Emulsion Phase Research Articles

Effects of fibre addition and processing on the stability, rheology and in vitro gastric digestion of whey protein-xanthan gum stabilised emulsions with high oil phase

The aim of work was to structure and characterise the high rapeseed oil emulsions stabilised by xanthan gum rich whey protein with an inclusion of commercially available added fibre (Vitacel HF0010 plus) as an additional stabiliser. The manufactured emulsions were also tested whether they can re-build the emulsion property after drying, water addition and re-emulsification. The emulsions with a ratio of 60/40 for rapeseed oil to water phase were obtained with a fibre inclusion at 0.25, 0.50 and 1.00% using a high shear homogenisation. Drying processing, rehydration and re-emulsification only led to re-build emulsion structure with 0.50 and 1.00% fibre. After re-emulsification, some fibre occurred as insoluble particles and were allocated at the oil-water interface or continuous phase of emulsion. Interestingly, processed sample with 1.00% fibre had the greatest instability when subjected to in vitro gastric digestion assay. All primary emulsions and processed emulsions with 0.50 and 1.00% fibre, were stable against coalescence with no oil loss and resulted in almost identical droplet size after a day 30 of storage at 4(±1)°C. All the structured emulsions showed shear-thinning behaviour. The fabricated emulsions showed a feature of regaining emulsion structure, which extend their applications in food formulation as clean label emulsions.

Bubble dynamics and thermochemical characteristics of bubbling fluidized bed methanation

Methanation is a promising technology to transform carbonaceous materials into high-value fuels, yet the relationship between multi-scale structures and reactor performance is still not well understood. Accordingly, the methanation process in a bubbling fluidized bed (BFB) reactor is investigated via the computational fluid dynamics-discrete element method (CFD-DEM) featuring thermochemical sub-models. A novel algorithm is developed for bubble identification and related information statistics. The effects of crucial operating parameters on bubble behaviours are quantified. Moreover, the underlying mechanism of mesoscale bubble behaviours is illuminated by linking with microscale particle dimensionless number and macroscale reactor performance. The results show that the bubble dynamics can be well captured by the novel bubble identification algorithm. Particle Reynolds number (Rep) and Nusselt number (Nup) have the highest values in the bubble phase and the lowest values in the emulsion phase. Decreasing inlet gas velocity, increasing particle size, and lowering operating temperature causes smaller volume ratios of the bubble phase to emulsion phase, thereby enhancing interphase heat and mass transfer and promoting methane concentration in the gas products.

A comprehensive assessment of endogenous bubbles properties in fluidized bed reactors via X-ray imaging

Properties of endogenous bubbles released during the devolatilization of a single biomass particle under inert conditions have been investigated by means of advanced X-ray imaging techniques. Distribution of void fraction showed that endogenous bubbles structure resembles that of classic bubbles observed in fluidized bed reactors, constituted by a cloud, wake and a central void region. A value of about 0.25 for the wake fraction has been obtained from experiments, which is in agreement with literature data for Geldart B particles. Volume of cloud region as a function of relative bubble velocity was generally well-described by the theoretical models of Davidson and Murray, showing effective recirculation of volatile matter around the bubble. Moreover, lack of mixing between bubbles and emulsion phase, as predicted by the Davidson's theory for classic bubbles, confirmed the bypass phenomenon observed for endogenous bubbles in previous studies. Owing to the non-invasive nature of the X-ray technique employed, it was possible to estimate the main features of endogenous bubbles with high accuracy. Knowledge provided in this work can be easily implemented to improve modelling of fluidized bed reactors applied to advanced thermochemical conversions, such as gasification and pyrolysis, of biomass and waste materials. • Devolatilization of biomass in fluidized beds generates endogenous bubbles • Advanced X-ray imaging provided comprehensive assessment of endogenous bubbles • Bubbles void fraction distribution is obtained by means of the Beer-Lambert law • Endogenous bubbles consist of a wake, cloud, and central gas-rich region • Endogenous bubbles strongly resemble traditional bubbles in bubbling regime

Changes in interfacial composition and structure of milk fat globules are crucial regulating lipid digestion in simulated in-vitro infant gastrointestinal digestion

The interfacial phospholipid and protein compositions of fat globule in human milk and three different infant formulas (F1: supplied with MFGM and OPO; F2: supplied with OPO and without MFGM; F3: supplied with MFGM and without OPO) were analyzed and compared, and the changes of interfacial composition and structure on their in-vitro infant gastrointestinal digestion were evaluated. The study from the interfacial properties of fat globule to illustrating the effect of interfacial composition and structure on lipolysis and proteolysis. The results showed that, both F1 and human milk had a similar interfacial phospholipid composition and higher sphingomyelin (SM) content. The interfacial protein composition of F1 was closer to human milk. F1 had the average particle size of 3.67 ± 0.12 μm and a phospholipid layer on the surface of triglyceride. Meanwhile, the relatively complete phospholipid ring structure in F1 could always be observed during gastric digestion, while was gradually destroyed during intestinal digestion. Moreover, F2 and F3 are significantly different from HM and F1 in composition and structure of fat globule. Although MFGM is added to commercial infant formula (F3), most MFGM still existed in the aqueous phase of emulsion in free form. Notable, F1 had similar in-vitro lipolysis and proteolysis properties to human milk. These results indicated that the simulation of human milk fat globule at the molecular level and structure feature was the key contributing to digestion behavior. • The abundant phospholipid ring structure were observed in F1. • F1 had sn-2 SFAs and OPO, which reduced the formation of calcium soap. • HM had the highest lipolysis rate of 86.3%, followed by F1 (82.9%) after digestion. • F1 had similar digestive properties to human milk and is superior to F2 and F3. • The simulation of HM fat at the molecular and structure is key to effect digestion.

Dual-responsive colloidosome-like microgels as the building blocks for phase inversion of Pickering emulsions.

The intelligent regulation of microgel-stabilized Pickering emulsions with multi-responsiveness is presently constrained to the processes of emulsification and destabilization. However, the expansion of multi-control over Pickering emulsions to involve phase inversion and the investigation of the accompanying processes and mechanisms present a great challenge. In this study, a microgel with dual responsiveness to both pH and temperature was synthesized using an emulsion template. The resulting microgel exhibited a robust colloidosome-like structure, distinguished by the presence of monolayer-adsorbed silica nanoparticles. The regulation of the packing of surface-covered silica nanoparticles was easily achieved through the swelling of the microgel matrix. Furthermore, the wettability of the microgel can be adjusted between hydrophilic and hydrophobic intervals, allowing for the effective and dual-responsive phase inversion of Pickering emulsions. Moreover, it has been observed that colloidosome-like microgels can lead to unique interfacial structures during the emulsification process, thereby elucidating the fundamental mechanism governing emulsion phase inversion.

Silk fibroin microgels as a platform for cell microencapsulation

Cell microencapsulation has been utilized for years as a means of cell shielding from the external environment while facilitating the transport of gases, general metabolites, and secretory bioactive molecules at once. In this light, hydrogels may support the structural integrity and functionality of encapsulated biologics whereas ensuring cell viability and function and releasing potential therapeutic factors once in situ. In this work, we describe a straightforward strategy to fabricate silk fibroin (SF) microgels (µgels) and encapsulate cells into them. SF µgels (size ≈ 200 µm) were obtained through ultrasonication-induced gelation of SF in a water-oil emulsion phase. A thorough physicochemical (SEM analysis, and FT-IR) and mechanical (microindentation tests) characterization of SF µgels were carried out to assess their nanostructure, porosity, and stiffness. SF µgels were used to encapsulate and culture L929 and primary myoblasts. Interestingly, SF µgels showed a selective release of relatively small proteins (e.g., VEGF, molecular weight, MW = 40 kDa) by the encapsulated primary myoblasts, while bigger (macro)molecules (MW = 160 kDa) were hampered to diffusing through the µgels. This article provided the groundwork to expand the use of SF hydrogels into a versatile platform for encapsulating relevant cells able to release paracrine factors potentially regulating tissue and/or organ functions, thus promoting their regeneration.Graphical

In Vitro-In Vivo Study of the Impact of Excipient Emulsions on the Bioavailability and Antioxidant Activity of Flavonoids: Influence of the Carrier Oil Type.

The influence of the carrier oil type on the bioavailability and bioactivity of flavonoids (quercetin, kaempferol, and apigenin) was examined using in vitro digestion, in situ intestinal perfusion, and pharmacokinetic studies. Here, medium-chain triglycerides (MCTs), long-chain triglycerides (LCTs), or MCT/LCT mixtures (1:1, w/w) served as the oil phase of excipient emulsions. Overall, the bioavailability and antioxidant activity of flavonoids increased when they were coingested with excipient emulsions. The in vitro bioaccessibility of flavonoids was affected by the carrier oil: LCT (17.9-22.8%) > MCT/LCT (12.1-13.7%) > MCT (9.2-12.6%). These differences were mainly attributed to the fact that the mixed micelles formed after the digestion of LCTs had larger hydrophobic domains to solubilize more flavonoids. However, in vivo pharmacokinetic experiments showed that the flavonoid concentrations in rat serum were comparable for all carrier oils (p > 0.05). Our results assist in formulating excipient emulsions to enhance the efficacy of flavonoids.

Predicting the emulsion phase inversion point during self-emulsification using an improved free energy model and determining the model applicability

In-situ emulsification has recently shown promise for increasing oil production in water flooding reservoirs owing to its easy procedure and polymer and surfactant properties. The phase inversion point (PIP) plays a vital role in emulsification technology. However, the existing free energy models have limited accuracy in the calculation of the PIP, and the models’ areas of applicability are not specified. The free energy model was improved in this study by classifying crude oil to enhance the prediction accuracy and expand the free energy model’s range of calculation. The applicable range of the model was defined by analyzing and comparing the distribution characteristics of interfacial tension (IFT) and PIP. Firstly, the effects of temperature, shear rate, shear time, salinity, and pH on the PIP were discussed. The experimental results showed that, among these external factors, only the temperature could change the PIP. Generally, the PIP decreased with increasing temperature. Second, different parameters a and b were obtained using the differential aggregation characteristics of oil and water.Then, to further analyze and demonstrate the new model’s accuracy, the experimental data of three new oil samples (crude oil D, G, and J) were collected and compared with the results of other models. The results showed that the new model could successfully fit the data; its average absolute error was 4.47%, while that of the previous models was about 40%. The other models were particularly unsuitable for calculating the PIP of heavy oil, but the new model’s inaccuracy was only 1.48%. Finally, the IFT and PIP data were analyzed and compared. The results showed that, for conventional crude oil, the IFT and PIP decreased with the temperature increase. The applicable conditions of the model were also clarified. The model is suitable for crude oil whose IFT decreases with temperature increase. The results of this study can be used in the petroleum industry and other industries dealing with mixed immiscible fluid transport.

Water-in-water emulsion stabilized by cellulose nanocrystals and their high enrichment effect on probiotic bacteria

HypothesisThe effect of the molecular weight and polymer concentration on the partition behavior of aqueous two-phase systems (ATPs) is significant for constructing water-in-water (W/W) emulsions. Hence, a long-term stable W/W emulsion system might be obtained through selecting the appropriate stabilizer and component phases, which could be a possible carrier for probiotics. ExperimentsCompared with the reported molecular weight difference between polyethylene oxide (PEO) and dextran (DEX) systems, PEO and dextran with lower molecular weight had been used for constructing the water in water (W/W) emulsion system. The W/W emulsions were stabilized using cellulose nanocrystals (CNCs), and the potential application of the W/W emulsion for the encapsulation of Lactobacillus was explored. FindingsEmulsion stability exhibited a “dose-effect” relationship with the CNCs concentration and was decreased with the increase of the DEX concentration. The emulsion phase separation rate was increased with increasing ionic strength and temperature. Both Lactobacillus Plantarum and Lactobacillus helveticus were highly inclined to the DEX phase, and the emulsion droplets were deformed and aggregated when the encapsulation amount was increased. This long-term stability would provide a promising approach for designing high-density culture and fermentation of probiotics.

Multiple Pickering emulsions fabricated by a single block copolymer amphiphile in one-step

The mixture of emulsifiers with opposite amphiphilicity was often necessary in generating multiple emulsions, whereas multiple emulsions might be generated by a single-component copolymer amphiphile. In this work, the emulsification of amphiphilic block copolymers poly (lauryl methacrylate)-b-poly (N-(2-methacryloylxyethyl) pyrrolidone) (PLMAm-b-PNMPn) in the water/dodecane systems was systematically studied by the confocal laser scanning microscopy and dynamic light scattering techniques. Interestingly, multiple emulsions instead of single emulsions were generated by employing single-component block copolymer amphiphiles PLMAm-b-PNMPn as emulsifiers under certain conditions. In specifically, the formation of multiple emulsions was highly depended on the molar ratio (rPNMP/PLMA = n/m) between the PNMP and PLMA segments regardless of the molecular weight of block copolymers. Through introducing an aggregation-induced emission amphiphile poly (N-(2-methacryloyloxyethyl) pyrrolidone)-b-poly (lauryl methacrylate-co-1-ethenyl-4-(1,2,2-triphenylethenyl) benzene) (PNMP35-b-P(LMA42-co-TPE16) into emulsifiers, the interfacial characters of multiple emulsions were also clarified. The complex emulsification of PLMAm-b-PNMPn was explained by a concordant manner based on the in-situ formed emulsifier mixture composed of PLMAm-b-PNMPn molecules and micelles, which were confirmed by the quantitative fluorescent analysis. It was found out that the preferred continuous phase of emulsions was mainly determined by the hydrophilicity of PLMAm-b-PNMPn molecules. However, the agglomeration of hydrophobic aggregates on the interfacial layer might inverse the amphiphilicity of mixed emulsifiers, and thereby resulting in the formation of multiple emulsions.

Bubble behaviors of geldart B particle in a pseudo two-dimensional pressurized fluidized bed

Pressurized fluidized beds have been developed in quite a few industrial applications because of intensified heat and mass transfer and chemical reaction. The bubble behaviors under elevated pressure, strongly influencing the fluidization and reaction conversion of the whole system, are of great research significance. In this work, the bubble behaviors of Geldart B particle in a pseudo two-dimensional (2D) pressurized fluidized bed were experimentally studied based on digital image analysis technique. The effects of pressure and fluidization gas velocity on the general bubble behaviors (i.e., size, shape and spatial distribution) and the dynamic characteristics, such as the time-evolution of voidage distribution and local flow regimes, were comprehensively investigated. Results show that increasing pressure reduces the stability of bubbles and facilitates gas passing through the emulsion phase, resulting in the “smoother” fluidization state with smaller bubbles and declined bubble fraction and standard deviation. The equivalent bubble diameter and bubble aspect ratio increase with the increasing gas velocity while decrease as pressure rises. The elevated pressure reduces bubbles extension in the vertical direction, prohibits the “short pass” of fluidization gas in large oblong bubbles/slugs and benefits the gas–solid interaction. The flow regimes variation with gas velocity is affected by the elevated pressure, and demonstrates different features in different local positions of the bed.

Pickering Emulsions Synergistically Stabilized by Aliphatic Primary Amines and Silica Nanoparticles.

Innovation in emulsion compositions is necessary to enrich emulsion formulations and applications. Herein, Pickering emulsions were prepared using silica nanoparticles and aliphatic primary amines with an oil-water ratio of 1:1 (v/v). Contact angle experiments revealed that the in situ hydrophobization of nanoparticles was caused by the surface adsorption of amine molecules. Notably, the interactions between amine compounds and the surface of silica nanoparticles were electrostatic attractions and mutual hydrogen bonding. The existence of hydrogen bonds was further confirmed by demulsification experiments using a chaotropic agent DMF and increasing temperatures. The hydrophobicity of silica nanoparticles can be effectively improved using most commercially available aliphatic primary amines such as n-hexylamine, n-octylamine, n-decylamine, dodecylamine, and tetradecylamine. The minimum concentrations of the aforementioned amines necessary for stabilizing the emulsions with 0.3 wt % silica nanoparticles are 3, 0.6, 0.3, 0.06, and 0.03 mM, respectively, decreasing significantly with increasing alkyl chain length. With the increase of the amine concentrations, the hydrophobicity of silica particles monotonically increased and finally resulted in the inversion of emulsions. The amine concentrations for emulsion phase inversion were 150, 40, 30, 20, and 20 mM, respectively, in the presence of 0.3 wt % silica nanoparticles. In this work, silica nanoparticles were hydrophobized using aliphatic primary amines. The composite stabilizers developed are useful for developing novel stimuli-responsive Pickering emulsions, while the synergistic effects introduced herein are also helpful in expanding the hydrophobization methods available for nanoparticles.

Encapsulation of Luminescent Gold Nanoclusters into Synthetic Vesicles.

Gold nanoclusters (Au NCs) are attractive luminescent nanoprobes for biomedical applications. In vivo biosensing and bioimaging requires the delivery of the Au NCs into subcellular compartments. In this view, we explore here the possible encapsulation of ultra-small-sized red and blue emitting Au NCs into liposomes of various sizes and chemical compositions. Different methods were investigated to prepare vesicles containing Au NCs in their lumen. The efficiency of the process was correlated to the structural and morphological aspect of the Au NCs' encapsulating vesicles thanks to complementary analyses by SAXS, cryo-TEM, and confocal microscopy techniques. Cell-like-sized vesicles (GUVs) encapsulating red or blue Au NCs were successfully obtained by an innovative method using emulsion phase transfer. Furthermore, exosome-like-sized vesicles (LUVs) containing Au NCs were obtained with an encapsulation yield of 40%, as estimated from ICP-MS.

Toward an improved understanding of emulsion stabilization at elevated temperatures by direct visualization and reversibility analysis

Harsh conditions of high temperature are often encountered during production and application of emulsions. For example, in crude oil recovery, the emulsification performance of natural emulsifiers in oil at elevated temperatures is crucial but rarely studied, largely due to the lack of appropriate apparatus. In the present work, the emulsion stabilization by asphaltenes and fines at elevated temperatures up to 200 °C was investigated by using a custom-made windowed cell, which permits real-time direct visualization of the emulsion phase. The temperature-reversibility of the prepared emulsions was analyzed under our controlled heating and cooling temperature cycle program. The resultant emulsions at room temperature from the proposed apparatus are consistent with the results obtained from the most widely used bottle test approach, confirming its validity. The emulsion volumes significantly reduced with the increasing temperature in both cases of asphaltenes and fines by 100% and 62% at maximum, respectively. The asphaltenes were unable to stabilize emulsions at the temperature of 150 °C and higher, while the fines can stabilize a 12 vol% emulsion layer even at 200 °C. Under our temperature cycle program, the asphaltenes-stabilized emulsions were reversible, indicating that the adsorption and desorption processes of asphaltenes from the interfaces did not irreversibly alter their interfacial activity. In contrast, the volumes of emulsions stabilized by the fines generally remained unchanged during the cooling operations, suggesting that the temperature-induced desorption of the Pickering particles from the interfaces irreversibly affects their re-adsorption. The high thermal stability of fines-stabilized emulsions is beneficial for their application in enhanced oil recovery at harsh reservoirs. The novel method of temperature-reversibility analysis is an effective tool to explore the stabilization mechanism of emulsion systems.

Long-term stable bioprocess-derived Pickering-type emulsions: Identification of key parameters for emulsion stability based on cell interaction at interface

Industrial implementation of highly potent biphasic whole-cell biocatalytic processes is often limited due to the formation of long-term stable Pickering-type emulsions, caused by the presence of cells. State-of-the-art-concepts for phase separation fail or include inefficient and costly strategies (centrifugation/de-emulsifiers). Using the phenomenon of catastrophic phase inversion (CPI), efficient phase separation can be achieved by addition of dispersed phase. To show the industrial applicability of CPI for phase separations of bioprocess-derived Pickering-type emulsions, the mutual influence of the emulsion components and thus emulsion phase behavior and stability has to be known. Characterizing several Pickering-type emulsions (stabilized by E. coliJM101 and P. putidaKT2440 cells), the cell radius, the wettability of cells, and the interfacial tension, were identified to be the most crucial parameters. On this basis, we suggest guidelines and estimation strategies for suitable process (window) selection, assisting in the introduction of these highly potent processes into industrial applications.

Ferrofluid high internal phase emulsion polymer foams for soft, magnetic materials

Magnetic components are an essential part of current electronics, although the materials used to make magnetic components are almost exclusively rigid and non-deformable. The high modulus and inflexible behavior of typical magnetic materials makes their integration into soft, deformable electronics challenging. Soft electronics, however, is a dynamic field pushing forward the state-of-the-art in wearable sensors, human-machine interaction, and biomimetic robots. In order to access the wide range of functionality of rigid electronics, magnetic materials must be made that are high performing and deformable. One previously unexplored route to creating such materials is the encapsulation of a high concentration of magnetic fluids, such as ferrofluids (FF), into an elastomer using high internal phase emulsification. In this work, the formulation factors required to make an effective ferrofluid high internal phase emulsion polymer foam (polyHIPE) utilizing polydimethylsiloxane (PDMS) were investigated such as the emulsifiers, polyHIPE curing kinetics, and the interaction of emulsified nanoparticles. The porous structure, magnetic properties, and mechanical properties of the final, successful FF/PDMS polyHIPE were subsequently characterized. Pores ranged between 10 and 50 μm with visible nanoparticle aggregation. FF/PDMS polyHIPE had an Ms of 18 A∙m2/kg and susceptibility of 0.69, which is reduced as compared to neat ferrofluid, as expected, but an improvement on ferrofluid polymer dispersions found in the literature. Coercivity and magnetic remanence also decreased with respect to the neat ferrofluid. Rheology demonstrated that the polyHIPE had a significantly lower modulus than the neat PDMS as well as a lower modulus than any magnetic composite material currently published. The FF/PDMS polyHIPE created in this work not only demonstrates the potential for deformable magnetic materials based on the emulsification of high concentrations of magnetic fluid into elastomers, but also the potential to create even higher performing materials using a higher concentration of magnetic fluid or ferrofluids with superior magnetic properties.

Influence of Refractive Index Differences on the Signal Strength for Raman-Spectroscopic Measurements of Double Emulsion Droplets

Double emulsions show great potential for encapsulating active substances and protecting them against external influences. However, they tend to become unstable during storage. Research on double emulsions, therefore, focuses on maintaining their microstructure during their shelf life. Optical measurement methods, such as Raman spectroscopy, have hardly been used to date to analyze the microstructure of double emulsions, mainly due to multiple scattering effects. This study investigates the influence of refractive index matching of double emulsion phases by measuring the Raman signal strength of the inner water phase for different refractive index combinations. Ammonium nitrate and glycerol are added to the inner and outer water phase, respectively, to change the refractive indices of both phases. Additionally, polyvinyl alcohol serves as an emulsifier in the outer water phase. The oil phase consists of silicone oil and Dowsil Resin XR 0497 as the emulsifier. The refractive index of the oil phase is kept constant. For individual phase boundaries of single droplets, the refractive index matching plays a minor role. However, if there are many droplets with correspondingly numerous phase boundaries, which leads to multiple scattering during the measurement, the matching has a significant influence on the signal strength of the inner phase. When measuring double emulsions, the phases should always be matched, as this results in higher signals and improves the sensitivity of the measurement.

Features of the coagulating and peptizing action of weakly basic and strongly basic cationic polyelectrolytes on rosin emulsions

It has been shown for the first time that cationic polyelectrolytes (weakly basic (polyamide-polyamine-epichlorohydrin resin (PPER)) and strongly basic (polydimethyldiallylammonium chloride (PDMDAAC) and copolymer of acrylamide with methylene chloride dimethylamminopropylacrylamide (CA MC DMAPA)), widely used in paper and cardboard technology as flocculants (existing technology), additionally participate in the processes of coagulation and peptization (proposed technology). It has been established that the coagulating ability of polyelectrolytes decreases in the series CA MC DMAPA > PDMDAAC > PPER, while the peptizing ability, on the contrary, increases. Peptizable coagulants with the size and ξ-potential that do not exceed 5200 nm and +15 mV, respectively, are formed in the presence of PPER, when its content in the dispersed system does not exceed 0.15 parts by weight / parts by weight of the dispersed phase of the rosin emulsion (RE). The first region of electrolytic coagulation RE (proposed technology) corresponds to the ratio of RE : electrolyte in the range from 1: 0.3 to 1: 0.6, while with an increased content of electrolyte in the dispersed system (existing technology), which is in the range of 1: 2.4 to 1: 3.0 , the coagulation process proceeds in the second region (the resulting coagulates are electrically neutral and coarse (size exceeds 5200 nm) and are not able to peptize). The peptization process proceeds in the dispersed system “RE (1.0 wt. parts) – PPER (0.04 wt. parts) – electrolyte (0.6 wt. parts)”. The presence of PPER promotes an increase in the ξ-potential of peptized particles from +35 to +50 mV. Unlike coagulates, such particles provide a shift in the sizing process from the traditional mode of homocoagulation to a more efficient mode of heteroadagulation. This results in an increase in the hydrophobicity and strength of paper (cardboard) by 29–36 and 28–38 %, respectively, as well as in an improvement in the printing properties of coated products by 12–15 %.

A fast and effective method for ammonium removal: Emulsion Liquid Membrane

In this study, ammonium was removed from an aqueous solution by using the Emulsion Liquid Membrane technique. The optimum values of the parameters that had effects on the removal process were determined and results were analyzed using statistical methods. As a result of the conducted experiments, it was determined that the volumetric ratio of the emulsion phase was 0.12, the effective internal phase source was H2SO4, the internal phase volumetric ratio was 0.42, the internal phase concentration was 0.36 N, the surfactant ratio was 2 %, the diluent ratio was 34/64 (mineral oil/toluene, %, v/v), homogenizer speed and time were 10,000 rpm and 1 min, agitation speed was 250 rpm, and external phase pH was 10.80. The fact that 98 % yield was achieved in a very short extraction time (15 s) under optimal conditions and the fact that the studies conducted on this subject in the literature are limited and different reveals the importance of this study obviously.

Lutein bioaccessibility in casein-stabilized emulsions is influenced by the free to acylated carotenoid ratio, but not by the casein aggregation state

Considering that carotenoids are found acylated to fatty acids in most edible fruits, the influence of the ratio of free to acylated lutein on the hydrolysis extent and bioaccessibility was evaluated by in vitro digestion. For this purpose, for the first time, esterified, free, or a mixture of both carotenoid forms was used in the lipid phase of emulsions stabilized by sodium caseinate (NaCas) and native phosphocaseinate (PPCN). Marigold petals was used as a source of lutein-rich extracts. The emulsions were characterized and the extent of ester hydrolysis, carotenoid recovery, and bioaccessibility were evaluated by LC-DAD-MS/MS. Besides low polydispersity, NaCas and PPCN stabilized emulsions exhibited a constant mean droplet diameter of about 260 and 330 nm, respectively, after 7 days. Caseins were completely digested after the gastric digestion step. Moreover, casein supramolecular structure did not significantly affect carotenoid bioaccessibility. Lutein was majorly found in its free form in all bioaccessible fractions. The carotenoid bioaccessibility increased from 3% to 40% by increasing the percentage of free carotenoids from 0.5 to 100% in the emulsions; but the carotenoid recovery and hydrolysis extent of lutein esters were not affected. In conclusion, emulsion-based systems for carotenoid delivery stabilized either by NaCas or PPCN provided similar carotenoid bioaccessibility. Furthermore, bioaccessibility was inversely dependent on the overall hydrophobicity of the carotenoid extract. Our results suggest that the low bioaccessibility of esterified carotenoids was a consequence of their limited hydrolysis extent. This study provides information that may help design emulsion-based systems stabilized by food protein as a vehicle for carotenoids.