Good Emulsion Stability Research Articles

Preparation and Properties of Nano-ZnO/ Organic Fluorine Modified Polyacrylate Finishing Agent

A nano-ZnO/organic fluorine-modified polyacrylate leather finishing agent was prepared using a mixture of a Silyl-modified nano-ZnO, dodecafluoroheptyl methacrylate (DFMA), methyl methacrylate (MMA) and butyl acrylate (BA) as raw materials. A semi-continuous seeded emulsion polymerization followed. The overall research objective was to improve the bacteriostatic, hydrophobicity and anti-aging properties of leather articles. The structure of the composite emulsion and its film were characterized and analyzed by FT-IR, TEM and XPS. The results showed that the latex particles had an obvious core-shell structure, a smooth surface and were monodisperse. The particle size of the emulsion ranged between 30 and 50 nm. The average value of Zeta potential was -40.1 mV which signified a good emulsion stability. The composite emulsion and its film had good UV resistance and water resistance. When the content of organic fluorine in the film was a maximum 20 %, the contact angle of a water drop on the finished leather, tensile strength and tear strength were 133.48°, 620 N and 61 N, respectively. When the content of nano-ZnO in the film was 1.0%, the average width of antibacterial band of finished leather was 2.1 mm. The finished leather also demonstrated a good anti-aging property.

Experimental techniques for the extraction of taro mucilage with enhanced emulsifier properties using chemical characterization

The objective of this study was to analyze existing taro mucilage extraction techniques for extraction of a pure product with high emulsifying action to chemically characterize the mucilage. Five taro mucilage extraction techniques were analyzed which used room temperature, 4 °C, or 80 °C, with or without ethanol precipitation. Protein was detected in the mucilage extracted by each method and is ideal for the emulsifying action. Only mucilage extracted at low temperature and precipitated with ethanol did not contain starch, which is considered an impurity in the product. Therefore, from the tested techniques, cold extraction was found to provide mucilage with good emulsion activity and stability, making it possible to be used as a natural emulsifier. This mucilage is primarily formed by arabinogalactans connected to proteins which form AGP glycoprotein, a macro-molecule responsible for the emulsifying action.

Comparative study of modified soy lecithins as oil in water (O/W) emulsifiers.

Crude commercial soybean lecithin from two different sources named (A) and (C) were modified physically, chemically, and enzymatically using phospholipase A2 enzyme (PLA2) in order to improve their emulsification properties. All the modified lecithin fractions were used in the preparation of oil-in-water (O/W) emulsions, in comparison with the crude lecithins as well as a standard acetone-insoluble lecithin purchased from the market. The emulsions stabilized by acetone-insoluble fractions showed the best physical stability during 3 months of storage after preparation, along with a relatively low particle size (PS) and polydispersity index (PDI) and a zeta-potential values that indicates a good emulsion stability. Hydroxylated lecithin (H2A and H2C) showed the most stable Zeta-potential (-55.3 and -50.8 mV) respectively with a relatively low particle size and poly-dispersity index of 284.0 nm and 0.378 respectively for A and 268.4 nm and 0.391 for C, while hydrolyzed lecithin (ENZ A and ENZ C) that possessed the lowest particle size had a moderate zeta-potential of -34.8 and -32.2 for A and C respectively. These results showed that the modification of crude lecithin is essential for the production of tailor-made products with specific surface-active properties-stabilizing emulsions to be used in different purposes.

Performance evaluation of a novel viscosity-reducing agent for heavy oil

Heavy oil has high viscosity, high content of resins-asphaltenes and poor fluidity, which makes it difficult to produce. In the early research, a novel viscosity-reducing agent with high molecular weights and various active groups was synthesized in the laboratory. Ion composition analysis of wastewater and heavy oil viscosity test of Jincai 27 well were carried out. The emulsifying and viscosity reducing properties of a novel viscosity-reducing agent for heavy oil under low shear condition were evaluated by water content change of emulsion phase and viscosity reduction rate. The results showed that under 50 °C and low shear (10∼20s−1) condition, the viscosity-reducing agent solution had a fast emulsifying speed for the heavy oil. The O/W emulsion with good emulsion stability formed after about 60min shear. The viscosity reduction rate for the heavy oil was above 90%. The emulsion micrographs showed that the emulsion was highly dispersed and the particle size was uniform with diameter of 2 microns or even lower. The viscosity value of viscosity-reducing agent solution with concentration higher than 1200 mg/L could reach 25.0mPa.s under 8.0s−1 shear rate and 50°C, which indicated that it had a certain thickening property. Artificial core flooding experiments showed that viscosity-reducing agent flooding could increase heavy oil recovery by more than 10% compared with water flooding.

Functional and instrumental textural properties of reduced-salt meat emulsions with konjac gel: Combined effects of transglutaminase, isolate soy protein, and alginate

ABSTRACT The functional and instrumental textural properties of reduced-salt meat emulsions (RSMEs) containing konjac gel, with combined transglutaminase (TG), isolated soy protein (ISP), and alginate were investigated to determine optimal quality characteristics. Control groups were produced using 1.2% salt (-) and 1.5% salt (+). RSMEs (1.2% salt) formulations contained T1 (konjac gel), T2 (konjac gel + TG), T3 (konjac gel + ISP), T4 (konjac gel + TG + ISP), T5 (konjac gel + alginate), and T6 (konjac gel + TG + alginate). The moisture content and myofibrillar protein solubility of all RSMEs (from T1 to T6) were significantly higher than that of control (-) (P < .05). T5 and T6 showed the lowest cooking loss and expressible fluid separation (P < .05), which means that T5 and T6 have good emulsion stability. Texture profile analysis of T6 were most similar to those of controls (+) with normal salt (1.5%) levels. in addition, the apparent viscosity of T6 was the maximal. These results indicated that T6 might successfully induce certain technical properties in RSMEs. Consequently, the combination of konjac gel, TG, and alginate are worthy to improve the quality of RSMEs.

Alginate-stabilized thixotropic emulsion gels and their applications in fabrication of low-fat mayonnaise alternatives

In this study, a series of emulsion gels were prepared by dispersing emulsified oil droplets into alginate (Alg) gel matrix, and the final emulsion gels contained 2% Alg (w/v), 0.5% Tween 80 (v/v) and gradient concentrations of oil phase fractions (5–30%, v/v). Subsequently, the effects of Ca2+ addition, heating, and freeze thawing treatments on the emulsion gels were also investigated by a combination of rheological tests, confocal and scanning electron microscopy techniques. It was found that within the range of 0–30% of oil phase fraction, 0–0.15% of CaCl2 addition (w/v), all the emulsion gels could achieve significant thixotropy and good emulsion stability, without discernible oil droplet coalescence observed after heating and/or freeze thawing treatments. The yield stress value and gel stiffness increased with increasing oil phase fraction and Ca2+ addition, which is attributed to the strengthened gel network cross-links in the emulsion gels, as confirmed by SEM results. Interestingly, after freeze thawing treatment, the gel stiffness was slightly improved, which may be due to the intermolecular self-association of Alg during freezing stage. Overall, these results show the potential application of Alg-stabilized emulsion gels in preparation of low-fat mayonnaise products and other similar emulsion foods.

Ultrasound and basic electrolyzed water: A green approach to reduce the technological defects caused by NaCl reduction in meat emulsions.

Meat emulsions were prepared by replacing water with basic electrolyzed water (BEW) and reducing NaCl content by 0, 10, 20, 30, 40, and 50%. The emulsions were sonicated in an ultrasound bath (25 kHz, 175 W, normal mode) for 0, 10, and 20 min. The physicochemical (pH, redox potential, water activity, and color parameters) and technological (cooking yield, emulsion stability, and texture) characteristics were evaluated. The US operation time of 20 min improved the emulsion stability, cooking yield, and texture of the emulsions with 10% and 20% NaCl reduction. The BEW-treated emulsions exhibited good fat retention and moderate water retention capacity. The combination of US and BEW for 20 min provided good emulsion stability and cooking yield for the formulations with up to 30% NaCl reduction, which exhibited texture profile similar to the control (0% NaCl reduction). Therefore, it is possible to produce reduced-salt meat emulsions using the combination of US and BEW.

Interfacial and colloidal characterization of oil-in-water emulsions stabilized by interface-tunable solid lipid nanoparticles

We evaluated the correlation between the interfacial characteristics of solid lipid nanoparticles (SLNs) and the interfacial/colloidal stability of SLN-stabilized emulsions. Herein, the interfacial properties of SLNs, particularly the surface load (Γs) of emulsifiers, were tuned by controlling the type/concentration of emulsifier used to prepare the SLNs. Increasing the Γs decreased the contact angle at the oil–water interface, which enhanced the displacement free energy of the SLNs at the interface. Moreover, the Γs of emulsifiers bound to the surface of SLNs covering oil droplets was linearly correlated with the SLN-own Γs. The size/ζ-potential of emulsions stabilized by SLNs covered by the highest concentration of emulsifiers was unchanged for 1 month, indicating good emulsion stability. The interfacial/colloidal stability of SLN-stabilized emulsions was thus enhanced by increasing the emulsifier concentration used to produce the SLNs. This study provides baseline data for developing SLN-stabilized emulsions for the food, cosmetic, and pharmaceutical industries.

Ultrasound-Assisted Preparation of Brazil Nut Oil-in-Water Emulsions Stabilized by Arabic Gum

The objective of this work is to evaluate the stability of Brazil nut oil emulsions with gum Arabic using ultrasound-assisted homogenization. The emulsions were prepared in a completely randomized design varying the time (2 and 4 min) and the ultrasound power (30 and 40%). The physicochemical properties of the emulsions (pH, conductivity, turbidity, zeta potential, surface tension, rheology and optical microscopy) were evaluated after the homogenization process and 4 hours later. The results showed that more energetic homogenization processes (longer duration and higher ultrasound power) favored the physicochemical properties, keeping the emulsions more stable. Thus, Brazil nut oil emulsions prepared with ultrasound-assisted showed good physic-chemical characteristics that can guarantee good emulsion stability during spray drying, guaranteeing efficiency and protection of the physical and chemical properties of the Brazil nut oil.

Surface engineered bacteria as Pickering stabilizers for foams and emulsions

The ability to manipulate the structure of food and increase the shelf life by enhanced stability using natural (e.g., biological) agents instead of synthetic surfactants is of interest to many food companies. Here we chemically modify the cell hydrophobicity of lactic acid bacteria Lactobacillus acidophilus (La5) using octenyl succinic anhydride (OSA) and investigate foams and emulsions produced with both the unmodified and modified cells in terms of the foamability, foam stability, emulsion storage stability and the microstructure. Cell hydrophobicity was effectively increased by OSA modification, and the modified bacteria adsorbed well on the oil-water or air-water interface to stabilize the foams or emulsions. Foamability and foam stability increased with OSA modification. Similarly, good emulsion stability against coalescence was observed over the studied period for the emulsions prepared with modified La5. Moreover, OSA modification only showed a modest lethal effect up to 6% OSA on bacteria based on the decline of cell viability and culturability depending on the degree of modification (0.5 log decrease for 6% OSA-modified cells but 5 log decrease for 10% OSA-modified cells in comparison to culturability of unmodified cells). From our results, we suggest that in future OSA-modified La5 cells may act as structural building blocks and fat substitution for food material creating texture and mouthfeel.

Preparation and emulsifying properties of trace elements fortified gum arabic

Gum arabic was enriched with trace elements (Zn2+, Fe3+, Fe2+) by ion exchange against ZnCl2, FeCl3 and FeCl2. Trace elements content, molecular parameters and emulsifying properties of the gum arabic rich in trace elements (GARTE) were characterized by flame atomic absorption spectrometry (FAAS), gel permeation chromatography-multi angle laser light scattering (GPC-MALLS), interfacial rheometer, laser particle analyzer and zeta potentiometry. With trace elements, molecular weight and arabinogalactan protein (AGP) content of gum arabic have increased probably due to the high surface energy leading to the aggregation of protein. GARTE has good emulsion stability performance with increasing molecular weight and AGP content compared to the control gum arabic. GARTE can be applied as a natural functional ingredient for trace element fortification, where the ferric ions and zinc ions are chelated by the self-assembled polymer host.

Uniform-Sized Silica Nanocapsules Produced by Addition of Salts to a Water-In-Oil Emulsion Template.

Size control of silica hollow particles was achieved using a water-in-oil (W/O) emulsion system, where interfacial condensation of organosilanes (octyltrichlorosilane and methyltrichlorosilane) took place around the aqueous droplets. Good emulsion stability was obtained using soybean oil as the oil phase because of its high viscosity. This high stability led to bimodal distributions in the sizes of the aqueous droplets and final hollow particles, with particle sizes observed of a few tens of nanometers and a few micrometers. The presence of NaCl was found to be required in the water phase to afford uniform-sized silica hollow spheres. Hydrolysis of the organosilanes caused a supersaturation of the aqueous NaCl solution dispersing in the oil continuous phase, followed by crystallization from droplets. Nanosized aqueous droplets acted as a template to form uniform-sized nanospherical hollow silica particles as a result of the diminishing number of larger aqueous droplets.

Native and modified Sorghum starches as wall materials in microencapsulation of nutmeg oleoresin

The effect of the partial or total substitution of gum arabic (GA) with native (NA), octenyl succinic anhydride (OSA) and succinylated (SUC) sorghum starches on microencapsulation of nutmeg oleoresin was studied using spray drying technique. The oleoresin with 10% load is emulsified by using three different combinations of GA along with native and modified sorghum starches. The proportion of GA and sorghum starch was fixed at 75:25, 50:50, and 25:75. Most of the feed emulsions were having good emulsion stability and lower emulsion viscosity. The highest oil retention of 95% with 84.07% encapsulation efficiency was achieved when GA: NA starch was used in the fraction of 25:75. The highest encapsulation efficiency of 95.38% was obtained by GA: OSA in a ratio of 75:25. Results obtained suggested that both NA and OSA starches could be considered as a good alternative to gum arabic for microencapsulation.

Stability Evaluations of Different Types of Vegetable Oil-based Emulsions.

The study was aimed at evaluating the effects of vegetable oils on emulsion stability. Palm olein (POo), olive oil (OO), safflower oil (SAF), grape seed oil (GSO), soybean oil (SBO) and sunflower oil (SFO) with different degree of saturation levels were chosen as major ingredient of oil phases. All the emulsions were stored at 4℃, 27℃ and 40℃ for 35 days and subjected to all the stability tests, including temperature variation, centrifuge test, cycle test, pH and slip melting point. The results indicated that POo exhibited the highest stability, followed by SAF, OO, GSO, SFO and SBO. In addition, the results implied that the degree of saturation levels of vegetable oils does give significant effect on emulsion stability based on the centrifuge testing for an approximate 30% usage level of oil. The POo-based emulsion exhibited good emulsion stability throughout the experimental period indicated that POo could be a good carrier oil for various applications in cosmetic industry.

Spelt (Triticum aestivum ssp. Spelta)– from Field to Cosmetics

Plants have been intensively used as sources of biologically active compounds. Recently, the attention was directed to spelt (Triticum aestivum ssp. spelta) as a promising source of antioxidant compounds. In the present study, the antioxidant activity and total phenolic content of Triticum spelta glycerin extracts were determined. Three different extraction techniques were performed – conventional, microwave- and ultrasound- assisted extractions. Best polyphenol content and antioxidant activity were resulted when heat reflux extraction was applied. Moreover, nourishing and regenerating cream (NRC) formulation was prepared by incorporating 1 % glycerin spelt extract. The physicochemical stability of this formulation was assessed as well as sensory and skin penetration caracteristics.The cosmetic preparation exhibited good emulsion and colour stability at all temperature tested (-10 °C; 25 °C and 40 °C) during 90 days. 85 % of volunteers assessed the skin penetration of NRC as good. The same percentage claimed pleasant odor caracteristic after application on skin. Based on these results it can be concluded that spelt is a promissing source of biologically active substances with various applications.

Black bean (Phaseolus vulgaris L.) protein hydrolysates: Physicochemical and functional properties

Black bean protein hydrolysates obtained from pepsin and alcalase digestions until 120min of hydrolysis were evaluated by gel electrophoresis, relative fluorescence intensity, emulsifying properties, light micrograph of emulsions and in vitro antioxidant activity. The emulsion stability of the bean protein hydrolysates were evaluated during 30days of storage. The pepsin-treated bean protein hydrolysates presented higher degree of hydrolysis than the alcalase-treated protein hydrolysates. The alcalase-treated bean protein hydrolysates showed higher surface hydrophobicity. Moreover, the protein hydrolysates obtained with alcalase digestion presented higher emulsion stability during 30-days than those obtained from pepsin digestion. The protein concentrate and especially the hydrolysates obtained from alcalase digestion had good emulsion stability and antioxidant activity. Thus, they could be exploited as protein supplements in the diet as nutritional and bioactive foods.

Emulsifying and Foaming Properties of Different Protein Fractions Obtained from a Novel Lupin Variety AluProt-CGNA(®) (Lupinus luteus).

The use of vegetable proteins as food ingredient is becoming increasingly important due to their high versatility and environmental acceptability. This work describes a chemical characterization and techno-functional properties (emulsifying and foaming properties) of 3 protein fractions obtained from a protein-rich novel lupin variety, AluProt-CGNA(®) . This nongenetically modified variety have a great protein content in dehulled seeds (60.6 g protein/100 g, dry matter), which is higher than soybean and other lupin varieties. A simple procedure was utilized to obtain 3 different fractions by using alkali solubilization and isoelectric precipitation. Fractions 1 and 3 were mainly composed of protein and polysaccharides (NNE), whereas fraction 2 was mainly composed by protein (97%, w/w). Fraction 3 presented interesting and potential foaming properties in comparison to the other fractions evaluated in the study. Besides, its solubility, foaming and emulsifying capacity were practically not affected by pH variations. The 3 fractions also presented good emulsion stability, reaching values above a 95%. SDS-PAGE showed that fractions 1 and 2 contained mainly conglutin α, β, and δ, but in different ratios, whereas fraction 3 contained mainly conglutin γ and albumins. The results of this work will provide better understanding for the utilization of each protein fractions as potential ingredients in food industry.

Production of rhamnolipids with a high specificity by Pseudomonas aeruginosa M408 isolated from petroleum-contaminated soil using olive oil as sole carbon source

Rhamnolipids (RLs) represent a very promising class of biosurfactants that have many applications as biocompatible and biodegradable emulsifiers. We have isolated a Pseudomonas aeruginosa strain, denoted strain M408, from petroleum-contaminated soil of the Liaohe oil field (northern China) that is able to produce RLs with a high specificity when grown on olive oil as the sole carbon source. Product analysis of these RLs showed that only di-RLs (F1 sample), including rhamnose (Rha)-Rha-C10-C10 and Rha-Rha-C10-C12/Rha-Rha-C12-C10, and a single mono-RL (F2 sample) of Rha-C10-C10 were produced by the isolate. Further testing revealed that these F1 and F2 products were able to reduce the surface tension of water to 31 and 27 mN/m, respectively. The critical micelle concentration was 120 and 60 mg/L for the F1 and F2 products, respectively. The F1 and F2 products also showed good emulsion stability, achieving an emulsion capacity of 87 and 90 %, respectively, with atoleine after 24 h at a low concentration of 100 mg/L. Maximum production of the RLs was obtained after optimization of the culture conditions, with a 6.85-fold increase in the yield of the RLs, up to 12.6 g/L, relative to the yield before optimization.

Self-assembled structural transition from vesicle phase to sponge phase and emulsifying properties in mixtures of arginine and fatty acids

Abstract Two fatty acids, octanoic acid (OA) and decanoic acid (DA) were separately mixed with a natural biological molecule, l -arginine (Arg), in aqueous solutions for comparative investigation. Self-assembled structures including micelles, vesicles, sponge structures, were observed by varying the compositions and chain length of fatty acids. The structures of vesicles and sponge phase were determined by freeze fracture-transmission electron microscope (FF-TEM). The transition of self-assembled structures, especially from vesicles to sponge structure, was significantly reflected in the change of rheological properties. The double hydrogen bonding formed between the guanidyl group of Arg and the carboxyl group of fatty acids is considered to be the crucial force, which drives the self-assembly process combining with other non-covalent interaction, electrostatic interaction and hydrophobic interaction. Depending on the nature of the fatty acid, the systems exhibit good emulsion stability.

Synthesis and Surface Properties of a Novel Sodium 3‐(3‐Alkyloxy‐3‐oxopropoxy)‐3‐oxopropane‐1‐sulfonate at the Air–Water Interface

AbstractThe present paper describes the synthesis and evaluation of surface properties of a novel series of anionic surfactant, namely sodium 3‐(3‐alkyloxy‐3‐oxopropoxy)‐3‐oxopropane‐1‐sulfonate with varying alkyl chain length (C8–C16). Synthesis involves initial formation of the 3‐alkyloxy‐3‐oxopropyl acrylate along with fatty acrylate during the direct esterification of fatty alcohol with acrylic acid in the presence of 0.5 % NaHSO4 at 110 °C followed by sulfonation of the terminal double bond of the 3‐alkyloxy‐3‐oxopropyl acrylate. Synthesized compounds were evaluated for surface and thermodynamic properties such as critical micelle concentration (CMC), surface tension at CMC (γcmc), efficiency of surface adsorption (pC20), surface excess (Γmax), minimum area per molecule at the air–water interface (Amin), free energy of adsorption (∆G°ads), free energy of micellization (∆G°mic), wetting time, emulsifying properties, foaming power and calcium tolerance. Effect of chain length on CMC follows the classic trend, i.e. decrease in CMC with the increase in alkyl chain length. High pC20 (&gt;3) value indicates higher hydrophobic character of the surfactant. These surfactants showed very poor wetting time and calcium tolerance, but exhibited good emulsion stability and excellent foamability. Foaming power and foam stability of C14‐sulfonate were found to be the best among the studied compounds. Foam stability of C14‐sulfonate was also studied at different concentrations over time and excellent foam stability was obtained at a concentration of 0.075 %. Thus this novel class of surfactant may find applications as foam boosters in combination with other suitable surfactants.