Wheat gluten-stabilized high internal phase emulsions as mayonnaise replacers

Improvement of processable properties of plant-based high internal phase emulsions by mung bean protein isolate based on pH shift treatment

BACKGROUND

High internal phase emulsions (HIPEs) are unique emulsion systems that transform liquid oil into solid-like fats, thus avoiding the use of saturated fat and leading to a healthier and more sustainable food system for consumers. HIPEs with oil volume fraction (ϕ) of 75-85% were fabricated with mung bean protein isolate (MPI) under different pH shift treatments at 1.0% concentration through the one-step method. In the present study, we investigated the physical properties, microstructures, processing properties, storage stability and rheological properties of HIPEs.

RESULTS

The results suggested that the properties of MPI under different pH shift treatments were improved to different degrees, stabilizing HIPEs (ϕ = 75-85%) with various processability to meet food processing needs. Under alkali shift treatment conditions, the particle size of MPI was significantly reduced with better solubility. Moreover, the exposure of hydrophobic groups increased the surface hydrophobicity of MPI, awarding MPI better emulsifying properties, which could stabilize the HIPEs with higher oil phase fraction. In addition, the MPI under pH 12 shift treatment (MPI-12) had the best oil-carrying ability to form the stable HIPEs with oil volume fraction (ϕ) up to 85%, which was the highest oil phase in preparing the HIPEs using plant protein solely at a low concentration under neutral conditions.

CONCLUSION

A series of stable HIPEs with different processing properties was simply and feasibly fabricated and these are of great potential in applying edible HIPEs. © 2024 Society of Chemical Industry.

Effect of a collagen peptide-fish oil high internal phase emulsion on the printability and gelation of 3D-printed surimi gel inks

The effect of a high internal phase emulsion (HIPE) on three-dimensional-printed surimi gel inks was studied. Increasing the concentration of collagen peptide decreased the particle size of HIPE droplets and improved the viscoelasticity and stability. For example, when the collagen peptide concentration was 5 wt%, the viscoelasticity of the HIPE was high, as indicated by the presence of small and uniform particles, which formed a monolayer in the outer layer of the oil droplets to form stable a HIPE. A HIPE was used as the filling material to fill the surimi gel network, which reduced the porosity of the network. Surimi protein and peptides have dual emulsifying effects on the stabilization of oil. After adding the emulsion, the texture, gel properties and rheological properties of the surimi were reduced, and its printing adaptability was improved. This study provides new ideas for the production of surimi and its application in 3D printing.

Developing animal fat substitute in low-fat meatballs: A strategy to use high internal phase emulsions stabilized by Prinsepia utilis Royle protein

In promoting healthy diet, developing animal fat substitutes for meat products has been a prominent trend in food science. In this study, Prinsepia utilis Royle protein (PuRP) with amphiphilic property was extracted from waste oil pomace. High internal phase emulsions (HIPEs) were prepared with a 75% oil phase and stabilized with 2% (w/v) PuRP due to their excellent elastic-gel property. Furthermore, the PuRP-HIPEs were used to substitute animal fat in low-fat meatballs. Below 100 mM ionic strength, the uniformly distributed PuRP-HIPEs exhibited an approximate Gaussian size distribution with an average particle size of about 100 μm. The PuRP-HIPEs exhibited good thermodynamic stability and improved the texture of meatballs. Additionally, the PuRP-HIPEs significantly increased the mobile water content in steamed meatballs, resulting in better water retention and distribution than the free-fat and lard-added meatballs. Overall, the PuRP-HIPEs could substitute 100% animal fat in meatballs and maintain their cooking characteristics.

Investigating the physicochemical, rheological, and sensory properties of low-fat mayonnaise prepared with amaranth protein as an egg yolk replacer

This study investigated the possibility of using amaranth protein isolate (API) as a plant-based substitute for egg yolk (EY) in the preparation of low-fat mayonnaise (LFM). The alkali extraction/acidic precipitation method was used to isolate amaranth protein; its functional properties were then studied. The results showed that besides its great water and oil absorption capacities, API had better emulsifying capacity and significantly higher (p < .05) emulsion stability at pH 2.0 than alkali pH values. Five mayonnaise samples with different API/EY combination ratios (%) (i.e., 0/0.75, 0.25/0.5, 0.375/0.375, 0.5/0.25, and 0.75/0) were prepared. The color, emulsion stability (ES), freeze-thaw stability (FTS), droplet size, structure, rheology, and sensory properties of samples were examined. API replacement showed no adverse effects on the L* value, ES, and sensory attributes (p > .05). Low API concentrations (0.25% and 0.375%) significantly (p < .05) increased the droplet size and decreased the FTS of LFM emulsion. High API concentrations (0.5% and 0.75%) had no significant effect (p > .05) on droplet size and formed emulsions with more tightly packed oil droplets. The Cross model was chosen best to describe the flow behavior of LFM samples (R 2 = 0.99). The sample with 0.75% API had significantly (p < .05) the highest values of η o (zero-shear viscosity) and λ (relaxation time), indicating greater interaction between the emulsion particles. All samples showed a weak gel structure (G' > G"). In conclusion, API can be considered an appropriate substitute for EY in LFM production, which can benefit human health and offer a new strategy for preparing vegan products.

Soy protein particles as stabilizers of heat-stable O/W emulsions with 20% protein content

In response to the increasing demand for nutritionally rich foods, consumer preference for protein-enriched beverages has grown. However, heat-induced protein aggregation and gelation significantly hinders the production of high-protein drinks. In this study, oil-in-water (O/W) emulsions with exceptional thermal stability were formulated using modified soy protein particles (MSPs). These MSPs effectively resisted gel formation, even at a protein concentration of up to 20% (w/v). In contrast, emulsions prepared with untreated soy proteins (SPs) experienced pronounced gelation under identical conditions. The compact structure of MSPs, in comparison to SPs, imparted resistance to heat-induced denaturation and aggregation. Additionally, the emulsion displayed heightened heat processing insensitivity, due to the enhanced hydrophobicity of MSPs and their rapid adsorption at the oil-water interface, resulting in a denser, more elastic, and resilient interfacial film. These findings provide practical insights for the formulation of protein-rich milk alternatives, meeting the evolving market demands.

Pea protein/carboxymethyl cellulose complexes prepared using a pH cycle strategy as stabilizers of high internal phase emulsions for 3D printing

The development of food-grade high internal phase emulsions (HIPEs) for 3D printing and the replacement of animal fats have attracted considerable attention. In this study, in order to improve the rheological properties and stability of pea protein to prepare HIPE, pea protein/carboxymethyl cellulose (pH-PP/CMC) was prepared and subjected to pH cycle treatment to produce HIPEs. The results showed that pH cycle treatment and CMC significantly reduced the droplet size of HIPEs (from 143.33 to 12.10 μm). At higher CMC concentrations, the interfacial tension of the PP solution decreased from 12.84 to 11.71 mN/m without pH cycle treatment and to 10.79 mN/m with pH cycle treatment. The HIPEs with higher CMC concentrations subjected to pH cycle treatment showed shear thinning behavior and higher viscoelasticity and recovered their solid-like properties after being subjected to 50 % strain, indicating that they could be used for 3D printing. The 3D printing results showed that the pH-PP/CMC HIPE with 0.3 % CMC had the finest structure. Our work provides new insights into developing food-grade HIPEs and facilitating their use in 3D printing inks as nutrient delivery systems and animal fat substitutes.

Quality Characteristics of Vegan Mayonnaise Produced Using Supercritical Carbon Dioxide-Processed Defatted Soybean Flour

Emulsifiers, like egg yolk (EY), are necessary for the formation of mayonnaise, which is an oil-in-water type of colloid. This study aimed to assess the potential of defatted soybean powder treated with supercritical carbon dioxide (DSF) to enhance the quality of plant-based mayonnaise as plant-based alternatives gain popularity. This study involved the production of DSF and the comparison of its quality attributes to those of mayonnaise made with varying amounts of control soy flour (CSF), DSF, and EY. It was found that mayonnaise made with an increased quantity of DSF showed better emulsion stability, viscosity, and a smaller, more uniform particle size when compared with CSF mayonnaise. Additionally, DSF mayonnaise was generally rated higher in sensory evaluation. The addition of approximately 2% DSF positively influenced the emulsion and sensory properties of the vegan mayonnaise, indicating that DSF is a promising plant-based alternative emulsifier for the replacement of animal ingredients.

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.

Production of Novel Bigels from Cold Pressed Chia Seed Oil By-Product: Application in Low-Fat Mayonnaise

The objective of this study was to produce an innovative bigel formulation by combining glycerol monostearate (GMS) oleogel with hydrogels stabilized by various agents, including cold pressed chia seed oil by-product gum (CSG), gelatin (G), and whey protein concentrate (WPC). The findings indicated that the choice of hydrogel influenced the rheological, textural, and microstructural properties of the bigels. The G' value of the bigel samples was higher than G″, indicating that all the bigels exhibited solid-like characteristics. In order to numerically compare the dynamic rheological properties of the samples, K' and K″ values were calculated using the power law model. K' values of the samples were found to be higher than K″ values. The K' value of bigel samples was significantly affected by the hydrogel (HG)/oleogel ratio (OG) and the type of stabilizing agent used in the hydrogel formulation. As the OG ratio of bigel samples increased, the K' value increased significantly (p < 0.05). The texture values of the samples were significantly affected by the HG/OG ratio (p < 0.05). The study's findings demonstrated that utilizing CSG, G, and WPC at an OG ratio more than 50% can result in bigels with the appropriate hardness and solid character. The low-fat mayonnaise was produced by using these bigels. The low-fat mayonnaise showed shear-thinning and solid-like behavior with G' values greater than the G″ values. Low-fat mayonnaise produced with CSG bigels (CSGBs) showed similar rheological properties to the full-fat mayonnaise. The results showed that CSG could be used in a bigel formulation as a plant-based gum and CSGB could be used as a fat replacer in low-fat mayonnaise formulation.

Formulations and assessments of structure, physical properties, and sensory attributes of soy yogurts: Effect of carboxymethyl cellulose content and degree of substitution

Soy yogurts present challenges, including absence of tender and slipperiness mouthfeel, and poor stability. This study aimed to investigate the impacts of carboxymethyl cellulose (CMC) with degrees of substitution of 0.7 (CMC0.7) and 1.2 (CMC1.2) at concentrations ranging from 0 % to 1.1 % on the stability, microstructure, rheology, tribology, and mouthfeel of soy yogurts. As the CMC concentration increased from 0 % to 0.3 %, soy yogurts displayed a coarser microstructure, decreased stability, and increased gel strength. As the concentration of CMC further increased from 0.5 % to 1.1 %, soy yogurts exhibited trends of a smoother microstructure, increased stability, and softer gel strength. Notably, soy yogurts with CMC0.7 demonstrated a superior water holding capacity (WHC) than soy yogurts with CMC1.2. Tribological measurements indicated that soy yogurts with CMC0.7 at a 0.7 % concentration had the lowest coefficient of friction (COF) value among most sliding speeds, showing a 23 % reduction compared to soy yogurts without CMC at a sliding speed of 10 mm/s. Moreover, sensory evaluation showed that soy yogurts with CMC0.7 at a 0.7 % concentration had the highest total score in mouthfeel evaluation. Therefore, the addition of CMC0.7 within the concentration range of 0.5 % to 1.1 % may produce stable and delicate yogurts.

A review of high internal phase Pickering emulsions: Stabilization, rheology, and 3D printing application

High internal phase Pickering emulsion (HIPPE) is renowned for its exceptionally high-volume fraction of internal phase, leading to flocculated yet deformed emulsion droplets and unique rheological behaviors such as shear-thinning property, viscoelasticity, and thixotropic recovery. Alongside the inherent features of regular emulsion systems, such as large interfacial area and well-mixture of two immiscible liquids, the HIPPEs have been emerging as building blocks to construct three-dimensional (3D) scaffolds with customized structures and programmable functions using an extrusion-based 3D printing technique, making 3D-printed HIPPE-based scaffolds attract widespread interest from various fields such as food science, biotechnology, environmental science, and energy transfer. Herein, the recent advances in preparing suitable HIPPEs as 3D printing inks for various applied fields are reviewed. This work begins with the stabilization mechanism of HIPPEs, followed by introducing the origin of their distinctive rheological behaviors and strategies to adjust the rheological behaviors to prepare more eligible HIPPEs as printing inks. Then, the compatibility between extrusion-based 3D printing and HIPPEs as building blocks was discussed, followed by a summary of the potential applications using 3D-printed HIPPE-based scaffolds. Finally, limitations and future perspectives on preparing HIPPE-based materials using extrusion-based 3D printing were presented.

Synergistic formulation approach for developing pea protein and guar gum enriched olive oil-in-water emulsion gels as solid fat substitutes: Formulation optimization, characterization, and molecular simulation

This study aimed to optimize the formulation of olive oil-in-water (O/W) emulsion gels by incorporating Pea Protein (PP) and Guar Gum (GG) as alternative options for solid fats. The optimum rheological (consistency index, apparent viscosity, recovery) and texture (firmness) properties of the emulsion gels were obtained using a mixture of 2 % PP, 1 % GG, 60 % Olive Oil (OO), and 37 % Water (W). The blend of PP2/GG1 showed the highest results for recovery and firmness, 111.27 % and 33.89 g, respectively. PP/GG blend emulsion gels exhibited higher absolute ζ-potential values, ranging between -72.3 and -77.4 mV. The polydispersity index (PDI) ranged from 0.185 to 0.535, with the most uniform distributions found in the PP/GG blend emulsion gels. Strong phase separation resistance indicated strong stability of PP-GG complex emulsion gels. Higher PP concentrations decreased emulsion oxidation. FTIR and XRD research showed that PP and GG interact strongly, indicating good compatibility. The free binding energy of the most stable configuration of the molecules was -6.8 kcal mol-1, indicating a high affinity. PP interacted with GG through 9 amino acid residues, with notable residues being Asp 224, Thr 235, Ala 332, Ile 334, and Arg 336, and their respective interaction distances ranged between 2.69 Å and 3.87 Å.

The freeze-thaw stability of flavor high internal phase emulsion and its application to flavor preservation and 3D printing

Volatilization of flavor substances may reduce consumers' perception of flavor, and the research on preservation of flavor substances by high internal phase emulsions (HIPEs) under freeze-thaw conditions is still blank. Herein, flavor HIPEs prepared by adding more than 15% litsea cubeba oil in the oil phase could be used as food-grade 3D printing inks, and showed better stability after 5 freeze-thaw cycles, which could be interpreted as the reduced ice crystal formation, more stable interface layer, and more flexible gel-like network structure resulting from the protein binding to flavor substances. The constructed HIPEs system in this study could preserve the encapsulated flavor substances perfectly after 5 freeze-thaw cycles. Overall, this study contributes a food-grade 3D printing ink, and provides a new method for the preservation of flavor substances under freezing conditions and expands the application range of flavor HIPEs in food industry.

Study of the effect of canola proteins-xanthan based Pickering emulsion as animal fat replacer in a food matrix produced from mechanically separated meat

Pickering emulsions stabilized by protein microgel, and hydrocolloid have shown desirable properties to be used as animal fat replacers. However, the potential applications of these structures as animal fat replacers in meat systems formulations have not been explored yet. Therefore, novel Pickering emulsions stabilized by canola proteins microgels and xanthan gum were developed, and their potential as animal fat replacer in meat systems was assessed for the first time. In the present study, 25, 50, 75, and 100% animal fat content were replaced by Pickering emulsion. Moreover, the obtained results revealed that complete fat replacement with canola proteins-based Pickering emulsion in meat emulsion improved its nutritional value by significantly enhancing the percentage of protein, monounsaturated and polyunsaturated fatty acid composition, and reduction of saturated fatty acid content compared to control (100% animal fat). Reformulation with PEs enhanced the meat systems' technological behavior such as emulsion stability and cooking loss, and oxidative stability. Also, significant total color difference (ΔE *) was observed only in samples with 100% fat replacement. Meat systems containing fat replacement ≤50% showed the closest texture parameters to the control sample. This study provides a promising alternative to replace animal fat with plant-based ingredients in meat systems.

Preparation of fat replacer utilizing gluten and barley β-glucan and the interaction between them

BACKGROUND

Fat replacers prepared from polysaccharides and proteins possess functional properties of both polysaccharides and proteins. In this study, an aqueous system of barley β-glucan (BBG) and gluten was prepared. The interactions between BBG and gluten (with/without extrusion modification) were studied. Triple analysis methods, including differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and low-field nuclear magnetic resonance (LF-NMR), were utilized to analyze the freezing-thawing and thermal evaporation process, as well as the distribution state of water. Meanwhile, fluorescence microscopic analysis, dynamic rheological analysis and electrophoresis analysis were used to study the structure and rheological properties of the system.

RESULTS

The results showed that BBG significantly increased the water-holding capacity of gluten, regardless of extrusion treatment, with the water absorption reaching about 4.8 to 6.4 times of its weight, which was 1 to 2.5 times higher than that without BBG. The triple analysis results suggested that BBG increased the binding capacity of the system to weakly bound water, hindered the aggregation of gluten and reduced the thermal decomposition temperature of the BBG and gluten composite system. After the gluten was extruded and homogenized with the BBG solution, the appearance of the composite system was more uniform and delicate.

CONCLUSIONS

In conclusion, BBG increased the water-holding capacity of the BBG and gluten composite system. With these changes, the composite system presented great potential for the preparation of polysaccharide-gluten fat replacer. © 2023 Society of Chemical Industry.

Improved antioxidant properties of pork patties by replacing fat with resveratrol-loaded MP-CS complex stabilized pickering emulsion

The characterization and antioxidant ability of Res-loaded MP-CS stabilized Pickering emulsion, and its effects of fat reduction (25%, 50%, 75%, and 100%) in meat patties on pH, color, texture, cooking yield and antioxidant activity were investigated. Fat substitute using emulsion had no significant effect on pH and cooking yield. The addition of emulsion increased L* value and reduced a* value. a* value of meat patties with resveratrol added were higher than those without resveratrol group. Hardness and chewiness of meat patties with 25% and 100% fat replacement was lower than 50% and 75% fat replacement. The addition of emulsion could improve the network structure of meat patties and enhance oxidative stability. Oxidative stability of meat patties was improved by Res-loaded MP-CS stabilized Pickering emulsion. The results showed that MP-CS stabilized Pickering emulsion had great potential to be used as fat substitute for developing low-fat meat products, and the addition of resveratrol can improve the antioxidant ability of substitute fat meat products.

Stability and Rheological Behavior of Mayonnaise-like Emulsion Co-Emulsified by Konjac Glucomannan and Whey Protein

The aim of this work was to study the physical stability and rheological properties of an oil-in-water emulsion stabilized by a konjac glucomannan-whey protein (KGM-WP) mixture at a konjac glucomannan concentration of 0.1-0.5% (w/w) and a whey protein concentration of 1.0-3.0% (w/w). The droplet size, microstructure, stackability, flow behavior, and viscoelastic properties were measured. The experimental results showed that with an increase in KGM and WP concentrations, the droplet size (D4,3) of the emulsion gradually decreased to 12.9 μm, and the macroscopic performance of the emulsion was a gel-like structure that can be inverted and resist flow and can also be extruded and stacked. The static shear viscosity and viscoelasticity generally increased with the increase of konjac glucomannan and whey protein concentration. Emulsions were pseudo-plastic fluids with shear thinning behavior (flow behavior index: 0.15 ≤ n ≤ 0.49) and exhibited viscoelastic behavior with a storage modulus (G') greater than their loss modulus (G″), indicating that the samples all had gel-like behavior (0.10 < n' < 0.22). Moreover, storage modulus and loss modulus of all samples increased with increasing KGM and WP concentrations. When the concentration of konjac glucomannan was 0.3% w/w, the emulsion had similar rheological behavior to commercial mayonnaise. These results suggested that the KGM-WP mixture can be used as an effective substitute for egg yolk to make a cholesterol-free mayonnaise-like emulsion. The knowledge obtained here had important implications for the application of protein-polysaccharide mixtures as emulsifiers/stabilizers to make mayonnaise-like emulsions in sauce and condiments.

pH-shift strategy improving the thermal stability and oxidation stability of rice starch/casein-based high internal phase emulsions for the application in fish cake

The thermal stability of the different pH-shift rice starch/casein-based high internal phase emulsions (SC-HIPE) were evaluated in the present study to verify potential in improving the quality of fish cake. The results showed that the pH-shift treatment improved thermal stability (from 27.23% to 76.33%) and oxidation time (from 5.01 h to 6.86 h) of SC-HIPE, which showed the smaller droplet size (decreased from 15.14 to 1.64 μm) and higher storage module. The breaking force of FC with thermal stable SC-HIPE (average 64.95 g) was higher than that with thermal unstable SC-HIPE (51.05 g). The cohesiveness, adhesiveness and chewiness could be improved by adding thermal stable SC-HIPE, compared with pork fat. Additionally, combining sensory evaluation, the thermal stable SC-HIPE improved the gel quality, thus it could be completely replaced pork fat in the preparation of FC, which provided theoretical guidance for the preparation and application of fat substitutes.

Development and characterization of self-emulsifying high internal phase emulsions using endogenous phospholipids from Antarctic krill oil

High internal phase emulsions (HIPEs) have emerged as a promising structured oil system in food industry. This study developed self-emulsifying HIPEs (SHIPEs) using Antarctic krill oil (KO) with endogenous phospholipids as surfactant and algae oil as a diluent. The influence of phospholipids self-assembly on SHIPEs formation was investigated by evaluating the microstructures, particle size, rheological properties, and water distribution. Results demonstrated that the concentration and self-assembly behavior of phospholipids dominated the SHIPEs formation. Optimized SHIPEs with desirable gel properties contained 10 wt% krill oil in the oil phase at an 80 wt% oil phase level. Furthermore, these SHIPEs exhibited excellent performance in 3D printing applications. Hydrated phospholipids formed lamellar network at the oil-water interface, enhancing gel strength by crosslinking oil droplets. These findings shed light on the self-assembly of phospholipids during HIPEs formation and highlight the potential phospholipids-rich marine lipids in SHIPEs for functional food products development.

Characteristics of reduced-fat mayonnaise prepared by oleaster as a fat replacer and natural antioxidant

Due to the disadvantages of consuming fat and synthetic preservatives, the demand to reduce them in lipid-based products like mayonnaise is increasing. In the current research, there were two goals, the first one was studying the effect of using oleaster flour in different concentrations (4%, 6%, and 8%) as a natural preservative, whereas the second one was studying the effect of oleaster as different fat replacement (FR) levels (10%, 20%, 30%, and 40%) on the physicochemical, antioxidant, and the rheological properties and stability of reduced-fat mayonnaise samples. Given results showed that with increasing the oleaster concentration, the antioxidant property increased significantly. The peroxide value after 60 days of storage for the 30% FR 8 was 2.01%, compared to the control sample without antioxidant and with TBHQ, which were 10% and 2.68%, respectively. The highest stability index (100%) was observed in the 30% FR and 40% FR samples. In terms of rheological characteristics, the 30% FR 8 oleaster showed the highest viscosity and the lowest frequency dependency. It can be concluded that oleaster has a high potential to be used in the formulation of low-fat mayonnaise as a fat replacer.

Updates on Plant-Based Protein Products as an Alternative to Animal Protein: Technology, Properties, and Their Health Benefits

Plant-based protein products, represented by "plant meat", are gaining more and more popularity as an alternative to animal proteins. In the present review, we aimed to update the current status of research and industrial growth of plant-based protein products, including plant-based meat, plant-based eggs, plant-based dairy products, and plant-based protein emulsion foods. Moreover, the common processing technology of plant-based protein products and its principles, as well as the emerging strategies, are given equal importance. The knowledge gap between the use of plant proteins and animal proteins is also described, such as poor functional properties, insufficient texture, low protein biomass, allergens, and off-flavors, etc. Furthermore, the nutritional and health benefits of plant-based protein products are highlighted. Lately, researchers are committed to exploring novel plant protein resources and high-quality proteins with enhanced properties through the latest scientific and technological interventions, including physical, chemical, enzyme, fermentation, germination, and protein interaction technology.

Edible HIPE-Gels and oleogels formed by synergistically combining natural triterpenoid saponin and citrus dietary fiber

High-internal-phase emulsion gels (HIPE-Gels) and oleogels were successfully fabricated through synergistically combination of natural triterpenoid Quillaja saponin (QS) and citrus dietary fiber (CDF). The amphiphilic QS significantly lowered the oil-water interface tension; whereas CDF could form compact structure at the interface as well as in the bulk under a hydrogen-bonding interaction with saponin. The combination endowed the emulsion gels with enhanced performance, such as decreasing droplet size, strengthening gel network structure and better viscoelastic. At a very low QS of 0.045 %, stable HIPE-Gels can be produced with 0.3 % CDF, which mainly attributing to the highly viscoelastic fiber networks in continuous phase and thus actively trap the QS-coated emulsion droplets. Consequently, the robust HIPE-Gels were applied as soft template to fabricate oleogels with controlled by QS and CDF loading. These findings proved an effective strategy towards structuring edible liquid oil into healthy gels for alternating saturated and trans fats in foods.

Capsaicin encapsulated in W/O/W double emulsions fabricated via ethanol-induced pectin gelling: Improvement of bioaccessibility and reduction of irritation

Capsaicin is a water-insoluble bioactive component with several beneficial physiological functions. However, the widespread application of this hydrophobic phytochemical is limited by its low water-solubility, intense irritation, and poor bioaccessibility. These challenges can be overcome by entrapping capsaicin within the internal water phase of water-in-oil-in-water (W/O/W) double emulsions via using ethanol to induce pectin gelling. In this study, ethanol was used both to dissolve capsaicin and to promote pectin gelation, thereby forming capsaicin-loaded pectin hydrogels that were used as the internal water phase of the double emulsions. Pectin addition improved the physical stability of the emulsions and led to a high encapsulation efficiency of capsaicin (>70 % after 7d storage). After simulated oral and gastric digestion, capsaicin-loaded double emulsions maintained their compartmentalized structure, avoiding capsaicin leakage in the month and stomach. The double emulsions were digested in the small intestine, thereby releasing the capsaicin. Capsaicin bioaccessibility was significantly enhanced after encapsulation, which was attributed to mixed micelle formation by the digested lipid phase. Furthermore, encapsulation of capsaicin within the double emulsions reduced the irritation in the gastrointestinal tissues of mice. This kind of double emulsion may have great potential for the development of more palatable capsaicin-loaded functional food products.

Biopolymer-based pickering high internal phase emulsions: Intrinsic composition of matrix components, fundamental characteristics and perspective

Pickering HIPEs have received tremendous attention in recent years due to their superior stability and unique solid-like and rheological properties. Biopolymer-based colloidal particles derived from proteins, polysaccharides and polyphenols have been demonstrated to be safety stabilizers for the construction of Pickering HIPEs, which can meet the demands of consumers for "all-natural" products and provide "clean-label" foods. Furthermore, the functionality of these biopolymers can be further extended by forming composite, conjugated and multi-component colloidal particles, which can be used to modulate the properties of the interfacial layer, thereby adjusting the performance and stability of Pickering HIPEs. In this review, the factors affecting the interfacial behavior and adsorption characteristics of colloidal particles are discussed. The intrinsic composition of matrix components and fundamental characteristics of Pickering HIPEs are emphatically summarized, and the emerging applications of Pickering HIPEs in the food industry are reviewed. Inspired by these findings, future perspectives concerning this field are also put forward, including (1) the exploration of the interactions between biopolymers used to produce Pickering HIPEs and target food ingredients, and the influence of the added biopolymers on the flavor and mouthfeel of the products, (2) the investigation of the digestion properties of Pickering HIPEs under oral administration, and (3) the fabrication of stimulus-responsive or transparent Pickering HIPEs. This review will give a reference for exploring more natural biopolymers for Pickering HIPEs application development.

Protein-Based Fat Replacers: A Focus on Fabrication Methods and Fat-Mimic Mechanisms

The increasing occurrence of obesity and other non-communicable diseases has shifted the human diet towards reduced calorie intake. This drives the market to develop low-fat/non-fat food products with limited deterioration of textural properties. Thus, developing high-quality fat replacers which can replicate the role of fat in the food matrix is essential. Among all the established types of fat replacers, protein-based ones have shown a higher compatibility with a wide range of foods with limited contribution to the total calories, including protein isolate/concentrate, microparticles, and microgels. The approach to fabricating fat replacers varies with their types, such as thermal-mechanical treatment, anti-solvent precipitation, enzymatic hydrolysis, complexation, and emulsification. Their detailed process is summarized in the present review with a focus on the latest findings. The fat-mimic mechanisms of fat replacers have received little attention compared to the fabricating methods; attempts are also made to explain the underlying principles of fat replacers from the physicochemical prospect. Finally, a future direction on the development of desirable fat replacers in a more sustainable way was also pointed out.

Characterization of bacterial cellulose nanofibers/soy protein isolate complex particles for Pickering emulsion gels: The effect of protein structure changes induced by pH

In this work, the influence of soy protein isolated at different pH values (1-9) on the self-assembly behaviors of bacterial cellulose nanofibers/soy protein isolate (BCNs/SPI) colloidal particles via anti-solvent precipitation were investigated. The results showed that the formation of BCNs/SPI at pH values of 1-5 was mainly driven by electrostatic interaction, while the formation of those at pH values of 5-9 was driven by weak molecular interactions including hydrogen bonding and steric-hindrance effect. The FTIR demonstrated that the conformation of protein involved a transition from order to disorder at the level of secondary structure as pH values were away from the isoelectric point. The fluorescence spectroscopy and UV-vis adsorption spectroscopy indicated that hydrophobic region of SPI at pH value of 5 displayed more exposed as compared with that at pH values away from the isoelectric point. The changes in structure conformation of SPI induced by pH values led to the changes in properties of the BCNs/SPI colloidal particles including particle size, microstructure, crystallinity, hydrophily, thermal stability, and rheological properties. Furthermore, the structures of BCNs/SPI colloidal particles at different pH values significantly affected the stability of Pickering emulsion gels stabilized by the corresponding complex colloidal particles. This study provided a theoretical basis for the design of food-grade Pickering emulsion gels stabilized by BCNs/SPI complex colloidal particles.

Protein-Based High Internal Phase Pickering Emulsions: A Review of Their Fabrication, Composition and Future Perspectives in the Food Industry

Protein-based high internal phase Pickering emulsions (HIPEs) are emulsions using protein particles as a stabilizer in which the volume fraction of the dispersed phase exceeds 74%. Stabilizers are irreversibly adsorbed at the interface of the oil phase and water phase to maintain the droplet structure. Protein-based HIPEs have shown great potential for a variety of fields, including foods, due to the wide range of materials, simple preparation, and good biocompatibility. This review introduces the preparation routes of protein-based HIPEs and summarizes and classifies the preparation methods of protein stabilizers according to their formation mechanism. Further outlined are the types and properties of protein stabilizers used in the present studies, the composition of the oil phase, the encapsulating substances, and the properties of the constituted protein-based HIPEs. Finally, future development of protein-based HIPEs was explored, such as the development of protein-based stabilizers, the improvement of emulsification technology, and the quality control of stabilizers and protein-based HIPEs.

Development of high-internal-phase emulsions stabilized by soy protein isolate-dextran complex for the delivery of quercetin

BACKGROUND

Protein-polysaccharide complexes have been widely used to stabilize high-internal-phase emulsion (HIPEs). However, it is still unknown whether soy protein isolate-dextran (SPI-Dex) complexes can stabilize HIPEs or what is the effect of Dex concentration on the HIPEs. Furthermore, the non-covalent interaction mechanism between SPI and Dex is also unclear. Therefore, we fabricated SPI-Dex complexes and used them to stabilize HIPEs-loaded quercetin and explore the interaction mechanism between SPI and Dex, as well as the effect of Dex concentration on the particle size, ζ-potential, microstructure, rheology, quercetin encapsulation efficiency, and gastrointestinal fate of the HIPEs.

RESULTS

Spectral analysis (fourier transform infrared spectroscopy, ultraviolet spectroscopy, and fluorescence spectroscopy) results identified the formation of SPI-Dex complexes, and indicated that the addition of Dex changed the spatial structure of SPI, whereas thermodynamic analysis (ΔH > 0, ΔS > 0) showed that hydrophobic interactions were the main driving forces in the formation of SPI-Dex complexes. Compared with HIPEs stabilized by SPI, the SPI-Dex complex-stabilized HIPEs had smaller particles (3000.33 ± 201.22 nm), as well as higher ζ-potential (-21.73 ± 1.10 mV), apparent viscosities, modulus, and quercetin encapsulation efficiency (98.19 ± 0.14%). In addition, in vitro digestion revealed that SPI-Dex complex-stabilized HIPEs significantly reduced the release of free fatty acid and improved quercetin bioaccessibility.

CONCLUSION

HIPEs stabilized by SPI-Dex complexes delayed the release of free fat acid and improved the bioaccessibility of quercetin, and may be help in designing delivery systems for bioactive substances with specific properties. © 2022 Society of Chemical Industry.

Progress in the Application of Food-Grade Emulsions

The detailed investigation of food-grade emulsions, which possess considerable structural and functional advantages, remains ongoing to enhance our understanding of these dispersion systems and to expand their application scope. This work reviews the applications of food-grade emulsions on the dispersed phase, interface structure, and macroscopic scales; further, it discusses the corresponding factors of influence, the selection and design of food dispersion systems, and the expansion of their application scope. Specifically, applications on the dispersed-phase scale mainly include delivery by soft matter carriers and auxiliary extraction/separation, while applications on the scale of the interface structure involve biphasic systems for enzymatic catalysis and systems that can influence substance digestion/absorption, washing, and disinfection. Future research on these scales should therefore focus on surface-active substances, real interface structure compositions, and the design of interface layers with antioxidant properties. By contrast, applications on the macroscopic scale mainly include the design of soft materials for structured food, in addition to various material applications and other emerging uses. In this case, future research should focus on the interactions between emulsion systems and food ingredients, the effects of food process engineering, safety, nutrition, and metabolism. Considering the ongoing research in this field, we believe that this review will be useful for researchers aiming to explore the applications of food-grade emulsions.

Formation, Structure and stability of high internal phase Pickering emulsions stabilized by BSPI-C3G covalent complexes

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The HIIPPE was stabilized by BSPI-C3G covalent particles.

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HIPPEs stabilized with 74% (v/v) oil phase fraction have a stable gel-like state.

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HIPPEs stability was the best with the 3 % (w/v) BSPI-C3G particle concentration.

Food-grade high internal phase Pickering emulsions (HIPPEs) are stabilized by protein-based particles, which have attracted extensive attention due to their good gel-like structure. The black soybean isolate protein/cyanidin-3-O-glucoside (BSPI-C3G) covalent particles were used as a particulate emulsifier to form stable HIPPEs with oil phase fractions (74 % v/v) and low particle concentrations (0.5 %–3 % w/v) The particle size distribution and microstructure demonstrated that the BSPI-C3G covalent particles acted as an interfacial layer and surrounded the oil droplets. As the concentration of BSPI-C3G particles increased from 0.5 % to 3 %, the droplet size, elasticity, antioxidant capacity of the heated or stored HIPPEs more stable. So, the HIPPEs had the best stability with the BSPI-C3G particle at 3 % (w/v) concentration. These findings may extend the application of BSPI and C3G in foods and provide the guidelines for the rational design of food-grade HIPPEs stabilized by protein/anthocyanin complexes.

Recent advances in self-assembly behaviors of prolamins and their applications as functional delivery vehicles

Prolamins are a group of storage proteins (zeins, kafirins, hordeins, secalins, gliadins, glutenins, and avenins) found in the endosperm of cereal grains and characterized by high glutamine and proline content. With the high proportion of nonpolar amino acids (40-80%) and peculiar solubility (alcohol (60-90%), acetic acid, and alkaline solutions), prolamins exhibit tunable self-assembly behaviors. In recent years, research practices of utilizing prolamins as green building materials of functional delivery vehicles to improve the health benefits of bioactive compounds have surged due to their attractive advantages (e.g. sustainability, biocompatibility, fabrication potential, and cost-competitiveness). This article covers the recent advances in self-assembly behaviors leading to the fabrication of nanoparticles, fibers, and films in the bulk water phase, at the air-liquid interface, and under the electrostatic field. Different fabrication methods, including antisolvent precipitation, evaporation induced self-assembly, thermal treatment, pH-modulation, electrospinning, and solvent casting for assembling nanoarchitectures as functional delivery vehicles are highlighted. Emerging industrial applications by mapping patents, including encapsulation and delivery of bioactive compounds and probiotics, active packaging, Pickering emulsions, and as functional additives to develop safer, healthier, and sustainable food products are discussed. A future perspective concerning the fabrication of prolamins as advanced materials to promote their commercial food applications is proposed.

Influence of an Edible Oil-Medium-Chain Triglyceride Blend on the Physicochemical Properties of Low-Fat Mayonnaise

Mayonnaise is a semisolid oil-in-water emulsion comprised of egg yolk, oil, and vinegar. One main problem with mayonnaise is its high fat content, so efforts have been made to develop low-fat sauces with similar characteristics to real mayonnaise. The purpose of this study was to evaluate the effect of medium-chain triglycerides (MCTs) blended with edible oil (soybean and olive oil) on the rheological, physicochemical, and sensory properties of low-fat mayonnaise. The results revealed that the shear viscosity decreased with the increase in medium-chain fatty acid (MCFA) contents and decreased with an increasing shear rate. Tan δ was <1, and a semisolid fluid with shear-thinning behavior was formed. The oscillation frequency test showed that the MCFA-containing mayonnaise was viscoelastic. The particle size and oil droplet analyses revealed that the emulsion droplet size and distribution were not significantly different in the MCT group compared to the control. The sensory evaluation demonstrated that the MCFA-containing mayonnaise was acceptable. This study illustrates that MCTs are a good substitute to produce the proper physicochemical properties of mayonnaise.

Egg Yolk-Free Vegan Mayonnaise Preparation from Pickering Emulsion Stabilized by Gum Nanoparticles with or without Loading Olive Pomace Extracts

The yolk-free mayonnaise was formed by Pickering emulsions stabilized by free and encapsulated olive pomace extracts (OPEs) in rocket seed [rocket seed gum nanoparticle (RSGNP)] and chia seed gum nanoparticles at different nanoparticle concentrations. The yolk-free mayonnaise and the control mayonnaise samples were compared in terms of appearance, microstructural, droplet size, emulsion stability, rheological, oxidative stability, and sensory properties. The droplet size decreased by increasing the nanoparticle concentration in yolk-free mayonnaise samples. The yolk-free mayonnaise samples prepared with OPE-loaded gum nanoparticle showed shear-thinning, solid-like and recoverable characteristics, which increased as the increase in the nanoparticle concentration. The emulsion stability and capacity increased by increasing the nanoparticle concentration in the yolk-free mayonnaise samples. OPE-loaded gum nanoparticle-stabilized yolk-free mayonnaise samples exhibited higher IP (induction period) values than the control samples. OPE-RSGNP 1% mayonnaise was observed to be the closest sample to the control sample with its sensory properties, general acceptability, and similar microstructural and rheological properties. The results of this study indicated that Pickering emulsions stabilized by gum nanoparticles could be used as healthy alternatives to the egg yolk in conventional mayonnaise.

Physicochemical Properties, Stability and Texture of Soybean-Oil-Body-Substituted Low-Fat Mayonnaise: Effects of Thickeners and Storage Temperatures

With the increasing consumer demand for low-fat and low-cholesterol foods, low-fat mayonnaise prepared from soybean oil body (SOB) substitute for egg yolk has great consumption potential. However, based on previous studies, it was found that the stability and sensory properties of mayonnaise substituted with SOB were affected due to there being less lecithin and SOB containing more water. Therefore, this study investigated the effects of different ratios of xanthan gum, pectin and modified starch as stabilizers on the apparent viscosity, stability, texture and microstructure of SOB-substituted mayonnaise. It was found that the apparent viscosity and stability of SOB-substituted mayonnaise increased significantly when xanthan gum, pectin and modified starch were added in a ratio of 2:1:1. Meanwhile, the emulsified oil droplets of SOB-substituted mayonnaise were similar in size and uniformly dispersed in the emulsion system with different thickener formulations. In addition, the storage stability of SOB-substituted mayonnaise was explored. Compared with full egg yolk mayonnaise, SOB-substituted mayonnaise had better oxidative stability and bacteriostatic, which is important for the storage of mayonnaise. This study provided a theoretical basis for the food industry application of SOB. Meanwhile, this study provided new ideas for the development and storage of low-fat mayonnaise.