Oil Volume Fraction Research Articles

Enhancing 3D printing performance of O/W emulsions with asparagus fibre

Asparagus fibre recovered from agricultural waste stream can be valorised as a natural ingredient for fibre enrichment in food products. This study investigated the effects of asparagus fibre on the 3D printing performance of oil-in-water (O/W) emulsions as edible inks. Emulsion gels were prepared by either varying the fibre concentration in the aqueous phase or varying the volume fraction of the oil phase. Printability, rheological properties, and microstructure of the samples were systematically evaluated. Our results show increasing fibre concentration (up to 9.9 %w/w) significantly improved 3D printing performance of the inks, which was attributed to their enhanced rheological properties. Interestingly, reducing the oil volume fraction from 72 to 66 %v/v (i.e., fibre concentration was kept at 9.9 %w/w) did not detrimentally influence the 3D printing quality. Microstructural analysis of the emulsions revealed that increasing fibre concentration led to smaller size and different surface morphology of the oil droplets. Fibre particles in the aqueous phase may hinder oil droplet movement, stabilizing emulsions during 3D printing. Our findings give new insights into the development of edible 3D-printed food products via fibre enrichment and oil reduction.

Peanut de-oiling at room temperature by micro-aqueous hydration: Co-destabilization driven by oleosome coalescence and protein aggregation

The peanut de-oiling industry currently lacks efficient processing technologies for de-oiling at low or room temperatures. A novel method, micro-aqueous extraction (MAE), offers over 93 % de-oiling efficiency at room temperature and is also effective for other oilseeds like sesame, camellia, and rapeseed. Despite its effectiveness, the exact mechanism behind oleosomes destabilization at a critical hydration level or oil volume fraction (φ ∼ 0.75) is not fully understood. This study investigates how MAE affects peanut oleosome size, paste stability, and the interfacial properties of surfactant proteins. Results showed that micro-aqueous hydration and agitation caused small droplets (85.6 vol% < 10 μm) to coalesce into larger droplets (90.0 vol% > 30 μm) due to press-induced rupture of the liquid film. Simultaneously, agitation decreased water mobility and protein intrinsic fluorescence, while increasing paste viscosity, leading to protein aggregation. This aggregation further promoted oleosome coalescence. Additionally, hydration and agitation weakened the ability of membrane proteins to stabilize oleosomes by increasing interfacial tension and decreasing dilatational storage modulus. The insights into the peanut oleosome destabilization mechanism for MAE provide a foundation for scaling up the process, with the potential to replace current hot and cold pressing techniques.

Enhancement of the formation and stability of low-fat Pickering emulsion gels stabilized with egg yolk granules-chitosan complex: Insights into the development of mayonnaise substitutes

This study employed egg yolk granules (EYG) in combination with chitosan (CS) to evaluate the feasibility of constructing low-fat Pickering emulsion gels and investigated the properties of emulsion gels with different oil volume fractions (0–50 %) to address the stability issue. The results showed that the self-supporting structure of the emulsion gels gradually increased at 0–40 % oil phase, and the oil droplet sizes were all smaller than 10 μm. However, when the oil phase reached 50 %, the emulsion showed water-oil phase separation. The addition of oil modified the state and movement of water molecules in the emulsion system, which in turn affected the water and oil loss rates. Notably, the emulsion gels exhibited similar rheological and textural characteristics to mayonnaise at 30 % oil phase. Furthermore, the emulsion gels demonstrated promising centrifugation and freeze-thaw stability. This study suggests an innovative and efficient approach to low-fat mayonnaise substitution with consistent quality.

Exploring the emulsifying properties of biopolymers from Ulva lactuca in stabilizing high internal phase emulsions

Seaweed is a promising raw material for food emulsion stabilizers due to its abundance, low cost, and rich content of various natural biological macromolecules. This study explores the potential of using Ulva lactuca (UL) to stabilize emulsions by employing high-pressure homogenization (HPH) to release its interfacial active components. The results demonstrate that UL extract (ULE) with emulsifying activity was gradually extracted as the HPH pressure increased from 100 to 800 MPa. Concentrating the macromolecular components, specifically polysaccharides and proteins, in the ULE via membrane filtration resulted in a concentrated fraction, referred to as ULER, which exhibited enhanced emulsification performance. By optimizing the oil volume fraction (φ) and pH, it was found that high internal phase emulsions (φ = 0.7–0.8) showed superior viscoelasticity and stability at pH 3–7. In terms of stability, it was observed that the emulsions stabilized by ULER maintained their structure over extended periods without significant phase separation. The strong interaction between exogenous Ca2⁺ and ULER increased the apparent viscosity and viscoelasticity of the emulsion. However, the addition of Ca2⁺ did not significantly enhance the stability of the ULER-stabilized emulsions and, in some cases, even led to a decrease in emulsion stability. This effect may be probably due to the specific interactions between the Ca2⁺ ions and the polysaccharides and proteins in the ULER, which can affect the network structure of the emulsion. Overall, this study highlights the potential of HPH treatment in processing UL to transform it into an effective emulsion stabilizer for applications in the food industry.

Fabrication and characterization of oleic acid/sesame protein isolate/ poly (vinyl) alcohol core-shell nanofibers: Mitigating lipid oxidation by emulsion electrospinning

Formulated oil-in-water (O/W) emulsions of oleic acid (OA) using sesame protein isolate (SPI) were processed via emulsion electrospinning with poly (vinyl) alcohol (PVA) to fabricate core-shell nanofibers for lipid oxidation prevention. The emulsion droplet size and viscosity increased as the oil volume fraction rose from 5 % to 30 %. The morphology tests and Fourier transform infrared spectroscopy (FTIR) confirmed the uniformity of nanofibers and OA encapsulation with hydrogen bonding. The thermal stability, mechanical properties, and water contact angle (WCA) of the nanofiber films improved with increased OA content. Encapsulation efficiency was 94.76 % and storage stability was maintained for 7 days in 5 % oil fraction nanofibers. The nanofibers showed lower oxidation and superior oxidative resistance to free OA, with the lowest peroxide value (POV, 2.14 mmol/L) and thiobarbituric acid-reactive substances (TBARS, 36.75 μmol/L). In conclusion, the OA/SPI/PVA (PE) core-shell nanofibers via emulsion electrospinning are efficient for fatty acid encapsulation in functional foods.

Ultra-stable high-internal-phase emulsions fabricated solely by hydrophilic cellulose nanofiber via inter-droplet jamming

High-internal-phase emulsions (HIPEs) has been increasing interest owing to their large surface area and controllable flow behavior, however, their heavy addition of emulsifiers, e.g., surfactants and surface-active particles, leads to high cost and emulsifier abuse. To solve these issues, we report a new strategy to prepare HIPEs by solely adding a surface-inactive, hydrophilic cellulose nanofiber (CNF). Compared to conventional HIPEs, the highly flocculated CNF is closely packed in the liquid films between oil droplets instead of anchoring at the oil-water interfaces, as referred to the inter-droplet jamming. An efficient jamming behavior is observed at a low CNF concentration (as low as 0.075 wt%) and at very high volume fractions of oil (near 0.85), maintaining the HIPEs over timescales of two years, without the liquid drainage or phase separation. This unexpected stability is mainly attributed to the increase by dozen orders of magnitude in the viscoelasticity of the jammed films as compared with that in the bulk phase, generating a significantly spatial barrier to prevent the depletion attraction between droplets. This simple approach should offer a new pathway to achieve nature-inspired, pure and controlled materials.

Novel Collagen-Based Emulsions Embedded with Palmarosa Essential Oil, and Chamomile and Calendula Tinctures, for Skin-Friendly Textile Materials.

Skin-friendly textile materials were obtained by applying oil-in-water emulsions based on palmarosa essential oil, chamomile, and calendula tinctures onto cotton fabrics. Different formulations based on these bioactive principles incorporated in collagen as polymeric matrices were prepared and immobilized on a plain weave textile structure from 100% cotton. The functionalized textile materials were characterized in terms of physicochemical, mechanical, antibacterial, and biocompatibility points of view. The pH values of the prepared emulsions were in the range of 4.81-5.23 and showed no significant differences after 4 h of storage. Moreover, the addition of a higher quantity of active principles (palmarosa essential oil and plant tinctures) caused slightly lower values of acidic pH. The electrical conductivity of the obtained emulsions increased with the decrease in the oil phases in the system. The highest values were obtained for the emulsion developed with the smallest volume fraction of active principle-palmarosa essential oil and plant tinctures. The emulsion that contained the least amount of collagen and the highest number of active principles exhibited the lowest stability. The textile materials treated with synthesized emulsions exerted antibacterial effects against S. aureus and E. coli strains and did not affect keratinocyte growth, spreading, and organization, highlighting the biocompatibility of these developed skin-friendly textiles.

Encapsulation of β-carotene in Pickering emulsions stabilized by self-aggregated chitosan nanoparticles: Factors affecting β-carotene stability

For conventional emulsions used to encapsulate easily degradable bioactive compounds, achieving small droplet size and high encapsulation capacity is a challenging. Pickering emulsions stabilized by self-aggregated chitosan particles may offer high encapsulation efficiency due to the robust mechanical barrier formed by solid particles adsorbed at the oil-water interface. Therefore, the effects of pH, chitosan concentration, oil volume fraction, homogenization pressure, and homogenization cycle on the stability of chitosan Pickering emulsions and the degradation of β-carotene were investigated. Effective interfacial adsorption of chitosan nanoparticles and moderate homogenization intensity facilitated the formation of small emulsion droplets. Unlike conventional emulsions, chitosan Pickering emulsions with smaller droplets provided enhanced protection for β-carotene. This enhancement was primarily attributed to the improved interfacial coverage of chitosan nanoparticles with smaller droplet sizes, which was advantageous for β-carotene protection. The optimal conditions for preparing β-carotene-loaded chitosan Pickering emulsions were as follows: pH 6.5, chitosan concentration of 1.0 wt%, oil volume fraction of 20 %, homogenization pressure of 90 MPa, and 6 homogenization cycles. These findings indicate that chitosan Pickering emulsions are well-suited for encapsulating β-carotene with both small droplet size and high encapsulation efficiency.

Flow field analysis and performance evaluation of a mini-hydrocyclone for ultra-low inlet flow rate

It is difficult for hydrocyclone to separate oil-water under the condition of ultra-low inlet flow rate, which commonly exist in the field of energy engineering. Mini-hydrocyclone is an effective technology to solve this problem. The flow field characteristics and oil droplet migration trajectory in the mini-hydrocyclone are the key to guide its efficient work. An innovative mini-hydrocyclone are studied via computational fluid dynamics (CFD) and experiment method. The good separation performance of mini-hydrocyclone for ultra-low inlet flow rate and tiny particle size of oil droplets is verified and analyzed. Furthermore, The distribution of velocity, oil volume fraction and oil migration trajectories in the mini-hydrocyclone are analyzed systematically. The effects of oil droplet size, inlet flow rate and split ratio on the separation performance of mini-hydrocyclone are investigated. The results show that the maximum separation efficiency of the mini-hydrocyclone for 1.0 L/min ultra-low inlet flow rate is 99.98 %, when the split ratio is 30 %, the oil phase volume fraction is 2 %. Moreover, the morphological and distribution of oil core in mini-hydrocyclone are basically consistent between simulation and experiment results, under the conditions of different operating parameters. The minimum error of numerical simulation and experiment results is less than 2.23 %, the accuracy of the numerical simulation method is verified.

Innovative insights into nanofluid-enhanced gear lubrication: Computational and experimental analysis of churn mechanisms

This study offers unique insights into the churn lubrication mechanism in gear transmission systems through the utilization of nanofluids for the first time. Various performance parameters of the prepared nanofluid lubrication oil are measured, along with the discussion of suspension stability. Based on the overset mesh method and VOF multiphase flow model, a rotating fluid domain calculation model considering the nanofluid-air two-phase is proposed. The high-speed nanofluid lubrication experiment platform is established to track churn phenomena and identify the oil volume fraction on the gear surface. Comparing simulation results with experimental data confirms the calculation accuracy in depicting oil flow and churn lubrication. Result shows that the interaction between droplets and the gear surface involves splash, rebound, adhesion, and diffusion. The nanofluid exhibits improved adsorption, resulting in a higher oil volume fraction. When the rotation speed is increased, intensified oil spatter and atomization are observed. The ranking of nanofluid lubrication performance is Al2O3, SiO2, Fe3O4, CuO, and TiO2 particles, which are approximately aligned with contact angle magnitudes. For 3 % nanoparticles concentration, less oil is swung off, more is drawn into the gear meshing zone, and subsequently squeezed out. Image recognition results align with numerical simulation, indicating that the oil distribution of nanofluid is better than that of base fluid lubrication. This work serves as a foundational exploration for future nanofluid lubrication and heat dissipation, offering insights into preventing oil film rupture, tooth surface wear, gluing and other failure mechanisms.

Thermally reversible emulsion gels and high internal phase emulsions based solely on pea protein for 3D printing

This work compared thermally reversible emulsion gels and high internal phase emulsions (HIPEs) based on pea protein for 3D printing at different oil volume fraction (ϕ) ranging from 0.2 to 0.8. Thermally reversible emulsion gels were obtained with ϕ from 0.2 to 0.65, which melt into liquid emulsion as temperature increased, and recovered into emulsion gels upon cooling as reflected by consistent rheological measurements. The Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed the transition between intermolecular β-sheet at 1630 cm−1 and intramolecular β-sheet at 1618 cm−1 through reversible H-bonds upon changes in temperature, which was responsible for the repeated thermo-reversibility. With ϕ increased to 0.74–0.8, HIPEs were confirmed by Scanning Electron Microscope (SEM) and Confocal Laser Scanning Microscope (CLSM), yet the thermo-reversibility was not maintained. In addition, the thermally reversible emulsion gels exhibited strong shear-thinning and thixotropic recovery through the untangling and reformation of the H-bonded gel network. Whereas deformation and restructuring of the close packed droplets were responsible for such behaviors in HIPEs. 3D printing test has further demonstrated excellent performance of thermally reversible emulsion-filled gel with ϕ 0.4, comparable to HIPE with ϕ 0.74 b y enabling printed objects with high shape fidelity (printability index (Pr) of 0.95–1.08) and shape stability (prints height maintenance (Hm) of 82.2%–87.8%). This research opens up thermally reversible emulsion gels solely from sustainable protein source for 3D printing, with low oil content and no synthetic ingredients needed.

Study on flow field of oil‐cooling permanent magnet synchronous motor with hairpin winding using porous medium model

AbstractThe oil cooling method has been widely used in the permanent magnet synchronous motor with hairpin winding. Because of the irregular shape of the hairpin end winding, there are complex oil circuits in the fluid domain, resulting in a large number of grids and a high computational cost. It is still a challenge to calculate the oil‐cooling performance of the hairpin end winding. Therefore, the porous medium model (PMM) is first proposed to replace the real hairpin end winding to analyse the oil‐cooling performance. By comparing oil volume fraction and velocity at different oil‐supplied conditions using three methods: experiments, real model (the non‐equivalent fluid domain model based on the real hairpin end winding) and PMM, the feasibility of using the PMM to calculate the oil‐cooling performance on the end winding is verified. The oil distribution of three methods is the same. The use of the PMM saves 80% of the number of grids, which improves the simulation efficiency. Relationships between the porosity, permeability and resistance coefficient and the geometry parameters of windings are determined. The results show that the flow field changes greatly with changes in porosity, permeability and resistance coefficient.

Fabrication of soy protein-polyphenol covalent complex nanoparticles with improved wettability to stabilize high-oil-phase curcumin emulsions.

Recent studies have shown that the wettability of protein-based emulsifiers is critical for emulsion stability. However, few studies have been conducted to investigate the effects of varying epigallocatechin gallate (EGCG) concentrations on the wettability of protein-based emulsifiers. Additionally, limited studies have examined the effectiveness of soy protein-EGCG covalent complex nanoparticles with improved wettability as emulsifiers for stabilizing high-oil-phase (≥ 30%) curcumin emulsions. Soy protein isolate (SPI)-EGCG complex nanoparticles (SPIEn) with improved wettability were fabricated to stabilize high-oil-phase curcumin emulsions. The results showed that EGCG forms covalent bonds with SPI, which changes its secondary structure, enhances its surface charge, and improves its wettability. Moreover, SPIEn with 2.0 g L -1 EGCG (SPIEn-2.0) exhibited a better three-phase contact angle (56.8 ± 0.3o) and zeta potential (-27 mV) than SPI. SPIEn-2.0 also facilitated the development of curcumin emulsion gels at an oil volume fraction of 0.5. Specifically, the enhanced network between droplets as a result of the packing effects and SPIEn-2.0 with inherent antioxidant function was more effective at inhibiting curcumin degradation during long-term storage and ultraviolet light exposure. The results of the present study indicate that SPIEn with 2.0 g L -1 EGCG (SPIEn-2.0) comprises the optimum conditions for fabricating emulsifiers with improved wettability. Additionally, SPIEn-0.2 can improve the physicochemical stability of high-oil-phase curcumin emulsions, suggesting a novel strategy to design and fabricate high-oil-phase emulsion for encapsulating bioactive compounds. © 2024 Society of Chemical Industry.

Stabilization of oil-water interface by non-interfacial adsorbed native starch granules using depletion attraction

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.

Tuning Lubrication Performance of Phase‐changing Emulsion‐filled Gels by Sugar alcohols

Lubrication by hydrogels is proving to be an emerging area in colloid science. Although oil‐driven friction reduction is predominant in literature, emulsion gel‐based lubrication has attracted very little attention to date. We hypothesize that an interplay of viscolelasticity and oil volume fraction may modulate lubricity of emulsion‐filled gels. Herein, phase‐change gelatin‐based emulsion‐filled gels with different sugar alcohol and oil droplet concentrations (0‐30 wt%) were tested for their lubrication performance. The rheological and tribological tests were analysed in conjunction with spectroscopic and structural characterizations in order to reveal structure‐function relationship. Structural characterizations demonstrated that hydrogen bonding was enhanced in pure gelatin gels with the increase of sugar alcohol (glycerol)‐replacement time, which enhanced the storage modulus (G') of the gel networks. Emulsified droplets served as active fillers further strengthening the G’ and strikingly the presence of glycerol reduced the thermo‐responsiveness of the emulsion‐filled gels. Emulsion‐filled gels containing sugar alcohols, irrespective of their type, can greatly reduce the friction coefficients (μ) between hydrophobic surfaces in the boundary and mixed regimes versus the systems without sugar alcohols. In the hydrodynamic regime, the friction coefficient of the system was proportional to the second plateau shear viscosity, regulated by the oil content.This article is protected by copyright. All rights reserved.

Accurate and non-contact measurement of volume percentages of oil-water fluids using microstrip sensors independent of the volume of sample using artificial neural network

Due to their moderate sensitivity, extremely cheap cost, ease of fabrication method, and, more crucially, the fact that they are non-invasive, planar microwave sensors have attracted a lot of interest from both industries and academics over the past years. These intriguing properties drive this field's research toward opening up a wide range of applications that go beyond oil and gas to include biological, material sensing, pollution monitoring, and other industrial uses. The main focus of this research is on the simulation and fabrication of a high-sensitivity, very small, and repeatable microwave sensor to measure volume fractions of oil and water in real-time. This sensor is designed by Ansys HFSS software and is made on the RT/Duroid 5880 (with εr = 2.2, thickness = 0.787 mm, loss tangent of 0.0009). In a polylactic acid (PLA) box made using a 3D printer, oil and water with different volume percentages will be placed on the microwave sensor in non-contact conditions. To determine volume percentages independent of the volume of the samples, different samples were analyzed in volumes of 5 ml, 10 ml, and 15 ml. The developed sensor includes two passing bands, and when exposed to crude oil with varying amounts of water, the frequencies of these bands, their insertion loss, and their prominence in these frequencies change. Due to the non-linear variations in the insertion loss, frequency, and prominence value of the two passbands, the MLP neural network is used in this study over other approaches for identifying the objective parameter. The MLP neural network's output was the water volume percentage, and its inputs were variations in the frequency, insertion loss, and prominence of the two passbands in the transmission response. Thanks to microwave sensors and artificial neural networks, volume fractions could be detected with high accuracy, independent of the volume of samples. The suggested microwave sensor could be a highly effective way to measure volume percentages in the oil sector because of its high accuracy, compact size, simplicity of transportation, non-contact feature, etc.

Impact of thermosonication at neutral pH on the structural characteristics of faba bean protein isolate dispersions and their physicochemical and techno-functional properties

The effect of thermosonication (TS) (90 °C, 10–30 min) on faba bean protein isolate (FPI) at pH 7 was investigated. The microstructural and techno-functional properties of TS-treated FPI were compared with native FPI or FPI treated with conventional prolonged heating (CH, up to 8 h) at 90 °C. TS treatment effectively converted FPI to amorphous aggregates containing predominant β-sheet secondary structures, as determined by Thioflavin T (ThT) fluorescence and circular dichroism (CD). According to sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), these amorphous aggregates could be formed by disulfide bonds. Additionally, TS treatment is efficient in disrupting large protein aggregates of FPI, thus improving their solubility. Both TS and CH treatments induced formation of viscoelastic FPI hydrogels, whose gel strength depends on the type and time of treatment. Hydrogels formation is likely to arise from the entanglement and interaction of protein aggregates as revealed by small angle neutron scattering (SANS) and scanning electron microscopy (SEM). TS-treated FPI was also used to prepare O/W emulsions and whose structural and physical properties were compared with those stabilised by untreated FPI. At all oil volume fractions (φ = 0.2, 0.5, and 0.7) and FPI concentrations (1, 3, and 5 wt %), emulsions stabilised by TS-treated FPI exhibited smaller oil droplet size, greater mechanical strength and superior stability compared to those stabilised by untreated FPI. The study suggests that TS treatment is promising in improving techno-functional properties of FPI; further studies are needed to exploit TS-treated plant proteins as a novel food ingredient in food product development.

Oil-Air Distribution Prediction Inside Ball Bearing with Under-Race Lubrication Based on Numerical Simulation

Oil/air two-phase flow distribution in the bearings is the basis for bearing lubrication status identification and precise thermal analysis of the bearing. In order to understand the fluid behavior inside the under-race lubrication ball bearing and obtain an accurate oil volume fraction prediction model. A numerical study of ball bearing with under-race lubrication is carried out to study oil-gas two-phase distribution inside the bearing, and the influence of several parameters is quantified, like bearing rotating speed, oil flow rate, oil viscosity, and oil density. The results indicate that the oil fraction in the bearing cavity between the inner and outer ring shows a periodic distribution along the circumference direction, and the period is the same as the number of under-race oil supply holes. Oil distribution alone radial direction is affected by the outer-ring-guiding cage and centrifugal force, leading to oil accumulation near the outer ring. Different bearing running conditions and oil characteristics do not change the oil distribution trend alone in circumference and radial direction, but the difference ratio. Finally, based on the numerical simulation results, a formula for the average oil volume fraction prediction in the bearing ring cavity is constructed.

Influence of Varying Oil-Water Contents on the Formation of Crude Oil Emulsion and Its Demulsification by a Lab-Grown Nonionic Demulsifier.

This study describes how varying oil/water contents affect emulsion formation and the impact they have on emulsion droplet size, viscosity, and interfacial behavior. Crude oil (continuous phase) volume fractions of 40, 50, 60, and 70 vol % were probed in the various W/O emulsions formed. Experimental results from optical morphology revealed the emulsion droplets kept reducing as the crude oil fraction kept increasing, while the droplets were nearly unnoticeable in the emulsions derived from 60 and 70% crude oil. The viscosity-shear rate of emulsions produced from 40, 50, and 60 vol % crude oil exhibited a non-Newtonian behavior owing to the substantial volume of water content in their emulsions, whereas the viscosity-shear rate of the emulsion with 70 vol % crude oil exhibited a Newtonian behavior similar to the pure crude oil, suggesting a thorough blending of oil-water at this crude oil fraction. Besides, the viscosity-temperature measurements revealed that the viscosity of these emulsions diminished as the temperature increased and the viscosity reduction became more noticeable in an emulsion comprising 70 vol % crude oil. In the interfacial assessment, the increased crude oil content in the produced emulsion led to a sharp reduction in the interfacial tension (IFT). The IFT values after 500 s contacts between the emulsion and water (surrounding phase) were 11.86, 10.02, 8.08, and 6.99 mN/m for 40, 50, 60, and 70 vol % crude oil, respectively. Demulsification experiments showed that water removal becomes more challenging with a large volume of crude oil and a small water content. Demulsification performances of the lab-grown nonionic demulsifier (NID) after 10 h of demulsification activity at room temperature (25 °C) were 98, 90, 17.5, and 10% for the emulsions formed from 40, 50, 60, and 70 vol % crude oil, respectively, indicating that the demulsification degree decreases with an increasing crude oil content. Viscosity-time determination was applied to affirm the activity of NID on the emulsion formulated with a 50% crude oil fraction. The injection of NID in this emulsion triggered a sharp viscosity reduction, indicating the adsorption of NID at the oil-water interface and disruption of emulsifiers, enabling emulsion stability.

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

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. 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. 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.