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Plant protein-based diets (e.g., egg or meat alternatives) have emerged as a promising approach for developing healthy and sustainable food systems. Mayonnaise, a formulated sauce prepared by mixing vegetable oil, egg yolk, vinegar and salt, is probably one of the most widely used condiments in the world today. In this paper, wheat gluten (WG) as an available and low-cost plant protein ingredient was used to prepare and stabilize oil-in-water high internal phase emulsions (HIPEs) as mayonnaise replacers via emulsification–evaporation method. Firstly, WG was dissolved into aqueous acetic acid/ethanol (55/45, v/v, pH 3.0) solution to form phase-separated WG particles, and then HIPEs were prepared through homogenization of high sunflower oil fraction (75 wt%) with WG particles suspension at 80 °C after evaporating ethanol completely. Compared with egg-based mayonnaise, HIPEs (especially for 1.0 wt% WG) exhibited very similar droplet size distribution, rheological behavior, near-perfect thixotropic recovery, and tribological property. These results demonstrated that HIPEs and mayonnaise might have similar sensory property and perceived texture such as creaminess, smoothness, and sliminess. The confocal laser scanning microscopy (CLSM) indicated that close-packed oil droplets could allow them to form homogeneous oil-in-protein network microstructure in HIPEs and mayonnaise, which might contribute to high viscoelasticity, consistency, and correct texture. In addition, thermal stability of HIPEs was much better than that of the mayonnaise. Design and construction of WG-stabilized oil-in-water HIPEs may provide a potential strategy for preparing mayonnaise replacers. [ABSTRACT FROM AUTHOR]

Water-in-water emulsions were formed by mixing aqueous solutions of the neutral polysaccharides guar and amylopectin. The effect of adding gelatin B on emulsions, both of a dispersed guar rich phase in a continuous amylopectin phase and the inverse, were investigated using confocal scanning laser microscopy as a function of the gelatin concentration between 0.25 and 1.5 wt% and the pH between pH 4 and pH 6. Gelatin was found to phase separate upon cooling below about 25 °C in a narrow pH range around pH 5 both in the pure guar phase and in the pure amylopectin phase forming distinct spherical domains. The phase diagram was established as a function of the gelatin concentration and the pH. In the emulsions, the gelatin phase separated first at the interface between the two phases forming a continuous layer at the droplet surface. In some conditions the layer persisted, but in others it broke up into distinct domains. Excess gelatin phase separated in the bulk amylopectin phase, particularly when it was the continuous phase. The gelatin redispersed into the bulk phases when the emulsions were heated to 30 °C. [Display omitted] • Gelatin phase separates during cooling in guar and amylopectin solutions. • Phase separation depends on the pH and is favored by aggregation of gelatin. • W/W/W emulsions can be formed in-situ using guar/amylopectin/gelatin. • Gelatin forms distinct domains or a continuous layer around dispersed droplets. • The formation of the gelatin layer on cooling is reversed by heating. [ABSTRACT FROM AUTHOR]

Abstract: The interfacial covalent cross-linking of emulsions can greatly enhance their tolerance to environmental stresses, and also contribute to formation of a new class of food products (e.g., oil gel, oil powder, and capsules). Algal oil is rich in ω-3 polyunsaturated fatty acids, while heat treatment makes it particularly susceptible to oxidation. In this study, microfluidization initiated interfacial covalent cross-linking of gliadin particles to stabilize emulsion as a novel technology to facilely construct structured algal oil product without any thermal or chemical treatment. The coarse emulsions with high algal oil volume fraction ( φ oil= 50%) stabilized by acidic gliadin particles were firstly homogenized using IKA homogenizer, and then emulsions were immediately subjected to mild alkaline pH-shifting processes. Finally, microfluidization initiated cross-linking of gliadin via intermolecular disulfide bonds to prepare stable structured emulsions. The droplet size distribution, FTIR, and SDS-PAGE of emulsions clearly verified that cross-linking was initiated by hydrophobic interaction under mild alkaline conditions, and interfacial disulfide cross-linking of gliadins was triggered by microfluidization. The viscoelastic and mechanical properties of emulsions showed homogenization pressure-dependent behavior. In addition, with increasing homogenization pressure, the increased oxidative stability with reduced lipid hydroperoxides and volatile hexanal of emulsions was also observed. Facile construction of cross-linking by microfluidization may provide a novel technology platform for gliadin based delivery system or edible oil structuring with functional characteristics. [ABSTRACT FROM AUTHOR]

This study aimed to decipher the specific role of the interfacial particle network and digestive metabolites within the glycation-tailored interaction mechanism based on the egg white microgel particles (EWGP)-integrated O/W emulsions. Results showed that the bridging extent of the interfacial particle network was significantly reinforced via the increased fibrous aggregates and the improved particles' surface activity (surface hydrophobicity and interface tension) after glycation with d -ribose (<2 wt‰). Besides, the more bridged interfacial network introduced the preferable physicochemical stability, viscoelastic properties, and curcumin retention to emulsions against UV-radiation, in vitro digestion, and storage at 25 °C. Moreover, glycation facilitated the accumulation of larger protein fragments (>10 kDa) and non-ionized long-chain free fatty acids, probably participating in the micellization and secondary stabilization of emulsions with the sustainable bioaccessibility enhancement of curcumin (10–25%) during digestion (1–6 h). Therefore, these findings would be enlightening in intuitively and delicately tailoring the physicochemical stability and delivery properties of emulsion systems according to the characteristics of interfacial particle network and digestive metabolites. Meanwhile, this research would facilitate the direct formulations of native protein matrices (e.g., fresh egg white) in various emulsions-based functional foods for satiation perception and physiological regulation. [Display omitted] • Glycation endowed EWGP with a fibrous cluster array for emulsions stabilization. • Glycation tailored the stabilization and delivery properties of emulsions. • Glycation enhanced the bridging extent of the interfacial network of emulsions. • Interfacial bridging extent was positively correlated with emulsion's stability. • Emulsion's larger digestive metabolites might be vital to its delivery properties. [ABSTRACT FROM AUTHOR]

The potential applications of emulsion systems prepared from solid particles are limitless across various fields. The emulsion, also known as Pickering emulsion, is constrained by the properties of the particles. An emulsion system prepared directly from unmodified, hydrophilic, natural starch granules was reported in the study. While the microstructure of this emulsion resembled that of Pickering emulsions, its formation mechanism was entirely different. The formation of the emulsion was governed by depletion attraction between hydrophilic polymers (Carboxymethyl cellulose, CMC) and amaranth starch granules. The microstructure and interfacial results revealed that the adsorption of starch granules at the oil-water interface was facilitated by depletion attraction induced by CMC, while their desorption was inhibited. Stability was maintained even at high oil volume fractions of up to 70%. The strength of depletion attraction in the emulsion could be controlled by varying the concentration of starch granules (3–7 w/v%), CMC (0.5–1.5 wt%), and the molecular weight of CMC, thus adjusting the microstructure and rheological properties of the emulsion. This technique could be widely applied to nature food particle, offering a new avenue for designing and manufacturing stable edible emulsion systems. [Display omitted] • Natural hydrophilic starch-based emulsion was successfully prepared through depletion attraction. • Untreated native starch granules were firstly used in the preparation of emulsions. • CMC as depletant enhanced the stability and rheological properties of emulsion. • The strength of depletion attraction was governed by the osmotic pressure induced by depletant. [ABSTRACT FROM AUTHOR]

The rheological behavior of fats or fat replacers is shaped by the interaction among colloidal assemblies giving rise to a specific structural network. We hypothesize that the capillary protein oleogels formation we proposed, in which colloidal protein particles are used as initial building blocks to form space-spanning networks, has linear and nonlinear rheological behaviors similar to fat crystal networks as represented in fractal rheo-mechanical models. Capillary protein oleogels and repulsive high internal-phase emulsions (HIPEs) differing in microstructure categories were therefore assembled for a systematic comparison, as both serve as motivating exemplars for fat replacement. Confocal laser scanning microscopy (CLSM) were employed to distinguish the structural characteristics. By employing both small- (SAOS) and large-amplitude oscillatory shear (LAOS) rheology via Chebyshev polynomial analysis, we examined the linear and nonlinear responses of capillary oleogels and HIPEs under relevant deformations. Differing from the caging effects of droplets within HIPEs, the hierarchical networks with attractive protein particles of capillary oleogels are responsible for interpreting the rheological characteristic parameters in SAOS rheology, and for enhancing resistance to deformation in LAOS due to the coexistence of interparticle interactions and cluster characteristics. The capillary oleogels with attractive protein particles show a similar behavior to that of the fat self-assembled fractal flocs or aggregates in the fractal rheo-mechanical models. These results give us hope that by tailoring the nano- and mesoscale structural organization within a fat replacer in a specific way, there is potential for achieving proper functionality in food products, such as plastic flow behavior. [Display omitted] • Capillary attractive oleogels and repulsive HIPEs were assembled for a systematic comparison in rheology. • Capillary oleogels reveal a two-step yielding signature under deformation. • Intracycle strain stiffening in capillary oleogels results from the coexistence of interparticle interactions and cluster characteristics. • The capillary oleogels show a similar behavior to that of the fat in the fractal rheo-mechanical models. [ABSTRACT FROM AUTHOR]

3D printing has been applied to create nutritious foods with tailored textures for the elderly. However, the edible materials that possess the elastoplastic properties and shear-thinning behavior required for direct-write 3D printing are limited. In this study, we developed a simple approach to fabricate Spirulina emulsion gels as edible 3D printable material by exploiting depletion attraction between emulsion droplets. By controlling the volume ratio of continuous and oil phases, mixing highly viscous Spirulina slurry and vegetable oil could form self-standing oil-in-water emulsion gels with elastoplastic rheological properties. Also, adding food polysaccharides into the continuous phase could act as depletants to drive the formation of emulsion gels. Auto-fluorescence spectroscopy and microscopy were employed to characterize the interfacial protein compositions of the emulsion, showing that phycobilisome (PBS) particles might play a dominant role in the formation of Spirulina emulsions. The depletion attraction could drive the adsorption of PBS particles onto the droplet interface, and the particle-armored droplets in the dispersed phase connected into a percolating droplet cluster, resulting in arrested dynamics and gelation. Overall, this novel approach can be applied by exploiting depletion attraction and opens up possibilities for using high-solids viscous food slurries to produce personalized 3D-printed foods. [Display omitted] • Self-standing emulsion gel is formed by mixing Spirulina slurry with vegetable oil. • PBS particles may play a dominant role in the formation of Spirulina emulsion. • Depletion attraction drives the adsorption of PBS particles onto droplet interface. • Particle-armored droplets are connected into a percolating cluster for gelation. • Polysaccharides as depletants modify the rheological properties of Spirulina emulsion. [ABSTRACT FROM AUTHOR]

Double emulsion is the most common multiple emulsion with compartmentalized internal structure. It can be used for delivery of both hydrophilic and hydrophobic bioactives and fat reduction in foods. However, conventional approach for stable double emulsion preparation often requires high dosage of synthetic surfactants (e.g., polyglycerol polyricinoleate, PGPR) and complicated two-step emulsification process. Herein, we report a facile approach to create stable double emulsion using particular emulsifier of edible chitosan/soy β-conglycinin (7S) complex nanoparticles via one-step emulsification. By modulating chitosan/7S complex ratio of particles and algal oil content in oil phase, water-in-oil-in-water (W/O/W) Pickering double emulsion was generated in most cases. The dominant mechanism for one-step generation of Pickering double emulsion can be attributed to the polyunsaturated fatty acids (PUFA) in algal oil. The binding of PUFA on particle surface contributes to hydrophobization of the chitosan/7S complex nanoparticles, leading to stabilization of W/O interface. Moreover, stability of the resultant Pickering double emulsions is correlated to particle contact angle. When using nanoparticles with chitosan/7S complex ratio of 1:2 and oil phase containing 40 wt% algal oil, particle contact angle at O/W interface is near 90°, which is the optimum condition to produce highly stable Pickering double emulsion. This facile approach for the fabrication of stable double emulsion is promising for a wide range of applications, particularly in food field. [Display omitted] • A W/O/W Pickering double emulsion was fabricated via one-step emulsification strategy. • Edible chitosan/7S complex particles were used as the interfacial stabilizers. • PUFA in algae oil could modulate particle wettability. • The resultant W/O/W Pickering double emulsion was stable over 50 days. [ABSTRACT FROM AUTHOR]

Abstract: Soybean oil bodies and oleosins are known to be useful in foods and other emulsion systems. The influence of NaCl addition (0–500 mM), thermal processing (30, 60, 90 and 120 °C, 30 min), and freeze-thaw cycling (−20 °C, 24 h/30 °C, 2 h) on the stability of uncoated and ι-carrageenan coated soybean oil body emulsions at pH 3 and 7 was analyzed using particle electrical charge, particle size distribution, creaming stability and confocal laser scanning microscopy measurements. The stability of the uncoated emulsions to NaCl addition depended on pH, which was attributed to electrostatic screening effects. For NaCl, the uncoated emulsions were relatively stable from 0 to 150 mM at pH 3, but aggregated at ≥ 50 mM at pH 7; however, the ι-carrageenan coated emulsions at pH 3 and 7 were stable at all NaCl concentrations. The thermal stability of uncoated and ι-carrageenan coated emulsions may be relative to pH and holding temperature. Both uncoated and ι-carrageenan coated emulsions were stable at pH 7, whereas the uncoated emulsions at pH 3 became unstable when heated above 90 °C, but the ι-carrageenan coated emulsion droplets at pH 3 only extensively coalesced at 120 °C. The ι-carrageenan coated emulsions at pH 3 and 7 exhibited little droplet aggregation after three freeze-thaw cycles in the presence of sucrose. These results suggest that ι-carrageenan coated soybean oil body emulsions have similar or improved stability compared to uncoated emulsions and may be utilized as functional soy products in the food and other industries. [Copyright &y& Elsevier]