Influence Of Emulsifier Type Research Articles

Characterization of Nanoemulsions Stabilized with Different Emulsifiers and Their Encapsulation Efficiency for Oregano Essential Oil: Tween 80, Soybean Protein Isolate, Tea Saponin, and Soy Lecithin.

The use of the appropriate emulsifier is essential for forming a stable nanoemulsion delivery system that can maintain the sustained release of its contents. Health concerns have prompted the search for natural biopolymers to replace traditional synthetic substances as emulsifiers. In this study, an oregano essential oil (OEO) nanoemulsion-embedding system was created using soybean protein isolate (SPI), tea saponin (TS), and soy lecithin (SL) as natural emulsifiers and then compared to a system created using a synthetic emulsifier (Tween 80). The results showed that 4% Tween 80, 1% SPI, 2% TS, and 4% SL were the optimal conditions. Subsequently, the influence of emulsifier type on nanoemulsion stability was evaluated. The results revealed that among all the nanoemulsions, the TS nanoemulsion exhibited excellent centrifugal stability, storage stability, and oxidative stability and maintained high stability and encapsulation efficiency, even under relatively extreme environmental conditions. The good stability of the TS nanoemulsion may be due to the strong electrostatic repulsion generated by TS molecules, which contain hydroxyl groups, sapogenins, and saccharides in their structures. Overall, the natural emulsifiers used in our study can form homogeneous nanoemulsions, but their effectiveness and stability differ considerably.

Influence of emulsifier type and encapsulating agent on the in vitro digestion of fish oil-loaded microcapsules produced by spray-drying

The influence of the emulsifier type and the encapsulating agent on the bioaccessibility of microencapsulated fish oil was investigated. Fish oil-loaded microcapsules were produced by spray-drying using carbohydrate-based encapsulating agents (glucose syrup or maltodextrin). Whey protein concentrate hydrolysate (WPCH) or Tween 20 (TW20) were used as the emulsifiers. The microcapsules were subjected to a three-phase in vitro digestion (oral, gastric, and intestinal phase) and the changes in the physicochemical properties of the samples were monitored throughout the simulated gastrointestinal tract (oil droplet size, ζ-potential, and microstructure). The lipolysis rate and extent were evaluated at the intestinal digestion phase. Contrary to the encapsulating agent, the emulsifier used in the infeed emulsion formulation significantly influenced lipid digestion. WPCH-based interfacial layer prevented oil droplets coalescence during and after processing more efficiently than TW20, which resulted in an increased specific surface area for lipases to adsorb and thus a higher bioaccessibility of the microencapsulated oil.

Quality by design enabled the development of stable and effective oil-in-water emulsions at compounding pharmacy: the case of a sunscreen formulation

It is widely accepted that the use of topical sunscreens has medical importance with potential to prevent skin damage by protecting from solar ultraviolet radiation (UVR) effects. Pharmaceutical emulsions require an optimal qualitative and quantitative combination of emollients, emulsifiers and others compounds such as softening agents and, for sunscreens, a combination of chemical and physical UV filters. Herein, we applied the quality by design (QbD) concept to achieve stable and effective compounded sunscreen emulsions. By using the statistical tool of design of experiments, it was possible to identify the influence of emulsifier type (with low and high Hydrophile-Lipophile Balance) and concentrations of emollient and softening agent on the achievement of formulations with suitable organoleptic and physicochemical features. Compounded emulsions with pleasant macroscopic aspects were obtained. Three formulations with physicochemical properties in targeted ranges were selected, namely pH ∼6.0, conductivity > 0.0 µS/cm2, spreadability factor ∼1–1.5 g/mm2, viscosity ∼12000 mPa.s and sunscreen protection factor ∼30. Freeze-thaw cycle and accelerated stability study under different storage conditions allowed selecting a stable emulsion that ensured photoprotection in biological assays. The QbD approach was essential to select the best, low-cost compounded sunscreen emulsion, with targeted physicochemical parameters.

The effects of feeding ratio on final properties of vinyl acetate-based latexes via semi-continuous emulsion copolymerization

Semi-continuous emulsion polymerization of vinyl acetate and dioctyl maleate (VAc/DOM) (60/40, w/w) was carried out with pre-emulsion feeding using potassium persulfate as an initiator. The influence of emulsifier type and its initial ratio were studied and the mixture of non-ionic emulsifiers; 30 and 10 mol ethoxylated nonylphenol (NP30 and NP10) at a ratio of 50/50 (w/w) provided better pre-emulsion and polymerization stability, and also final latex stability. In addition, two series of experiments were conducted to determine the effect of initiator and reactive surfactant, oligomeric N-methylol acrylamide (o-NMA) amount in the initial reactor charge on the latex properties. By increasing the initial initiator amount from 10 to 50 wt%, the average particle size of the latexes decreased from 203 to 143 nm. As expected, the amount of initiator strongly affected the particle charge and the highest zeta potential value was obtained when 50 wt% of the initiator was initially present in the reactor, showing the increased latex stability. On the other hand, it was detected that the colloidal properties of the copolymer latexes were significantly affected by the change of initial charge of o-NMA. The o-NMA amount exceeding 50 wt% caused coagulation. When all o-NMA was initially fed, the highest viscosity value, 9878 cP; lowest zeta potential value, − 5 mV; and the highest surface tension value, 37.5 mN m−1, were obtained. Consequently, the change in the initial charge of emulsifier, initiator, and reactive surfactant has played an important role on the colloidal stability of VAc/DOM latexes.

Influence of emulsifier type on the spray-drying properties of model infant formula emulsions

The objective of this study was to compare the drying performance and physicochemical properties of model infant formula (IF) emulsions containing 43, 96 and 192 g L−1 protein, oil and maltodextrin (MD), respectively, prepared using different emulsifier systems. Emulsions were stabilised using either whey protein isolate (WPI), whey protein hydrolysate (WPH; DH 8%), WPH + CITREM (9 g L−1), WPH + lecithin (5 g L−1) or WPH conjugated with maltodextrin (DE 12) (WPH-MD). Homogenised emulsions had 32% solids content and oil globules with mean volume diameter <1 μm. Powders were produced by spray-drying with inlet and outlet temperatures of 170 and 90 °C, respectively, to an average final moisture content of 1.3%. The extent of powder build-up on the dryer wall increased in the order; WPH- MD << WPH ≤ WPI < WPH + LEC ≤ WPH + CIT. The same trend was observed for the extent of spontaneous primary powder agglomeration, as confirmed by particle size distribution profiles and scanning electron micrographs, where the WPH-MD and WPH + CIT powders displayed the least and greatest extent of agglomeration, respectively. Analysis of elemental surface composition of the powders showed that surface fat, protein and carbohydrate decreased in the order; WPH + CIT > WPH + LEC > WPH > WPH- MD > WPI, WPI > WPH > WPH- MD > WPH + LEC > WPH + CIT and WPH- MD > WPI > WPH > WPH + LEC > WPH + CIT, respectively. Additionally, differences in wettability, surface topography and oil globule distribution within the powder matrix and in reconstituted powders were linked to the emulsifier system used. Inclusion of the WPH-MD conjugate in the formulation of IF powder significantly improved drying behaviour and physicochemical properties of the resultant powder, as evidenced by lowest powder build-up during drying and greatest emulsion quality on reconstitution, compared to the other model formula systems.

Comparison of emulsifying properties of food-grade polysaccharides in oil-in-water emulsions: Gum arabic, beet pectin, and corn fiber gum

Emulsions are utilized in the food, pharmaceutical, and personal care industries to provide specific physicochemical properties and functional attributes. In many applications, it is desirable to use natural ingredients to formulate emulsions to create “label-friendly” products. In this study, the impact of three polysaccharide-based emulsifiers on the formation and stability of oil-in-water emulsions prepared using high-pressure microfluidization were compared: gum arabic, corn fiber gum, and beet pectin. The surface activities of these emulsifiers were characterized using interfacial tension measurements. The influence of emulsifier type, concentration, and homogenization pressure on the efficiency of emulsion formation was examined. The impact of oil type (medium chain triglycerides, corn oil, fish oil, and lemon oil) on the ability of the different emulsifiers to form emulsions was also investigated. The stability of the emulsions was monitored during storage at ambient temperature. Emulsions could be produced using all three polysaccharide-based emulsifiers, with the mean particle diameter decreasing with increasing emulsifier concentration and homogenization pressure. Gum arabic and beet pectin were more effective emulsifiers than corn fiber gum, with a lower amount of emulsifier required and smaller droplets being produced. This effect was attributed to a greater reduction in interfacial tension and stronger adsorption leading to more efficient droplet disruption and less re-coalescence within the homogenizer for gum arabic and beet pectin. Emulsions prepared using corn fiber gum were susceptible to flocculation and coalescence. This study provides valuable information for choosing polysaccharide-based emulsifiers for utilization in food and beverage industries.

Influence of emulsifier type on the antifungal activity of cinnamon leaf, lemon and bergamot oil nanoemulsions against Aspergillus niger

Only exiguous data are currently available on the antifungal properties of essential oil (EO) nanoemulsions against spore-forming microorganisms. The aim of this work is to develop physically stable nanoemulsion-based delivery systems for different EOs (cinnamon leaf, lemon, and bergamot), to exploit their antifungal properties against Aspergillus niger. The inhibition of mycelial radial growth and spore germination were used as indicators of antifungal activity of the nanoemulsions, which were prepared at 3 wt% EO, using non-ionic Tween 80 (T80) or anionic whey protein isolate (WPI) (1 wt%) as emulsifiers, and sunflower oil (1 wt%) as ripening inhibitor. The nanoemulsions were physically stable over seven days of accelerated aging at 35 °C.The minimal inhibitory concentration of free cinnamon leaf and of both citrus EOs were 0.35 and 5.50 μg/g, respectively. The encapsulation of cinnamon leaf EO in nanoemulsions significantly enhanced the inhibiting effect against A. niger mycelial growth and spore germination, with respect to the free EO. In contrast, for citrus EOs, the encapsulation in nanoemulsions generally decreased the antifungal activity, likely because of the nanoemulsion acting as a hydrophobic sink for the main constituents of citrus EOs. The emulsifier played a fundamental role in the resulting antifungal activity, with WPI-based nanoemulsions being more effective in inhibiting the mycelial growth and the spore germination of A. niger than T80-based ones. The antifungal action was correlated to the morphological alterations observed in A. niger, such as the loss of cytoplasm in fungal hyphae and hyphal tip. The results of this study show the importance of nanoemulsions design in the development of efficient and stable natural antifungal agents for food applications.

Fabrication of oil-in-water nanoemulsions by dual-channel microfluidization using natural emulsifiers: Saponins, phospholipids, proteins, and polysaccharides

Nanoemulsions are utilized within the food, pharmaceutical, and personal care industries because of their unique physicochemical properties and functional attributes: high optical clarity; prolonged stability; and, enhanced bioavailability. For many applications, it is desirable to utilize natural ingredients to formulate nanoemulsions so as to create “label-friendly” products. In this study, we compared the effectiveness of a number of natural emulsifiers at fabricating corn oil-in-water nanoemulsions using dual-channel microfluidization. These emulsifiers were either amphiphilic biopolymers (whey protein and gum arabic) or biosurfactants (quillaja saponin and soy lecithin). Differences in the surface activities of these emulsifiers were characterized using interfacial tension measurements. The influence of emulsifier type, concentration, and homogenization pressure on the efficiency of nanoemulsion formation was examined. The long-term stability of the fabricated nanoemulsions was also monitored during storage at ambient temperature. For all of the natural emulsifiers, nanoemulsions could be produced by dual-channel microfluidization, with the mean particle diameter decreasing with increasing emulsifier concentration and homogenization pressure. Whey protein isolate and quillaja saponin were more effective at forming nanoemulsions containing fine droplets than gum arabic and soy lecithin, with a lower amount of emulsifier required and smaller droplets being produced. This effect was attributed to faster emulsifier adsorption and a greater reduction in interfacial tension leading to more efficient droplet disruption within the homogenizer for saponins and whey proteins. This study highlights the potential of dual-channel microfluidization for efficiently producing label-friendly nanoemulsions from natural emulsifiers.

Influence of emulsifier type on the in vitro digestion of fish oil-in-water emulsions in the presence of an anionic marine polysaccharide (fucoidan): Caseinate, whey protein, lecithin, or Tween 80

The influence of an anionic marine polysaccharide (fucoidan) on the gastrointestinal fate of emulsified fish oils stabilized by different types of natural and synthetic emulsifier was examined: whey protein isolate (WPI); caseinate; lecithin; Tween 80. Oil-in-water emulsions in the absence and presence of fucoidan were passed through a simulated gastrointestinal tract (GIT) that included mouth, stomach, and small intestine phases. The change in droplet properties (particle size, charge, and organization) was measured throughout the GIT and the rate and extent of lipid digestion was measured in the small intestine phase. The presence of fucoidan increased the initial digestion rate of caseinate- and WPI-stabilized emulsions due to its ability to modulate lipid droplet aggregation. The fucoidan appeared to suppress isoelectric aggregation of the droplets, which increased the surface area of lipids available for the lipase molecules. On the other hand, the presence of fucoidan had little impact on the digestion of emulsions stabilized by lecithin or Tween 80, since it did not strongly impact the lipid droplet aggregation state. These results have important implications for the fabrication of functional foods and beverages that can control lipid digestion in the gastrointestinal tract.

Influence of emulsifier type on gastrointestinal fate of oil-in-water emulsions containing anionic dietary fiber (pectin)

The influence of emulsifier type and dietary fiber addition on the gastrointestinal fate of emulsified lipids was investigated using a simulated gastrointestinal tract (GIT): mouth; stomach; small intestine. The emulsions tested contained lipid droplets coated with different emulsifiers (sodium caseinate, Tween 80, or lactoferrin), as well as different initial levels of low methoxy pectin (0%, 0.025% and 0.5% w/w). In the absence of pectin, the initial rate of lipid digestion depended strongly on emulsifier type: being 20.5, 18.6, and 6.4 %FFA min−1 for Tween 80, lactoferrin, and caseinate, respectively. However, complete lipid digestion occurred for all these emulsions by the end of the small intestine phase. The slower initial rate of lipid digestion in the caseinate-stabilized emulsions was attributed to extensive droplet flocculation in the gastric phase, which would restrict the access of lipase to lipid droplet surfaces. Pectin addition increased the rate of lipid digestion in caseinate-stabilized emulsions (e.g., by 100% for 0.025% pectin), which was attributed to its ability to suppress droplet flocculation. Conversely, high levels of pectin in the Tween 80- and lactoferrin-stabilized emulsions decreased the initial rate of lipid digestion (e.g., by >35% for 0.5% pectin), possibly due to calcium binding or gel forming effects. These results indicate that the rate and extent of lipid digestion can be controlled by using different emulsifiers or by adding dietary fibers, which may be useful information for the rational design of functional foods and beverages.

The Influence of Emulsifier Type on Conventional Properties, Thermal Behavior, and Microstructure of Styrene-butadiene-styrene Polymer Modified Bitumen

This work addresses the impact of emulsifier on the physical properties, thermal behavior and microstructure of styrene-butadiene-styrene (SBS) polymer modified bitumen (PMB) using conventional tests, differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy. The results show that emulsifier B demonstrates the best contribution during emulsification of SBS PMB whereas emulsifier C shows nondesirable impact. Emulsifier B improves the thermal stability of SBS PMB while emulsifiers A and C contribute negatively. FTIR results indicate no further chemical reaction on SBS PMB during emulsification with emulsifier A and B and slight physical and chemical change with emulsifier C.

Organosilicone modified styrene-acrylic latex: preparation and application

In this paper, organosilicone modified styrene-acrylic (OSA) latexes for waterproof coating were synthesized through core–shell emulsion polymerization. The influence of emulsifier type and dosage on the size, size distribution and morphology of the latex was systematically investigated. The water absorbance and thermal decomposition behavior and the mechanical properties of the waterproof coating depending on the organosilicone introduced on the latex shell were also studied. Transmission electron microscopy and dynamic light scattering results indicated that the particles had a regular spherical morphology with different diameters and distributions. Thermal gravimetric analysis results revealed that the thermal stability of the latex films was improved with the introduction of organosilicone. The waterproof property of the OSA latex film was obviously increased as compared to that of the styrene-acrylic latex film. The tensile strength and fracture elongation of the elastic waterproof building coating made of the OSA latex and cement powder were significantly greater than that made of the styrene-acrylic latex and cement powder.

Nanoemulsions produced with varied type of emulsifier and oil content: An influence of formulation and process parameters on the characteristics and physical stability

The aim of the present study was to prepare oil-in-water nanoemulsions stabilized with a novel natural alkyl polyglucoside surfactant and to compare them with corresponding lecithin/polysorbate 80 - based nanoemulsions in terms of physicochemical properties and physical stability. Nanoemulsions were prepared by high pressure homogenization, using 20, 30 and 40% (w/w) medium chain triglyceride as oil phase, and 4, 6 and 8% (w/w) lecithin/polysorbate 80 mixture (1/1) or caprylyl/capryl glucoside as emulsifiers. The influence of emulsifier type, emulsifier concentration and oil content was investigated with respect to changes in particle size, particle size distribution, surface charge and physical stability. The influence of production parameters (number of homogenization cycles, type of homogenization process, homogenization pressure) on particle size was also investigated. Analysis was performed by photon correlation spectroscopy, laser diffraction, zeta potential, pH and electrical conductivity measurements. All formulations produced revealed a small droplet size ranging from 147 to 228 nm and a very narrow size distribution (polydispersity index range 0,072-0,124). Zeta potentials were about -20 mV and -50 mV for nanoemulsions stabilized with lecithin/polysorbate 80 and caprylyl/capryl glucoside, respectively. The results obtained during the stability studies (6 months at 25?C and 1 month at 40?C) indicated that nanoemulsion stability was influenced by their composition. Acquired results also suggested the most appropriate production parameters: 9 homogenization cycles, homogenization pressure of 500 bar and discontinuous process of homogenization.

Microstructural design to reduce lipid oxidation in oil-inwater emulsions

The influence of emulsifier type (Tween 20 and sodium caseinate (CAS)) and oil phase volume fraction (5% and 30%) on emulsion oxidative stability was investigated. The primary and secondary lipid oxidation products of emulsions stored at 40°C were measured over 7 days. The results indicated that the oxidative stability of samples stabilised with CAS was significantly higher compared with emulsions stabilised with Tween 20. We propose that this is due to iron binding ability of CAS. Moreover, the impacts of Pickering emulsions (Silica particles) on lipid oxidation were studied and compared with Tween 20 stabilised emulsions. The results showed that silica particles could increase the oxidative stability of 20% sunflower oil-in-water emulsions by acting as a physical barrier between pro-oxidants located in continuous phase and hydroperxide at droplet interface.

Influence of emulsifier type on lipid oxidation in fish oil‐enriched light mayonnaise

AbstractThe oxidative stability of fish oil‐enriched light mayonnaise (40% oil) and the influence of two different emulsifiers, egg yolk and milk protein‐based emulsifier, were evaluated. Moreover, the effects of different fish oil concentrations (4, 10 and 14%) and storage temperatures (2 and 20°C) were investigated. As expected, the results showed that lipid oxidation increased with storage temperature, and at 20°C with increasing fish oil concentrations. On the basis of the findings in this study, a storage temperature of 20°C for 4 months cannot be recommended for light mayonnaise due to significant lipid oxidation even in mayonnaises without fish oil. However, enrichment of light mayonnaises with 4% fish oil without adding antioxidant did not result in increased oxidation when stored at 2°C, and thus seems feasible; however, this has to be confirmed by sensory analysis. Surprisingly, our hypothesis that substitution of egg yolk with a less iron‐containing emulsifier (milk protein‐based emulsifier) could increase the oxidative stability of fish oil‐enriched mayonnaises was not confirmed. These findings suggest that the initial quality of the emulsifiers was more important than its iron content in terms of lipid oxidation.

Influence of emulsifier type on in vitro digestibility of lipid droplets by pancreatic lipase

Abstract The objective of this study was to investigate the influence of interfacial composition on the in vitro digestion of emulsified lipids coated by various emulsifiers by pancreatic lipase. Sodium caseinate, whey protein isolate (WPI), lecithin and Tween 20 were used to prepare corn oil-in-water emulsions (3 wt% oil). Pancreatic lipase (1.6 mg/mL) and/or bile extract (5.0 mg/mL) were added to each emulsion and the particle charge, droplet aggregation, microstructure and free fatty acids released were measured. In the absence of bile extract, the amount of free fatty acids released per unit volume of emulsion was much lower for lipid droplets coated by Tween 20 (13 ± 16 μmol ml−1) than those coated by lecithin (75 ± 20 μmol ml−1), sodium caseinate (220 ± 24 μmol ml−1) or WPI (212 ± 6 μmol ml−1). In the presence of bile extract, there was an appreciable increase in the amount of free fatty acids released in all the emulsions, with the most appreciable effects being observed in the Tween 20-stabilized emulsions. The stability of the emulsions to droplet flocculation and coalescence during hydrolysis was also strongly dependent on emulsifier type, with the WPI emulsions being the least stable and the Tween 20 emulsions being the most stable. Our results suggest that the access of pancreatic lipase to emulsified fats decreases in the following order: proteins (caseinate and WPI) > phospholipids (lecithin) > non-ionic surfactants (Tween 20). These results may have important consequences for the design of foods with either increased or decreased lipid bioavailability.

Development and in-vitro evaluation of modified release tablets including ethylcellulose microspheres loaded with diltiazem hydrochloride

In this study, development of modified release tablet formulations containing diltiazem hydrochloride-loaded microspheres to be taken once rather than two or three times a day was attempted. For this purpose, ethylcellulose microspheres were prepared by emulsion-solvent evaporation technique. The influence of emulsifier type and drug/polymer ratio on production yield, encapsulation efficiency, particle size, surface morphology and in-vitro release characteristics of the microspheres was evaluated. Suitable microspheres were selected and tabletted using different tabletting agents, Ludipress®, Cellactose®80, Flow-Lac®100 and excipients Compritol®888 ATO, Kollidon®SR. Tablets were evaluated from the perspective of physical and in-vitro drug release characteristics. It was seen that type and ratio of the excipients played an important role in the tabletting of the microspheres. As a result, two tablet formulations containing 180 mg diltiazem hydrochloride and using either Compritol®888 ATO or Kollidon®SR were designed successfully and maintained drug release for 24 h with zero order and Higuchi kinetics, respectively.

Influence of emulsifier type and content on functional properties of polysaccharide lipid-based edible films.

This study investigates the effect of different types of surfactant (glycerol monostearate, Tween 60, and Tween 80) on water vapor permeability (WVP), tensile strength (TS), percentage elongation at breaking (E), and structure of an emulsified edible film composed of cornstarch, methylcellulose, and cocoa butter or soybean oil. Factorial designs at two levels were used to analyze the effect of emulsifier (EM) and lipid content on the functional properties of film. Results showed that the effects of independent variables on WVP, TS, and E depend on surfactant and lipid type. The presence of EM significantly decreased the WVP of cocoa butter films but did not improve the barrier or mechanical properties of soybean oil-based film.

Influence of emulsifier type on freeze-thaw stability of hydrogenated palm oil-in-water emulsions

The influence of emulsifier type (Tween 20, whey protein isolate, casein) on the physical properties of 20 wt% hydrogenated palm oil-in-water emulsions after crystallization of (i) the oil phase only or (ii) both the oil and water phases has been examined. Emulsion stability was assessed by differential scanning calorimetry measurements of fat destabilization after cool–heat cycles, and by measurements of mean particle size, oiling off, and gravitational separation after isothermal storage (−20 to 37 °C). Tween 20-stabilized emulsions showed appreciable fat destabilization at temperatures where the oil phase was partially crystalline, which was attributed to partial coalescence. Protein-stabilized emulsions were stable under these conditions, which was mainly attributed to the relatively thick interfacial membranes surrounding the droplets. When both oil and water phases crystallized, there was complete destabilization of Tween 20- and casein-stabilized emulsions, and extensive destabilization of whey protein-stabilized emulsions, which was attributed to ice crystallization. The results of this study could facilitate the development of frozen food products with improved properties.