Oil Droplets Research Articles

Enhancing demulsification efficiency and sustaining constant separation flux in oil/water emulsions via Janus membrane inspired by spider silk

Conventional special wettable membranes for the separation of the surfactant-stabilized oil/water emulsions primarily rely on the “size-sieving” mechanism, which enhances efficiency by reducing the pore size, leading to a trade-off between separation flux and efficiency. Inspired by spider silk, we developed a novel Janus membrane (JPSPP) capable of high demulsification capacity and constant separation flux. This membrane combines a superhydrophobic PS@PDMS membrane (PPM) with spindle-knotted structures on a negatively charged superhydrophilic PAN@SAS membrane (PSM) through electrospinning. The synergy of electrostatic force generated by charged surfaces, the Laplace pressure created by spindle-knotted geometry, and the wettability gradient resulting from asymmetric wettability enhance the demulsification capacity. The high and constant separation flux was achieved as Laplace pressure drives rapid coalescence of demulsified oil droplets towards the top of the spindle-knotted structures, facilitating oil detachment and efficient water permeation downward. As a result, the JPSPP membrane achieved a separation efficiency exceeding 99.9 %, with a constant separation flux of up to 1952.27 L m−2 h−1, representing a 3–4 folds improvement compared to the pure PAN membranes (PM). The separation performance of the JPSPP still maintains excellent separation performance with efficiency above 98.3 % and a slight attenuation in flux after twenty filtration cycles. The research proposes groundbreaking solutions that significantly enhance the demulsification efficiency and maintain a constant separation flux for oil/water emulsions, with the potential to profoundly impact multiple industries including food processing, energy production, and the petroleum industry, etc.

Endocytosis-Inspired Zwitterionic Gel Tape for High-Efficient and Sustainable Underoil Adhesion.

Marine oil exploration is important yet greatly increases the risk of oil leakage, which will result in severe environment pollution and economic losses. It is an urgent need to develop effective underoil adhesives. However, realizing underoil adhesion is even harder than those underwater, due to the stubborn attachment of a highly viscous oil layer on target surface. Here, inspired by endocytosis, a tough gel tape composed of zwitterionic polymer network and zwitterionic surfactants is developed. The amphiphilic surfactants can form micelle to capture the oil droplets and transport them from the interface to gel via electrostatic attraction of polymer backbone, mimicking the endocytosis and achieving robust underoil adhesion. Benefiting from the oil-resistance of polymer backbone, the gel further realizes a combination of i) long-term adhesion with high durability, ii) repeated adhesion in oil, and iii) renewable adhesion efficiency after exhausted use. The tape exhibits an ultra-high adhesive toughness of 2446.86 J m-2 to stainless steel in silicone oil after 30 days' oil-exposure; such value of adhesive toughness surpasses many of those achieved in underwater adhesion and is greater than underoil adhesion performance of commercial tape. The strategy illustrated here will motivate the design of sustainable and efficient adhesives for wet environments.

Formulation, characterization, and stability of morin hydrate-loaded nanoemulsion

Morin hydrate (MH) is a bioflavonoid belonging to flavonol class. Despite its pharmacological activities, MH has inherent low aqueous solubility and chemical instability hindering biological applications of this flavonol. In this regard, this study aimed to develop and characterize nanoemulsion containing MH. Nanoemulsion formulations were prepared using phase inversion temperature method and characterized by size, polydispersity index (PdI), physical stability, AFM analysis, incorporation efficiency (IE), and in vitro release. Following the formulation design, F10 formulation was chosen to incorporate MH. Nanoemulsion containing MH (MH-NE) showed droplet size in nanometric scale (< 100 nm) with homogeneous size distribution (PdI < 0.1). In addition, good physical stability of MH-NE was demonstrated using analytical photocentrifugation method where the light transmission profiles did not change throughout the emulsions. According to AFM analysis, oil droplets were mostly spherical or semi-spherical having sizes uniformly distributed. The IE of MH into nanoemulsion was approximately 100%, and in vitro release profile of this flavonol from formulation was gradual throughout the experiment. Therefore, using a reproducible method of low energy emulsification we developed a stable colloidal dispersion of nanoemulsion containing MH.

The Influencing Factors and Mechanism of Anionic and Zwitterionic Surfactant on Viscosity Reduction in Heavy O/W Emulsions.

The high viscosity of heavy crude oil has been an obstacle to its safe production and economic transportation. In this work, a screened emulsified viscosity reducer system is conducted. Experimental results demonstrate that the most effective viscosity reducing agent comprises sodium oleate (NaOl) and cocamidopropyl betaine (CAB-35) in a ratio of 1:2, achieving a viscosity reduction rate of 94.65%. Additionally, the interfacial tension between oil and water decreases from 27 to 4 mN/m with 0.1 mass % TEOA and NaOH in a 1:1 ratio. The oil droplet size is uniformly distributed with D mean is 14 μm and D 50 is 11 μm. Droplets flocculate as the salinity increases to 0.2 mol/L, which corresponds to the apparent increase of viscosity. The adsorption of long alkyl chain lipophilic groups on surfactant molecules at the oil-water interface and the water film alters the wettability of pipe steel to water-wet, further enhancing the application of emulsification and viscosity reduction effects. The primary mechanism behind the viscosity reduction in emulsification is attributed to strong electrostatic interactions stemming from molecular electrostatic potential distributions.

Multifunctional membranes with super-wetting interface and in-situ Fenton-like sites for efficient oil-in-water emulsion separation

The surge in oil-in-water (O/W) emulsions poses a threat to the ecological environment. Membrane separation technology can achieve complete O/W emulsion separation through size sieving; however, its efficiency is limited by membrane fouling. In this study, an efficient O/W separation membrane with passive and positive anti-fouling properties was fabricated using Fe3O4 functionalized attapulgite (ATP) nanofibers. The anti-fouling mechanism of the multifunctional membranes for the separation of various O/W emulsions was studied. During separation process, a hydration layer, which mitigates oil adhesion with binding energy as low as −169 kcal·mol−1, forms on the interface of Fe3O4-ATP. When a cationic surfactant is present, positively charged oil droplets are attracted to the membrane surface, where they compress against each other, leading to demulsification and escape. Synergistic effects including electrostatic shielding, interaction energy, and steric hindrance were demonstrated through characterization and simulation. Our findings showed that the membrane exhibited a high filtration efficiency with an oil rejection of over 99 % and a steady flux of over 73 % of its initial value. After filtration, oil fouling degraded into smaller sizes and escaped from the membrane structure through the Fenton-like catalytic function of Fe3O4, resulting in a flux recovery ratio of up to 90 %. This study provides a reference for the construction of multifunctional membranes for efficient separation processes and advancing anti-fouling research on membrane interfaces.

Analysis of Aceclofenac, Ketorolac, and Sulindac in Human Urine Using the Microemulsion Electrokinetic Chromatography Method

A method to determine aceclofenac, ketorolac, and sulindac in human urine samples using microemulsion electrokinetic chromatography (MEEKC) has been developed in this study. The optimization of MEEKC conditions was carried out by changing the microemulsion compositions including the buffer pH, borate salt concentration, surfactant concentration, co-surfactant concentration, organic modifier concentration, and oil droplet concentration. The optimum separation of selected drugs was obtained with a composition of microemulsion containing 10 mM borate buffer pH 9, 0.5% sodium dodecyl sulphate (SDS), 6.6% n-butanol, 6.0% acetonitrile, and 0.8% ethyl acetate. Excellent linearity was obtained in the range concentration of 25 to 200 ppm with r2 &gt; 0.999. Limits of detection (LOD, S/N = 3) and limits of quantification (LOQ, S/N = 10) were 2.72 to 4.75 and 9.08 to 15.85 ppm, respectively. The solid-phase extraction (SPE) method using C-18 as an adsorbent and the solid phase micro-tip extraction (SPMTE) method using multiwalled carbon nanotubes (MWCNTs) as an adsorbent were used to clean-up and pre-concentrate the urine samples prior to the MEEKC analysis. The best recoveries of the selected drugs in the spiked urine sample were 91 to 103% with RSD of 1.26 to 4.03% (n = 3) using the SPE-MEEKC method.

Fabrication, digestion behavior and β-carotene bioaccessibility of emulsion-filled double-network gel: Effect of corn fiber gum/soy protein isolate ratio and surfactant types

Emulsion fortified with β-carotene was added to corn fiber gum (CFG)/soy protein isolate (SPI) double network gel matrix to obtain emulsion-filled gels (EFG) via dual induction of laccase and glucono-δ-lactone. Protein digestion was accompanied by the release of β-carotene from gel matrix during in vitro digestion. The surfactant types and corn fiber gum/soy protein isolate ratio affected the β-carotene bioaccessibility via changing oil-water interfacial composition and emulsion particle size during in vitro digestion. As compared with Tween-20 EFGs, emulsion droplets released from SPI EFGs was more susceptible to flocculation, followed with coalescence due to proteolysis of interfacial SPI during gastric digestion. The resulting oil droplets with large particle size exhibited lower lipase adsorption, thus reducing the free fatty acid content and β-carotene bioaccessibility. The confocal laser scanning microscope (CLSM) observation confirmed that protein hydrolysate from gel matrix were adsorbed onto the oil-water interface competing with Tween-20 during intestinal digestion. For EFGs with higher CFG content, steric hindrance of CFG molecules and less emulsion release could inhibit droplet flocculation, thus enhancing β-carotene bioaccessibility.

Mixed superoleophilic/superoleophobic hard granular media for coalescence of oil-in-water-emulsion

To enhance the coalescence separation efficiency of oil/water emulsions, the coalescence mechanism of oil droplets between two media of opposite wettability was investigated. A coalescent-bed comprising a mix of superhydrophobic and superoleophilic quartz sand, along with superhydrophilic and underwater superoleophobic quartz sand, was constructed in a coalescer. Single-factor and response surface experiments were used to study the effects of oleophilic/oleophobic sand mixing ratio, apparent velocity, initial oil concentration, bed thickness, sand particle size on coalescence-separation performance, and to determine the optimal experimental conditions. Employing the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, the agglomeration mechanism of oil droplets within the mixed particle bed was analyzed based on interfacial energy dynamics. Results indicate that the mixing ratio of the two sands significantly influences coalescence separation performance. An optimal oleophilic/oleophobic sand mixing ratio of 1:1 yielded a mass factor of 0.69 kPa−1, showcasing superior coalescence separation efficiency and an optimal balance of separation efficiency and pressure drop. Under the optimal conditions of apparent velocity of 2.7 m/h, initial oil concentration of 471.9 mg/L, bed thickness of 12.6 cm and mixed sand particle size of 0.5 mm, the oil/water separation efficiency reached 98.08 % ± 0.87 %, with effluent oil droplet size being 2.5 to 3 times larger than at the inlet. Analysis of the oil droplet coalescence mechanism revealed a synergistic effect between the two quartz sands, enhancing oil removal performance. The strong affinity of oil to the superhydrophobic and superoleophilic sand surface increases oil droplet wetting and coalescence efficiency, while the water attraction on the superhydrophilic and underwater superoleophobic sand surface forms a stable water film, improving the flux of the continuous water phase and reducing pressure drop across the bed. This study demonstrates that combining quartz sands of opposite wettability not only overcomes the limitations of single-wettability surfaces in coalescing oil removal but also achieves high efficiency and low energy consumption in oil removal.

Potential of Raman-Reflectance Combination in Quantifying Liver Steatosis and Fat Droplet Size: Evidence From Monte Carlo Simulations and Phantom Studies.

This study explores a combined strategy of Raman and reflectance spectroscopy for quantifying liver fat content and fat droplet size, crucial in assessing donor livers. By using Monte Carlo simulations and experimental setups with oil-in-water phantoms, our findings indicate that Raman scattering can solely differentiate between varying fat contents. At the same time, reflectance intensity is influenced by both fat content and oil droplet size, with a more pronounced sensitivity to fat droplet size. This study demonstrates the efficacy of combined Raman and reflectance spectroscopy in assessing liver steatosis and fat droplet size, potentially aiding in assessing donor livers for transplantation.

Meat exudate metabolomics reveals the impact of freeze-thaw cycles on meat quality in pork loins

The aim of this study was to explore the effects of freeze-thaw (FT) cycles on meat quality, myofibrillar protein gelation and emulsification properties, and exudate metabolome changes in pork loins. Meat tenderness improved (P < 0.05), whereas water-holding capacity (WHC), meat color attributes declined (P < 0.05) with FT cycles. Multiple FT accelerated meat lipid and protein oxidations. Decreases in strength and WHC of myofibrillar protein gels with FT cycles were confirmed. Myofibrillar protein emulsions with more FT cycles showed a decrease in the emulsifying activity index (P < 0.001) and larger oil droplets, resulting in poorer storage stability. A total of 501 metabolites were tentatively identified in pork exudates, with 21 metabolites significantly correlated (P < 0.05 and r > 0.6) with meat quality attributes. These results demonstrated the potential of using the metabolomic information from exudates to elaborate on or even predict the FT cycles, or meat quality.

Effect of polysaccharide on structures and gel properties of microgel particle reconstructed soybean protein isolate/polysaccharide complex emulsion gels as solid fat mimetic

In this work, a soybean protein isolate (SPI)/polysaccharide microgel particle reconstructed emulsion gels (MPEG) were fabricated through heat-induced gel (HG)–microgel particle–transglutaminase (TG) induced gel process in the presence of four polysaccharides (κ-carrageenan, κC; konjac glucomannan, KGM; high-acyl gellan, HA and xanthan gum, XG). HG exhibited a higher springiness than that of pig back fat (PBF) regardless of polysaccharide type and concentration. After forming MPEG, the springiness was significantly lowered at ≥0.6 % κC, which made MPEG exhibit similar springiness of PBF; while SPI/KGM, SPI/XG and SPI/HA systems failed to regulate the springiness property. Rheological behavior revealed the loss in elasticity, the increase in the plastic deformation of SPI/κC MPEG, while KGM, XG and HA systems still exhibited elasticity dominated rheological properties. Compared with KGM, XG, the presence of excess κC and HA disturbed the continuous protein network structure, resulting to the aggregation of microgel particles and oil droplets. Disulfide bonds and hydrophobic interactions mainly contributed to the formation of MPEG, while the addition of κC weakened the contribution of them, which was not conducive to the formation of gel network. This study provides a guidance on the development of solid fat mimetic based on the microgel particle emulsion gels.

Enhanced propagation of free films with fast spread-out phenomena under the influence of megahertz surface acoustic waves

In this study, a novel approach for enhancing the rapid spreading of free liquid film on lithium niobate (LiNbO3) substrate under megahertz (MHz) surface acoustic wave (SAW) excitation is presented by treating it with surfactants. Through the design of a specific interdigital transducer structure, it was discovered that exciting the SAW at a frequency of 32.3 MHz can achieve optimal spreading performance for water droplets on the surface of surfactant-treated LiNbO3 substrate. The maximum average velocity reaches 1.76 mm/s at position P2 = 1250 μm in the water film front, and the stable film spreading speed shows a 204.9% increase compared to the existing research. Simultaneously, through the investigation of the spreading experiment phenomenon of silicone oil and de-ionized water droplets at varying frequencies, we have discovered the dynamic mechanism of “reverse phase” propagation in liquid film for the first time. This entails that the advancing edge of the wetting film demonstrates a spreading motion law that is opposite to the traditional spreading phenomena, with the spreading velocity in the central exceeding that on both sides. Our research demonstrates that this microfluidic device developed by SAWs enhances the spreading efficiency of the free films, enabling rapid expansion of the target liquid to form a high-surface area film layer. This advancement holds promise for overcoming the limitations of low sensitivity and short response time in the field of rapid pathological diagnosis in contemporary medicine.

Improvement of the Diagnostic Method for the Detection of Parasite Eggs Using the Formalin Ethyl Acetate Concentration Technique.

The formalin-ethyl acetate (FEA) concentration method is commonly used in routine clinical practice to detect parasite eggs in feces. This procedure involves extraction of oil with the organic solvent ethyl acetate (EA), which reduces fecal sediment and provides a cleaner background for microscopic analysis. However, clinically, some sediment failed to float after EA treatment. Hexane, commonly used in the food oil extraction from oilseeds did not float the feces. Gas chromatography-mass spectrometry (GC-MS) analysis showed that neither the amount of the oil nor the classes of the oil determined was differed whether hexane or EA was used to float the feces. Oil red, Bodipy and Calcofluor staining showed that the unabsorbed oil droplets in the fecal sediment were trapped within the leaf structure. HCl or acetic acid was added to see if the acid residue could dissolve the cellulose of the leaf to promote the bulk float. Our result showed that the fecal bulk contained the loosened mesophyll cell wall. The addition of acid residues improved fecal bulk float. The proximity of cellulose fiber to EA, but not hexane, may enhance the efficacy of oil extraction from cellulose. This is the first report that the interaction of cellulose with ethyl acetate in fecal solution has an effect on bulk float. This study improves the understanding of fecal bulk flotation and may assist in the visualization of parasite eggs in clinical practice with non-floating fecal samples in the FEA concentration method.

An investigation of the mechanism of emulsion stabilization in octenyl succinic anhydride-modified tamarind seed polysaccharide

Previous studies have shown that octenyl succinic anhydride-modified tamarind seed polysaccharide (OTSP) is an effective emulsion stabilizer. In this study, the fine structure and interfacial behavior of OTSP were investigated using a variety of methods to elucidate its mechanism for stabilizing emulsions. First, the results of nuclear magnetic resonance indicated that the esterification reaction occurred at the 6th carbon atom of glucose, which was not replaced by xylose in the main chain of TSP. Then, the studies of the interfacial behavior showed that OTSP adsorbed more at the oil-water interface than TSP, and that the intermolecular interactions of OTSP were stronger than those of TSP. The adsorption of OTSP at the interface was dominated by diffusion. Compared to TSP, OTSP formed a denser and more flexible interfacial layer and was resistant to large deformations and high-frequency perturbation. Molecular dynamics simulations revealed the presence of an Ω-like structure in the OTSP molecule. This structure reduced the degree of ordering of its molecular chains, resulting in a more flexible and looser structure that facilitated the rearrangement of OTSP molecules at the interface. The hydrophobic groups anchored the OTSP to the surface of the oil droplets, fixing them in the network structure, further restricting droplet movement and thus improving emulsion stability. The results of this study contribute to the understanding of the mechanism of polysaccharide-stabilized emulsion, which is of great significance in promoting the application of TSP in the food industry.

Incorporation of coenzyme Q10-loaded nanoemulsions in soy protein gels and assessment of the effects in their microstructure and bioaccessibility of the bioactive

Coenzyme Q10 (CoQ10) is a potent antioxidant that provides multiple health benefits, but its incorporation into foods is challenging due to its high hydrophobicity. This study aimed to develop soy protein isolate (SPI) gels filled with CoQ10-loaded nanoemulsion. Minimum gelation concentration tests were performed at pH 5, 6 and 7, as well as 11, 13 and 15 (SPI% w/w), to determine the best conditions for gel production. Gels with 15% SPI at pH 7 and various aqueous phase replacements by YNano Q10 (25%–85%) were produced. Uniaxial compression tests indicated that oil droplets were active particles interacting with the microgels of SPI, which structured the protein network. According to the confocal laser scanning microscopy (CLSM) micrographs, the gel structure was formed by microgels, common for SPI gels, and nanodroplets occupied the gels’ pores, possibly interacting with each other and with the protein matrix, forming a type of “emulsion network”; the scanning electron microscopy data corroborated the CLSM results. The stability of CoQ10 was evaluated using instrumental colorimetry and showed that the bioactive was highly stable after 45 days of storage according to instrumental color measurements. Regarding the release of CoQ10 during in vitro static digestion, the bioactive was present in the final digesta of gastric phase (GP) and intestinal phase (IP), indicating that EFGs protected the active against the harsh conditions of the gastrointestinal tract. Notably, the higher the amount of nanoemulsion, the higher the concentration of CoQ10 present in the digesta, and the presence of nanoemulsion droplets did not influence on protein hydrolysis.

Organic-inorganic hybrid-modified polyester/cotton fabric: Strategy for enhanced flame retardancy, chemical stability and amphiphobicity

As surface treatments for the application of functional components to substrates have gained increasing attention, there is a growing interest in endowing fabrics with multiple functionalities in addition to flame retardancy. This study describes the successful formation of a fluorination treatment of Al2O3 cross-linked onto the surface of a self-assembled PEI/PA coating for polyester/cotton (PC) fabrics. This coating approach aims to improve the flame retardancy, amphiphobicity, chemical stability, and self-cleaning properties of PC fabrics. The treated fabrics demonstrated exceptional fire resistance, with a significant reduction of 55.4 % in the peak heat release rate (pHRR) during combustion. Correspondingly, there was a decrease of 53.8 % in the peak release rate of CO2, while the limiting oxygen index increased from 17.9 % to 30.4 %. Additionally, the contact angles of water, glycol, and peanut oil droplets before and after treatment increased from 20.4°, 65.1°, and 34.6° to 146.0°, 143.1°, and 97.9°, respectively. The coating exhibits durable self-cleaning performance in both ambient and hot water and remains stable across a pH range of 1–14. This research offers a viable pathway for achieving flame retardancy on fabrics while enhancing their multifunctionality.

Theoretical and experimental investigation of the impact of oil functional groups on the performance of smart water in clay-rich sandstones

This research investigated the effect of ion concentration on the performance of low salinity water under different conditions. First, the effect of injection water composition on interparticle forces in quartz-kaolinite, kaolinite-kaolinite, and quartz-oil complexes was tested and modeled. The study used two oil samples, one with a high total acid number (TAN) and the other with a low TAN. The results illustrated that reducing the concentration of divalent ions to 10 mM resulted in the electric double layer (EDL) around the clay and quartz particles and the high TAN oil droplets, expanding and intensifying the repulsive forces. Next, the study investigated the effect of injection water composition and formation oil type on wettability and oil/water interfacial tension (IFT). The results were consistent with the modeling of interparticle forces. Reducing the divalent cation concentration to 10 mM led to IFT reduction and wettability alteration in high TAN oil, but low TAN oil reacted less to this change, with the contact angle and IFT remaining almost constant. Sandpack flooding experiments demonstrated that reducing the concentration of divalent cations incremented the recovery factor (RF) in the presence of high TAN oil. However, the RF increment was minimal for the low TAN oil sample. Finally, different low salinity water scenarios were injected into sandpacks containing migrating fines. By comparing the results of high TAN oil and low TAN oil samples, the study observed that fine migration was more effective than wettability alteration and IFT reduction mechanisms for increasing the RF of sandstone reservoirs.

Polypeptide N-acetylgalactosaminyltransferase-15 regulates adipogenesis in human SGBS cells

Adipogenesis involves intricate molecular mechanisms regulated by various transcription factors and signaling pathways. In this study, we aimed to identify factors specifically induced during adipogenesis in the human preadipocyte cell line, SGBS, but not in the mouse preadipocyte cell line, 3T3-L1. Microarray analysis revealed distinct gene expression profiles, with 1460 genes induced in SGBS cells and 1297 genes induced in 3T3-L1 cells during adipogenesis, with only 297 genes commonly induced. Among the genes uniquely induced in SGBS cells, we focused on GALNT15, which encodes polypeptide N-acetylgalactosaminyltransferase-15. Its expression increased transiently during adipogenesis in SGBS cells but remained low in 3T3-L1 cells. Overexpression of GALNT15 increased mRNA levels of CCAAT-enhancer binding protein (C/EBPα) and leptin but had no significant impact on adipogenesis in SGBS cells. Conversely, knockdown of GALNT15 suppressed mRNA expression of adipocyte marker genes, reduced lipid accumulation, and decreased the percentage of cells with oil droplets. The induction of C/EBPα and peroxisome proliferator-activated receptor γ during adipogenesis was promoted or suppressed in SGBS cells subjected to overexpression or knockdown of GALNT15, respectively. These data suggest that polypeptide N-acetylgalactosaminyltransferase-15 is a novel regulatory molecule that enhances adipogenesis in SGBS cells.

Development of Oleogel-in-Water High Internal Phase Emulsions with Improved Physicochemical Stability and Their Application in Mayonnaise.

Egg-free mayonnaise is receiving greater attention due to its potential health benefits. This study used whey protein isolate (WPI) as an emulsifier to develop high internal phase emulsions (HIPEs) based on beeswax (BW) oleogels through a simple one-step method. The effects of WPI, NaCl and sucrose on the physicochemical properties of HIPEs were investigated. A novel simulated mayonnaise was then prepared and characterized. Microstructural observation revealed that WPI enveloped oil droplets at the interface, forming a typical O/W emulsion. Increase in WPI content led to significantly enhanced stability of HIPEs, and HIPEs with 5% WPI had the smallest particle size (11.9 ± 0.18 μm). With the increase in NaCl concentration, particle size was increased and ζ-potential was decreased. Higher sucrose content led to reduced particle size and ζ-potential, and slightly improved stability. Rheological tests indicated solid-like properties and shear-thinning behaviors in all HIPEs. The addition of WPI and sucrose improved the structures and viscosity of HIPEs. Simulated mayonnaises (WE-0.3%, WE-1% and YE) were then prepared based on the above HIPEs. Compared to commercial mayonnaises, the mayonnaises based on HIPEs exhibited higher viscoelastic modulus and similar tribological characteristics, indicating the potential application feasibility of oleogel-based HIPEs in mayonnaise. These findings provided insights into the development of novel and healthier mayonnaise alternatives.

Acid Hydrolysis of Quinoa Starch to Stabilize High Internal Phase Emulsion Gels.

Starch nanocrystals (SNCs) to stabilize high internal phase emulsions (HIPEs) always suffer low production efficiency from acid hydrolysis. Due to its small granule size, Quinoa starch (QS) was selected to produce SNCs as a function of acid hydrolysis time (0-4 days), and their structural changes and potential application as HIPEs' stabilizers were further explored. With increasing the acid hydrolysis time from 1 day to 4 days, the yield of QS nanocrystals decreased from 30.4% to 10.8%, with the corresponding degree of hydrolysis increasing from 51.2% to 87.8%. The occurrence of QS nanocrystals was evidenced from the Tyndall effect and scanning electron microscopy with particle size distribution. The relative crystallinity of QS subjected to different hydrolysis times (0-4 days) increased from 22.27% to 26.18%. When the acid hydrolysis time of QS was 3 and 4 days, their HIPEs showed self-standing after inversion, known as high internal phase emulsion gels (HIPE gels), closely related to their densely packed interfacial architecture around oil droplets, seen on an optical microscope, and relatively high apparent viscosity. This study could provide a theoretical guidance for the efficient production and novel emulsification of SNCs from QS to HIPE gels.