Emulsion Stability Research Articles

Effect of starch categories and mass ratio of TA/starch on the emulsifying performance and stability of emulsions stabilized by tannic acid-starch complexes

This study compounded natural corn starch (CS), mung bean starch (MBS) and potato starch (PS) with tannic acid (TA) to stabilize O/W Pickering emulsion. The effect of TA/starch mass ratio (0–0.25) and three starch categories on particle properties, emulsifying properties, lipid oxidation, freeze-thaw stability, emulsion powder and digestive properties were comprehensibly investigated. In detail, the TA/starch complexes size increased gradually (91.14 nm–200.87 nm) and the hydrophobicity first increased and then decreased (TA/CS > TA/MBS > TA/PS) with increasing TA/starch mass ratio. In addition, the emulsifying ability of TA/starch complexes also increased first and then decreased with increasing mass ratio, especially TA/CS system was the best, which was the same as the hydrophobicity conclusion (θow = 80.46°). Moreover, four starch-based emulsion application characteristics were further evaluated to reveal interface structure. Compared to CS and PS system, TA/MBS emulsion had stronger ability to resist the oil oxidation (TBA = 2.54 μg/mL), destruction of ice crystal (whiter emulsion powder) and digestive enzymes (FFAs = 75.33 %). It mainly attributed to the crosslinking network structure and the highest surface load of TA/MBS complexes. This study would provide new ideas for the design and application of emulsifying properties and emulsion stability.

Physicochemical and digestive properties of curcumin stabilized by quaternized chitosan/sodium alginate nanoemulsion coatings

Curcumin (Cur) is a bioactive substance, but its instability limits its use in the food system. Thus, a new polysaccharide-based coating is developed by combining quaternized chitosan (QCS) with sodium alginate (SA) in this study to improve the bioaccessibility and stability of Cur. The microstructure of the emulsion was characterized by fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and low-field pulsed nuclear magnetic resonance imaging (LF-NMR). The thermal, ionic strength, and pH stability of emulsions were measured. Results indicate that QCS/SA (1:1)-Cur is more stable than other three nanoemulsion systems and the encapsulation rate of which reaches 90.62 %. It also shows higher stability in gastric fluid, excellent bioaccessibility and FFAs in intestinal fluid, as well as significant antibacterial property, antioxidant activity and water dispersibility. This study introduces a new method for obtaining stable, functional Cur-coated systems for food applications.

Spray dried protein concentrates from white button and oyster mushrooms produced by ultrasound-assisted alkaline extraction and isoelectric precipitation.

In the present study, the optimization of ultrasound-assisted alkaline extraction (UAAE) and isoelectric precipitation (IEP) was applied to white button (WBM) and oyster (OYM) mushroom flours to produce functional spray dried mushroom protein concentrates. Solid-to-liquid ratio (5-15% w/v), ultrasound power (0-900 W) and type of acid [HCl or acetic acid (AcOH)] were evaluated for their effect on the extraction and protein yields from mushroom flours submitted to UAAE-IEP protein extraction. Prioritized conditions with maximized protein yield (5% w/v, 900 W, AcOH, for WBM; 5% w/v, 900 W, HCl for OYM) were used to produce spray dried protein concentrates from white button (WBM-PC) and oyster (OYM-PC) mushrooms with high solids recovery (62.3-65.8%). WBM-PC and OYM-PC had high protein content (5.19-5.81 g kg-1), in addition to remarkable foaming capacity (82.5-235.0%) and foam stability (7.0-162.5%), as well as antioxidant phenolics. Highly pH-dependent behavior was observed for solubility (> 90%, at pH 10) and emulsifying properties (emulsification activity index: > 50 m2 g-1, emulsion stability index: > 65%, at pH 10). UAAE-IEP followed by spray drying increased surface hydrophobicity and free sulfhydryl groups by up to 196.5% and 117.5%, respectively, which improved oil holding capacity (359.9-421.0%) and least gelation concentration (6.0-8.0%) of spray dried mushroom protein concentrates. Overall, the present study showed that optimized UAAE-IEP coupled with spray drying is an efficient strategy to produce novel mushroom protein concentrates with enhanced functional attributes for multiple food applications. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Utilization of black cumin (Nigella sativa L.) cake proteins as a sustainable food ingredient: A comparative study with commercial proteins for antioxidant, techno-functional and vegan cheese properties

This study aimed to compare the antioxidant, techno-functional and vegan cheese properties of black cumin cake protein concentrate (BPC) with those of commercial proteins. The BPC (63% protein, w/w) showed greater antioxidant potential (TEAC: 247 μmol Trolox/g; ORAC: 211 μmol Trolox/g; iron chelation capacity: 35.5 μmol Trolox/g) than potato protein isolate (PPI), but comparable antioxidant potential with soy protein isolate (SPI). The BPC had slightly lower water binding capacity (7 g/g) than SPI (8.8 g/g), but 1.7 and 1.9-fold higher oil binding capacity (5.4 g/g) than PPI and SPI, respectively. All proteins showed similar emulsion capacity (EC) and stability (ES) at high protein concentrations (≥1%), but BPC showed the highest EC and ES at low protein concentrations (≤0.5%). BPC showed higher least gelling concentration (LGC: 14%) than PPI and SPI (LGCs for both 10%). However, the texture profile analysis showed that the heat-induced gels of BPC were firm but easily chewable. Moreover, BPC gels showed the highest springiness and resilience. The BPC-based spreadable vegan cheese was softer (firmness: 5.52 N), more easily spreadable (spreadability value: 6.23 N s), but less adhesive and sticky than SPI- and PPI-based spreadable vegan cheeses. SPI-based cheese showed the highest viscoelastic moduli followed by PPI and BPC with similar viscoelastic moduli. SPI-based cheese demonstrated the most favorable sensory properties, but BPC showed acceptable overall sensory properties. This work proved that black cumin proteins could be utilized to novel spreadable black vegan cheese. Further studies are needed to develop novel black-colored vegan food such as black milk, ice-cream, sausage, cake, crackers etc.

Discovery and characterization of novel lipopeptides produced by Virgibacillus massiliensis with biosurfactant and antimicrobial activities

The study aimed to evaluate the biosurfactants (BSs) production by SM-23 strain of Virgibacillus identified by phenotypical and WGS analysis as Virgibacillus massiliensis. We first demonstrated the lipopeptides production by Virgibacillus massiliensis specie and studied their biochemical and molecular analysis as well as their biological potential. The GC–MS analysis indicated that methyl.2-hyroxydodecanoate was the major fatty acid compound with 33.22%. The maximum BSs production was obtained in LB medium supplemented by 1% olive oil (v/v) at 30 °C and 5% NaCl with 1.92 g/l. The obtained results revealed the significant biosurfactants/bioemulsifier potential compared to triton X100 with E24 of 100%, and an emulsification stability SE of 83%. The lipopeptides types were identified by FTIR analysis. A strong antimicrobial action was observed by the produced lipopeptides by the agar diffusion method against E.coli, K. pneumoniae, S. aureus, Fusarium sp, Alternaria sp, and Phytophtora sp. The complete genome sequencing showed genes involved in the synthesis of multiple compounds identified as amphipathic cyclic lipopeptides such as locillomycin/locillomycin B/locillomycin C and bacillibactin. Our results highlighted significant lipopeptides properties displayed by V. massiliensis that can be exploited to develop a novel strategy in the formulation of natural biocidal and fungicidal agents.

Enhanced emulsification properties of microalgae protein through gellan gum conjugation: Mechanistic insights and applications in curcumin encapsulation and delivery

The emulsification properties of microalgae protein (MP) are poor, especially under acidic and neutral conditions, which may limit the broad applications of MP in food processing. This study aims to explore the effects of gellan gum (GG) on the emulsification properties of MP. Firstly, MP-GG complexes were prepared and their structures characterized. Subsequently, MP-GG complexes stabilized emulsions were prepared and their stability evaluated. Finally, these emulsions were employed for the encapsulation and delivery of curcumin to evaluate their potential as an efficient nutrient delivery medium. Results indicated that MP-GG complexes were formed under various pH conditions, with pH 6 identified as optimal for complexes stability (zeta-potential value was −31 mV). UV–vis and fluorescence spectroscopy demonstrated that GG did not significantly alter the MP's structure but induced slight conformational changes, leading to the burial of some amino acid residues. Zeta potential measurements confirmed that MP-GG complexes were stabilized by strong electrostatic repulsions. The increase of GG content was conducive to providing more negative charge and promoting the dissolution and dispersion of the MP-GG complexes (MP: GG = 1: 1). Emulsions stabilized by MP-GG complexes exhibited smaller droplet sizes and improved stability compared to those stabilized by MP alone, especially at oil phase volume fractions of 60 % and 70 %. Rheological analysis indicated that GG enhanced emulsion stability by increasing viscosity, and higher oil phase volume fractions facilitated better MP-GG complexes adsorption on oil droplets, strengthening network structures of emulsions. During in vitro simulated gastrointestinal digestion, emulsions with a 70 % oil phase exhibited higher curcumin retention rate (31.09 %) and lower curcumin bioaccessibility (13.23 %) compared to those with a 60 % oil phase. This suggests that emulsions with higher oil phase volume fractions may be more suitable for colon-targeted curcumin delivery, with potential applications in promoting colon health. These findings confirm that the complexation of MP and GG was an effective way to improve the emulsification properties of MP. Emulsions stabilized by MP-GG complexes can serve as stable nutritional delivery systems for fat-soluble bioactive compounds.

STUDY ON THE INFLUENCING FACTORS OF DEMULSIFIER ON THE OIL-WATER INTERFACE VISCOELASTICITY

Water flooding is a commonly used development method in oilfields, and the water cut of the output fluid of oil wells gradually increases with the increase of injected water in water wells. Due to the presence of natural surfactants such as gum, asphaltene and organic acid in crude oil, it is easy to form a high strength viscoelastic oilwater interfacial film and a stable emulsion. To facilitate the storage and transportation of crude oil, it is necessary to demulsify the crude oil emulsion. In this paper, the CQ crude oil was taken as the research object, and the effects of demulsifier type, concentration, demulsifier temperature and oil-water properties on the viscoelasticity of oil-water interfacial film were investigated by using rheometer and then the demulsification mechanism was explored. The results show that the lower the interfacial film strength, the better the demulsifier. In addition, with the increase of demulsifier concentration and temperature, the oil-water interfacial viscoelasticity decreases and the interfacial film strength further decreases. In general, the demulsification effect will be significantly improved with the increase of demulsifier concentration and temperature, and the dehydration effect will be better. The research results can provide theoretical guidance for the field application of demulsification.

THE ROLE OF OIL-IN-WATER EMULSION COMPONENTS ON SANDSTONES PERMEABILITY

This work studies the stability of oil-in-water emulsions and proposes a new methodology to evaluate the impact of different emulsion's components (sodium chloride, surfactant, and oil) on permeability decline during the injection into natural rocks. Stable emulsions were obtained by varying surfactant and oil concentrations and stirring speed. Emulsions, proven to be stable for more than 24h, were used in coreflooding tests. First, coreflooding experiments were conducted by injecting brine, which provided a permeability reduction of 7% and 20% in rocks measuring approximately 20mD and 120mD, respectively. Then, a surfactant solution was injected, resulting in a decline in permeability from 17 to 23% in the studied scenarios. Finally, emulsions with 0.05 and 0.01wt% oil concentrations were injected, and permeability was reduced to around 65% of its original value in low permeability rocks. Results show that damage due to oil droplets retention was intensive in the scenarios studied.

Globular proteins as Pickering emulsion stabilizers: Particles or surfactants?

Can globular proteins be considered as Pickering emulsion stabilizers? In recent years, there has been a growing interest in the study of Pickering emulsions due to their unique properties. Among these, protein-stabilized Pickering emulsions have garnered significant attention, thanks to their environmentally friendly nature and wide-ranging applications across various industries. Pickering emulsions are typically classified separately from surfactant-stabilized emulsions due to their distinct stabilization mechanisms and remarkable resistance to coalescence. Although proteins have long been considered as particles in the context of Pickering emulsions, a debate still exists regarding their classification. In this work, we aim to address this debate by investigating the rheological and interfacial activity aspects of bovine serum albumine (BSA) proteins at silicone oil-water interfaces in the context of silicone oil-in-water emulsions. For rheological analysis and comparisons, emulsions were also formulated with surfactants and particles. Our results show that proteins can present both surfactant-like and particle-like behavior in terms of interfacial activity and microscopic structures with varying formulation parameters (pH). Rheological modelling, additionally, indicate similar behavior between emulsions with particles, surfactants and proteins. Thus, the challenge of categorizing proteins definitively as one or the other persists.

Non-aqueous Pickering emulsions stabilized by natroglaucocerinite-like layered double hydroxides particles

This study explores non-aqueous Pickering emulsions stabilized by natroglaucocerinite-like layered double hydroxides (Zn/Al LDH), featuring two immiscible phases: glycerin (Gly) and various oils (silicone, castor, soybean, or vaseline) over a span of 15 days. The stability of the emulsions was assessed through macroscopic observations of flocculation, creaming, sedimentation, and coalescence. The wettability of the solid particles at the phase interface was analyzed using tensiometry and contact angle measurements, while fluorescence microscopy was used to determine the type of emulsion. Emulsification effectiveness was found to be influenced by the glycerin volume fraction, oil type, and LDH particle concentration. Oils like silicone and vaseline required both a higher LDH concentration and glycerin fraction for complete oil emulsification, whereas castor and soybean oils showed better emulsification at higher glycerin fractions. These findings underscore the potential of LDH as a versatile and eco-friendly solution for applications that demand the reduction or control of specific solvents.

PH- and temperature-dual responsive polymer emulsion for rapid release of drag reducer

Slick water fracturing fluid is widely used in major oil fields due to its low cost and high drag reduction. Polyacrylamide emulsions drag reducers play a decisive role in slick water fracturing. The dissolution rate of polymer emulsions drag reducers was increased by adding hydrophilic surfactants, but the stability of the emulsions is poor, which limits its wide application. In order to solve the contradiction between the stability of polymer emulsion and rapid release of drag reducer. Here, a P(AA-AM-AMPS) polymer emulsion drag reducer with dual stimulation response of pH and temperature was designed. Surfactant (D400/OA) with dual responses to pH and temperature is synthesized by using oleic acid (HOA) and polyether amine 400 (D400). D400/OA shows a remarkable pH- and temperature-responsive behavior due to the pH- and temperature-induced structural transformation of D400/OA. Interestingly, D400/OA-stabilized monomer emulsion exhibits an obvious pH- and temperature-induced structural transformation. Meanwhile, The D400/OA-stabilized monomer emulsion has remarkable stability, which benefits the inverse emulsion polymerization of P(AM-AA-AMPS) polymer. The obtained P(AM-AA-AMPS) polymer emulsion maintain stability whose particle size nearly unchanged by storing for 15 days. Interestingly, P(AM-AA-AMPS) polymer emulsion can be released completely by changing the pH or temperature of the aqueous solution. The apparent viscosity of P(AM-AA-AMPS) polymer, in either the alkaline (pH=10.31) solution of 25±2 °C or neutral (pH=7) solution of 70±2 °C, respectively required 40 s and 8 min to reached a maximum value of 96 mPa·s. The release rate of P(AM-AA-AMPS) polymer emulsion is further enhanced under the dual responsive of temperature (70±2 ℃) and pH (10.31) and it takes only 20 s, In addition, the drag reduction rate of P(AM-AA-AMPS) polymer emulsion is 72 % when completely released under the dual responsive of temperature and pH, showing a remarkable drag reduction property. The D400/OA-stabilized P(AM-AA-AMPS) polymer emulsion are expected to meet the demand for the production enhancement of the oil and gas reservoirs.

The Synergic Effect of Brine Salinity and Dispersed Clay Particles on Water-in-Heavy Oil Emulsion: Insight into Asphaltene Structure and Emulsion Stability

Summary The research on enhancing oil recovery in sandstone reservoirs through low-salinity waterflooding (LSWF) has been well-documented, while there have been few studies conducted on the impact of emulsion formation in heavy oil due to the incompatibility between the injected brine, clay particles, and heavy oil components. In this study, we explored the synergic role of asphaltene and clay in the process of LSWF by introducing an innovative and thorough experimental approach. Our findings presented new insights into how LSWF in clay-rich sandstone reservoirs can influence the behavior and properties of the water-in-heavy oil emulsions. In this regard, we contacted the heavy oil and brine (with and without clay) for 20 days at 90°C. Then, the emulsion was centrifuged to separate the oil and brine phases. The oil phase was examined by conducting the viscosity, interfacial tension (IFT), Fourier transform infrared spectroscopy (FTIR), and asphaltene onset point (AOP) precipitation experiments. Significant decreases in viscosity and asphaltene precipitation values were observed when crude oil was exposed to clay solutions, as indicated by viscosity and IP-143 results. Furthermore, the zeta potential of clay particles suspended in various brines was determined to assess the electrostatic aspects of rock-oil interactions. The analysis of the emulsion phase indicated that the emulsion stability in the presence of clay increased because of the improvement of asphaltene contribution in the interface. This trend aligns with the zeta potential measurement results. In addition, after examining the pH and conductivity of aged brine in the presence and absence of clay, it was observed that the clay caused the release of hydrogen ions in the brine and then bonded with the dissolved cations, leading to improvement in the emulsion stability. Ultimately, the asphaltene molecular structure was compared via scanning electron microscopy (SEM) and attenuated total reflection analysis before contact with the brine and after separation from the emulsion phase. The results indicated a decrease in the concentration of aliphatic groups in the molecular structure of the remaining asphaltene following the aging of the oil bulk. These new findings can potentially mitigate unwanted emulsion damage in the LSWF in heavy oil recovery.

Structure and stabilization of water-in-water emulsions in the presence of two types of microgels

HypothesisWater-in-water emulsions can be stabilized by colloidal particles that spontaneously adsorb at the interface. Different types of particles have been shown to exhibited different impact on the microstructure and stability. The combination of two different types of particles is expected to show a synergistic effect on the emulsion stability. ExperimentsSynthetic bis-hydrophilic microgels (BIS) and protein microgels (PRO) were studied in emulsions formed by mixing polyethylene oxide (PEO) and Dextran (DEX) as well as in the individual phases. The arrangement of particles at the interface was monitored using confocal laser scanning microscopy and the effect on the microstructure and stability of the emulsions was is evaluated during aging. FindingsThe adsorption and arrangement of particles at the interface depended mainly on their affinity for each phase. Formation of a mixed layer significantly increased the stability of the emulsions compared to emulsions with the individual microgels. BIS and PRO co-aggregated in the PEO phase, which affects their arrangement at the interface and the emulsion stability. In some cases, added BIS spontaneously fully replaced PRO that was absorbed at the interface.

Maillard reacted wheat gluten and polydextrose complex enhances the emulsifying properties and stability of Pickering emulsion

This study aims to explore the characteristics and stability of Pickering emulsion based on the Maillard reaction products of polydextrose (PDX) and gluten. The effects of the PDX:gluten ratio (from 0.0:1 P0.0G1 to 2.4:1 P2.4G1) during Maillard reaction on Pickering emulsion quality were examined. The degree of PDX grafting to gluten increased from 0.51%±0.05% to 18.99%±0.98% when the PDX:gluten ratio increased from 0.2:1 to 2.2:1. Scanning electron microscopy and infrared spectroscopy confirmed the structural change and covalent interaction of PDX–gluten conjugate. The P2.2G1 conjugate showed a higher emulsification activity (1.82±0.04 m2/g) compared with P0.0G1 (0.97±0.05 m2/g). The particle size, ζ-potential value and confocal laser scanning microscopic image of PDX–gluten conjugate-based emulsion were compared with those of gluten-based emulsion to illustrate the stability role of PDX–gluten conjugate in the interfacial layer of Pickering emulsion. This study demonstrated that the Maillard reacted gluten–PDX conjugate was a potential stabilizer for Pickering emulsions. These findings provided a foundation knowledge for the construction of Pickering emulsion based on PDX–gluten conjugates.

Perilla oil emulsions stabilized by casein-dextran sulfate nanocomplexes with and without curcumin

Protein-polysaccharide nanocomplexes are potential particulate emulsifiers to improve physical and chemical stability of emulsions containing polyunsaturated fatty acids. This study prepared nanocomplex dispersions with 2.0 % w/v sodium caseinate and 0–0.4 % w/v dextran sulfate (DS) with and without 0.1 % w/v curcumin. The dispersions exhibited a Z-average diameter of 124.61–182.46 nm, a polydispersity index of 0.37–0.52, and a zeta potential between −30.1 and −34.9 mV, with a curcumin encapsulation efficiency of higher than 75 %. These nanocomplexes were used to emulsify 60 % v/v perilla oil (PO) through shear homogenization and sonication. Emulsions showed discrete droplets in light and confocal laser scanning microscopy. The creaming index decreased as DS concentration increased, remaining below 6 % after 30 days of storage Emulsions had >70 % DS, >80 % caseinate, and 100 % curcumin adsorbed on the oil droplet surface. For oxidative stability at 55 °C for 15 days, emulsions prepared with 2.0 % w/v caseinate and 0.4 % w/v DS, with and without curcumin, showed a maximum of 40 % reduction in the peroxide value and 71 % reduction in the thiobarbituric reactive substances value from those of bulk PO. The present study showed the significance of casein-DS nanocomplexes for the physical and chemical stability of PO emulsions.

PH-shifting treatment improved the emulsifying ability of gelatin under low-energy emulsification

The effects of pH-shifting treatments (pH 3, 5, 7, 9, and 11) on the stability of gelatin emulsions made by low-energy stirring were investigated. pH-shifting treatments significantly enhanced the ESI and EAI of the emulsion (P < 0.05) and reduced its particle size (P < 0.05) under low-energy emulsifying conditions. The pH11–7 shifting treatment significantly increased the degree of depolymerization and the level of ordered structure of gelatin (P < 0.05). These transformations resulted in a significant increase in the exposure of hydrophobic and negatively charged residues (P < 0.05) on the surface of gelatin, facilitating a faster adsorption rate of gelatin onto the oil-water interface as well as an increase in the amount of gelatin adsorbed at the interface. Moreover, the alkali-shifting treatment promoted the formation of a thin viscoelastic interfacial film, which contributed to the enhanced stability of the emulsion.

Fabrication of cellulose nanofibers/epigallocatechin gallate complexes: Insights into structure, antioxidant properties and enhanced emulsion performance.

In this work, cellulose nanofiber/epigallocatechin gallate (CNF/EGCG) complexes at different ratio were fabricated and the effects on characteristics and stability of emulsions under different oil phase fraction (φ) were investigated. The results of functional groups indicated the formation of CNF/EGCG complexes via hydrogen bond interaction, leading to enhanced antioxidant activity as the proportion of EGCG increased. The complexes exhibited more fragments but pure CNF were more homogenously dispersed in the aqueous phase. Enhancing the EGCG content reduced the droplet size of emulsions firstly before increased, while the apparent viscosity and viscoelastic properties displayed a contrary trend. Emulsion gels with smaller droplet size, higher apparent viscosity, excellent viscoelastic properties and physical stability could be formed at φ=0.5 while emulsions at φ=0.3 exhibited slight creaming. The emulsions at lower CNF/EGCG ratio presented better oxidative stability, which was ascribed to the higher antioxidant activity of the complexes and the thicker interfacial film. Results suggest that EGCG could be combined with CNF to improve the emulsion performance and be applied in extending the shelf-life of the emulsion-based products.

Stabilization of gels and emulsions in the ternary water/eugenol/poloxamer 407-system: Physicochemical characterization and potential application as encapsulation platforms

The ternary system water/eugenol/poloxamer 407 can form a variety of phases that are strongly influenced by the mixture composition and the thermal history of the system. In this study, we investigated the stabilization of emulsion and gel-like systems in which eugenol is encapsulated in a poloxamer 407 matrix. Our results reveal the complex interplay between poloxamer 407 and eugenol compositions in the stabilization single-phase systems at 25ºC. Increasing concentrations of poloxamer were found to incorporate higher amounts of eugenol into emulsion-like dispersions, effectively preventing coalescence and Ostwald ripening. However, high concentrations of poloxamer 407 induced gelation of these dispersions, resulting in eugenol-loaded poloxamer 407 gels. The thermal annealing of the emulsions at 65°C for 1 h followed by equilibration at room temperature allows the extension of the compositional range for the formation of homogeneous single-phase systems providing a strategy to modulate the phase diagram of the ternary system. Additionally, the encapsulation of hydrophobic pesticides in gel-like matrices was investigated, showing uniform distribution and consistent loading capacity (approximately 0.70 % w/w) across different pesticides which may contribute to facilitate the environmental distribution and efficacy of the encapsulated molecules. This research highlights the potential of eugenol/poloxamer 407-based systems as an environmentally friendly platform for the encapsulation and delivery of hydrophobic active molecules, offering a versatile solution for various applications.

Influence of pH and salt conditions on extraction efficiency and functional properties of Macrotermes nigeriensis protein concentrate for food applications

The search for alternative proteins from non-conventional sources for food processing has become important due to the shortage of conventional protein sources. Protein extractability from Macrotermes nigeriensis and its functional properties were investigated under various conditions of pH (2–10) and salt concentration (0.1–1.0 M). Extracted proteins were precipitated through pH adjustment and micellization, respectively. Results showed that maximum protein extractability was 68% and 62.1% at 0.5 M salt concentration and pH10.0, respectively. Salt-extracted protein-rich fraction (SP) had the highest protein composition (68.68 ± 0.41 g/100 g), seconded by alkaline-extracted protein-rich fraction (AP) (62.91 ± 0.53 g/100 g), compared with the raw and defatted fraction (34.36 ± 0.44 and 42.12 ± 0.15 g/100 g), respectively. The highest emulsion capacity (49%) and emulsion stability (35%) were recorded in alkaline pH 10.0. In comparison, the highest foaming capacity (24%) and foaming stability (16%) were recorded in the salt-extracted fraction at 6%. This information could be useful for further studies on the food application potential of proteins isolated from edible M. nigeriensis.Graphical

Differential binding of gallic acid and epigallocatechin gallate to whey protein affects the interfacial adsorption and gastric digestion of O/W emulsion

Whey protein isolate (WPI) was reacted with 20, 120, and 240 μmol/g gallic acid (GA) or epigallocatechin gallate (EGCG) at 21 °C. Equilibrium dialysis testing indicated a stronger binding capacity of whey proteins with EGCG compared to GA. Both phenolics, especially EGCG, tended to reduce the adsorption of WPI at the oil–water interface and decreased the elasticity modulus (Ed) of the interfacial film. Yet, binding with 20 μmol/g of EGCG and GA (less so) resulted in significantly improved emulsifying activity of WPI, but the emulsion stability was decreased at all phenolic concentrations (except at 240 μmol/g). There was an overall improvement of pepsinolysis of both α-lactalbumin and β-lactoglobulin. In comparison with GA, EGCG yielded more pronounced effects on WPI interfacial adsorption, dilatational rheology, and peptic digestion.