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Oil-in-water Emulsions (oil-in-water + emulsion)
Selected AbstractsThe Emulsifying Properties of Commercial Milk Protein Products in Simple Oil-in-Water Emulsions and in a Model Food SystemJOURNAL OF FOOD SCIENCE, Issue 6 2000S.R. Euston ABSTRACT: The emulsifying properties of six commercial milk protein products were studied. The products were separated into one of two groups depending on whether they contained aggregated (micellar) casein or disordered protein (casein or whey protein). Disordered proteins had a greater emulsifying ability than aggregated proteins. Dispersion of aggregated protein in dissociating buffer improved the emulsifying ability. Comparison of emulsion properties in simple oil-in-water emulsions with those in a model coffee whitener formulation showed that the lower emulsifying ability of aggregated protein could be partially compensated by other ingredients. [source] Application of toxicity identification evaluation procedures for characterizing produced water using the tropical mysid, Metamysidopsis insularisENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2004Najila Elias-Samlalsingh Abstract Toxicity identification evaluations (TIEs) were performed on seven produced water (PW) effluents from inland discharge facilities operated in Trinidad and Tobago, a Caribbean tropical country with one of the oldest commercial oil industries in the world. The research was performed to determine the presence and magnitude of toxicity and characterize which toxicants are responsible for observed effects. Marine effluent toxicity characterizations with Metamysidopsis insularis revealed high whole acute toxic-unit response for produced water ranged from 8.1 to >17.0 acute toxic-unit (initial toxicity test) and 5.7 to 1,111 acute toxic-unit (baseline toxicity test). Toxicity test results for all sites except one, which had the highest toxicity, are comparative with similar studies on produced water. The toxicological causality of this complex mixture differed for each PW with nonpolar organics being consistently toxic in all samples. Other potential toxicants contributing to overall toxicity to a much lesser extent were metals, ammonia, and volatile organic compounds. With the use of sodium thiosulfate and filtration manipulations for only PW6 sample, there was very slight reduction in toxicity; therefore, oxidants and filterable materials were not a great contributing factor. Whole effluent toxicity also can be attributed to ionic imbalance and the very stable oil-in-water emulsion that consists of fine oil droplets (less than 0.1,10 ,m with an average diameter of 2.5 ,m). This investigation is the first of its type in Trinidad and demonstrates clearly the applicability of this test method and local test species for evaluating complex effluents in tropical environments. [source] Microgel-Based Stimuli-Responsive CapsulesADVANCED FUNCTIONAL MATERIALS, Issue 4 2009Sebastian Berger Abstract In this paper, a preparation of stimuli-responsive capsules based on aqueous microgels is described. Microgel particles act as stabilizers for oil-in-water emulsion and organize themselves on the surface of chloroform droplets containing the biodegradable polymer poly(4-hydroxybutyrate- co -4-hydroxyvalerate) (PHBV). After chloroform evaporation, composite capsules consisting of a thin PHBV wall with integrated microgels are obtained. Due to the presence of microgels acting as sensitive building blocks, the capsules respond to different stimuli (temperature, solvent concentration). Preliminary results indicate that the capsule dimensions and morphology can be tuned by microgel and PHBV concentration in water and chloroform, respectively. [source] Scaffolds Based on Biopolymeric Foams,ADVANCED FUNCTIONAL MATERIALS, Issue 1 2005A. Barbetta Abstract A new approach for the preparation of hydrophilic and biocompatible porous scaffolds is described. The procedure involves the derivatization of a biopolymer by the introduction of vinylic moieties, formation of a high-internal-phase oil-in-water emulsion, and its subsequent polymerization. The ensuing materials are characterized by a highly porous morphology represented by pores completely interconnected by a plurality of holes. The hydrophilic and biocompatible nature of these materials make them good candidates for application as scaffolds for tissue engineering. [source] MF59® -adjuvanted vaccines for seasonal and pandemic influenza prophylaxisINFLUENZA AND OTHER RESPIRATORY VIRUSES, Issue 6 2008Angelika Banzhoff Abstract, Influenza is a major cause of worldwide morbidity and mortality through frequent seasonal epidemics and infrequent pandemics. Morbidity and mortality rates from seasonal influenza are highest in the most frail, such as the elderly, those with underlying chronic conditions and very young children. Antigenic mismatch between strains recommended for vaccine formulation and circulating viruses can further reduce vaccine efficacy in these populations. Seasonal influenza vaccines with enhanced, cross-reactive immunogenicity are needed to address these problems and can confer a better immune protection, particularly in seasons were antigenic mismatch occurs. A related issue for vaccine development is the growing threat of pandemic influenza caused by H5N1 avian strains. Vaccines against strains with pandemic potential offer the best approach for reducing the potential impact of a pandemic. However, current non-adjuvanted pre-pandemic vaccines offer suboptimal immunogenicity against H5N1. For both seasonal and pre-pandemic vaccines, the addition of adjuvants may be the best approach for providing enhanced cross-reactive immunogenicity. MF59®, the first oil-in-water emulsion licensed as an adjuvant for human use, can enhance vaccine immune responses through multiple mechanisms. A trivalent MF59-adjuvanted seasonal influenza vaccine (Fluad®) has shown to induce significantly higher immune responses to influenza vaccination in the elderly, compared with non-adjuvanted vaccines, and to provide cross-reactive immunity against divergent influenza strains. Similar results have been generated with a MF59-adjuvanted H5N1 pre-pandemic vaccine, which showed higher and broader immunogenicity compared with non-adjuvanted pre-pandemic vaccines. [source] 20-O-,-D-Glucopyranosyl-20 (S)-protopanaxadiol (compound K) induces expression of hyaluronan synthase 2 gene in transformed human keratinocytes and fibroblasts and increases hyaluronan in hairless mouse skinINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 6 2004S. Kim Ginsenosides, the major active ingredient of ginseng, show a variety of biomedical efficacies such as anti-aging, anti-oxidation and anti-inflammatory activities. To understand the effects of 20-O-,-D-glucopyranosyl-20 (S)-protopanaxadiol (compound K), one of the major metabolites of ginsenosides on the skin, we assessed the expression level of approximately 100 transcripts in compound K-treated HaCaT cells using cDNA microarray analysis. Compound K treatment induced differential expression of 40 genes, which have been reported to be involved in the organization of the structure of the extracellular matrix as well as defense responses in human skin cells. One of the most interesting findings is a two-fold increase in hyaluronan synthase2 (HAS2) gene expression by compound K. We found that change in expression of HAS2 gene represents a specific response of HaCaT cells to compound K because hyaluronan synthase 1,3 was not changed by treatment with compound K. We also demonstrated that the compound K effectively induced hyaluronan synthesis in human skin cells and hairless mouse skin. A human clinical study indicated that topical application of compound K containing oil-in-water emulsion showed improvement of xerosis, wrinkle and fine lines in the aged skin. We concluded that compound K has anti-aging effects by the induction of HAS2 gene expression and following hyaluronan synthase. [source] Recovery of lipase by adsorption at the n -hexadecane,water interfaceJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 11 2003Hui-Min Wang Abstract A novel separation process based on the hydrophobic adsorption at the n -hexadecane,water interface was developed for the recovery of Acinetobacter radioresistens lipase from a pre-treated fermentation broth. In a mixture containing water, lipase and n -hexadecane, a water-in-oil emulsion was formed when the n -hexadecane-to-water ratio (o/w ratio) was larger than 3, and a large amount of lipase was found to be adsorbed at the interface. Compared with the oil-in-water emulsion (occurring when o/w ratio < 3), the water-in-oil emulsion generated smaller droplets and larger interfacial area, and was more stable. The harvested emulsion phase could be centrifuged to give an aqueous, concentrated lipase solution. Adsorption of lipase at the interface could be described by the Langmuir isotherm. For lipase concentrations ranging from 8.4 to 87.2 U cm,3, a single-stage adsorption resulted in a six- to four-fold concentration and 16,45% activity recovery, where lipase concentration was the dominant factor. A method using data from a single-stage adsorption to predict multiple-stage operation was described, and the agreement between the experimental and the predicted results was good. To improve the enzyme recovery, a multiple-run adsorption process was proposed. The use of salts enhanced the hydrophobic interaction between lipase and n -hexadecane. Advantages of the proposed process include simple operation, low operational cost, environmentally friendly, no requirement for pre-concentration of the enzyme solution, and negligible enzyme denaturation. Copyright © 2003 Society of Chemical Industry [source] Effects of Docosahexaenoic Acid Content in Triacylglycerol on Human Taste PerceptionJOURNAL OF FOOD SCIENCE, Issue 6 2002T. Koriyama ABSTRACT: To elucidate the contribution of docosahexaenoic acid (DHA) in triacylglycerol to tuna oil specific taste effects, suppression of bitterness and enhancement of umami, we conducted sensory analysis employing an oil-in-water emulsion prepared with taste substances and the oils differed in the DHA content. The tuna oil specific taste effects were linearly dependent on DHA content. The increase of DHA in oil also linearly enhanced umami and flavor (continuity and richness) of synthetic tuna extract. These results indicate that DHA, a major fatty acid of tuna oil, greatly contributes to tuna oil specific effects on basic tastes and flavor. [source] ODOR PERCEPTION OVER LIQUID EMULSIONS CONTAINING SINGLE AROMA COMPOUNDS: EFFECTS OF AROMA CONCENTRATION AND OIL VOLUME FRACTIONJOURNAL OF SENSORY STUDIES, Issue 6 2002CHANTAL BROSSARD ABSTRACT This study aimed to check the hypothesis that aroma concentration in the aqueous phase of an oil-in-water emulsion controlled the odor intensity of single aroma compounds. A set of flavored oil-in-water emulsions, prepared according to a 22 experimental design (aroma concentration, oil volume fraction) with two central points, was assessed for odor intensity by a 24-member panel during four sessions. In each session, three of the four-studied aroma molecules (benzaldehyde, ethyl butyrate, linalool and acetophenone) were investigated. Whatever the aroma, the experimental data showed that the oil volume fraction of the emulsion (from 0.12 to 0.48) did not influence the odor intensity. For each emulsion composition, aroma concentrations at equilibrium in both phases were calculated using the oil-water partition coefficient of the compound. Odor intensities, estimated from aroma concentration in the aqueous phase using previously reported modeling of odor intensity above water solutions, were then compared to experimental data. It is confirmed that the perceived odor intensity is governed by the aroma concentration in the aqueous phase at the time of the trial and not by the averaged apparent concentration in the emulsion. [source] Effect of medium molecular weight xanthan gum in rheology and stability of oil-in-water emulsion stabilized with legume proteinsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2005Evdoxia M Papalamprou Abstract Xanthan gum is a water-soluble extracellular polysaccharide that has gained widespread commercial use because of its strong pseudoplasticity and tolerance to high ionic strength, which bring unique rheological properties to solutions. This study compares and evaluates the emulsifying properties of oil-in-water (30:70 v/v) emulsions stabilized with lupin and soya protein isolates and medium molecular weight xanthan gum. The protein was obtained by an isoelectric precipitation method and the polysaccharide was produced by Xanthomonas campestris ATCC 1395 in batch culture in a laboratory fermenter (LBG medium) without pH control. The addition of xanthan gum in the emulsion formulation enhances emulsion stability through the phenomenon of thermodynamic incompatibility with the legume protein, resulting in an increase of the adsorbed protein at the interface. The emulsion stability is also enhanced by a network structure built by the polysaccharide in the bulk phase. Copyright © 2005 Society of Chemical Industry [source] Preparation of oily core polyamide microcapsules via interfacial polycondensation,POLYMER INTERNATIONAL, Issue 4 2003L Soto-Portas Abstract Microcapsules obtained by interfacial polycondensation from an original system based on the polyaddition of specific di- or polyamines and more classical acyl chloride molecules were studied. The originality of the system lies in the fact that the encapsulated agent is the internal phase allowing its incorporation without an organic solvent, which is an advantage from the point of view of environmental protection. Once the optimal parameters of the emulsion were determined, the membrane formation was studied by optimizing the emulsification and reaction times in relation to simultaneous acyl chloride hydrolysis. The microcapsules were obtained by interfacial polycondensation between an excess of amine functions (diamine and diethylenetriamine) and acyl chloride (sebacoyl chloride and 1,3,5-benzene tricarbonyl trichloride) from an oil-in-water emulsion in the presence of 88% hydrolyzed poly(vinyl alcohol) as a surfactant. Various formulations in terms of COCl concentration, crosslinking agent concentration, excess of amine functions, emulsification and reaction times were prepared. The hydrolysis of acyl halide functions is the main parameter which influences the growth of the membrane. The increase in acyl chloride function concentration allows compensation for that lost by hydrolysis, and increases the encapsulation yield to about 90%. The degree of crosslinking of the membrane was controlled in order to minimize the subsequent release of oil by the addition of trifunctional monomers. An optimal formulation was developed offering high encapsulation yield and optimal elastic behaviour. Almost spherical capsules, with a membrane thickness of approximately 500,nm, relatively smooth internal walls and crumpled external walls, were observed by scanning electron microscopy. © 2003 Society of Chemical Industry [source] Effect of oil content and processing conditions on the thermal behaviour and physicochemical stability of oil-in-water emulsionsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 1 2009Megan Tippetts Summary The destabilisation mechanism of oil-in-water (o/w) emulsions was studied as a function of oil content (20% and 40% o/w), homogenisation conditions and crystallisation temperatures (10, 5, 0, ,5 and ,10 °C). A mixture of anhydrous milk fat and soya bean oil was used as the lipid phase and whey protein isolate (2 wt%) as emulsifier. Crystallisation and melting behaviours were analysed using differential scanning calorimetry. Physicochemical stability was measured with a vertical scan macroscopic analyser. Emulsions with 20% oil were found to be less stable than those with 40% oil. For 20% o/w emulsions, the crystallisation was delayed and inhibited in emulsions with smaller droplets and promoted in emulsions with larger droplets when compared with 40% o/w emulsions. Depending on the droplet sizes in the emulsion, the formation of lipid crystals (in combination with the emulsifier) either stabilises (small droplets) or destabilises (big droplets) the emulsion. [source] Evaluation of a simple batch distillation process for treating wastes from metalworking industriesJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2004P Cañizares Abstract A simple batch distillation process for the treatment of two types of industrial waste generated in a metalworking factory has been evaluated. Both types of waste are oil-in-water emulsions composed of numerous compounds and each type has a high content of water-soluble species. The water-soluble nature of the wastes precludes the use of conventional treatment technologies, such as ultrafiltration or chemical emulsion breaking, since they need to be complemented with additional treatment processes that would probably increase the cost considerably. A simple characterization of the liquid,vapour equilibrium and a scale-up study has demonstrated the applicability of this technology. The process allows 90% of the waste to be recovered as water, thus achieving the required quality limits for discharge into a municipal wastewater treatment plant. An approximate estimation of capital investment and operating costs for an existing case has shown the economic viability of this process. Copyright © 2004 Society of Chemical Industry [source] EFFECT OF FLAXSEED GUM ON QUALITY AND STABILITY OF A MODEL SALAD DRESSING,JOURNAL OF FOOD QUALITY, Issue 4 2000S. STEWART ABSTRACT Flaxseed gum was evaluated for its application as a stabilizer for salad dressing. It was found that for stabilization to occur the concentration of gum had to be higher than 0.45% (w/w). Solvent quality affected the stability of model oil-in-water emulsions. Flaxseed gum stabilized emulsions were stable at pHs greater than 2.8. Lower values caused the polysaccharide to have a compact configuration or caused cleavage of the polymer creating instability. Larger mean droplet size and creaming were observed when the pH was too low or the gum concentration was not sufficient for coverage. Salt addition greatly affected the rheological properties of the polysaccharide; however, the electrolyte improved the emulsifying capabilities of the egg yolk protein. Aging weakened the polymer network structure as shown by a decrease in Newtonian viscosity with a corresponding increase in phase angle confirming the transformation to a more fluid system. [source] Influence of Flocculation on Optical Properties of EmulsionsJOURNAL OF FOOD SCIENCE, Issue 3 2001W. Chantrapornchai ABSTRACT: The influence of droplet flocculation on the optical properties of 1 and 10 wt% oil-in-water emulsions with and without dye was investigated. Flocculation was induced by addition of SDS micelles to the aqueous phase of emulsions to increase the depletion attraction between droplets. Droplet flocculation caused the spectral reflectance and L -value (lightness) of emulsions to decrease, and the magnitude of the a - and b - values to increase, but the changes were rather small. Similar trends were observed for emulsions with and without dye. Overall, emulsion optical properties were dominated by light scattering from droplets rather than flocs. [source] The Emulsifying Properties of Commercial Milk Protein Products in Simple Oil-in-Water Emulsions and in a Model Food SystemJOURNAL OF FOOD SCIENCE, Issue 6 2000S.R. Euston ABSTRACT: The emulsifying properties of six commercial milk protein products were studied. The products were separated into one of two groups depending on whether they contained aggregated (micellar) casein or disordered protein (casein or whey protein). Disordered proteins had a greater emulsifying ability than aggregated proteins. Dispersion of aggregated protein in dissociating buffer improved the emulsifying ability. Comparison of emulsion properties in simple oil-in-water emulsions with those in a model coffee whitener formulation showed that the lower emulsifying ability of aggregated protein could be partially compensated by other ingredients. [source] Effects of sand and process water pH on toluene diluted heavy oil in water emulsions in turbulent flowAICHE JOURNAL, Issue 1 2009Chandra W. Angle Abstract The presence of sand in heavy oil production is known to enhance oil recovery. Sand can also be detrimental depending on the properties of the sand,water interface. In this process, the water soluble material interacts with both sand and oil droplets and affects emulsion stability. The formation and stability of heavy oil-in-water emulsions during turbulent flow using batch process stirred-tank mixing of oil, sand, and water were investigated at three pH. Size distributions were measured by laser diffraction. High-speed video photomicrography was used to observe the process during mixing. Results showed that the presence of sand enhanced formation of stable, fine emulsion at basic pH 8.5. When the pH of the water was reduced below 6.5 both sand and droplets surface properties changed, the emulsions became less stable and coalescence was apparent. The sand grains acted as coalescers at low pH and enhanced breakage at high pH. © Her Majesty the Queen in Right of Canada, as represented by the Minister of Natural Resources, 2008 AIChE J, 2009 [source] ODOR PERCEPTION OVER LIQUID EMULSIONS CONTAINING SINGLE AROMA COMPOUNDS: EFFECTS OF AROMA CONCENTRATION AND OIL VOLUME FRACTIONJOURNAL OF SENSORY STUDIES, Issue 6 2002CHANTAL BROSSARD ABSTRACT This study aimed to check the hypothesis that aroma concentration in the aqueous phase of an oil-in-water emulsion controlled the odor intensity of single aroma compounds. A set of flavored oil-in-water emulsions, prepared according to a 22 experimental design (aroma concentration, oil volume fraction) with two central points, was assessed for odor intensity by a 24-member panel during four sessions. In each session, three of the four-studied aroma molecules (benzaldehyde, ethyl butyrate, linalool and acetophenone) were investigated. Whatever the aroma, the experimental data showed that the oil volume fraction of the emulsion (from 0.12 to 0.48) did not influence the odor intensity. For each emulsion composition, aroma concentrations at equilibrium in both phases were calculated using the oil-water partition coefficient of the compound. Odor intensities, estimated from aroma concentration in the aqueous phase using previously reported modeling of odor intensity above water solutions, were then compared to experimental data. It is confirmed that the perceived odor intensity is governed by the aroma concentration in the aqueous phase at the time of the trial and not by the averaged apparent concentration in the emulsion. [source] Influence of composition and structure of oil-in-water emulsions on retention of aroma compoundsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2002Dr Saskia M van Ruth Abstract The influence of the composition and structure of oil-in-water emulsions on aroma retention was examined for 20 volatile compounds. Compositional and structural parameters included the fraction of emulsifier phase, the fraction of lipid phase and the particle size distribution of the dispersed lipid phase in the emulsion. Air/liquid partition coefficients of dimethyl sulphide, 1-propanol, diacetyl, 2-butanone, ethyl acetate, 1-butanol, 2-pentanol, propyl acetate, 3-methyl-1-butanol, ethyl butyrate, hexanal, butyl acetate, 1-hexanol, 2-heptanone, heptanal, ,-pinene, 2-octanone, octanal, 2-nonanol and 2-decanone were determined by static headspace gas chromatography. The hydrophobicity of the compounds determined the influence of the compositional and structural parameters of the emulsions on air/liquid partitioning. Increase of the emulsifier fraction increased the retention of mainly hydrophilic aroma compounds and decreased the retention of hydrophobic compounds. Higher lipid levels led to increased retention of hydrophobic compounds and release of hydrophilic compounds. Emulsions with larger particles showed increased aroma retention, which was independent of the lipid fraction and the polarity of the aroma compounds. The data demonstrated a profound effect of both composition and structure of oil-in-water emulsions on the air/liquid partitioning of the 20 aroma compounds under equilibrium conditions. © 2002 Society of Chemical Industry [source] Biodegradable hollow fibres containing drug-loaded nanoparticles as controlled release systemsPOLYMER INTERNATIONAL, Issue 12 2002Giovanni Polacco Abstract A ,multiple' delivery system was studied, consisting of hollow microfibres containing drug-loaded nanoparticles. Both fibres and nanoparticles are made of biodegradable polymers, so that the system does not need any surgical operation to be removed. The main advantage of the system is that it allows the contemporaneous release of different kinds of drugs. Copolymers of poly(lactic acid) and ,-caprolactone were used for the preparation of the fibres through both wet and dry,wet spinning procedures. Two types of nanoparticles, gelatin and poly(DL -lactide- co -glycolide) nanoparticles, were prepared by simple water-in-oil and oil-in-water emulsions, respectively. Drugs such as dexamethasone and methotrexate were used to load the particles. The technique employed for the preparation of the nanoparticles filled fibres was described and the drug release characteristics of this system were investigated and compared with those of the free nanoparticles. © 2002 Society of Chemical Industry [source] Sauce hollandaise, mit drei Sternen oder als Tüte aus dem Supermarkt.CHEMIE IN UNSERER ZEIT (CHIUZ), Issue 3 2008Delikate Grenzflächen Teil Die mit Eigelb aufgeschlagenen Saucen gehören zum Feinsten, was eine gute Küche bieten kann. Die physikalisch-chemischen Grundlagen dieser empfindlichen Öl-in-Wasser-Emulsionen machen die manuelle Herstellung mühselig. Deswegen bieten Supermärkte für die schnelle Küche verschiedenste Fertigprodukte an, wobei vor allem kalorienarme Produkte vom Verbraucher gefragt sind. Die Rezepturen verschiedener Fertigprodukte werden mit denen selbstgemachter Saucen verglichen. Auf wissenschaftlicher Basis wird ein narrensicheres Rezept zur Herstellung einer klassischen und einer leichteren Variante der Sauce hollandaise vorgestellt. Egg yolk based sauces belong to the most delicious dishes in gourmet cuisine. Unfortunately, the physical-chemical bases of these unstable oil-in-water emulsions make the manufacturing process quite time consuming. Therefore, supermarkets offer various convenience foods and especially low-calorie products play an especially prominent role. The recipies of various fast food sauces are analyzed with respect to their hydrocolloid components and compared with those of homemade sauces. Foolproof and science based recipies are given for a classical and a lighter version of Sauce hollandaise. [source] | ||||||||||||||||||||||||||||