO) showed higher peroxide value than PE (5 %). Malondialdehyde (MDA) content of AO was 156.02 mmol/kg oil after 30 day storage period at 45 °C. Comparatively, PE (5 %) possessed lower MDA content (36.02 mmol/kg oil). The findings revealed that starch nanoparticles can be used as stabilizer in Pickering emulsions for stabilization and preventing lipid oxidation in polyunsaturated fatty acid rich oils. This study introduces a sustainable approach to enhance the stability of apricot seed oil using underutilized starch nanoparticles.

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.

Wide pH, Adaptable High Internal Phase Pickering Emulsion Stabilized by a Crude Polysaccharide from Thesium chinense Turcz

The ultrasound-assisted extraction conditions of Thesium chinense Turcz. crude polysaccharide (TTP) were optimized, and a TTP sample with a yield of 11.9% was obtained. TTP demonstrated the ability to stabilize high-internal-phase oil-in-water emulsions with an oil phase volume reaching up to 80%. Additionally, the emulsions stabilized by TTP were examined across different pH levels, ionic strengths, and temperatures. The results indicated that the emulsions stabilized by TTP exhibited stability over a wide pH range of 1-11. The emulsion remained stable under ionic strengths of 0-500 mM and temperatures of 4-55 °C. The microstructure of the emulsions was observed using confocal laser scanning microscopy, and the stabilization mechanism of the emulsion was hypothesized. Soluble polysaccharides formed a network structure in the continuous phase, and the insoluble polysaccharides dispersed in the continuous phase, acting as a bridge structure, which worked together to prevent oil droplet aggregation. This research was significant for developing a new food-grade emulsifier with a wide pH range of applicability.

Effects of Exidia yadongensis polysaccharide as emulsifier on the stability, aroma, and antioxidant activities of fat-free stirred mango buffalo yogurt

Because of the poor stability and rheological properties of fat-free stirred yogurt fortified with fruit pulp, new functional polysaccharides as a natural emulsifier, which can increase viscosity in the aqueous phase, may be needed. This study aimed to evaluate the effects of Exidia yadongensis polysaccharide (EYP) as emulsifier on the stability, aroma, and antioxidant activities of mango buffalo yogurt at 4 °C for 25 days. The yogurt with 15 g/L EYP gave a higher content of 215 g/L total solids, 11.3 g/L exopolysaccharides, 0.10 g/L total polyphenols, 630.5 g/L water-holding capacity, and 11.43 g/kg total free amino acids, and maintained better texture, DPPH scavenging activity of 54.05 % and OH scavenging rates of 67.16 %. Moreover, the EYP exhibited the expected ability to weaken postacidification, syneresis, and growth of microorganism, and greatly promote the textural, rheological properties, suspension stability, microstructure, and aroma profiles of stirred mango-flavored buffalo yogurt (p < 0.05). In addition, the addition of 15 g/L EYP can inhibit protein degradation and improve the stability of secondary structure of the protein complex in mango yogurt during 25 days of storage. Therefore, EYP (15 g/L) could be used as natural positive functional factors and emulsifiers in such fat-free stirred yogurt industry.

Characterization, stability, and curcumin bioaccessibility of buckwheat flower polysaccharide conjugate emulsion

In this study, buckwheat flower polysaccharide conjugates (BFPCs) were synthesized and evaluated for their emulsification properties. The stability of BFPC-stabilized emulsions was assessed through particle size analysis, zeta potential measurements, microscopic observations, and rheological tests. Gum Arabic served as a control to compare BFPC's emulsifying efficacy across varying storage conditions, including exposure to metal ions, pH variations, and different heat treatment temperatures. Results showed that BFPC significantly lowered interfacial tension (16.2 mN/m) and effectively stabilized emulsions containing 60 wt% medium-chain triglycerides at a concentration of 1.0 wt%. Over a 20-day storage period, BFPC emulsions demonstrated robust resistance to heat (60-90°C), acidic conditions (pH 2.0-9.0), and ion concentrations (Na+, Ca2+). Moreover, in a high oil phase emulsion, BFPC enhanced the bioavailability of curcumin to 27.05%, markedly higher than the 7.10% observed without emulsification, underscoring its potential in nutrient delivery applications. PRACTICAL APPLICATION: Due to its excellent resistance, long-time emulsifying stability under different conditions, and its good effect in curcumin embedding, BFPC has a broad prospect and can be widely used under various conditions in food industry.

Octenyl succinic anhydride tigernut starch: Structure, physicochemical properties and stability of curcumin-loaded Pickering emulsion

In recent years, there has been increasing attention to starch particle-stabilized Pickering emulsions. In this study, the tigernut starch (TNS) was isolated from the tigernut meal, and further octenyl succinic anhydride tigernut starch (OSATNS) was prepared by a semi-dry method. The structure of OSATNS was analyzed and characterized by degrees of substitution (DS), contact angle, SEM, and FTIR. OSATNS was then used to stabilize the curcumin-loaded Pickering emulsion to improve the water solubility and stability of the curcumin. The results showed that OSATNS with 3 %-9 % OSA exhibited a DS range of 0.012 to 0.029, and its contact angle increased from 69.23° to 84.76°. SEM revealed that TNS consisted of small starch particles averaging 7.71 μm, and esterification did not significantly alter their morphology or size. FTIR analysis confirmed successful OSA incorporation by revealing two new peaks at 1732 cm-1 and 1558 cm-1. After 7 days of storage, Pickering emulsions stabilized with OSATNS-9 % exhibited superior stability and curcumin retention compared to Tween 80 emulsions, maintaining retention rates above 80 % even after different heat treatments. In conclusion, this study shows the potential application of OSATNS in stabilizing Pickering emulsions and demonstrates its good thermal stability and protection against curcumin during storage.

Hot-water soluble fraction of starch as particle-stabilizers of oil-in-water emulsions: Effect of dry heat modification

Dry heat treatment (DHT) ranging from 130 to 190 °C was employed to modify corn starch. The hot-water soluble fraction (HWS) of the DHT-modified starch was isolated, and its capacity and mechanism for stabilizing O/W emulsions were investigated. Corn starch underwent a significant structural transformation by DHT at 190 °C, characterized by a 7.3 % reduction in relative crystallinity, a tenfold decrease in weight-average molecular weight from 95.21 to 8.11 × 106 g/mol, and a degradation of over one-third of the extra-long chains of amylopectin (DP > 36) into short chains (DP 6-12). These structural modifications resulted in a substantial formation of soluble amylopectin, leading to a sharp increase in the HWS content of corn starch from 3.16 % to 85.06 %. This augmented HWS content surpassed the critical macromolecule concentration, prompting the formation of HWS nanoaggregates. These nanoaggregates, with an average particle size of 33 nm, functioned as particle stabilizers, ensuring the stability of the O/W emulsion through the Pickering mechanism. The O/W emulsion stabilized by HWS nanoaggregates exhibited noteworthy centrifugal and storage stability, with rheological properties remaining nearly unchanged over a storage period of 180 days. Given its straightforward preparation process, the HWS of DHT-modified starch could be a promising natural emulsifier.

Dual-Responsive "Egg-Box" Shaped Microgel Beads Based on W1/O/W2 Double Emulsions for Colon-Targeted Delivery of Synbiotics

In this study, for enhancing the resistance of probiotics to environmental factors, we designed a microgel beads delivery system loaded with synbiotics. Multiple droplets of W1/O/W2 emulsions stabilized with zein-apple pectin hybrid nanoparticles (ZAHPs) acted as the inner "egg," whereas a three-dimensional network of poly-L-lysine (PLL)-alginate-CaCl2 (Ca) crosslinked gel layers served as the outermost "box." ZAHPs with a mass ratio of 2:1 zein-to-apple pectin showed excellent wettability (three-phase contact angle = 89.88°). The results of the ζ-potentials and Fourier transform infrared spectroscopy demonstrate that electrostatic interaction forces and hydrogen bonding were the main forces involved in the formation of ZAHPs. On this basis, we prepared W1/O/W2 emulsions with other preparation parameters and observed their microstructures by optical microscopy and confocal laser scanning microscope. The multi-chambered structures of W1/O/W2 emulsions were successfully visualized. Finally, the W1/O/W2 emulsions were coated with PLL-alginate-Ca using the solution extrusion method. The results of the in vitro colonic digestion stage reveal that the survival rate of probiotics in the microgel beads was about 75.11%, which was significantly higher than that of the free. Moreover, probiotics encapsulated in microgel beads also showed positive storage stability. Apple pectin would serve as both an emulsifier and a prebiotic. Thus, the results indicate that the "egg-box" shaped microgel beads, designed on the basis of pH-sensitive and enzyme-triggered mechanisms, can enhance the efficiency of probiotics translocation in the digestive tract and mediate spatiotemporal controlled release.

Influence of carboxymethyl cellulose on the stability, rheology, and curcumin bioaccessibility of high internal phase Pickering emulsions

Recently, there has been a focus on using biopolymer-based particles to stabilize high internal phase Pickering emulsions (HIPPEs) due to the notable advances in biocompatibility and biodegradability. In this work, the complex particles of peanut protein isolate and carboxymethyl cellulose (CMC) with various substitution degrees (DS; 0.7 and 0.9) and weight average molecular weights (Mw; 90, 250, and 700 kDa) were prepared and characterized as novel stabilizers. For the obtained four types of morphologically distinct particles, the complex particles formed by CMC (0.9 DS and 250 kDa) showed cluster structures with an average size of 1.271 μm, equally biphasic wettability with three-phase contact angles of 91.5°, and the highest diffusion rate at the oil-water interface. HIPPEs stabilized by these particles exhibited more elastic behavior due to the smaller tanδ and higher viscosity, as well as excellent thixotropic recovery properties and stability against heating, storage, and freeze-thawing. Furthermore, confocal laser scanning microscopy verified that these particles formed a dense interfacial layer around the oil droplets, which could resist flocculation and coalescence between oil droplets during in vitro digestion. The improved bioaccessibility of curcumin-loaded HIPPEs made these delivery systems potentially apply in functional foods.

Konjac glucomannan-assisted fabrication of stable emulsion-based oleogels constructed with pea protein isolate and its application in surimi gels

Konjac glucomannan (KGM) is widely used as a stabilizer for the structuring of highly unsaturated oils. This study aimed to investigate the changes in structure and functional properties of soybean oil - based oleogels (emulsion template method) prepared with different amounts of KGM-modified pea isolate protein (PPI). The findings revealed that the oleogels formed three - dimensional networks through van der Waals interactions and hydrogen bonding between the stretched PPI and KGM. As the amount of KGM increased, the oil droplets were more uniformly dispersed within the continuous PPI - KGM rigid network, especially when the ratio of PPI to KGM was 4:1. This formulation also showed the highest thixotropy (73.2 %) and the best oil binding capacity (94 %). Cryo - SEM revealed that the oleogel - prepared surimi gels successfully enclosed oil droplets in a dense matrix through a dual stabilization mechanism. Additionally, the incorporation of oleogels significantly improved the textural properties of surimi in comparison to directly adding oil.

Emulsions delivery systems of functional substances for precision nutrition

Many functional substances are chemically unstable and exhibit variable water/oil solubility, reducing their bioavailability and efficacy. It is necessary to devise effective measures to improve the unfavorable properties of functional substances and maximize their potential benefits in nutritional interventions. Therefore, the development and application of edible emulsion-based delivery systems for these functional substances using food-grade materials would be highly beneficial for the food industry. In recent years, Pickering emulsions have garnered significant attention in the scientific community due to their characteristic of being free from surfactants. This section focuses on emphasizing the design and preparation of emulsion delivery systems based on functional substances. Additionally, we summarize the current applications of emulsion delivery systems in functional substances. This chapter also discusses the potential advantages of Pickering emulsion systems in the precise nutrition field, including high targeting specificity and nutritional intervention for various diseases. Well-designed Pickering emulsion delivery carriers for functional substances can enhance their stability in food processing and in vivo digestion. To meet the nutritional needs of specific populations for functional foods, utilizing emulsion delivery systems to improve the bioavailability of functional substances will provide a theoretical basis for the precise nutrition of functional substances in functional foods.

Stabilization mechanisms and digestion properties of Pickering emulsions prepared with tempo-oxidized hyaluronic acid/chitosan nanoparticles: From the perspective of oxidation degree

In this study, the stabilization mechanism and digestion behavior of Pickering emulsion prepared by a combination of chitosan (CS) and TEMPO-oxidized hyaluronic acid (HA) were investigated. Conductometric titration was used to determine the degree of oxidation and carboxylate content of TEMPO-oxidized HA. The results showed that the degree of oxidation increased proportionally with increasing oxidation time, and the electrostatic and hydrogen bonding interactions with CS were significantly enhanced. The results of FTIR and TEM showed the formation of CS/oxidized HA nanoparticles (CS/oxidized-HANPs). In addition, the contact angle of CS/oxidized-HANPs is closed to 77°, thereby providing higher desorption energy at the interface. Rheological results showed that the Pickering emulsion exhibited a gel-like network structure and higher viscosity. In vitro digestion results suggested that the quercetin (Que) bioaccessibility of the CS/oxidation HANps-stabilized Pickering emulsion with an oxidation time of 20 min was better than that of the conventional emulsion prepared with CS alone. The research is expected to develop novel polysaccharide-based Pickering emulsion delivery systems for functional compounds.

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.

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.

Pickering emulsion biocatalysis: Bridging interfacial design with enzymatic reactions

Non-homogeneous enzyme-catalyzed systems are more widely used than homogeneous systems. Distinguished from the conventional biphasic approach, Pickering emulsion stabilized by ultrafine solid particles opens up an innovative platform for biocatalysis. Their vast specific surface area significantly enhances enzyme-substrate interactions, dramatically increasing catalytic efficiency. This review comprehensively explores various aspects of Pickering emulsion biocatalysis, provides insights into the multiple types and mechanisms of its catalysis, and offers strategies for material design, enzyme immobilization, emulsion formation control, and reactor design. Characterization methods are summarized for the determination of drop size, emulsion type, interface morphology, and emulsion potential. Furthermore, recent reports on the design of stimuli-responsive reaction systems are reviewed, enabling the simple control of demulsification. Moreover, the review explores applications of Pickering emulsion in single-step, cascade, and continuous flow reactions and outlines the challenges and future directions for the field. Overall, we provide a review focusing on Pickering emulsions catalysis, which can draw the attention of researchers in the field of catalytic system design, further empowering next-generation bioprocessing.

Anisotropic materials based on carbohydrate polymers: A review of fabrication strategies, properties, and applications

Anisotropic structures exist in almost all living organisms to endow them with superior properties and physiological functionalities. However, conventional artificial materials possess unordered isotropic structures, resulting in limited functions and applications. The development of anisotropic structures on carbohydrates is reported to have an impact on their properties and applications. In this review, various alignment strategies for carbohydrates (i.e., cellulose, chitin and alginate) from bottom-up to top-down strategies are discussed, including the rapidly developed innovative technologies such as shear-induced orientation through extrusion-based 3D/4D printing, magnetic-assisted alignment, and electric-induced alignment. The unique properties and wide applications of anisotropic carbohydrate materials across different fields, from biomedical, biosensors, smart actuators, soft conductive materials, to thermal management are also summarized. Finally, recommendations on the selection of fabrication strategies are given. The major challenge lies in the construction of long-range hierarchical alignment with high orientation degree and precise control over complicated architectures. With the future development of hierarchical alignment strategies, alignment control techniques, and alignment mechanism elucidation, the potential of anisotropic carbohydrate materials for scalable manufacture and clinical applications will be fully realized.

Physicochemical characterization and environmental stability of a curcumin-loaded Pickering nanoemulsion using a pea protein isolate-dextran conjugate via the Maillard reaction

This study investigated pea protein isolate (PPI) and dextran (DX) conjugates produced via the Maillard reaction as Pickering stabilizers for various food applications. The results found that as heating time increased (0-5 h), the grafting degree heightened. The PPI-DX conjugate exhibited a rough porous surface in contrast to native PPI, accompanied by changes in molecular weight and secondary structure. Additionally, the aggregation of low-solubility PPI was partially inhibited due to the contribution of increased solubility and reduced surface hydrophobicity by glycation. Curcumin-loaded Pickering nanoemulsions stabilized with PPI-DX had smaller droplets and higher curcumin encapsulation (greater than80 %) than PPI-stabilized nanoemulsions. PPI-DX adsorbed on the interface showed improved physical stability compared to PPI alone, even after various pH conditions and three heat treatments. The nanoemulsion stabilized with PPI-DX demonstrated improved apparent viscosity and dispersion stability. These findings highlight the effectiveness of PPI-DX conjugates as stabilizers for developing stable and functional Pickering nanoemulsions.

Emulsification Characteristics of Insoluble Dietary Fibers from Pomelo Peel: Effects of Acetylation, Enzymatic Hydrolysis, and Wet Ball Milling

To improve the application potential of pomelo peel insoluble dietary fiber (PIDF) in emulsion systems, acetylation (PIDF-A), cellulase hydrolysis (PIDF-E), and wet ball milling (PIDF-M) were investigated in this paper as methods to change the emulsification properties of PIDF. The impact of the methods on PIDF composition, structure, and physicochemical properties was also assessed. The results demonstrated that both acetylation modification and cellulase hydrolysis could significantly improve the emulsification properties of PIDF. The emulsions stabilized with PIDF-A and PIDF-E could be stably stored at 25 °C for 30 d without phase separation at particle concentrations above 0.8% (w/v) and had higher storage stability: The D4,3 increments of PIDF-A- and PIDF-E-stabilized emulsions were 0.98 μm and 0.49 μm, respectively, at particle concentrations of 1.2% (w/v), while the storage stability of PIDF-M-stabilized emulsion (5.29 μm) significantly decreased compared with that of PIDF (4.00 μm). Moreover, PIDF-A showed the highest water retention capacity (21.84 g/g), water swelling capacity (15.40 mL/g), oil retention capacity (4.67 g/g), and zeta potential absolute (29.0 mV) among the PIDFs. In conclusion, acetylation modification was a promising method to improve the emulsifying properties of insoluble polysaccharides.

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.

Improving the emulsifying capacity of brewers' spent grain arabinoxylan by carboxymethylation

Arabinoxylan derived from brewers' spent grain was carboxymethylated, and the emulsifying capacity of carboxymethylated arabinoxylans (CMAX) with different degrees of substitution (DS) was investigated. Results showed that carboxymethylation greatly enhanced the emulsifying capacity and emulsion stability of CMAX compared to the initial arabinoxylan. CMAX developed decreased ζ-potential, higher hydrophilicity, and improved interfacial adsorption capacity. Consequently, the denser and stronger interface on the oil droplet was formed, and the stabilizing mechanism was altered. Moreover, CMAX with lower DS could effectively stabilize emulsions during storage at a concentration of 0.5 % and pH between 6 and 7. Higher DS, however, led to poorer emulsion stability and greater flocculation as a result of the fragile interface formed by excess intermolecular ionic force. The research found CMAX potential in emulsion stabilizing and further applications in food processing.

Effect of surface acetylation of chitin nanocrystals on the preparation and viscoelasticity of sunflower seed oil-in-water Pickering emulsions

Acetylated chitin nanocrystals (ChNCs) were used as stabilizer in this work to prepare sunflower seed oil-in-water emulsions for the morphological and rheological studies. The results revealed that the acetylation with moderate degree of substitution (0.38) reduced hydrophilicity and increased surface charge level of rod-like ChNCs, and as a result, significantly improved the emulsifying ability of ChNCs. At the same oil/water ratio and particle loading, the emulsions stabilized with the acetylated ChNCs had far smaller droplet size (∼3 μm) as compared to the emulsions stabilized with the pristine ChNCs (5-7 μm). The increased droplets numbers and improved surface coating level resulted in the enhanced viscous resistance and yield stress level, which improved the physical stability of the acetylated ChNC-stabilized emulsions as a result. In addition, the droplet clusters easily formed in this system, contributing to weak strain overshoot and decreased large-deformation sensitivity during dynamic shear flow. Therefore, the acetylated ChNC-stabilized system showed enhanced transient stress overshoot during startup flow and weakened thixotropy during cyclic ramp shear flow as compared to the pristine ChNC-stabilized system. The relationships between surface acetylation of ChNCs and flow behavior of emulsions were then established, which provide valuable information on the modulation of the ChNC-stabilized Pickering emulsions.

Emulsion for stabilizing β-carotene and curcumin prepared directly using a continuous phase of polysaccharide-rich Schizophyllum commune fermentation broth

In this study, we examined the effect of Schizophyllum commune fermentation broth (SCFB) rich in polysaccharides (SCFP) on the stability and bioaccessibility of β-carotene and curcumin. An SCFB-stabilized oil-in-water (o/w) emulsion (SCFBe) was prepared using SCFB as the continuous phase, and then evaluated for storage stability using an SCFP-based emulsion (SCFPe) as the control. The findings revealed that SCFBe is more stable at 60 °C than SCFPe, and stratification or droplet size varied at differing pH levels (3-9) and concentrations of Na+ (0.1-0.5 M) and Ca2+ (0.01-0.05 M). Since the absolute value of the zeta potential of SCFBe is much lower at 60 °C than that at 4 °C and 25 °C, a higher temperature (60 °C) may enhance the reactivity of polysaccharides and proteins in SCFB to improve the stability of SCFBe. Both the protective impact of SCFB on functional food molecules and their capacity to block lipid oxidation increased as polysaccharide content improved. The bioaccessibility of β-carotene after in vitro simulated gastrointestinal digestion is 11.18 %-12.28 %, whereas that of curcumin is 31.64 %-33.00 %. By fermenting edible and medicinal fungi in liquid, we created a unique and environmentally friendly approach for getting food-grade emulsifiers without extraction.

Emulsifying properties of O/W emulsion stabilized by soy protein isolate and γ-polyglutamic acid electrostatic complex

In order to improve the emulsifying properties of soy protein around isoelectric point, soy protein isolate (SPI) and γ-polyglutamic acid (γ-PGA) complexes were prepared by electrostatic interaction. The formation of SPI-γ-PGA electrostatic complex and emulsifying properties were investigated by monitoring turbidity, zeta potential, intrinsic fluorophores, emulsion characterization, and microstructure observation. The results showed that the formation of SPI-γ-PGA electrostatic complex was identified through turbidimetric analysis and zeta-potential measurement. Intrinsic fluorescence spectrum indicated internal structure changes of electrostatic complexes. Furthermore, SPI-γ-PGA complex-stabilized emulsions showed better stability with small droplet sizes and slow growth as well as the uniform microstructure around the isoelectric point (pH 4.0-5.0) than SPI-formed emulsions. Under the different thermal treatments and ionic strengths, emulsions stabilized by SPI-γ-PGA-soluble complex resulted in improved emulsion stability to environmental stresses. This may be attributed to the increased steric repulsion and electrostatic repulsion by SPI-γ-PGA complexes at oil-water interfaces. The findings derived from this research would provide theoretical reference about SPI-γ-PGA electrostatic complex that can be applied in acid beverages and developed a novel plant-based sustainable stabilizer for emulsions. PRACTICAL APPLICATION: The electrostatic interaction between SPI and γ-PGA improved the emulsifying characteristics of soy protein around isoelectric point. The results derived from this research would expand applications of SPI-γ-PGA-soluble electrostatic complex that can be applied in acid beverages, as well as a novel plant-based sustainable stabilizer for emulsions.

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.

Fabrication and characterization of a novel zein/pectin/pumpkin seed oil Pickering emulsion and the effects of myricetin on oxidation stability

In this study, zein/pectin/pumpkin seed oil (PSO) Pickering emulsions (ZPPEs) were fabricated loading with myricetin (MYT), and the quality control methods of oxidation stability were innovatively investigated. The microstructure and particle properties of zein-pectin particles were determined. The zein to pectin ratio of 5:3 and oil phase fraction (φ = 50 %) turned out as the most optimal conditions for the stabilization of myricetin-loaded ZPPEs. The expected oil-in-water emulsion-type structure was confirmed by confocal laser scanning microscopy (CLSM). The internal 3D structure of Pickering emulsions (Lugol's solution improved the water-phase contrast) was imaged by micro-computed tomography (Micro-CT) for the first time. Results showed a sponge like structure of water phase in emulsion with 42 μm as mean droplet size. Light-induced oxidation was evaluated with the PetroOxy method and malondialdehyde (MDA) assays. Encapsuling ZPPEs with MYT could prevent the light induced oxidation, especially, loading of MYT at the core of the emulsion. The analysis of Electronic nose (E-nose) was used to analyze the odor before and after UV-induced oxidation, and showed a good discrimination. This study provided a new approach to prepare ZPPEs with high oxidation stability. Micro-CT, PetroOxy and E-nose could be new methods for characterization and quality assessment of Pickering emulsions.

Improvement of physicochemical properties, microstructure and stability of lotus root starch/xanthan gum stabilized emulsion by multi-frequency power ultrasound

Multi-frequency power ultrasound was applied as an environmentally friendly technique to control the nanoparticles (LS/XG-NPs) embedded with lotus root starch/xanthan gum, with the aim of enhancing the stability of Pickering emulsions. The present investigation was centered on evaluating the impact of ultrasound technology on various aspects of the emulsions, encompassing their mean particle size, particle size distribution, zeta potential, microstructure, rheological characteristics, and environmental stability. The findings of this study indicate that ultrasonic treatment enhanced the adsorption of LS/XG-NP onto oil droplets surface, resulting in a reduction in their size. Additionally, ultrasonic treatment decreased the viscosity and Brownian motion rate of the emulsion stabilized by LS/XG-NP, leading to increased fluidity. Furthermore, the emulsion's thermal stability and resistance to environmental oxidation were significantly enhanced through ultrasonic treatment. The Pickering emulsions that were prepared using ultrasound demonstrated excellent resistance to acid, alkali (pH 2-8) and salt ions (50-300 mM NaCl) for a period of 30 days during storage. It was worth anticipating that ultrasound-assisted LS/XG-NPs could efficiently retard the volatilization of fishy odor components within fish oil. Taken together, the present research has evinced the efficacy of ultrasound in enhancing the stability of Pickering emulsions coated with LS/XG-NPs. These findings offer significant novel insights into the advancement of ultrasound-assisted Pickering emulsions that are stabilized with starch-based or biopolymeric materials.

Low-Frequency Ultrasound Effects on Cellulose Nanocrystals for Potential Application in Stabilizing Pickering Emulsions

Cellulose, in the form of cellulose nanocrystals (CNCs), is a promising biomaterial for stabilizing Pickering emulsions (PEs). PEs are commonly formed using low-frequency ultrasound (LFU) treatment and impact CNC properties. The present study investigated the specific effects of LFU treatment on CNCs' chemical and physical properties. CNCs were characterized using dynamic light scattering, ζ;-potential determination, Fourier transform infrared spectroscopy, X-ray diffraction, and contact angle measurement. CNC suspensions were studied using rheological analysis and static multiple light scattering. LFU treatment broke CNC aggregates and modified the rheological behavior of CNC suspensions but did not affect the CNCs' chemical or crystallographic structures, surface charge, or hydrophilic properties. During the storage of CNC suspensions and PEs, liquid crystal formation was observed with cross-polarized light. Hypotheses related to the impact of liquid crystal CNCs on PE stability were proposed.

Encapsulation of mint essential oil: Techniques and applications

Mint essential oil (MEO) is an outstanding antibacterial and antioxidant agent, that can be considered as a promising natural preservative, flavor, insecticide, coolant, and herbal medicine. However, the low solubility and volatility of MEO limits its extensive applications. In order to utilize MEO in different products, it is essential to develop treatments that can overcome these limitations. More recently, encapsulation technology has been developed as a promising method to overcome the shortcomings of MEO. In which, sensitive compounds such as essential oils (EOs) are entrapped in a carrier to produce micro or nanoparticles with increased stability against environmental conditions. Additionally, encapsulation of EOs makes transportation and handling easier, reduces their volatility, controls their release and consequently improves the efficiency of these bioactive compounds and extends their industrial applications. Several encapsulation techniques, such as emulsification, coacervation, ionic gelation, inclusion complexation, spray drying, electrospinning, melt dispersion, melt homogenization, and so on, have been emerged to improve the stability of MEO. These encapsulated MEOs can be also used in a variety of food, bioagricultural, pharmaceutical, and health care products with excellent performance. Therefore, this review aims to summarize the physicochemical and functional properties of MEO, recent advances in encapsulation techniques for MEO, and the application of micro/nanocapsulated MEO in different products.

Research progress on chitin/chitosan-based emulsion delivery systems and their application in lipid digestion regulation

Excessive lipid intake is linked to an elevated risk of health problems. However, reducing lipid contents may influence food structure and flavor. Some alternatives are needed to control the lipid absorption. Emulsions are common carriers for lipids, which can control the hydrolysis and absorption of lipids. Chitin (Ch) and chitosan (CS) are natural polysaccharides with good biodegradability, biocompatibility, and unique cationic properties. They have been reported to be able to delay lipolysis, which can be regarded as one of the most promising agents that regulates lipid digestion (LiD). The application of Ch/CS and their derivatives in emulsions are summarized in this review with a focus on their performances and mechanisms for LiD regulation, aiming to provide theoretical guidance for the development of novel Ch/CS emulsions, and the regulation of LiD. A reasonable design of emulsion interface can provide its resistance to the external environment and then control LiD. The properties of emulsion interface are the key factors affecting LiD. Therefore, systematic study on the relationship between Ch/CS-based emulsion structure and LiD can not only instruct the reasonable design of emulsion interface to accurately regulate LiD, but also provide scientific guidelines for applying Ch/CS in functional food, medicine and other fields.

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

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

Stabilization of High Internal Phase Oil-in-Water Emulsions Using "Whole" Gracilaria lemaneiformis Slurry

In this study, a Gracilaria lemaneiformis slurry (GLS) was prepared using low-energy mechanical shearing. The resulting GLS, which was rich in polysaccharides, was utilized as an effective stabilizer for oil-in-water emulsions. The microstructures and stability of the resulting emulsions were controlled by adjusting the emulsion formulations, including Gracilaria lemaneiformis (GL) mass concentration and oil volume fraction (φ). The optimized GL mass concentration and φ conditions yielded high internal phase emulsions (HIPEs) with gel-like textures. Moreover, the presence of exogenous Ca2+ resulted in bridging structures in the emulsions, enhancing their viscoelasticity and forming a robust physical barrier against droplet coalescence. Our findings highlight the effectiveness of the GLS as an emulsifier for stabilizing HIPEs. Notably, this method relies solely on physical processes, aligning with the desirability of avoiding chemical additives, particularly in the food industry.

Nanocellulose-stabilized Pickering emulsions: Fabrication, stabilization, and food applications

Pickering emulsions have been widely studied due to their good stability and potential applications. Nanocellulose including cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and bacterial cellulose nanofibrils (BCNFs) has emerged as sustainable stabilizers/emulsifiers in food-related Pickering emulsions due to their favorable properties such as renewability, low toxicity, amphiphilicity, biocompatibility, and high aspect ratio. Nanocellulose can be widely obtained from different sources and extraction methods and can effectively stabilize Pickering emulsions via the irreversible adsorption onto oil-water interface. The synergistic effects of nanocellulose and other substances can further enhance the interfacial networks. The nanocellulose-based Pickering emulsions have potential food-related applications in delivery systems, food packaging materials, and fat substitutes. Nanocellulose-based Pickering emulsions as 3D printing inks exhibit good injectable and gelling properties and are promising to print spatial architectures. In the future, the utilization of biomass waste and the development of "green" and facile extraction methods for nanocellulose production deserve more attention. The stability of nanocellulose-based Pickering emulsions in multi-component food systems and at various conditions is an utmost challenge. Moreover, the case-by-case studies on the potential safety issues of nanocellulose-based Pickering emulsions need to be carried out with the standardized assessment procedures. In this review, we highlight key fundamental work and recent reports on nanocellulose-based Pickering emulsion systems. The sources and extraction of nanocellulose and the fabrication of nanocellulose-based Pickering emulsions are briefly summarized. Furthermore, the synergistic stability and food-related applications of nanocellulose-stabilized Pickering emulsions are spotlighted.

Lignin nanoparticles as co-stabilizers and modifiers of nanocellulose-based Pickering emulsions and foams

Nanocellulose is very hydrophilic, preventing interactions with the oil phase in Pickering emulsions. This limitation is herein addressed by incorporating lignin nanoparticles (LNPs) as co-stabilizers of nanocellulose-based Pickering emulsions. LNP addition decreases the oil droplet size and slows creaming at pH 5 and 8 and with increasing LNP content. Emulsification at pH 3 and LNP cationization lead to droplet flocculation and rapid creaming. LNP application for emulsification, prior or simultaneously with nanocellulose, favors stability given the improved interactions with the oil phase. The Pickering emulsions can be freeze-dried, enabling the recovery of a solid macroporous foam that can act as adsorbent for pharmaceutical pollutants. Overall, the properties of nanocellulose-based Pickering emulsions and foams can be tailored by LNP addition. This strategy offers a unique, green approach to stabilize biphasic systems using bio-based nanomaterials without tedious and costly modification procedures.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10570-023-05399-y.

Protein-Stabilized Emulsion Gels with Improved Emulsifying and Gelling Properties for the Delivery of Bioactive Ingredients: A Review

In today's food industry, the potential of bioactive compounds in preventing many chronic diseases has garnered significant attention. Many delivery systems have been developed to encapsulate these unstable bioactive compounds. Emulsion gels, as colloidal soft-solid materials, with their unique three-dimensional network structure and strong mechanical properties, are believed to provide excellent protection for bioactive substances. In the context of constructing carriers for bioactive materials, proteins are frequently employed as emulsifiers or gelling agents in emulsions or protein gels. However, in emulsion gels, when protein is used as an emulsifier to stabilize the oil/water interface, the gelling properties of proteins can also have a great influence on the functionality of the emulsion gels. Therefore, this paper aims to focus on the role of proteins' emulsifying and gelling properties in emulsion gels, providing a comprehensive review of the formation and modification of protein-based emulsion gels to build high-quality emulsion gel systems, thereby improving the stability and bioavailability of embedded bioactive substances.

The research advance of resistant starch: structural characteristics, modification method, immunomodulatory function, and its delivery systems application

Resistant starch, also known as anti-digestion enzymatic starch, which cannot be digested or absorbed in the human small intestine. It can be fermented in the large intestine into short-chain fatty acids (SCFAs) and metabolites, which are advantageous to the human body. Starches can classify as rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS), which possess high thermal stability, low water holding capacity, and emulsification characteristics. Resistant starch has excellent physiological functions such as stabilizing postprandial blood glucose levels, preventing type II diabetes, preventing intestinal inflammation, and regulating gut microbiota phenotype. It is extensively utilized in food processing, delivery system construction, and Pickering emulsion due to its processing properties. The resistant starches, with their higher resistance to enzymatic hydrolysis, support their suitability as a potential drug carrier. Therefore, this review focuses on resistant starch with structural features, modification characteristics, immunomodulatory functions, and delivery system applications. The objective was to provide theoretical guidance for applying of resistant starch to food health related industries.