Oil Droplet Size Research Articles

Replacement of milk fat by rapeseed oil stabilised emulsion in commercial yogurt

The incorporation of lipid droplets and further characterization of matrices within dairy products may be possible using such adjacent particles as protein complexes/lipids. Among the range of varied emulsions and their functionalities, great attention has recently focused on the fabrication of high internal phase types. Feasibly, stable alternatives structured with health-beneficial lipids like those derived from plants could replace saturated fatty acids. As a fat replacement strategy, the fate of incorporated HIPE would require some adjustments either with storage stability and/or structural feat for the food matrix. Therefore, the replacement of milk fat by rapeseed oil stabilised emulsion in commercial yogurt was investigated. This involved 25%, 50% and 75% rapeseed oil respectively assigned as low (LIPE), medium (MIPE), and high internal phase emulsion (HIPE). Specifically, emulsions were examined by droplet size, encapsulation, pH, zeta potential, phase separation, and rheology. The fat free yogurt supplemented by HIPE were examined by droplet size, zeta potential, pH, color, sensory, texture and microbiological aspects against positive (regular milk fat) and negative (fat free) yogurt controls. Results showed increasing rapeseed oil contents would form smaller droplet-like emulsions. Within the yogurt matrix however, incorporating HIPE would seemingly reduce oil droplet size without much compromise to bacterial viability, sensory, or texture. Overall, this simple method of lipid alternation shows promise in dairy products.

Effect of Diacylglycerol Crystallization on W/O/W Emulsion Stability, Controlled Release Properties and In Vitro Digestibility.

Water-in-oil-in-water (W/O/W) emulsions with high-melting diacylglycerol (DAG) crystals incorporated in the oil droplets were fabricated and the compositions were optimized to achieve the best physical stability. The stability against osmotic pressure, encapsulation efficiency and in vitro release profiles of both water- and oil-soluble bioactives were investigated. The presence of interfacial crystallized DAG shells increased the emulsion stability by reducing the swelling and shrinkage of emulsions against osmotic pressure and heating treatment. DAG crystals located at the inner water/oil (W1/O) interface and the gelation of the inner phase by gelatin helped reduce the oil droplet size and slow down the salt release rate. The DAG and gelatin-contained double emulsion showed improved encapsulation efficiency of bioactives, especially for the epigallocatechin gallate (EGCG) during storage. The double emulsions with DAG had a lower digestion rate but higher bioaccessibility of EGCG and curcumin after in vitro digestion. DAG-stabilized double emulsions with a gelled inner phase thus can be applied as controlled delivery systems for bioactives by forming robust interfacial crystalline shells.

A clean label O/W pickering emulsion stabilized by pectin-containing lignocellulosic nanofibrils isolated from apple pomace

With the increasing demand for clean-label food, LCNF is considered a promising candidate to replace artificial surfactants in O/W emulsion. However, the isolation of LCNF usually requires the use of costly and toxic oxidants or grafting reagents to introduce charged groups for higher fibrillation degree and better emulsifying properties. In this study, a new pectin-containing apple nanofibril (A-NF) with native dissociated carboxyl groups (-COO-) was successfully produced from apple pomace by alkaline demethylation followed by high-pressure homogenization. These “native” charged A-NFs are 10–30 nm in diameter and ∼1 μm in length, and can be well dispersed in water for several months due to the release of up to 1.30 mmol/g nanofibrils of -COO- from the insoluble pectin (ISP) fraction by alkaline demethylation. Among A-NFs, A–NF–24h showed the best emulsifying properties (70.85 m2/g of EAI and 94.71% of ESI) and highest emulsion stability (∼1.00 μm of the oil droplet size during 14-day storage). Emulsion microstructure showed that LCNF not only irreversibly adsorbed at the oil-water interface, providing electrostatic stability, but also offered depletion stability by fabricating an entangled network with the unabsorbed portion. Moreover, molecular dynamics simulations further explained that the A-NF system displayed lower absorption energy of −1659.43 kJ/mol and diffusion cofactor of oil molecules of 16.67 μm2/s than that of CNF system at the interface, thus enhancing the emulsion stability. Altogether, these native A-NFs exhibit good colloidal stability, comparable emulsifying properties and emulsion stability, and have promising applications in clean-label O/W emulsions.

Soy protein isolate/carboxymethyl cellulose sodium complexes system stabilized high internal phase Pickering emulsions: Stabilization mechanism based on noncovalent interaction

The interactions between carboxymethyl cellulose sodium and proteins can regulate the interfacial and rheological properties of HIPEs, which plays a leading role in the stabilities of HIPEs. This article prepared various ratios of soluble soy protein isolate/carboxymethyl cellulose sodium (SPI/CMC) complexes in different proportions and examined the impact of various ratios of complexes on the structure and interface properties of complexes systems. Additionally, it explored the co-emulsification mechanism of HIPEs using SPI and CMC. At appropriate ratios of SPI/CMC, SPI and CMC mainly combine through non covalent binding and form complexes with smaller particle sizes and stronger electrostatic repulsion. The interfacial properties indicated that adding appropriate CMC increased the pliability and reduced the interfacial tension, while also enhancing the wettability of SPI/CMC complexes. At the ratio of 2:1, the SPI/CMC complexes-stabilized HIPPEs exhibited smaller oil droplets size, tighter droplet packing, and thicker interfacial film through the bridging of droplets and the generation of stronger gel-like network structures to prevent the coalescence/flocculation of droplets. These results suggested that the appropriate ratios of SPI/CMC can improve the physical stability of HIPEs by changing the structure and interface characteristics of the SPI/CMC complexes. This work provided theoretical support for stable HIPEs formed with protein-polysaccharide complexes.

Structural modification of oat protein by thermosonication combined with high pressure for O/W emulsion and model salad dressing production

Oat protein is becoming an important ingredient in beverages and formulated foods owing to its high nutritive value and bland flavor; yet, its functionality remains largely unexplored. This study sought to enhance the surface activity of oat protein isolate (OPI) through high-intensity ultrasound (HIU; at 20 or 60 °C) combined with high pressure homogenization (HP; 30 MPa) treatments. Sonication disturbed the protein conformation and significantly improved surface hydrophobicity (19.7%) and ζ-potential (15.7%), which were further augmented by subsequent HP (P < 0.05). Confocal microscopy revealed a uniform oil droplet distribution in emulsions prepared with HIU+HP combination treated OPI, and the oil droplet size decreased up to 35.6% when compared to that of non-treated OPI emulsion (d = 1718 nm). Emulsifying activity was greater for HIU+HP than for HIU, and the viscosity followed a similar trend. Moreover, while emulsions prepared with HIU or HP treated OPI were more stable than control, the 60 °C HIU+HP combination treatment yielded the maximum stability. In corroboration, a model salad dressing prepared from HIU+HP treated OPI displayed a homogenous oil droplet distribution and an improved viscosity. Therefore, thermosonication combined with high pressure homogenization may be suitable for salad dressings and other oil-imbedded food products.

Tunable rheological properties of high internal phase emulsions stabilized by phosphorylated walnut protein/pectin complexes: The effects of pH conditions, mass ratios, and concentrations

The current study reported high internal phase emulsions (HIPEs) stabilized by phosphorylated walnut protein/pectin complexes (PWPI/Pec) and elucidated how their rheological properties were modulated by pH conditions, mass ratios, and concentrations of the complexes. At pH 3.0, the HIPEs stabilized by PWPI/Pec exhibited smaller oil droplet sizes, as well as higher storage modulus (G') and flow stress, in comparison to those stabilized by the complexes formed at pH 4.0–6.0. These observations can be directly linked to pH-dependent changes in particle size, surface hydrophobicity, and wettability of the PWPI/Pec complexes. Rheological analysis revealed that all generated HIPEs displayed weak strain overshoot behavior, irrespective of pH conditions. Notably, HIPEs stabilized by PWPI/Pec at mass ratios of 2:1 and 4:1 showed enlarged oil droplet sizes, lower G' and flow stress but higher flow strain with unaffected loss factor compared to those stabilized by PWPI/Pec 1:1. However, reducing the concentration of PWPI/Pec led to a simultaneous decrease in G', flow stress, and flow strain, along with a significant increase in the loss factor of the HIPEs. Furthermore, the HIPEs formed with 1% PWPI/Pec 1:1 at pH 3.0 demonstrated excellent stability against heat treatment and long-term storage. These results provide valuable insights into the modulation of rheological characteristics of HIPEs and offer guidance for the application of walnut protein-based stabilizers in HIPE systems.

A superhydrophilic battery sponge with positive and negative electrodes for the demulsification of oil-in-water emulsions

A battery sponge (BS), with the superhydrophilic positive and negative electrode, was modified for demulsifying various oil-in-water emulsions without power device. Two mechanisms of BS, same charge-BS (SC-BS, BS electrode first contact with same charged emulsion) and opposite charge-BS (OC-BS, BS electrode first contact opposite charged emulsion), were explored. The positive electrode PEI@PDA@PU (PPP) and negative electrode OA@PEI@PDA@PU (OPPP) were singularly compared with BS to elucidate the demulsification performance and mechanism. Among them, OC-BS achieved the best effect: it reduced the emulsion zeta potential to below 20 mV (absolute value); separation efficiency exceeded 99.9 %; the demulsified oil droplets coalesced inside the sponge; and residual oil droplet size of filtrate was larger than the original emulsions. Furthermore, OC-BS adapted to various emulsions, can be recycled 30 cycles (separation efficiency ≥ 99.5%), and possessed high stability. The optimally-performing OC-BS was due to the repeated action of synergistic superhydrophilic positive and negative electrodes on the charged oil of emulsion, which were demulsified to the maximum degree inside the superhydrophilic sponge. It was electrostatic action, hydrophobic effect, capillary force, and oil viscosity played the main role in oil–water separation. SC-BS only demulsified the oil droplets twice. PPP was affected by emulsion type. OPPP performance was stable but unremarkable. Meanwhile, positively and negatively charged BS could also attract cationic/anionic dyes in wastewater. The results demonstrated that BS can be effectively utilized as a demulsification material and applied to purify various emulsions.

Comparative effects of W/O and O/W emulsions on the physicochemical properties of silver carp surimi gels

The comparative effects of water-in-oil (W/O) and oil-in-water (O/W) emulsions on the physicochemical characteristics of silver carp surimi gels were investigated. The breaking force of surimi gels was 188.72 g, which decreased with increasing W/O emulsion but remained constant by adding O/W emulsion. The hardness decreased with increasing W/O emulsion, while the other parameters to TPA maintained constant whether the W/O or O/W emulsion was added. The yellowness value of surimi gels was 1.30, which increased with increasing W/O emulsion while remained constant after adding O/W emulsion. The water-holding capacity of surimi gels was invariant when emulsions increased. After emulsions added to surimi gels, no changes in the surimi protein interactions were found in electrophoretic patterns and Fourier transform infrared spectra. The increasing W/O emulsion enlarged the droplet size of oil and then destroyed the surimi gel network structure, while the oil droplets were evenly dispersed with increasing O/W emulsion.

Injection of l-arginine or l-lysine before freezing delays the emulsifying and gelling properties deterioration of myofibrillar proteins of frozen porcine Longissimus lumborum muscle.

This study aimed to investigate the effects of injecting l-arginine and l-lysine solution before freezing and after thawing on the emulsifying and gelling properties of myofibrillar proteins (MPs) of frozen porcine longissimus dorsi. The results showed that the pre-freezing injections were more effective in alleviating the decrease in emulsifying properties of MPs compared with the post-thawing injections, as evidenced by higher emulsion creaming index, oil droplet size, interfacial absorptive protein amount, and viscoelasticity. Additionally, the pre-freezing injections could effectively mitigate the damage to the gelling properties of MPs, as evidenced by the formation of a homogeneous and compact gel network with stronger water retention, strength and chemical forces, as well as a higher proportion of non-flowing water, whereas the post-thawing injections could not. These results demonstrated that the injection of l-arginine and l-lysine solution before freezing could delay freezing-induced damage to the emulsifying and gelling properties of MPs, keeping the processing characteristics of frozen porcine.

Using Computation Fluid Dynamics to Determine Oil Droplet Breakup Parameters during Emulsion Atomization with Pressure Swirl Nozzles

A wide range of commercial powdered products are manufactured by spray drying emulsions. Some product properties are dependent on the oil droplet size, which can be affected by fluid mechanics inside the spray nozzle. However, most of the key flow parameters inside the nozzles are difficult to measure experimentally, and theoretical estimations present deviations at high shear rates and viscosities. Therefore, the purpose of this study was to develop a computational model that could represent the multiphase flow in pressure swirl nozzles and could determine the deformation stresses and residence times that oil droplets experience. The multiphase flow was modelled using the Volume-of-Fluid method under a laminar regime. The model was validated with experimental data using the operating conditions and the spray angle. The numerically calculated shear stresses were found to provide a better prediction of the final oil droplet size than previous theoretical estimations. A two-step breakup mechanism inside of the nozzle was also proposed. Additionally, some of the assumptions used in the theoretical estimations could not be confirmed for the nozzles investigated: No complete air core developed inside of the nozzle during atomization, and the shear stress at the nozzle outlet is not the only stress that can affect oil droplet size. Elongation stresses cannot be neglected in all cases.

Aggregation, toxicity, and biodegradability study of an ionic liquid-based formulation for effective oil spill remediation

Chemical dispersants are extensively used for marine oil spill remediation. However, the increased toxicity and low biodegradability of these dispersants restrict their employment in the marine environment. Hence, in this work, we have developed an eco-friendly formulation composed of an ionic liquid,1-butyl-3-methylimidazolium lauroyl sarcosinate [BMIM][Lausar] and sorbitan monooleate (Span) 80. Micellar and interfacial parameters, dispersion effectiveness, as well as the toxicity and biodegradability of the developed formulation were investigated. Micellar properties confirmed a high degree of synergism among the surfactant molecules and the formation of stable micelle. The dispersion effectiveness, at dispersant-to-oil ratio (DOR) of 1:25 (v/v), against three crude oils (Arab, Ratawi, and Doba) was assessed. We achieved a dispersion effectiveness of 68.49%, 74.05%, and 83.43% for Ratawi, Doba, and Arab crude oil, respectively, using a 70:30 (w/w) ratio of Span 80 to [BMIM][Lausar]. Furthermore, the results obtained from optical microscopy and particle size analysis (PSA) indicated that the oil droplet size decreased with higher DOR. Additionally, acute toxicity experiments were conducted on zebrafish (Danio rerio) using the developed formulation, confirming its non-toxic behavior, with LC50 values of 800 mg/L after 96 h. The formulation also exhibited high biodegradability, with only 25.01% of the original quantity remaining after 28 days. Hence, these results suggest that the new formulation has the potential to be a highly effective and environmentally friendly dispersant for oil spill remediation.

Cinnamon essential oil Pickering emulsions: Stabilization by bacterial cellulose nanofibrils and applications for active packaging films

Pickering emulsions are emulsions stabilized by solid particles with a wide range of potential applications as they typically provide more stable systems than surface-stabilized emulsions. Among the various solid stabilizers, bacterial cellulose (BC) may open up new opportunities for future Pickering emulsions due to its unique nano-size, amphiphilicity and other excellent properties. In this study, BC, TEMPO-oxidized BC (TOBC) and dialdehyde cellulose (DAC) were used as emulsifiers to stabilize cinnamon essential oil (CEO) Pickering emulsions. The microstructure, oil droplet size distribution, storage and loss moduli of the Pickering emulsions were affected by the type of emulsifier used. Compared to BC and DAC nanofibers, TOBC nanofibers exhibited better emulsifying capacity. TOBC (1%)-stabilized Pickering emulsion showed smaller droplet size, narrower size distributions, better stability and sustained release ability. Moreover, the Pickering emulsions showed high antibacterial activities against Gram-positive bacteria S. aureus and Gram-negative bacteria E. coli. Active gelatin composite films containing TOBC (1%)-stabilized CEO Pickering emulsions were successfully fabricated and showed good antibacterial and antioxidant properties, which make them suitable for food packaging application.

Emulsification Properties of Garlic Aqueous Extract: Effect of Heat Treatment and pH Modification.

Despite the broad research available in the literature dealing with garlic health benefits, little information is found regarding the functional properties of garlic components. The aim of this study was to evaluate the emulsification properties of garlic water-soluble compounds (GWSC), encompassing proteins, saponins, and carbohydrates, after heat treatment (10 min at 95 °C) or pH adjustments (2.5, 3.5, and 7.8). After the various treatments, the extracts were used as such or filtrated (0.45 µm), and 10% soybean oil-in-water emulsions were prepared using low (0.48%) or high (6.55% wt/wt) extract concentrations. Results showed that whereas at low GWSC concentrations, both heating and acidifying resulted in the formation of bigger oil droplet sizes (i.e., from d32 = 0.36 µm using unmodified extract to d32 = 7-22 µm at pH 2.5 with or without extract filtration), the effects were opposite at the highest GWSC concentration. In the latter, heat treatment clearly reduced the droplet size as observed from the micrographs as well as the degree of creaming, though the occurrence of depletion and/or bridging flocculation was still strong. The acidification of the extract at this high GWSC concentration significantly reduced the droplet size, as observed from the micrographs; however, a strong flocculation was observed. Removal of protein aggregates, and possibly also saponin micelles, from the extract resulted in an obvious increase in emulsion droplet size. This research brings valuable insights on this study and utilisation of novel natural food emulsifiers from plant sources.

Important Role and Properties of Granular Nanocellulose Particles in an In Vitro Simulated Gastrointestinal System and in Lipid Digestibility and Permeability.

This research evaluated the role and feasibility of the granular nanocellulose particles (GNC) from sugarcane bagasse obtained from enzymatic hydrolysis in reducing lipid digestibility and permeability in an in vitro simulated gastrointestinal (GI) system. GNC concentration (0.02%, w/v) had significantly affected the released free fatty acids (FFA), with a reduction of approximately 20%. Pickering emulsion of a GNC and olive oil simulation mixture revealed higher oil droplet size distribution and stability in the initial stage than the vortexed mixture formation. The difference in particle size distribution and zeta potential of the ingested GNC suspension and GNC-olive oil emulsion were displayed during the in vitro gastrointestinal simulation. GNC particles interacted and distributed surrounding the oil droplet, leading to interfacial emulsion. The GNC concentration (0.01-0.10%, w/v) showed low toxicity on HIEC-6 cells, ranging from 80.0 to 99% of cell viability. The release of FFA containing the ingested GNC suspension and GNC-olive oil emulsion had about a 30% reduction compared to that without the GNC digestion solution. The FFA and triglyceride permeability through the HIEC-6 intestinal epithelium monolayer were deceased in the digesta containing the ingested GNC and emulsion. This work indicated that GNC represented a significantly critical role and properties in the GI tract and reduced lipid digestion and absorption. This GNC could be utilized as an alternative food additive or supplement in fatty food for weight control due to their inhibition of lipid digestibility and assimilation.

Rheological, textural properties and storage stability of mayonnaise formulated with protein hydrolysate derived from yellow mealworm (Tenebrio molitor)

Abstract Yellow mealworm (Tenebrio molitor), the larva stage of darkling beetle, confers high nutritional and functional protein and it can serve as a sustainable protein source. The present study therefore evaluated the effect of replacing the egg yolk as emulsifier with yellow mealworm protein hydrolysate powder (YMPH) (0-100%) at 20% increment levels on the rheological and textural properties, colour attributes, emulsion microstructure and storage stability of mayonnaise. The emulsion stability results demonstrated that mayonnaise with up to 60% substitution of YMPH displayed excellent storage stability for 3 weeks (&lt;2% phase separation). In terms of textural properties, all samples showed no significant difference () in firmness whereas consistency decreased steadily with increasing YMPH concentration levels. Microstructure observation of all mayonnaise formulations demonstrated a gradual increase in oil droplet size in parallel with the increase in YMPH concentration. For rheological properties, all mayonnaise exhibited similar gel-like behaviour with greater storage modulus (G’) than loss modulus (G”) and loss tangent (tan δ) less than 1.0. For the colour attributes, increasing YMPH level led to significant decrease () in the L* and b* factors from 73.0 to 27.2 and 23.9 to 8.1, respectively. However, the overall a* factor value increased significantly () from 1.11 to 5.10 as the YMPH concentration increased. This study revealed that insect-based protein hydrolysate has a good potential to serve as an emulsifier.

Surface Functionalization of Sugarcane-Bagasse-Derived Cellulose Nanocrystal for Pickering Emulsion Gel: Microstructural Properties and Stability Efficiency.

An environmentally friendly Pickering stabilizer was developed by upcycling sugarcane bagasse (SCB) into a cellulose nanocrystal (CNC), which was subjected to surface modification by using quaternary ammonium compound to enhance its amphiphilic characteristics. The changes in microstructural properties of modified cellulose nanocrystal (m-CNC), such as surface functional group, thermal stability, surface morphology, elemental composition, and particle size distribution were investigated. Results indicated the success of quaternary ammonium compound grafting with the presence of a trimethyl-alkyl chain on the cellulose structure, while the m-CNC preserves the needle-like nanoparticles in length of ~534 nm and width of ~20 nm. The colloidal profile of m-CNC-stabilized oil-water emulsion gels with different concentrations of m-CNC (1-5 wt%), and oil:water (O:W) ratios (3:7, 5:5, 7:3) were examined. The emulsion gel stability study indicated that the optimal concentration of m-CNC (3 wt%) was able to stabilize all the emulsion gels at different O:W ratios with an emulsion index of >80% for 3 months. It is the minimum concentration of m-CNC to form a robust colloidal network around the small oil droplets, leading to the formation of stable emulsion gels. The emulsion gel with O:W ratio (3:7) with 3 wt% of m-CNC rendered the best m-CNC-oil-droplets dispersion. The m-CNC effectively retained the size of oil droplets (<10 μm for 3 months storage) against coalescence and creaming by creating a steric barrier between the two immiscible phases. Furthermore, the emulsion gel exhibited the highest viscosity and storage modulus which was able to prevent creaming or sedimentation of the emulsion gels.

Simulating dispersion of oils from a subsea release comparing mechanical and chemically enhanced dispersion — An experimental study of the influence of oil properties

The main objective with subsea mechanical dispersion (SSMD) is to influence the fate of an oil spill in the marine environment by significantly reducing oil droplet sizes from subsea release of oil. Earlier studies have indicated that the capability of SSMD to reduce oil droplet sizes is comparable to subsea dispersant injection (SSDI).Earlier testing of SSMD has mainly used a low viscus paraffinic oil. Focus for this study was to study SSMD and SSDI effectiveness using five oil types spanning out a wide variation of relevant oil properties. Effectiveness was quantified as the reduction in oil droplet sizes measured by a Silhouette camera. Testing of the two technologies were completed in the same experiment on a simulated subsea release.The results show a variation in effectiveness for both technologies as a function of oil properties. SSMD and SSDI showed comparable effectiveness for all oils tested.

Numerical and experimental investigation of dispersed oil-in-water flow in porous media

Reservoir heterogeneity continues to be a major challenge in the oil industry's efforts to minimize the water cut, improve the volumetric sweep efficiency, and, ultimately, increase oil recovery. Injection of oil-in-water (O/W) dispersions can regulate the permeability contrast between these layers. Dispersed oil droplets can propagate into the reservoir and partially plug porous spaces in high-mobility zones. This study is devoted to highlighting a number of areas where there is a lack of knowledge concerning O/W dispersion injection in porous media in order to evaluate the entrapment mechanisms, pressure drop, and permeability reduction. A series of O/W dispersion injection experiments were conducted on various cylindrical sandstone core plugs. The effluent shows a significant decline in oil droplet size. A mathematical model based on the experimental setup was developed to describe the dynamics of the dispersion flow. The finite element method (FEM) was employed to numerically solve the governing equations. The numerical model involves the discretization of convection-diffusion, modified Darcy, and pressure equations. Verification of the numerical model was performed by comparing the pressure drop and permeability decline to the results of analytical solutions. The model was validated relatively well against experimental data. Finally, the current study provides a fundamental insight into a number of factors that may influence O/W dispersions flow in porous media. However, further research and improvements to the model complexity are required for field applications.

ИССЛЕДОВАНИЕ ИЗМЕНЕНИЯ ВЯЗКОСТИ СМАЗОЧНО-ОХЛАЖДАЮЩЕЙ ЖИДКОСТИ В ЗАВИСИМОСТИ ОТ РАЗМЕРА МАСЛЯНЫХ КАПЕЛЬ, КОНЦЕНТРАЦИИ ДИСПЕРСНОЙ ФАЗЫ И ВВЕДЕНИЯ ТВЕРДОФАЗНЫХ ВЫСОКОДИСПЕРСНЫХ МОДИФИКАТОРОВ

One of the ways to increase processing productivity and ensure high quality of the treated surface is the correct choice and use of lubricants and coolants. The solution to the problems of increasing efficiency was implemented by choosing the compositions of lubricants and coolants, which were prepared based on fat-and-oil waste products. This will ensure a reduction in the environmental burden on the environmental system. Also, the greatest attention has recently been paid to evaluating the effect of lubricants modified with carbon materials, in particular, carbon nanotubes and graphite. Due to the particular features of their physical and mechanical properties, carbon modifiers have an impact on cutting processes and rules of the impact have not been sufficiently studied so far. This article continues the study of changes in the viscosity of a water-oil emulsion coolant from varying the oil droplets size, the dispersed phase concentration and the introduction of solid-phase highly dispersed modifiers. It was found that reducing the size of oil droplets, increasing the concentration of the dispersed phase and modifying the water-oil emulsion coolant with highly dispersed carbon materials lead to an increase in viscosity.

Effect of Heat Treatment on Yellow Field Pea (Pisum sativum) Protein Concentrate Coupled with Membrane Ultrafiltration on Emulsification Properties of the Isolated >50 kDa Proteins.

The aim of this paper was to determine the emulsification properties of protein aggregates obtained from heat pretreated yellow field pea protein concentrate (PPC). PPC dispersions were prepared in distilled water (adjusted to pH 3.0, 5.0, 7.0, or 9.0), heated in a water bath (100 °C) for 30 min, centrifuged and the supernatant passed first through a 30 kDa membrane and, then, the first retentate (>30 kDa) through a 50 kDa membrane. The 50 kDa membrane separation yielded a second retentate (>50 kDa proteins), which was isolated for emulsification studies. The near UV circular dichroic spectra of the protein samples showed more unfolded structures at pH 3.0 and 5.0 than at pH 7.0 and 9.0. The presence of small and spherical oil droplets of emulsions stabilized by the >50 kDa proteins at pH 3.0, 7.0, and 9.0 was confirmed by confocal laser scanning microscopy images. Emulsions stabilized at pH 7.0 and 9.0 had a narrower size distribution range than at pH 3.0 and 5.0. A narrow oil droplet size distribution range and lower interfacial protein concentrations of the emulsions stabilized by the >50 kDa proteins were observed at the corresponding pH of the heat treatment when compared to other pH values. Emulsions stabilized by the >50 kDa proteins exhibited a relatively low flocculation and coalescence index, which infers relative stability. The results from this work suggest that heat pretreatment of the PPC led to the formation of new protein aggregates, especially FT9 with enhanced emulsification properties, at some of the test conditions when compared to the unheated PPC.