Standard practice for fluorescent liquid penetrant testing using the hydrophilic Post-Emulsification process

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 This practice covers procedures for fluorescent penetrant examination utilizing the hydrophilic post-emulsification process. It is a nondestructive testing method for detecting discontinuities that are open to the surface such as cracks, seams, laps, cold shuts, laminations, isolated porosity, through leaks, or lack of fusion and is applicable to in-process, final, and maintenance examination. It can be effectively used in the examination of nonporous, metallic materials, both ferrous and nonferrous, and of nonmetallic materials such as glazed or fully densified ceramics and certain nonporous plastics and glass. 1.2 This practice also provides a reference: 1.2.1 By which a fluorescent penetrant examination hydrophilic post-emulsification process recommended or required by individual organizations can be reviewed to ascertain their applicability and completeness. 1.2.2 For use in the preparation of process specifications dealing with the fluorescent penetrant examination of materials and parts using the hy...

Analysis of biosurfactants from industrially-viable Pseudomonas strain isolated from crude oil suggests how rhamnolipids congeners affect on emulsification property and antimicrobial activity

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Palashpriya eDas

2014-12-01

Full Text Available Rhamnolipid biosurfactants produced mainly by Pseudomonas sp. had been reported to possess a wide range of potential industrial application. These biosurfactants are produced as monorhamnolipid (MRL and di-rhamnolipid (DRL congeners. The present study deals with rhamnolipid biosurfactants produced by three bacterial isolates from crude oil. Biosurfactants produced by one of the strains (named as IMP67 was found to be very efficacious based on its critical micelle concentration (CMC value and hydrocarbon emulsification property. Strikingly, antimicrobial and anti-biofilm potential of this biosurfactant were higher than biosurfactants produced by other two strains. Thin layer chromatography (TLC analysis and rhamnose quantification showed that the rhamnolipids of IMP67 had more MRL congeners than biosurfactants of the other two strains. Emulsification and antimicrobial actions were affected by manual change of MRL and DRL congener proportions. Increase of MRL proportion enhanced emulsification index and antimicrobial property to Gram negative bacteria. This result indicated that the ratio of MRL and DRL affect the emulsification potentials of rhamnolipids, and suggested that high emulsification potentials might enhance rhamnolipids to penetrate the cell wall of Gram negative bacteria. In consistent, rhamnolipids of IMP67 reduced the MIC of some antibiotics against bacteria, suggesting the potential of biosurfactant as antibiotics synergist.

Purification of Drug Loaded PLGA Nanoparticles Prepared by Emulsification Solvent Evaporation Using Stirred Cell Ultrafiltration Technique.

Science.gov (United States)

Paswan, Suresh K; Saini, T R

2017-12-01

The emulsifiers in an exceedingly higher level are used in the preparation of drug loaded polymeric nanoparticles prepared by emulsification solvent evaporation method. This creates great problem to the formulator due to their serious toxicities when it is to be administered by parenteral route. The final product is therefore required to be freed from the used surfactants by the conventional purification techniques which is a cumbersome job. The solvent resistant stirred cell ultrafiltration unit (Millipore) was used in this study using polyethersulfone ultrafiltration membrane (Biomax®) having pore size of NMWL 300 KDa as the membrane filter. The purification efficiency of this technique was compared with the conventional centrifugation technique. The flow rate of ultrafiltration was optimized for removal of surfactant (polyvinyl alcohol) impurities to the acceptable levels in 1-3.5 h from the nanoparticle dispersion of tamoxifen prepared by emulsification solvent evaporation method. The present investigations demonstrate the application of solvent resistant stirred cell ultrafiltration technique for removal of toxic impurities of surfactant (PVA) from the polymeric drug nanoparticles (tamoxifen) prepared by emulsification solvent evaporation method. This technique offers added benefit of producing more concentrated nanoparticles dispersion without causing significant particle size growth which is observed in other purification techniques, e.g., centrifugation and ultracentrifugation.

Emulsification properties of soy bean protein

Directory of Open Access Journals (Sweden)

WENPU CHEN

2014-12-01

Full Text Available Chen W, Li X, Rahman MRT, Al-Hajj NQM, Dey KC, Raqib SM. 2014. Emulsification properties of soy bean protein. Nusantara Bioscience 6: 196-202. Emulsion stability and emulsifying ability are two important factors in food industry. Soy protein has the great of interest because of its amphilic structure. β-Conglycinnin and glycinin are main components in soy protein which can be used as emulsifiers in food processing. However, due to its size and molecular weight, the emulsifying ability of soy protein is limited. By chemical, physical and enzymatic modification, the emulsifying ability of soy protein can be improved. The addition of polysaccharides in emulsion is common. The interaction of polysaccharides and proteins are being discussed in this review. In some complex food emulsion, the function of soy protein molecules and emulsifier at the interface need to be investigated in the future study.

Lambda-Cyhalothrin Nanosuspension Prepared by the Melt Emulsification-High Pressure Homogenization Method

OpenAIRE

Pan, Zhenzhong; Cui, Bo; Zeng, Zhanghua; Feng, Lei; Liu, Guoqiang; Cui, Haixin; Pan, Hongyu

2015-01-01

The nanosuspension of 5% lambda-cyhalothrin with 0.2% surfactants was prepared by the melt emulsification-high pressure homogenization method. The surfactants composition, content, and homogenization process were optimized. The anionic surfactant (1-dodecanesulfonic acid sodium salt) and polymeric surfactant (maleic rosin-polyoxypropylene-polyoxyethylene ether sulfonate) screened from 12 types of commercially common-used surfactants were used to prepare lambda-cyhalothrin nanosuspension with ...

Emulsification in binary liquids containing colloidal particles: a structure-factor analysis

International Nuclear Information System (INIS)

Thijssen, Job H J; Clegg, Paul S

2010-01-01

We present a quantitative confocal-microscopy study of the transient and final microstructure of particle-stabilized emulsions formed via demixing in a binary liquid. To this end, we have developed an image-analysis method that relies on structure factors obtained from discrete Fourier transforms of individual frames in confocal image sequences. Radially averaging the squared modulus of these Fourier transforms before peak fitting allows extraction of dominant length scales over the entire temperature range of the quench. Our procedure even yields information just after droplet nucleation, when the (fluorescence) contrast between the two separating phases is scarcely discernible in the images. We find that our emulsions are stabilized on experimental timescales by interfacial particles and that they are likely to have bimodal droplet-size distributions. We attribute the latter to coalescence together with creaming being the main coarsening mechanism during the late stages of emulsification and we support this claim with (direct) confocal-microscopy observations. In addition, our results imply that the observed droplets emerge from particle-promoted nucleation, possibly followed by a free-growth regime. Finally, we argue that creaming strongly affects droplet growth during the early stages of emulsification. Future investigations could clarify the link between quench conditions and resulting microstructure, paving the way for tailor-made particle-stabilized emulsions from binary liquids.

Emulsification index of petroleum products by bacteria isolated from mangrove; Taxa de emulsificacao de derivados do petroleo por bacterias isoladas de mangue

Energy Technology Data Exchange (ETDEWEB)

Krepsky, Natascha; Queiroz, Fernanda; Barcelos, Mabel Araujo de; Fontana, Luis Francisco; Bittencourt, Jose Augusto Pires; Pimenta, Alessandro L.; Silva, Frederico Sobrinho da; Bispo, Maria das Gracas Silveira; Crapez, Mirian Araujo Carlos [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Programa de Pos-graduacao em Biologia Marinha]. E-mail: mirian@vm.uff.br

2003-07-01

Oil spillage during ship transportation or at gas stations may be deleterious to environment due to its affinity for organic matter and its prompt distribution over the ground water surface, limiting bioremediation. The usage of bacterial surfactants can enhance the removal of petroleum hydrocarbons from the impacted area. Thus, the study of bacterial emulsification is relevant for improved environmental decontamination programs. Three Bacillus spp. were isolated from mangrove sediment of APA de Guapimirim -RJ, a protection area previously impacted with petroleum hydrocarbon. Emulsification index was quantified from gasoline, kerosene and Arabian light. The bacteria showed a high emulsification index, especially for gasoline, that seemed to be related to its biomass. Our results indicated a possible utilization of this biosurfactant in the environmental remediation on areas impacted with gasoline or Arabian light. (author)

Role of medium-chain fatty acids in the emulsification mechanistics of self-micro-emulsifying lipid formulations.

Science.gov (United States)

Hasan, Naser M Y

2014-12-01

The objective of the present study was to design and develop stable o/w microemulsions comprising Miglyol 812, Imwitor 988 and Tagat TO as a non ionic surfactant. This was based on particle size measurements and phase behavior studies. The empirical role of incorporating medium-chain mono/di-glycerides in the lipid matrix in the mechanistic processes of emulsification was also established in various simulating physiological conditions. The efficiency of self-emulsification was evaluated under conditions of varying key compositions in the lipid mixtures; oil, cosurfactant and surfactant. Droplet diameter was measured using laser diffraction and light scattering techniques. Equilibrium phase studies were performed and phase boundaries were determined for the lipid-water systems. Microemulsion systems were produced from blends of Miglyol 812, Imwitor 988 and Tagat TO. An optimized formulation consisted of {Miglyol 812/Imwitor 988} and Tagat TO spontaneously self-emulsified in water producing dispersions with droplet diameters of ∼50 nm. Phase equilibrium diagrams have revealed significant enhancement in the water-solubilized region (L2) without any presence of liquid crystalline materials. Potential SMEDDS formulations for the bioavailability enhancement of poorly water-soluble compounds were developed by mixing blends of {Miglyol 812/Imwitor 988} and Tagat TO as a non-ionic surfactant. 'Diffusion and stranding' appears to be the dominant mechanism of emulsification.

Effect of emulsification on the skin permeation and UV protection of catechin.

Science.gov (United States)

Yoshino, Sachie; Mitoma, Tomoaki; Tsuruta, Keiko; Todo, Hiroaki; Sugibayashi, Kenji

2014-06-01

An anti-aging effect may be obtained by skin application of tea catechins (Camellia sinensis) since they have high ultraviolet (UV)-protection activity. In this study, the skin permeation of catechin (C), epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECg) and epigallocatechin gallate (EGCg) was determined and compared, and the effect of emulsification on the skin permeation of C was measured. The UV-protective effect of C was also determined. The in vitro skin permeability of each catechin derivative was determined using side-by-side diffusion of cells. The UV-protective effect of C was determined by applying different concentrations of C to the solution or emulsion on a three-dimensional cultured human skin model or normal human epidermal keratinocytes with UV-irradiation. ECg and EGCg with gallate groups showed lower skin permeability than C, EC and EGC without gallate groups, suggesting that the skin permeability of catechin derivatives may be dependent on the existence of a gallate group. Interestingly, the skin permeation of C was increased by an o/w emulsification. In addition, the C emulsion showed a significantly higher UV-protective effect by C than that with its aqueous solution. These results suggest that the o/w emulsion of catechin derivatives is probably useful as a cosmetic formulation with anti-aging efficacy.

Development of novel cilostazol-loaded solid SNEDDS using a SPG membrane emulsification technique: Physicochemical characterization and in vivo evaluation.

Science.gov (United States)

Mustapha, Omer; Kim, Kyung Soo; Shafique, Shumaila; Kim, Dong Shik; Jin, Sung Giu; Seo, Youn Gee; Youn, Yu Seok; Oh, Kyung Taek; Lee, Beom-Jin; Park, Young Joon; Yong, Chul Soon; Kim, Jong Oh; Choi, Han-Gon

2017-02-01

The objective of this study was to develop a novel solid self-nanoemulsifying drug delivery system (SNEDDS) using a membrane emulsification technique involving Shirasu porous glass (SPG) which produced very small and uniform emulsion droplets, resulting in enhanced solubility, dissolution and oral bioavailability of poorly water-soluble cilostazol. The effects of carriers on the drug solubility were assessed, and pseudo-ternary phase diagrams were plotted. Among the liquid SNEDDS formulations tested, the liquid SNEDDS composed of peceol (oil), Tween 20 (surfactant) and Labrasol (cosurfactant) at a weight ratio of 15/55/30, produced the smallest emulsion droplet size. The cilostazol-loaded liquid SNEDDS formulation was suspended in the distilled water and subjected to SPG membrane emulsification. Calcium silicate was added as a solid carrier in this liquid SNEDDS, completely suspended and spray-dried, leading to the production of a cilostazol-loaded solid SNEDDS. The emulsion droplet size, solubility and dissolution of the emulsified solid SNEDDS were assessed as compared to the solid SNEDDS prepared without emulsification. Moreover, the physicochemical characteristics and pharmacokinetics in rats were evaluated with the emulsified solid SNEDDS. The emulsified solid SNEDDS provided significantly smaller and more uniform nanoemulsions than did the non-emulsified solid SNEDDS. The emulsified solid SNEDDS showed significantly higher drug solubility and dissolution as compared to the non-emulsified solid SNEDDS. The crystalline drug in it was converted into the amorphous state. Moreover, in rats, it gave significantly higher initial plasma concentrations and AUC compared to the drug powder, suggesting its improved oral bioavailability of cilostazol. Thus, this novel solid SNEDDS developed using a membrane emulsification technique represents a potentially powerful oral delivery system for cilostazol. Copyright © 2016 Elsevier B.V. All rights reserved.

Quantifying the Pathway and Predicting Spontaneous Emulsification during Material Exchange in a Two Phase Liquid System.

Science.gov (United States)

Spooner, Stephen; Rahnama, Alireza; Warnett, Jason M; Williams, Mark A; Li, Zushu; Sridhar, Seetharaman

2017-10-30

Kinetic restriction of a thermodynamically favourable equilibrium is a common theme in materials processing. The interfacial instability in systems where rate of material exchange is far greater than the mass transfer through respective bulk phases is of specific interest when tracking the transient interfacial area, a parameter integral to short processing times for productivity streamlining in all manufacturing where interfacial reaction occurs. This is even more pertinent in high-temperature systems for energy and cost savings. Here the quantified physical pathway of interfacial area change due to material exchange in liquid metal-molten oxide systems is presented. In addition the predicted growth regime and emulsification behaviour in relation to interfacial tension as modelled using phase-field methodology is shown. The observed in-situ emulsification behaviour links quantitatively the geometry of perturbations as a validation method for the development of simulating the phenomena. Thus a method is presented to both predict and engineer the formation of micro emulsions to a desired specification.

Nanospheres of alginate prepared through w/o emulsification and internal gelation with nanoparticles of CaCO3

NARCIS (Netherlands)

Paques, J.P.; Sagis, L.M.C.; Rijn, van C.J.M.; Linden, van der E.

2014-01-01

Gelled nanospheres of alginate are prepared through a single step technique involving emulsification and gelation. CaCO3 nanoparticles, together with glucono delta-lactone (GDL), are dispersed in an alginate solution, which is subsequently dispersed in an oil phase and followed by gelation of the

Miniemulsification process - different form of spontaneous emulsification

Energy Technology Data Exchange (ETDEWEB)

El-Aasser, M.S.; Lack, C.D.; Vanderhoff, J.W.; Fowkes, F.M.

1988-01-15

The miniemulsification process involves the use of low concentrations of mixed emulsifier combinations of an ionic surfactant (e.g. sodium lauryl sulfate) and a cosurfactant (e.g. long-chain fatty alcohol - cetyl alcohol). The product is an oil-in-water miniemulsion with an average droplet diameter of 100-400 nm, and excellent shelf stability. The dominant presence of liquid crystals in the aqueous mixed emulsifier system, under conditions of the miniemulsification process, was confirmed by consideration of phase diagrams, conductivity and birefringence studies. Unexpectedly, interfacial tension studies showed relatively high values of 5-15 dyn cm/sup -1/. In spite of these high interfacial tensions, spontaneous emulsification was found at the oil-water interface, contrary to what is known in the field. Adsorption and electrophoretic mobility studies suggested that the miniemulsification process takes place by unidirectional swelling of the lamellar bilayers in the aqueous mixed emulsifier liquid crystal system as a result of absorption of oil, followed by subdivision of these entities. The stability of miniemulsions formed by this process is influenced by a steric component in the mixed emulsifier complex adsorbed at the oil-water interface.

Optimization of folic acid nano-emulsification and encapsulation by maltodextrin-whey protein double emulsions.

Science.gov (United States)

Assadpour, Elham; Maghsoudlou, Yahya; Jafari, Seid-Mahdi; Ghorbani, Mohammad; Aalami, Mehran

2016-05-01

Due to susceptibility of folic acid like many other vitamins to environmental and processing conditions, it is necessary to protect it by highly efficient methods such as micro/nano-encapsulation. Our aim was to prepare and optimize real water in oil nano-emulsions containing folic acid by a low energy (spontaneous) emulsification technique so that the final product could be encapsulated within maltodextrin-whey protein double emulsions. A non ionic surfactant (Span 80) was used for making nano-emulsions at three dispersed phase/surfactant ratios of 0.2, 0.6, and 1.0. Folic acid content was 1.0, 2.0, and 3.0mg/mL of dispersed phase by a volume fraction of 5.0, 8.5, and 12%. The final optimum nano-emulsion formulation with 12% dispersed phase, a water to surfactant ratio of 0.9 and folic acid content of 3mg/mL in dispersed phase was encapsulated within maltodextrin-whey protein double emulsions. It was found that the emulsification time for preparing nano-emulsions was between 4 to 16 h based on formulation variables. Droplet size decreased at higher surfactant contents and final nano-emulsions had a droplet size<100 nm. Shear viscosity was higher for those formulations containing more surfactant. Our results revealed that spontaneous method could be used successfully for preparing stable W/O nano-emulsions containing folic acid. Copyright © 2016 Elsevier B.V. All rights reserved.

Petroleum and derivatives emulsification by bacterial consortium of sea meeds from Enseada do Forno-Armacao de Buzios (RJ); Emulsificacao de petroleo e seus derivados pelos consorcios bacterianos de algas da Enseada do Forno-Armacao dos Buzios (RJ)

Energy Technology Data Exchange (ETDEWEB)

Silva, Frederico S. da; Crapez, Mirian A.C.; Krepsky, Natascha; Fontana, Luiz F.; Baptista-Neto, Jose Antonio [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)]. E-mail: fred@igeo.uff.br

2004-07-01

Constant petroleum spill over natural habitats made necessary alternatives for environmental damage mitigation and recuperation. Bio surfactants can be used as an alternative for oil spill once they reduce surface oil tension, making them soluble in water or can make it available from the sediments. Bacterial consortia were isolated and bio amplified from Caulerpa (C), Laurencia (L) and Dictyota (D) algae biofilm. Bacterial carbon (CB); surface tension (TS); Emulsification index (E{sub 24}) and non-aqueous (A) and aqueous (B) emulsification of gasoline, kerosene and Arabian Light were estimated in 0, 7, 15 and 30 days of incubation. Results show a decrease of Laurencia and Caulerpa CB. However, Dictyota showed an increase at CB. Laurencia TS showed no significant reduction at days 7 and 15. For Dictyota and Caulerpa there was a increase at day 7 and reduction at day 15. E{sub 24} was higher than 70% for all the three substances and consortia tested. Laurencia bacteria consortia presented emulsification B for Arabian Light and emulsification A for gasoline and kerosene. Caulerpa consortia emulsified all compounds. All bacterial consortia isolated were surfactant producer, with emulsification A and B, being indicated for recuperation of environments contaminated with oil and its derivatives compounds. (author)

Development of method of optimized flavor production systems design based on nano-emulsification Kawista (Feronia limonia) Fruit extraction

Science.gov (United States)

Suyanto, A.; Noor, E.; Fahma, F.; Rusli, M. S.; Djatna, T.

2018-01-01

‘Kawista’ (Feronia limonia) as a tropical fruit has unique flavor that can be applied as a flavor for food products. Flavor as volatile components are unstable by environment factors such as temperature and storage. Flavor nano emulsification form to improve the stability towards environment and increase its use in food products. Research carried out is system development of the nano emulsification Kawista extract flavor with sonication method. The best treatments are selected by Response Surface Methodology (RSM) for independent variable are amplitude (70-100%), time (90-150s) and temperature (5-45°C) controlled by the software of the device. The Flavor Extraction by maceration technique extended highest yield and flavor components. Nano-emulsions made with composition 1% (w/w) flavor extract, 2% (w/w) surfactant (tween 80), 0.25% Gum, and 96.75% (w/w) deionized water. The probe of sonication successfully for preparing stable O/W nano emulsions at amplitude, time and temperature 81.01%, 150s, 45°C, respectively. Characteristic of nano-emulsions i.e energy input (15.489J), viscosity (2.076 mPa.s), droplet size (13.446nm), and Polydispersity index (0.469).

Production of micron-sized polymer particles for additive manufacturing by melt emulsification

Energy Technology Data Exchange (ETDEWEB)

Fanselow, Stephanie; Schmidt, Jochen; Wirth, Karl-Ernst; Peukert, Wolfgang, E-mail: Wolfgang.Peukert@fau.de [Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstrasse 4, 91058 Erlangen (Germany)

2016-03-09

Melt emulsification is an advanced top-down approach that permits to produce spherical particles and thus widens the availability of polymer feed materials for additive manufacturing. In the process the polymer is molten in a continuous phase and droplet breakup is realized in a rotor-stator-device. The stabilization of the newly formed surfaces is quite challenging. Therefore, a new method to identify an appropriate emulsifier by measuring the interfacial tension between the polymer and continuous phase using a high pressure / high temperature cell is presented. The obtained powders are characterized by scanning electron microscopy (SEM) and by a Zimmermann tensile strength tester to determine the powder flowability. The processability of the polymer powders for additive manufacturing is investigated and demonstrated by building single layers by laser beam melting.

Comparison of spray congealing and melt emulsification methods for the incorporation of the water-soluble salbutamol sulphate in lipid microparticles.

Science.gov (United States)

Scalia, Santo; Traini, Daniela; Young, Paul M; Di Sabatino, Marcello; Passerini, Nadia; Albertini, Beatrice

2013-02-01

Salbutamol sulphate is widely used as bronchodilator for the treatment of asthma. Its use is limited by the relatively short duration of action and hence sustained delivery of salbutamol sulphate offers potential benefits to patients. This study explores the preparation of lipid microparticles (LMs) as biocompatible carrier for the prolonged release of salbutamol sulphate. The LMs were produced using different lipidic materials and surfactants, by classical melt emulsification-based methods (oil-in-water and water-in-oil-in-water emulsions) and the spray congealing technique. For the LMs obtained by melt emulsification a lack of release modulation was observed. On the other hand, the sustained release of salbutamol sulphate was achieved with glyceryl behenate microparticles prepared by spray congealing. These LMs were characterized by scanning electron microscopy, X-ray diffractometry and differential scanning calorimetry. The drug loading was 4.72% (w/w). The particle size distribution measured by laser diffraction and electrical zone sensing was represented by a volume median diameter (Dv(50)) of 51.7-71.4 µm. Increasing the atomization air pressure from 4 to 8 bar produced a decrease of the Dv(50) to 12.7-17.5 µm. Incorporation of the hydrophilic salbutamol sulphate into LMs with sustained release characteristics was achieved by spray congealing.

INTERFACIAL ENERGY DURING THE EMULSIFICATION OF WATER-IN-HEAVY CRUDE OIL EMULSIONS

Directory of Open Access Journals (Sweden)

V. Karcher

2015-03-01

Full Text Available Abstract The aim of this study was to investigate the interfacial energy involved in the production of water-in-oil (W/O emulsions composed of water and a Brazilian heavy crude oil. For such purpose an experimental set-up was developed to measure the different energy terms involved in the emulsification process. W/O emulsions containing different water volume fractions (0.1, 0.25 and 0.4 were prepared in a batch calorimeter by using a high-shear rotating homogenizer at two distinct rotation speeds (14000 and 22000 rpm. The results showed that the energy dissipated as heat represented around 80% of the energy transferred to the emulsion, while around 20% contributed to the internal energy. Only a very small fraction of the energy (0.02 - 0.06% was stored in the water-oil interface. The results demonstrated that the high energy dissipation contributes to the kinetic stability of the W/O emulsions.

Fabrication of magnetic and fluorescent chitin and dibutyrylchitin sub-micron particles by oil-in-water emulsification.

Science.gov (United States)

Blanco-Fernandez, Barbara; Chakravarty, Shatadru; Nkansah, Michael K; Shapiro, Erik M

2016-11-01

Chitin is a carbohydrate polymer with unique pharmacological and immunological properties, however, because of its unwieldy chemistry, the synthesis of discreet sized sub-micron particles has not been well reported. This work describes a facile and flexible method to fabricate biocompatible chitin and dibutyrylchitin sub-micron particles. This technique is based on an oil-in-water emulsification/evaporation method and involves the hydrophobization of chitin by the addition of labile butyryl groups onto chitin, disrupting intermolecular hydrogen bonds and enabling solubility in the organic solvent used as the oil phase during fabrication. The subsequent removal of butyryl groups post-fabrication through alkaline saponification regenerates native chitin while keeping particles morphology intact. Examples of encapsulation of hydrophobic dyes and nanocrystals are demonstrated, specifically using iron oxide nanocrystals and coumarin 6. The prepared particles had diameters between 300-400nm for dibutyrylchitin and 500-600nm for chitin and were highly cytocompatible. Moreover, they were able to encapsulate high amounts of iron oxide nanocrystals and were able to label mammalian cells. We describe a technique to prepare sub-micron particles of highly acetylated chitin (>90%) and dibutyrylchitin and demonstrate their utility as carriers for imaging. Chitin is a polysaccharide capable of stimulating the immune system, a property that depends on the acetamide groups, but its insolubility limits its use. No method for sub-micron particle preparation with highly acetylated chitins have been published. The only approach for the preparation of sub-micron particles uses low acetylation chitins. Dibutyrylchitin, a soluble chitin derivative, was used to prepare particles by oil in water emulsification. Butyryl groups were then removed, forming chitin particles. These particles could be suitable for encapsulation of hydrophobic payloads for drug delivery and cell imaging, as well as

Effect of emulsification and spray-drying microencapsulation on the antilisterial activity of transcinnamaldehyde.

Science.gov (United States)

Trinh, Nga-Thi-Thanh; Lejmi, Raja; Gharsallaoui, Adem; Dumas, Emilie; Degraeve, Pascal; Thanh, Mai Le; Oulahal, Nadia

2015-01-01

Spray-dried redispersible transcinnamaldehyde (TC)-in-water emulsions were prepared in order to preserve its antibacterial activity; 5% (w/w) TC emulsions were first obtained with a rotor-stator homogeniser in the presence of either soybean lecithin or sodium caseinate as emulsifiers. These emulsions were mixed with a 30% (w/w) maltodextrin solution before feeding a spray-dryer. The antibacterial activity of TC alone, TC emulsions with and without maltodextrin before and after spray-drying were assayed by monitoring the growth at 30 °C of Listeria innocua in their presence and in their absence (control). Whatever the emulsifier used, antilisterial activity of TC was increased following its emulsification. However, reconstituted spray-dried emulsions stabilised by sodium caseinate had a higher antibacterial activity suggesting that they better resisted to spray-drying. This was consistent with observation that microencapsulation efficiencies were 27.6% and 78.7% for emulsions stabilised by lecithin and sodium caseinate, respectively.

Numerical Study of Surfactant Dynamics during Emulsification in a T-Junction Microchannel.

Science.gov (United States)

Riaud, Antoine; Zhang, Hao; Wang, Xueying; Wang, Kai; Luo, Guangsheng

2018-04-18

Microchannel emulsification requires large amounts of surfactant to prevent coalescence and improve emulsions lifetime. However, most numerical studies have considered surfactant-free mixtures as models for droplet formation in microchannels, without taking into account the distribution of surfactant on the droplet surface. In this paper, we investigate the effects of nonuniform surfactant coverage on the microfluidic flow pattern using an extended lattice-Boltzmann model. This numerical study, supported by micro-particle image velocimetry experiments, reveals the likelihood of uneven distribution of surfactant during the droplet formation and the appearance of a stagnant cap. The Marangoni effect affects the droplet breakup by increasing the shear rate. According to our results, surfactant-free and surfactant-rich droplet formation processes are qualitatively different, such that both the capillary number and the Damköhler number should be considered when modeling the droplet generation in microfluidic devices. The limitations of traditional volume and pressure estimation methods for determining the dynamic interfacial tension are also discussed on the basis of the simulation results.

Lambda-Cyhalothrin Nanosuspension Prepared by the Melt Emulsification-High Pressure Homogenization Method

Directory of Open Access Journals (Sweden)

Zhenzhong Pan

2015-01-01

Full Text Available The nanosuspension of 5% lambda-cyhalothrin with 0.2% surfactants was prepared by the melt emulsification-high pressure homogenization method. The surfactants composition, content, and homogenization process were optimized. The anionic surfactant (1-dodecanesulfonic acid sodium salt and polymeric surfactant (maleic rosin-polyoxypropylene-polyoxyethylene ether sulfonate screened from 12 types of commercially common-used surfactants were used to prepare lambda-cyhalothrin nanosuspension with high dispersity and stability. The mean particle size and polydispersity index of the nanosuspension were 16.01 ± 0.11 nm and 0.266 ± 0.002, respectively. The high zeta potential value of −41.7 ± 1.3 mV and stable crystalline state of the nanoparticles indicated the excellent physical and chemical stability. The method could be widely used for preparing nanosuspension of various pesticides with melting points below boiling point of water. This formulation may avoid the use of organic solvents and reduce surfactants and is perspective for improving bioavailability and reducing residual pollution of pesticide in agricultural products and environment.

Preparation and characterization of solid lipid nanoparticles containing cyclosporine by the emulsification-diffusion method

Directory of Open Access Journals (Sweden)

Zaida Urbán-Morlán

2010-08-01

Full Text Available Zaida Urbán-Morlán1, Adriana Ganem-Rondero1, Luz María Melgoza-Contreras2, José Juan Escobar-Chávez1,2, María Guadalupe Nava-Arzaluz1, David Quintanar-Guerrero11División de Estudios de Posgrado (Tecnología Farmacéutica, Facultad de Estudios Superiores Cuautitlán-Universidad Nacional Autónoma de México, Estado de México, México; 2Departamento de Sistemas Biológicos, Universidad Autónoma Metropolitana-Xochimilco, Calzada del Hueso, Colonia Villa Quietud, MéxicoAbstract: Solid lipid nanoparticles (SLNs have been used for carrying different therapeutic agents because they improve absorption and bioavailability. The aim of the study was to prepare lipidic nanoparticles containing cyclosporine (CyA by the emulsification-diffusion method and to study their physicochemical stability. Glyceryl behenate (Compritol® ATO 888 and lauroyl macrogolglycerides (Gelucire® 44/14 were used as carrier materials. Nanoparticles with good stability were obtained with Gelucire®, while it was difficult to obtain stable systems with Compritol®. Systems with Gelucire® were characterized by particle size, Z-potential, differential scanning calorimetry (DSC, scanning electron microscopy (SEM, entrapment efficiency and in vitro release. Particle size and Z-potential were evaluated for at least three months. With a high CyA content (≥60 mg in Gelucire® SLNs, variations in size were greater and particle size also increased over time in all batches; this effect may have been caused by a probable expulsion of the drug due to the lipid’s partial rearrangement. While the Z-potential decreased 10 mV after three months, this effect may be explained by the superficial properties of the drug that make the molecules to be preferably oriented at the solid-liquid interface, causing a change in the net charge of the particle. SEM confirmed size and shape of the nanoparticles. DSC studies evidenced that CyA affects the lipid structure by a mechanism still unknown

Computational Fluid Dynamics (CFD-Based Droplet Size Estimates in Emulsification Equipment

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Jo Janssen

2016-12-01

Full Text Available While academic literature shows steady progress in combining multi-phase computational fluid dynamics (CFD and population balance modelling (PBM of emulsification processes, the computational burden of this approach is still too large for routine use in industry. The challenge, thus, is to link a sufficiently detailed flow analysis to the droplet behavior in a way that is both physically relevant and computationally manageable. In this research article we propose the use of single-phase CFD to map out the local maximum stable droplet diameter within a given device, based on well-known academic droplet break-up studies in quasi-steady 2D linear flows. The results of the latter are represented by analytical correlations for the critical capillary number, which are valid across a wide viscosity ratio range. Additionally, we suggest a parameter to assess how good the assumption of quasi-steady 2D flow is locally. The approach is demonstrated for a common lab-scale rotor-stator device (Ultra-Turrax, IKA-Werke GmbH, Staufen, Germany. It is found to provide useful insights with minimal additional user coding and little increase in computational effort compared to the single-phase CFD simulations of the flow field, as such. Some suggestions for further development are briefly discussed.

OPTIMASI PROSES PEMBUATAN BUBUK OLEORESIN LADA (Piper nigrum MELALUI PROSES EMULSIFIKASI DAN MIKROENKAPSULASI (Optimization Process Production Powder of Oleoresin Pepper (Piper nigrum by Process of Emulsification and Microencapsulation

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Firdaus Syafi'i

2016-10-01

Full Text Available The aim of this study was to improve the quality of pepper product by optimize process of emulsification and microencapsulation. The experimental design used in this study was Response Surface Methodology (RSM. The results showed that the selected emulsifier was arabic gum that had the highest solubility in water (99.78%. The optimum point of emulsification occured at 15% of concentration arabic gum and 4 minutes of homogenization time with the result was solubility in water 99.80%, and emulsion stability 97.78%. The optimum point of microencapsulation process occured at 3:1 of maltodextrin and sodium caseinate ratio, 10% of coating material concentration, and 180°C of drying temperature with the result was essential oil content 1.04%, solubility in water 98.18%, surface oil 0.20%, water content 2.45%, oil recovery 77.07%, and the yield of microcapsule 69.87% Keywords: Pepper oleoresin, RSM, emulsification, microencapsulation ABSTRAK Penelitian ini bertujuan untuk memperbaiki kualitas mutu produk oleoresin lada melalui optimasi proses emulsifikasi dan mikroenkapsulasi. Rancangan percobaan yang digunakan adalah Response Surface Methodology (RSM. Hasil penelitian menunjukkan bahan pengemulsi yang terpilih adalah gum arab yang memiliki kelarutan tertinggi dalam air (99,78%. Titik optimum proses emulsifikasi terjadi pada konsentrasi gum arab 15% dan lama homogenisasi 4 menit yang memberikan nilai kelarutan dalam air 99,80% dan stabilitas emulsi 97,15%. Titik optimum proses mikroenkapsulasi terjadi pada rasio maltodekstrin dan natrium kaseinat (3:1, konsentrasi bahan penyalut 10%, dan suhu inlet pengeringan 180°C yang memberikan nilai kadar minyak atsiri 1,04%, kelarutan dalam air 98,18%, kadar surface oil 0,20%, kadar air 2,45%, oil recovery 77,07%, dan rendemen 69,87% Kata kunci: Oleoresin lada, RSM, emulsifikasi, mikroenkapsulasi

Release kinetics and cell viability of ibuprofen nanocrystals produced by melt-emulsification.

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Fernandes, A R; Dias-Ferreira, J; Cabral, C; Garcia, M L; Souto, E B

2018-06-01

The clinical use of poorly water-soluble drugs has become a big challenge in pharmaceutical development due to the compromised bioavailability of the drugs in vivo. Nanocrystals have been proposed as a formulation strategy to improve the dissolution properties of these drugs. The benefits of using nanocrystals in drug delivery, when compared to other nanoparticles, are related to their production facilities, simple structure, and suitability for a variety of administration routes. High pressure homogenization (HPH) is the most promising production process, which can be employed at low or high temperatures. Ibuprofen nanocrystals with a mean size below 175 nm, and polydispersity below 0.18, have been produced by melt-emulsification, followed by HPH. Two nanocrystal formulations, differing on the surfactant composition, have been produced, their in vitro ibuprofen release tested in Franz diffusion cells and adjusted to several kinetic models (zero order, first order, Higuchi, Hixson-Crowell, Korsmeyer-Peppas, Baker-Lonsdale and Weibull model). Cell viability was assessed at 3, 6 and 24 h of incubation on human epithelial colorectal cells (Caco-2) by AlamarBlue ® colorimetric assay. For both formulations, Caco-2 cells viability was dependent on the drug concentration and time of exposure. Copyright © 2018 Elsevier B.V. All rights reserved.

Addition of Zinc Improves the Physical Stability of Insulin in the Primary Emulsification Step of the Poly(lactide-co-glycolide Microsphere Preparation Process

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Chandrasekar Manoharan

2015-04-01

Full Text Available In this study, the effect of zinc on insulin stability during the primary emulsification step of poly(lactide-co-glycolide microspheres preparation by the water-in-oil-in-water (w/o/w double emulsion solvent evaporation technique was evaluated. Insulin was emulsified at homogenization speeds of 5000 and 10,000 rpm. Insulin was extracted from the primary w/o emulsion by a method previously reported from our laboratory and analyzed by comprehensive analytical techniques. The differential scanning calorimetry thermograms of insulin with zinc showed a single peak around 83 °C with calorimetric enthalpy values similar to native insulin. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE of extracted insulin showed a single intense band around 6 kDa, demonstrating the preservation of primary structure. High performance liquid chromatography (HPLC analysis revealed that no degradation products were formed during the homogenization process. Insulin aggregates residing at the w/o interfaces were found to be of non-covalent nature. In addition, observation of a single characteristic peak for insulin at m/z 5808 in the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF mass spectrum confirmed the absence of insulin degradation products and covalent dimers. Presence of zinc preserved the secondary structure of insulin as indicated by circular dichroism. In conclusion, these results show that with the addition of zinc, insulin stability can be improved during the primary emulsification step.

Production of BCG alginate-PLL microcapsules by emulsification/internal gelation.

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Esquisabel, A; Hernández, R M; Igartua, M; Gascón, A R; Calvo, B; Pedraz, J L

1997-01-01

A biocompatible emulsification method for microencapsulation of live cells and enzymes within a calcium alginate matrix applied to Bacillus Calmette-Guérin (BCG) has been developed. Small-diameter alginate beads (microcapsules) were formed via internal gelation of an alginate solution emulsified within vegetable oil. Five different oils (sesame, sweet almond, perhydrosqualene, camomile and jojoba) were used. The rheological analysis of the oils showed a Newtonian behaviour, with viscosities = 30.0, 37.7, 51.2, 59.3 and 67.1 mPa.s for perhydrosqualene, jojoba, camomile, sesame and sweet almond oil respectively. The particle size of the microcapsules obtained ranged from 30.3 microns for the microcapsules prepared with sweet almond oil to 57.0 microns for those made with perhydrosqualene. The mean particle diameter obtained was found to be dependent on the viscosity of the oil employed, according to the equation: phi (micron) = 76.6-0.628 eta (mPa.s) (r2 = 0.943). The encapsulated BCG was identified by the Difco TB stain set K, followed by observation under optical microscopy. Freeze-drying of the microcapsules was carried out to ensure their stability during storage. Two batches of microcapsules (those prepared with sesame and jojoba oil) and four types of cryoprotectors (glucose, trehalose, mannitol and sorbitol), at three concentration levels (5, 10 and 20% w/v) were studied. The parameters evaluated were particle size, physical appearance, reconstitution of lyophilizates and microscopical evaluation. For both batches of microcapsules the best results were obtained with trehalose 5%, showing particle sizes of 42.1 microns in the case of the microcapsules prepared with sesame oil, and of 45.3 microns for those prepared with jojoba.

Adsorption of phospholipids at oil/water interfaces during emulsification is controlled by stress relaxation and diffusion.

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Hildebrandt, Ellen; Nirschl, Hermann; Kok, Robbert Jan; Leneweit, Gero

2018-05-16

Adsorption of phosphatidylcholines at oil/water interfaces strongly deviates from spread monolayers at air/water surfaces. Understanding its nature and consequences could vastly improve applications in medical nanoemulsions and biotechnologies. Adsorption kinetics at interfaces of water with different oil phases were measured by profile analysis tensiometry. Adsorption kinetics for 2 different phospholipids, DPPC and POPC, as well as 2 organic phases, squalene and squalane, show that formation of interfacial monolayers is initially dominated by stress-relaxation in the first minutes. Diffusion only gradually contributes to a decrease in interfacial tension at later stages of time and higher film pressures. The results can be applied for the optimization of emulsification protocols using mechanical treatments. Emulsions using phospholipids with unsaturated fatty acids are dominated much more strongly by stress-relaxation and cover interfaces very fast compared to those with saturated fatty acids. In contrast, phospholipid layers consisting of saturated fatty acids converge faster towards the equilibrium than those with unsaturated fatty acids.

Emulsification of waste cooking oils and fatty acid distillates as diesel engine fuels: An attractive alternative

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Eliezer Ahmed Melo Espinosa

2016-06-01

Full Text Available The scope of this paper is to analyze the possibility and feasibility of the use of emulsification method applied to waste cooking oils and fatty acid distillates as diesel engine fuels, compared with other commonly used methods. These waste products are obtained from the refining oil industry, food industry and service sector, mainly. They are rarely used as feedstock to produce biofuels and other things, in spite of constitute a potential source of environmental contamination. From the review of the state of arts, significant decreases in exhaust emissions of nitrogen oxides, cylinder pressure as well as increases of the ignition delay, brake specific fuel consumption, hydrocarbon, smoke opacity, carbon monoxide, particulate matters to emulsified waste cooking oils and fatty acid distillates compared with diesel fuel are reported. In some experiments the emulsified waste cooking oils achieved better performance than neat fatty acid distillates, neat waste cooking oils and their derivatives methyl esters.

Production of Concentrated Pickering Emulsions with Narrow Size Distributions Using Stirred Cell Membrane Emulsification.

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Manga, Mohamed S; York, David W

2017-09-12

Stirred cell membrane emulsification (SCME) has been employed to prepare concentrated Pickering oil in water emulsions solely stabilized by fumed silica nanoparticles. The optimal conditions under which highly stable and low-polydispersity concentrated emulsions using the SCME approach are highlighted. Optimization of the oil flux rates and the paddle stirrer speeds are critical to achieving control over the droplet size and size distribution. Investigating the influence of oil volume fraction highlights the criticality of the initial particle loading in the continuous phase on the final droplet size and polydispersity. At a particle loading of 4 wt %, both the droplet size and polydispersity increase with increasing of the oil volume fraction above 50%. As more interfacial area is produced, the number of particles available in the continuous phase diminishes, and coincidently a reduction in the kinetics of particle adsorption to the interface resulting in larger polydisperse droplets occurs. Increasing the particle loading to 10 wt % leads to significant improvements in both size and polydispersity with oil volume fractions as high as 70% produced with coefficient of variation values as low as ∼30% compared to ∼75% using conventional homogenization techniques.

A study of the effectiveness and energy efficiency of ultrasonic emulsification.

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Li, Wu; Leong, Thomas S H; Ashokkumar, Muthupandian; Martin, Gregory J O

2017-12-20

Three essential experimental parameters in the ultrasonic emulsification process, namely sonication time, acoustic amplitude and processing volume, were individually investigated, theoretically and experimentally, and correlated to the emulsion droplet sizes produced. The results showed that with a decrease in droplet size, two kinetic regions can be separately correlated prior to reaching a steady state droplet size: a fast size reduction region and a steady state transition region. In the fast size reduction region, the power input and sonication time could be correlated to the volume-mean diameter by a power-law relationship, with separate power-law indices of -1.4 and -1.1, respectively. A proportional relationship was found between droplet size and processing volume. The effectiveness and energy efficiency of droplet size reduction was compared between ultrasound and high-pressure homogenisation (HPH) based on both the effective power delivered to the emulsion and the total electric power consumed. Sonication could produce emulsions across a broad range of sizes, while high-pressure homogenisation was able to produce emulsions at the smaller end of the range. For ultrasonication, the energy efficiency was higher at increased power inputs due to more effective droplet breakage at high ultrasound intensities. For HPH the consumed energy efficiency was improved by operating at higher pressures for fewer passes. At the laboratory scale, the ultrasound system required less electrical power than HPH to produce an emulsion of comparable droplet size. The energy efficiency of HPH is greatly improved at large scale, which may also be true for larger scale ultrasonic reactors.

The effect of calcium on the composition and physical properties of whey protein particles prepared using emulsification.

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Westerik, Nieke; Scholten, Elke; Corredig, Milena

2015-06-15

Protein microparticles were formed through emulsification of 25% (w/w) whey protein isolate (WPI) solutions containing various concentrations of calcium (0.0-400.0mM) in an oil phase stabilized by polyglycerol polyricinoleate (PGPR). The emulsions were heated (at 80°C) and the microparticles subsequently re-dispersed in an aqueous phase. Light microscopy and scanning electron microscopy (SEM) images revealed that control particles and those prepared with 7.4mM calcium were spherical and smooth. Particles prepared with 15.0mM calcium gained an irregular, cauliflower-like structure, and at concentrations larger than 30.0mM, shells formed and the particles were no longer spherical. These results describe, for the first time, the potential of modulating the properties of dense whey protein particles by using calcium, and may be used as structuring agents for the design of functional food matrices with increased protein and calcium content. Copyright © 2015. Published by Elsevier Ltd.

Antitumor activity of docetaxel-loaded polymeric nanoparticles fabricated by Shirasu porous glass membrane-emulsification technique

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Yu YN

2013-07-01

Full Text Available Yunni Yu,1,* Songwei Tan,1,2,* Shuang Zhao,1 Xiangting Zhuang,1 Qingle Song,1 Yuliang Wang,1 Qin Zhou,2,3 Zhiping Zhang1,2 1Tongji School of Pharmacy, 2National Engineering Research Center for Nanomedicine, 3College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People’s Republic of China *These authors contributed equally to this work Abstract: Docetaxel (DTX has excellent efficiency against a wide spectrum of cancers. However, the current clinical formulation has limited its usage, as it causes some severe side effects. Various polymeric nanoparticles have thus been developed as alternative formulations of DTX, but they have been mostly fabricated on a laboratory scale. Previously, we synthesized a novel copolymer, poly(lactide-D-α-tocopheryl polyethylene glycol 1000 succinate (PLA-TPGS, and found that it exhibited great potential in drug delivery with improved properties. In this study, we applied the Shirasu porous glass (SPG membrane-emulsification technique to prepare the DTX-loaded PLA-TPGS nanoparticles on a pilot scale. The effect of several formulation variables on the DTX-loaded nanoparticle properties, including particle size, zeta potential, and drug-encapsulation efficiency, were investigated based on surfactant type and concentration in the aqueous phase, organic/aqueous phase volumetric ratio, membrane-pore size, transmembrane cycles, and operation pressure. The DTX-loaded nanoparticles were obtained with sizes of 306.8 ± 5.5 nm and 334.1 ± 2.7 nm (mean value ± standard deviation, and drug-encapsulation efficiency of 81.8% ± 4.5% and 64.5% ± 2.7% for PLA-TPGS and poly(lactic-co-glycolic acid (PLGA nanoparticles, respectively. In vivo pharmacokinetic study exhibited a significant advantage of PLA-TPGS nanoparticles over PLGA nanoparticles and Taxotere. Drug-loaded PLA-TPGS nanoparticles exhibited 1.78-, 6.34- and 3.35-fold higher values for area under the curve, half-life, and mean

Skin permeation of D-limonene-based nanoemulsions as a transdermal carrier prepared by ultrasonic emulsification.

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Lu, Wen-Chien; Chiang, Been-Huang; Huang, Da-Wei; Li, Po-Hsien

2014-03-01

Nanoemulsions can be used for transporting pharmaceutical phytochemicals in skin-care products because of their stability and rapid permeation properties. However, droplet size may be a critical factor aiding permeation through skin and transdermal delivery efficiency. We prepared D-limonene nanoemulsions with various droplet sizes by ultrasonic emulsification using mixed surfactants of sorbitane trioleate and polyoxyethylene (20) oleyl ether under different hydrophilic-lipophilic balance (HLB) values. Droplet size decreased with increasing HLB value. With HLB 12, the droplet size was 23 nm, and the encapsulated ratio peaked at 92.3%. Transmission electron microscopy revealed spherical droplets and the gray parts were D-limonene precipitation incorporated in spherical droplets of the emulsion system. Franz diffusion cell was used to evaluate the permeation of D-limonene nanoemulsion through rat abdominal skin; the permeation rate depended on droplet size. The emulsion with the lowest droplet size (54 nm) achieved the maximum permeation rate. The concentration of D-limonene in the skin was 40.11 μL/cm(2) at the end of 360 min. Histopathology revealed no distinct voids or empty spaces in the epidermal region of permeated rat skin, so the D-limonene nanoemulsion may be a safe carrier for transdermal drug delivery. Copyright © 2013 Elsevier B.V. All rights reserved.

Methyl Salicylate-Based Vortex-Assisted Surfactant-Enhanced Emulsification Microextraction and HPLC for Determination of Fungicides in Honey Samples.

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Santaladchaiyakit, Yanawath; Bunchamnan, Jutamas; Tongsa, Darunee; Srijaranai, Supalax

2017-12-01

Methyl salicylate based vortex-assisted surfactant-enhanced emulsification microextraction (MeSA-VASEME) has been developed and applied for rapid preconcentration of fungicides (i.e., carbendazim, thiabendazole, and fluberidazole) in honey samples followed by high performance liquid chromatographic analysis. MeSA was used as an extraction solvent, while surfactant was used to enhance the extraction performance under the dispersion by vortex agitation. The optimum MeSA-VASEME conditions were 100 μL MeSA, 2.0 mmol L‒1 sodium dodecyl sulfate, and vortex agitation at 1200 rpm for 90 s. Preconcentration factors were obtained in the range of 32-40. The limit of detection in the studied honey samples was 0.5 μg L‒1. The recovery of the spiked target fungicides at 20, 50, and 100 μg L‒1 were 81.5-116.8 % with the relative standard deviation below 11%. The proposed method is simple, sensitive, less organic solvent consuming, inexpensive, and a rapid procedure for the residue analysis of fungicides in honey samples.

An inert 3D emulsification device for individual precipitation and concentration of amorphous drug nanoparticles.

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Lorenz, T; Bojko, S; Bunjes, H; Dietzel, A

2018-02-13

Nanosizing increases the specific surface of drug particles, leading to faster dissolution inside the organism and improving the bioavailability of poorly water-soluble drugs. A novel approach for the preparation of drug nanoparticles in water using chemically inert microfluidic emulsification devices is presented in this paper. A lithographic fabrication sequence was established, allowing fabrication of intersecting and coaxial channels of different depths in glass as is required for 3D flow-focusing. Fenofibrate was used as a model for active pharmaceutical ingredients with very low water solubility in the experiments. It was dissolved in ethyl acetate and emulsified in water, as allowed by the 3D flow-focusing geometry. In the thread formation regime, the drug solution turned into monodisperse droplets of sizes down to below 1 μm. Fast supersaturation occurs individually in each droplet, as the disperse phase solvent progressively diffuses into the surrounding water. Liquid antisolvent precipitation results in highly monodisperse and amorphous nanoparticles of sizes down to 128 nm which can be precisely controlled by the continuous and disperse phase pressure. By comparing optically measured droplet sizes with particle sizes by dynamic light scattering, we could confirm that exactly one particle forms in every droplet. Furthermore, a downstream on-chip concentration allowed withdrawal of major volumes of only the continuous phase fluid which enabled an increase of particle concentration by up to 250 times.

Diffusion of Acetic Acid Across Oil/Water Interface in Emulsification-Internal Gelation Process for Preparation of Alginate Gel Beads

Institute of Scientific and Technical Information of China (English)

LIU Xiu-dong; YU Wei-ting; LIN Jun-zhang; MA Xiao-jun; YUAN Quan

2007-01-01

Alginate has been widely used in cell microencapsulation and drug delivery systems in the form of gel beads or microcapsules. Although an alternative novel emulsification-internal gelation technology has been established and both the properties and the potential applications of the beads in drug delivery systems have been studied, the mechanism has not been well understood compared with the traditional droplet method( external gelation technology). On the basis of our previous knowledge that the novel technology is composed of complicatedly consecutive processes with multistep diffusion and re action, and the diffusion of acetic acid across oil/water interface being the prerequisite that determines the occurrence and rate for the reactions and the structures and properties of final produced gel beads, a special emphasis was placed on the diffusion process. With the aid of diffusion modeling and simple experimental design, the diffusion rate constant and diffusion coefficient of acetic acid across oil/water interface were determined to be in the orders of magnitude of 10-6 and 10-16, respectively. This knowledge will be of particular importance in understanding and interpreting the formation, structure of the gel beads and the relationship between the structure and properties and guiding the preparation and quality control of the gel beads.

Enhancing emulsification and antioxidant ability of egg albumin by moderately acid hydrolysis: Modulating an emulsion-based system for mulberry seed oil.

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Chang, Jing; Kang, Xu; Yuan, Jiang-Lan

2018-07-01

Mulberry seed oil (MSO) is a kind of potential health-care lipids. This study, we investigated unsaturated fatty acids profiles of freshly squeezed MSO by GC-MS and modulated an oil-in-water emulsion system stabilized by acid hydrolyzed egg albumin (AHEA) to protect MSO from oxidation. The results showed that the content of total unsaturated fatty acids in MSO was almost 80%, of which 9, 12- and 10, 13-linoleic acid was over 60% and 10% respectively. In the case of the MSO-in-AHEA emulsions, it was observed that acid hydrolysis improved emulsifying effect, emulsifying stability and antioxidant activity of egg albumin (EA). The hydrolysates of EA (1%, w/w) acid hydrolyzed for 4 h at 85 °C had the best DPPH radical scavenging efficiency. It was suitable for EA to hydrolyze for 4 to 12 h at pH 2.5 and 85 °C because of their better emulsification and oxidation stability than the others. The results about AHEA could be valuable for designing delivery and protect systems for MSO or other bioactive component to avoid their oxidative damage or control their release. Copyright © 2018 Elsevier Ltd. All rights reserved.

Emulsification based dispersive liquid microextraction prior to flame atomic absorption spectrometry for the sensitive determination of Cd(II) in water samples

International Nuclear Information System (INIS)

Rahimi-Nasrabadi, Mehdi; Banan, Alireza; Zahedi, Mir Mahdi; Pourmortazavi, Seied Mahdi; Nazari, Zakieh; Asghari, Alireza

2013-01-01

We report on the application of emulsification-based dispersive liquid micro extraction (EB-DLME) to the preconcentration of Cd(II). This procedure not only possesses all the advantages of routine DLLME, but also results in a more stable cloudy state which is particularly useful when coupling it to FAAS. In EB-DLME, appropriate amounts of the extraction solvent (a solution of dithizone in chloroform) and an aqueous solution of sodium dodecyl sulfate (SDS; acting as a disperser) are injected into the samples. A stable cloudy microemulsion is formed and Cd(II) ion is extracted by chelation. After phase separation, the sedimented phase is subjected to FAAS. Under optimized conditions, the calibration curve for Cd(II) is linear in the range from 0.1 to 25 μg L −1 , the limit of detection (at S/N = 3) is 30 pg L −1 , the relative standard deviations for seven replicate analyses (at 0.56 μg L −1 of Cd(II)) is 4.6 %, and the enrichment factor is 151. EB-DLME in our opinion is a simple, efficient and rapid method for the preconcentration of Cd(II) (and most likely of many other ions) prior to FAAS determination. (author)

Continuous synthesis of drug-loaded nanoparticles using microchannel emulsification and numerical modeling: effect of passive mixing

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Ortiz de Solorzano I

2016-07-01

Full Text Available Isabel Ortiz de Solorzano,1,2,* Laura Uson,1,2,* Ane Larrea,1,2,* Mario Miana,3 Victor Sebastian,1,2 Manuel Arruebo1,2 1Department of Chemical Engineering and Environmental Technologies, Institute of Nanoscience of Aragon (INA, University of Zaragoza, 2CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN, Centro de Investigación Biomédica en Red, Madrid, 3ITAINNOVA, Instituto Tecnológico de Aragón, Materials & Components, Zaragoza, Spain *These authors contributed equally to this work Abstract: By using interdigital microfluidic reactors, monodisperse poly(d,l lactic-co-glycolic acid nanoparticles (NPs can be produced in a continuous manner and at a large scale (~10 g/h. An optimized synthesis protocol was obtained by selecting the appropriated passive mixer and fluid flow conditions to produce monodisperse NPs. A reduced NP polydispersity was obtained when using the microfluidic platform compared with the one obtained with NPs produced in a conventional discontinuous batch reactor. Cyclosporin, an immunosuppressant drug, was used as a model to validate the efficiency of the microfluidic platform to produce drug-loaded monodisperse poly(d,l lactic-co-glycolic acid NPs. The influence of the mixer geometries and temperatures were analyzed, and the experimental results were corroborated by using computational fluid dynamic three-dimensional simulations. Flow patterns, mixing times, and mixing efficiencies were calculated, and the model supported with experimental results. The progress of mixing in the interdigital mixer was quantified by using the volume fractions of the organic and aqueous phases used during the emulsification–evaporation process. The developed model and methods were applied to determine the required time for achieving a complete mixing in each microreactor at different fluid flow conditions, temperatures, and mixing rates. Keywords: microchannel emulsification, high-throughput synthesis, drug-loaded polymer

γ-Oryzanol nanoemulsions produced by a low-energy emulsification method: an evaluation of process parameters and physicochemical stability.

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Zhong, Jinfeng; Liu, Xiong; Wang, Yonghua; Qin, Xiaoli; Li, Zeling

2017-06-21

γ-Oryzanol is a natural antioxidant and nutraceutical compound, which makes it a good candidate for nutraceuticals, food supplements and pharmaceutical preparations. However, the incorporation of γ-oryzanol into aqueous formulations is rather difficult and its bioavailability can be severely decreased because of its water-insoluble property. In this study, γ-oryzanol-enriched nanoemulsion based fish oil and medium-chain triglyceride as carrier oils were proposed. The main objective was to optimize process parameters to form stable nanoemulsions and evaluate their physicochemical stability. The formulations of stable γ-oryzanol nanoemulsions were composed of 10% mixed carrier oils (weight ratio of fish oil to medium-chain triglyceride = 3 : 7) and 10% mixed surfactants (weight ratio of Tween 80 to Span 20 = 3 : 1). The nanoemulsions were stable at a broad pH range of 2-7 and high salt concentrations (≤0.8 mol L -1 ) and sucrose levels (≤16%). The nanoemulsions were much more stable at heating temperatures below 50 °C than at elevated heating temperatures (60 and 70 °C). The nanoemulsions maintained their physical stability at various storage temperatures (5-37 °C) for 18 days. Nanoemulsions at 5 and 23 °C had lower peroxide values and anisidine values than those at an elevated storage temperature (37 °C). These results demonstrate that the low-energy emulsification method can produce γ-oryzanol-enriched nanoemulsions using fish oil and medium-chain triglyceride as carrier oils, and provide useful information for producing bioactive lipids-loaded nanoemulsions for food systems, personal care and pharmaceutical products.

Síntesis de microcápsulas de poliurea a partir de aminas renovables, mediante doble emulsificación Synthesis of polyurea microcapsules from renewable amines by double emulsification

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Paula Mazo

2011-01-01

Full Text Available En este trabajo se realizó la microencapsulación de un perfume comercial mediante una doble emulsificación, la coraza de poliurea fue sintetizada por la reacción de Lisina con dos diisocianatos comerciales, uno aromático y otro alifático. En la síntesis se evaluó el efecto que tiene la relación molar amina:diisocianato y el tipo de emulsificante. Se optimizó el tamaño de partícula utilizando un diseño factorial 32 y análisis de superficie de respuesta, las variables fueron: cantidad de alcohol polivinílico y la relación de fase dispersa a fase continua. Las microcápsulas se caracterizaron mediante: análisis de calorimetría diferencial de barrido (DSC, espectroscopía infrarroja (IR, microscopía electrónica de barrido (SEM y tamaño medio de partícula. La doble emulsificación permite un mayor rendimiento de encapsulación del perfume, las micropartículas presentan un menor tamaño de partícula cuando: se emplea diisocianato aromático, un aumento de coloide protector (PVA y una disminución de la fase dispersa.This paper reports on the microencapsulation of a commercial perfume by means of a double emulsification, where the polyurea shell was synthesized by the reaction of lysine with two commercial di-isocyanates (aromatic and aliphatic. In the synthesis the factors evaluated were the amine:di-isocyanate molar ratio and the type of emulsifier. The particle size was optimized using a 3² factorial design and response surface analysis, with the following variables: amount of polyvinyl alcohol and the relationship of the disperse phase to continuous phase. The microcapsules were characterized using differential scanning calorimetry analysis (DSC, infrared spectroscopy (IR, scanning electron microscopy (SEM and mean particle size. The double emulsification allows for a greater yield in the encapsulation of perfume. Furthermore, the microparticles have a smaller particle size when the aromatic di-isocyanate was used, also

In situ emulsification microextraction using a dicationic ionic liquid followed by magnetic assisted physisorption for determination of lead prior to micro-sampling flame atomic absorption spectrometry

International Nuclear Information System (INIS)

Shokri, Masood; Beiraghi, Asadollah; Seidi, Shahram

2015-01-01

For the first time, a simple and efficient in situ emulsification microextraction method using a dicationic ionic liquid followed by magnetic assisted physisorption was presented to determine trace amounts of lead. In this method, 400 μL of 1.0 mol L −1 lithium bis (trifluoromethylsulfonyl) imide aqueous solution, Li[NTf 2 ], was added into the sample solution containing 100 μL of 1.0 mol L −1 1,3-(propyl-1,3-diyl) bis (3-methylimidazolium) chloride, [pbmim]Cl 2 , to form a water immiscible ionic liquid, [pbmim][NTf 2 ] 2 . This new in situ formed dicationic ionic liquid was applied as the acceptor phase to extract the lead-ammonium pyrrolidinedithiocarbamate (Pb-APDC) complexes from the sample solution. Subsequently, 30 mg of Fe 3 O 4 magnetic nanoparticles (MNPs) were added into the sample solution to collect the fine droplets of [pbmim][NTf 2 ] 2 , physisorptively. Finally, MNPs were eluted by acetonitrile, separated by an external magnetic field and the obtained eluent was subjected to micro-sampling flame atomic absorption spectrometry (FAAS) for further analysis. Comparing with other microextraction methods, no special devices and centrifugation step are required. Parameters influencing the extraction efficiency such as extraction time, pH, concentration of chelating agent, amount of MNPs and coexisting interferences were studied. Under the optimized conditions, this method showed high extraction recovery of 93% with low LOD of 0.7 μg L −1 . Good linearity was obtained in the range of 2.5–150 μg L −1 with determination coefficient (r 2 ) of 0.9921. Relative standard deviation (RSD%) for seven repeated measurements at the concentration of 10 μg L −1 was 4.1%. Finally, this method was successfully applied for determination of lead in some water and plant samples. - Highlights: • A dicationic ionic liquid was used as the extraction solvent, for the first time. • A simple and efficient in situ emulsification microextraction

Evaluation of Time-Temperature Integrators (TTIs) with Microorganism-Entrapped Microbeads Produced Using Homogenization and SPG Membrane Emulsification Techniques.

Science.gov (United States)

Rahman, A T M Mijanur; Lee, Seung Ju; Jung, Seung Won

2015-12-28

A comparative study was conducted to evaluate precision and accuracy in controlling the temperature dependence of encapsulated microbial time-temperature integrators (TTIs) developed using two different emulsification techniques. Weissela cibaria CIFP 009 cells, immobilized within 2% Na-alginate gel microbeads using homogenization (5,000, 7,000, and 10,000 rpm) and Shirasu porous glass (SPG) membrane technologies (10 μm), were applied to microbial TTIs. The prepared micobeads were characterized with respect to their size, size distribution, shape and morphology, entrapment efficiency, and bead production yield. Additionally, fermentation process parameters including growth rate were investigated. The TTI responses (changes in pH and titratable acidity (TA)) were evaluated as a function of temperature (20°C, 25°C, and 30°C). In comparison with conventional methods, SPG membrane technology was able not only to produce highly uniform, small-sized beads with the narrowest size distribution, but also the bead production yield was found to be nearly 3.0 to 4.5 times higher. However, among the TTIs produced using the homogenization technique, poor linearity (R(2)) in terms of TA was observed for the 5,000 and 7,000 rpm treatments. Consequently, microbeads produced by the SPG membrane and by homogenization at 10,000 rpm were selected for adjusting the temperature dependence. The Ea values of TTIs containing 0.5, 1.0, and 1.5 g microbeads, prepared by SPG membrane and conventional methods, were estimated to be 86.0, 83.5, and 76.6 kJ/mol, and 85.5, 73.5, and 62.2 kJ/mol, respectively. Therefore, microbial TTIs developed using SPG membrane technology are much more efficient in controlling temperature dependence.

Determination of personal care products and hormones in leachate and groundwater from Polish MSW landfills by ultrasound-assisted emulsification microextraction and GC-MS.

Science.gov (United States)

Kapelewska, Justyna; Kotowska, Urszula; Wiśniewska, Katarzyna

2016-01-01

Determination of the endocrine disrupting compounds (EDCs) in leachate and groundwater samples from the landfill sites is very important because of the proven harmful effects of these compounds on human and animal organisms. A method combining ultrasound-assisted emulsification microextraction (USAEME) and gas chromatography-mass spectrometry (GC-MS) was developed for simultaneous determination of seven personal care products (PCPs): methylparaben (MP), ethylparaben (EP), propylparaben (PP), buthylparaben (BP), benzophenone (BPh), 3-(4-methylbenzylidene)camphor (4-MBC), N,N-diethyltoluamide (DEET), and two hormones: estrone (E1) and β-estradiol (E2) in landfill leachate and groundwater samples. The limit of detection (LOD)/limit of quantification (LOQ) values in landfill leachate and groundwater samples were in the range of 0.003-0.083/0.009-0.277 μg L(-1) and 0.001-0.015/0.002-0.049 μg L(-1), respectively. Quantitative recoveries and satisfactory precision were obtained. All studied compounds were found in the landfill leachates from Polish municipal solid waste (MSW) landfills; the concentrations were between 0.66 and 202.42 μg L(-1). The concentration of pollutants in groundwater samples was generally below 0.1 μg L(-1).

Application of ultrasound-assisted emulsification microextraction for simultaneous determination of aminophenol isomers in human urine, hair dye, and water samples using high-performance liquid chromatography.

Science.gov (United States)

Asghari, Alireza; Fazl-Karimi, Hamidreza; Barfi, Behruz; Rajabi, Maryam; Daneshfar, Ali

2014-08-01

Aminophenol isomers (2-, 3-, and 4-aminophenols) are typically classified as industrial pollutants with genotoxic and mutagenic effects due to their easy penetration through the skin and membranes of human, animals, and plants. In the present study, a simple and efficient ultrasound-assisted emulsification microextraction procedure coupled with high-performance liquid chromatography with ultraviolet detector was developed for preconcentration and determination of these compounds in human fluid and environmental water samples. Effective parameters (such as type and volume of extraction solvent, pH and ionic strength of sample, and ultrasonication and centrifuging time) were investigated and optimized. Under optimum conditions (including sample volume: 5 mL; extraction solvent: chloroform, 80 µL; pH: 6.5; without salt addition; ultrasonication: 3.5 min; and centrifuging time: 3 min, 5000 rpm min(-1)), the enrichment factors and limits of detection were ranged from 42 to 51 and 0.028 to 0.112 µg mL(-1), respectively. Once optimized, analytical performance of the method was studied in terms of linearity (0.085-157 µg mL(-1), r (2) > 0.998), accuracy (recovery = 88.6- 101.7%), and precision (repeatability: intraday precision water samples. © The Author(s) 2014.

Ultrasound-assisted surfactant-enhanced emulsification microextraction with solidification of floating organic droplet followed by high performance liquid chromatography for the determination of strobilurin fungicides in fruit juice samples.

Science.gov (United States)

Liang, Pei; Liu, Guojiao; Wang, Fang; Wang, Wanting

2013-05-01

A novel method, ultrasound-assisted surfactant-enhanced emulsification microextraction with solidification of floating organic droplet (UASEME-SFOD), has been developed for the extraction of four strobilurin fungicides (kresoxim-methyl, picoxystrobin, pyraclostrobin and trifloxystrobin) in fruit juices. In the UASEME-SFOD technique, Tween 80 was used as emulsifier, and 1-undecanol was used as extraction solvent without using any organic dispersive solvent. Several parameters that affect the extraction efficiency, such as the kind and volume of extraction solvent, the type and concentration of the surfactant, extraction time, extraction temperature and salt addition were investigated and optimized. Under the optimum extraction condition, the method yields a linear calibration curve in the concentration range from 5 to 10,000 ng mL(-1) for the targeted analytes with the correlation coefficient ranging from 0.9991 to 0.9998. The enrichment factors were in the range between 95 and 135, and the limits of detection of the method were 2-4 ng mL(-1). The fruit juice samples were successfully analyzed using the proposed method, and the relative recoveries at fortified levels of 50 and 100 ng mL(-1) were in the range of 82.6-97.5%. Copyright © 2013 Elsevier B.V. All rights reserved.

Emulsification with microstructures

NARCIS (Netherlands)

Dijke, van K.C.

2009-01-01

A dispersion is a multiphase product in which at least one phase is dispersed into another phase. In emulsions, those phases are immiscible liquids, for example oil and water. Many products which we use in everyday life are emulsions. One can think of ointments, paints, or sun protection cream, but

When oil spills emulsify

International Nuclear Information System (INIS)

Bobra, M.; Fingas, M.; Tennyson, E.

1992-01-01

Cleanup operations of oil spills must take into account the numerous detrimental effects attributable to the emulsification of spilled oil into a stable water-in-oil mousse. The incorporation of water greatly increases the volume of the polluted material. The viscous nature of mousse impedes the efficient operation of most mechanical recovery equipment and results in a cohesive slick that resists dispersion, both natural and artificial. The rate at which spilled oil emulsifies determines the effective window of opportunity for specific countermeasures. Much has been learned from previous studies on petroleum emulsification, but is still remain a poorly understood phenomenon. Although most crude oils can be emulsified, not all spills result in the formation of stable mousse. The formation of mousse results from a complex series of processes. Whether an oil will form mousse or not, and if so, at what rate, depends on an array of different factors including the properties of the oil and the prevailing environmental conditions. We need a greater understanding of the emulsification process to better predict the emulsification behavior of oil spills and utilize the most appropriate countermeasures available. In this paper, the authors report on work to elucidate the role that physicochemical factors play in determining an oil's tendency to emulsify. The authors studied the emulsification behavior of oils of known composition to examine the importance of oil chemistry in the emulsification process

Ligandless, ion pair-based and ultrasound assisted emulsification solidified floating organic drop microextraction for simultaneous preconcentration of ultra-trace amounts of gold and thallium and determination by GFAAS.

Science.gov (United States)

Fazelirad, Hamid; Taher, Mohammad Ali

2013-01-15

In the present work, a new, simple and efficient method for simultaneous preconcentration of ultra-trace amounts of gold and thallium is developed using an ion pair based-ultrasound assisted emulsification-solidified floating organic drop microextraction procedure before graphite furnace atomic absorption spectrometry determination. This methodology was used to preconcentrate the ion pairs formed between AuCl(4)(-) and TlCl(4)(-) and [C(23)H(42)]N(+) in a microliter-range volume of 1-undecanol. Several factors affecting the microextraction efficiency, such as HCl volume, type and volume of extraction solvent, sonication time, sample volume, temperature, ionic strength and [C(23)H(42)]NCl volume were investigated and optimized. Under the optimized conditions, the enrichment factor of 441 and 443 and calibration graphs of 2.2-89 and 22.2-667 ng L(-1) for gold and thallium were obtained, respectively. The intra- and inter-day precision of ± 4.4 and ± 4.9% for Au and ± 4.8 and ± 5.4% for Tl were obtained. The detection limit was 0.66 ng L(-1) for Au and 4.67 ng L(-1) for Tl. The results show that the liquid-liquid pretreatment using ion pair forming, is sensitive, rapid, simple and safe method for the simultaneous preconcentration of gold and thallium. The method was successfully applied for determination of gold and thallium in natural water and hair samples. Copyright © 2012 Elsevier B.V. All rights reserved.

The Effect of Emulsion Intensity on Selected Sensory and Instrumental Texture Properties of Full-Fat Mayonnaise

Science.gov (United States)

Olsson, Viktoria; Håkansson, Andreas

2018-01-01

Varying processing conditions can strongly affect the microstructure of mayonnaise, opening up new applications for the creation of products tailored to meet different consumer preferences. The aim of the study was to evaluate the effect of emulsification intensity on sensory and instrumental characteristics of full-fat mayonnaise. Mayonnaise, based on a standard recipe, was processed at low and high emulsification intensities, with selected sensory and instrumental properties then evaluated using an analytical panel and a back extrusion method. The evaluation also included a commercial reference mayonnaise. The overall effects of a higher emulsification intensity on the sensory and instrumental characteristics of full-fat mayonnaise were limited. However, texture was affected, with a more intense emulsification resulting in a firmer mayonnaise according to both back extrusion data and the analytical sensory panel. Appearance, taste and flavor attributes were not affected by processing. PMID:29342128

The breakup of oil spills in the marine environment

International Nuclear Information System (INIS)

Zeidan, E.; Zahariev, K.; Li, M.; Garrett, C.

1997-01-01

Existing theories of oil slick disintegration under stormy conditions were examined. A novel empirical model suitable for use in oil spill models was developed in an effort to demonstrate the many difficulties encountered in modeling the emulsification process. Chief among the difficulties is the prediction of the onset and extent of oil spill emulsification. The empirical model was described in some detail using surface active constituents and energy available from wind and waves as the controlling parameters. The resulting chart, if used in the marine environment, can predict localized emulsification and a more realistic behaviour of oil spills. 43 refs., 6 figs

Upscaling microstructured emulsification devices

NARCIS (Netherlands)

Sahin, S.

2016-01-01

Emulsions, which are dispersions of two immiscible liquids (e.g. oil and water), are part of our daily life through many products that we use such as milk, mayonnaise, salad dressings, ice cream, lotions, shampoos, medicines, wall paints, etc. Many quality attributes of these products such as

Analytical modeling and numerical optimization of the biosurfactants production in solid-state fermentation by Aspergillus fumigatus - doi: 10.4025/actascitechnol.v36i1.17818

Directory of Open Access Journals (Sweden)

Gabriel Castiglioni

2014-01-01

Full Text Available This is an experimental, analytical and numerical study to optimize the biosurfactants production in solid-state fermentation of a medium containing rice straw and minced rice bran inoculated with Aspergillus fumigatus. The goal of this work was to analytically model the biosurfactants production in solid-state fermentation into a column fixed bed bioreactor. The Least-Squares Method was used to adjust the emulsification activity experimental values to a quadratic function semi-empirical model. Control variables were nutritional conditions, the fermentation time and the aeration. The mathematical model is validated against experimental results and then used to predict the maximum emulsification activity for different nutritional conditions and aerations. Based on the semi-empirical model the maximum emulsification activity with no additional hydrocarbon sources was 8.16 UE·g-1 for 112 hours. When diesel oil was used the predicted maximum emulsification activity was 8.10 UE·g-1 for 108 hours.

Vinyl Chloride Emulsion Polymerization Reaction: Effect of Various Formulations

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Seyed Mehrdad Jalilian

2013-01-01

Full Text Available A mixture  of  sodium  lauryl  sulfate  (SLS  as  ionic  emulsifer  and  stearyl alcohol as non-ionic emulsifer was employed in a vinyl chloride emulsion polymerization  reaction  to  study  the  infuence  of  various  interactive parameters involved in the reaction system. It was found that the particle size was dependent on the amount and type of emulsifer. The average particle size of polyvinyl chloride was dropped by higher amount of emulsifying agents.  At the gel point, more heat was generated by higher amount of vinyl chloride fed into the reaction system. The molecular weight of the polymer was decreased by increases in reaction temperature while,  it  increased by augmenting  the amount of emulsifer. According to the 13C NMR and FTIR spectroscopic data no defect was detected in the chain structure of synthetic polyvinylchloride product. An optimization of polymerization reaction condition was reached based on ultimate particle size desired for its favorable distribution in plastisols.

Mixing Time, Inversion and Multiple Emulsion Formation in a Limonene and Water Pickering Emulsion

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Laura Sawiak

2018-05-01

Full Text Available It has previously been demonstrated that particle-stabilized emulsions comprised of limonene, water and fumed silica particles exhibit complex emulsification behavior as a function of composition and the duration of the emulsification step. Most notably the system can invert from being oil-continuous to being water-continuous under prolonged mixing. Here we investigate this phenomenon experimentally for the regime where water is the majority liquid. We prepare samples using a range of different emulsification times and we examine the final properties in bulk and via confocal microscopy. We use the images to quantitatively track the sizes of droplets and clusters of particles. We find that a dense emulsion of water droplets forms initially which is transformed, in time, into a water-in-oil-in-water multiple emulsion with concomitant changes in droplet and cluster sizes. In parallel we carry out rheological studies of water-in-limonene emulsions using different concentrations of fumed silica particles. We unite our observations to propose a mechanism for inversion based on the changes in flow properties and the availability of particles during emulsification.

Relationship between concentration of surfactant and pressure for droplet creation, and effect on droplet size in microchannel O/W emulsification; Maikurochaneru ni yoru O/W nyukaho ni okeru kaimen kasseizai nodo to ekiteki seisei atsuryoku no kankei, oyobi koreraga ekitekikei ni oyobosu eikyo

Energy Technology Data Exchange (ETDEWEB)

Kawakatsu, T.; Komori, H.; Oda, N.; Yonemoto, T. [Tohoku Univ., Sendai (Japan). Graduate School of Engineering

1998-03-01

O/W (oil in water) emulsion is produced by micro-channel emulsification method, and the effects of surfactant concentration on the pressures at which droplet generation starts and stops are evaluated in connection with the water phase and oil phase interfacial tension. In addition, the effects of surfactant concentration and operational pressure on the droplet size are investigated by measuring the generated droplet distribution, mean droplet size, standard deviation, geometrical standard deviation, and the possibility of producing mono-dispersion emulsion whose droplet size is large than 10 micron. The breakthrough pressure and the minimum pressure for droplet generation become low with the increase of SDS (sodium lauryl sulfate) concentration. The surfactant concentration, however, is found to have no effect on the breakthrough pressure and the minimum pressure for droplet generation when the SDS concentration exceeds the critical micelle concentration. It is true also for a system added with NaCl. As regards droplet size, uniform 20{mu}m droplet is obtained irrespective of the surfactant concentration and pressure. 13 refs., 10 figs., 2 tabs.

Microencapsulation of Algal Oil Using Spray Drying Technology

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Xueshan Pan

2018-01-01

Full Text Available This work aims at developing a process of microencapsulation of algal oil containing ≥40 % docosahexaenoic acid (DHA using spray drying technology. Purity Gum® 2000 and Capsul®, both obtained from waxy corn starch, were chosen as the encapsulation materials. The effects of emulsification conditions on the droplet size, stability, viscosity and surface tension, and the effects of spraying conditions on the particle size, moisture content and surface oil content were investigated successively. The morphology of emulsion droplets and the microcapsules was observed by optical microscope and scanning electron micro scopy. The results showed that the produced spherical microcapsules were smooth and free of pores, cracks, and surface indentation when shear velocity was 8.63 m/s in the first step of emulsification, homogenization pressure was 1.75·10˄8 Pa and number of passes through homogenization unit was six for fine emulsification, rotational speed of spray disk was 400 s-1, and air inlet temperature was 170 °C. Therefore, it was concluded that the emulsification and encapsulation of algal oil containing DHA with above process was feasible.

Comparison of some indigenous bacterial strains of pseudomonas ssp. for production of biosurfactants

International Nuclear Information System (INIS)

Sahafeeq, M.; Kokub, D.; Khalid, Z.M.; Malik, K.A.

1991-01-01

Some indigenous pseudomonas spp. were found to have the ability of emulsification, lowering the surface and interfacial tensions, and formation of high reciprocal CMCs. Six strains of Pseudomonas spp were compared for biosurfactant production grown on hexadecane. Supernatant from whole culture broth of these strains could lower surface tension from 65 mN/m to 28-32 nM/m, interfacial tension from 40 nM/m to 1-3 mN/m and had high reciprocal CMCs. When compared for emulsification ability by the culture broth of these strains, the emulsification index (E24) was found to range between 60-65. Biosurfactant containing culture broth of some strains could retain the property up to 80 C, pH of 13 and sodium chloride concentration for 17% which indicates their possible role in some depleted oil well. (author)

Evolución de las propiedades reológicas de emulsiones aceite vegetal en agua durante el proceso de emulsificación y almacenamiento

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Gallegos, C.

2000-08-01

Full Text Available This paper deals with the evolution of the rheological properties and droplet size distributions (DSD of oil-in-water emulsions, stabilized by non-ionic surfactant, with time. The emulsification process has been followed by the evolution of the torque with the emulsification time and follows a first-order kinetic equation. From the experimental results obtained it is apparent that the rheology and DSD of the emulsions studied depends on the emulsification time and temperature of emulsification, as well as, the agitation speed. An increase in the emulsification time, at 15ºC, yields lower values of the mean droplet size and, subsequently, an increase in the linear viscoelasticity functions of the emulsions. However, above 25ºC, the emulsification process may be modified because a higher degree of coalescence may take place at long emulsification time. A «depletion-flocculation» mechanism due to the presence of surfactant, in form of micelles, in the continuous phase of the emulsions.Se estudia la evolución de las propiedades reológicas y de la distribución de tamaños de las gotas (DTG de emulsiones aceite vegetal en agua, estabilizadas con un tensioactivo no iónico, durante los períodos de emulsificación y de almacenamiento. La cinética del proceso de emulsificación se ha seguido a través de la variación del par de torsión con el tiempo de emulsificación, ajustándose a una ecuación de primer orden. De los resultados obtenidos puede deducirse que la evolución de las características reológicas y de DTG de las emulsiones estudiadas depende principalmente del tiempo y temperatura de emulsificación y de la velocidad de agitación. A 15ºC, un aumento del tiempo de emulsificación produce una disminución del diámetro medio de gota y, por tanto, un aumento de las funciones viscoelásticas lineales. Sin embargo, a temperaturas superiores a 25ºC el proceso es mucho más complejo, pudiendo favorecerse el proceso de

Isolation of biosurfactant-producing marine bacteria and characteristics of selected biosurfactant

Directory of Open Access Journals (Sweden)

Kulnaree Phetrong

2007-05-01

Full Text Available Biosurfactant-producing marine bacteria were isolated from oil-spilled seawater collected from harbors and docks in Songkhla Province, Thailand. Haemolytic activity, emulsification activity toward nhexadecane,emulsion of weathered crude oil, drop collapsing test as well as oil displacement test were used to determine biosurfactant producing activity of marine bacteria. Among two-hundred different strains, 40strains exhibited clear zone on blood agar plates. Only eight strains had haemolytic activity and were able to emulsify weathered crude oil in marine broth during cultivation. Eight strains named SM1-SM8 wereidentified by 16S rRNA as Myroides sp. (SM1; Vibrio paraheamolyticus (SM2; Bacillus subtilis (SM3; Micrococcus luteus (SM4; Acinetobacter anitratus (SM6; Vibrio paraheamolyticus (SM7 and Bacilluspumilus (SM8. However, SM5 could not be identified. Strain SM1 showed the highest emulsification activity against weathered crude oil, by which the oil was emulsified within 24 h of cultivation. In addition, strainSM1 exhibited the highest activity for oil displacement test and emulsification test toward n-hexadecane. The emulsification activity against n-hexadecane of crude extract of strain SM1 was stable over a broadrange of temperature (30-121oC, pH (5-12 and salt concentration (0-9% NaCl, whereas CaCl2 showed an adverse effect on emulsifying activity.

Factors having implications on re-retinal detachments after silicone oil removal

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Manish P Nagpal

2012-01-01

Full Text Available Aim: To investigate factors having implications on re-retinal detachments (reRD after silicone oil removal (SOR. Materials and Methods: A retroprospective study of 412 eyes (with attached retina after vitrectomy with silicone oil for rhegmatogenous RD which underwent SOR was conducted and were followed up for six months after SOR. They were studied for various factors like encirclage, 360° retinopexy, oil emulsification at the time of SOR, duration of oil tamponade and previous retinal surgeries prior to SOR with their implications on reRD after SOR. Results: Encirclage, 360 laser barrage, both, emulsification of oil (P=0.021, P=0.001, P=0.001, P=0.001, respectively were associated with lower risks of reRD after SOR whereas duration of tamponade (P=0.980 was not. Conclusion: Factors like encirclage, 360 retinopexy, their combination, oil emulsification reduced the incidence of re RD after SOR whereas duration of tamponade does not have statistical significant correlation with re RD after SOR.

Flotation extraction of tributyl phosphate from s olutions

International Nuclear Information System (INIS)

Skrylev, L.D.; Tkachenko, N.V.; Sazonova, V.F.

1983-01-01

Results of investigations, conducted for revealing the possibility of flotation extraction of emulsificated and actually dissolved extractants, tributyl phosphate (TBP) in particular, are given. The possibility of flotation extraction of emulsificated and actually dissolved TBP by its non-reagent flotation was established experimeptally. It was also established that the kinetics of flotation TBP extraction is described by the equation, similar to the reaction equation of the first order. The process of non-reagent TBP flotation proceeds most successfully in pH=6.5-7.5 range

From Single Microparticles to Microfluidic Emulsification

DEFF Research Database (Denmark)

Kinoshita, K.; Ortiz, Elisa Parra; Hussein, Abdirazak

2016-01-01

The micropipette manipulation technique is capable of making fundamental single particle measurements and analyses. This information is critical for establishing processing parameters in systems such as microfluidics and homogenization. To demonstrate what can be achieved at the single particle l...... a very useful tool for understanding microsphere-processes and hence can help to establish process conditions without resorting to expensive and material-consuming bulk particle runs....

Application of Ultrasound-assisted Emulsification Microextraction ...

African Journals Online (AJOL)

NICOLAAS

cNuclear Fuel Cycle Research School, Nuclear Science & Technology Research Institute, Atomic ... method, fine droplets of toluene were formed and dispersed in the sample with the help of ..... Validation for spiked water samples was carried out by using a .... emission spectrometry as a fast technique for the simultaneous.

Application of Ultrasound-assisted Emulsification Microextraction ...

African Journals Online (AJOL)

Several factors influencing the extraction efficiency, such as the nature and volume of organic solvent, extraction temperature, ionic strength and centrifugation time, were investigated and optimized. Using optimum extraction conditions a detection limit of 0.1 μg L–1 and a good linearity in a calibration range of 0.25–250 μg ...

Formulation, Characterization and Properties of Hemp Seed Oil and Its Emulsions

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Veronika Mikulcová

2017-04-01

Full Text Available The formulation, characterization, and anticipated antibacterial properties of hemp seed oil and its emulsions were investigated. The oil obtained from the seeds of Cannabis sativa L. in refined and unrefined form was characterized using iodine, saponification, acid values, and gas chromatography, and was employed for the preparation of stable oil-in-water emulsions. The emulsions were prepared using pairs of non-ionic surfactants (Tween, Span. The effects of the emulsification method (spontaneous emulsification vs. high-intensity stirring, hydrophilic lipophilic balance (HLB, type and concentration of surfactant, and oil type on the size and distribution of the emulsion particles were investigated. It was found that the ability to form stable emulsions with small, initial particle sizes is primarily dependent on the given method of preparation and the HLB value. The most efficient method of emulsification that afforded the best emulsions with the smallest particles (151 ± 1 nm comprised the high-energy method, and emulsions stable over the long-term were observed at HBL 9 with 10 wt % concentration of surfactants. Under high-intensity emulsification, refined and unrefined oils performed similarly. The oils as well as their emulsions were tested against the growth of selected bacteria using the disk diffusion and broth microdilution methods. The antibacterial effect of hemp seed oil was documented against Micrococcus luteus and Staphylococcus aureus subsp. aureus. The formulated emulsions did not exhibit the antibacterial activity that had been anticipated.

Asphalt emulsion; Asphalt nyuzai ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Suzuki, T. [Toa Doro Kogyo Co. Ltd., Tokyo (Japan)

1994-12-28

The emulsification, manufacture, type, applications, etc. of asphalt emulsion were introduced. The emulsification of asphalt is obtained by mixing heated asphalt into an emulsification liquid where emulsifier is added to water and then agitating it. The emulsifier has both hydrophilic and lipophilic parts in the same molecule, prevents collision between asphalt particles after being arranged properly on the surface of asphalt particles, and prevent separation into water and asphalt. The emulsion is available for penetration and for mixing depending on applications and can be classified into cation emulsion, anion emulsion, and nonionic emulsion according to the property. The emulsion is mainly applied to road pavement, reaching approximately 90 % of the total manufactured emulsion. It is also used for other areas such as the filler of a slab race of each bullet train of Sanyo, Tohoku, and Jyoetsu and is also applied to the formation of a water-proof layer by spraying a high-concentration emulsion with rubber, agricultural water channels using asphalt emulsion and nonwoven cloth, etc. in civil engineering and agricultural fields. 2 refs., 13 figs., 8 tabs.

Sustained release formulations of citronella oil nanoemulsion using cavitational techniques.

Science.gov (United States)

Agrawal, Naveen; Maddikeri, Ganesh L; Pandit, Aniruddha B

2017-05-01

Nanoemulsion synthesis has proven to be an effective way for transportation of immobile, insoluble bioactive compounds. Citronella Oil (lemongrass oil), a natural plant extract, can be used as a mosquito repellent and has less harmful effects compared to its available market counterpart DEET (N, N-Diethyl-meta-toluamide). Nanoemulsion of citronella oil in water was prepared using cavitation-assisted techniques while investigating the effect of system parameters like HLB (Hydrophilic Lipophilic Balance), surfactant concentration, input energy density and mode of power input on emulsion quality. The present work also examines the effect of emulsification on release rate to understand the relationship between droplet size and the release rate. Minimum droplet size (60nm) of the emulsion was obtained at HLB of 14, S/O 1 ratio of 1.0, ultrasound amplitude of 50% and irradiation time of 5min. This study revealed that hydrodynamic cavitation-assisted emulsification is more energy efficient compared to ultrasonic emulsification. It was also found that the release rate of nanoemulsion enhanced as the droplet size of emulsion reduced. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of prerigor pressurization on the emulsifying capacity of muscle protein

Energy Technology Data Exchange (ETDEWEB)

Elgasim, E.A.; Kennick, W.H.; Anglemier, A.F.; Elkhalifa, E.A.; Koohmaraie, M.

1982-05-01

The emulsifying capacities of pressure treated and control muscle homogenates, sarcoplasmic protein and myofibrillar proteins of ovine and bovine longissimus muscles were determined at 2, 6, 24 and 168 hr postmortem. The pH of the intact muscle, muscle homogenate and myofibrillar protein extract were taken at these times. Before onset of rigor mortis, the emulsifying capacity of muscle homogenate from the control samples was higher than the pressure treated samples. At 24 and 168 hr postmortem, the pressure treated and control samples were not significantly different (P>0.05) for emulsifying capacity. At 2 hr postmortem, the emulsifying capacity of myofibrillar protein extract from control samples was higher (P<0.05) than that from pressure treated samples; thereafter, the emulsification curve for the pressure treated samples was higher than that of the control. The emulsification capacity of sarcoplasmic proteins from control muscles was slightly, but consistently, higher than that from pressure treated muscles throughout the test period. Overall, the emulsification capacity of muscle proteins was not detrimentally affected by pressure treatment.

超声乳化-原位聚合法制备薄荷脑微胶囊%Preparation of Microcapsules Containing Menthol by Ultrasonic Emulsification and In-situ Polymerization

Institute of Scientific and Technical Information of China (English)

施云舟; 王彪; 朱方亮

2013-01-01

Microcapsules containing menthol were prepared by ultrasonic emulsification and in-situ polymerization. Effects of polymerization condition on morphology, structure, particle size and the distribution of the microcapsules were studied. Scanning electronic microscopy (SEM), optical microscopy (OM), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), laser particle size measurement were used for characterization. The results revealed that the release of menthol was effectively delayed because of the protection of wall material,; uniform particle size and good dispersion could be achieved by adjusting poly-condensation reaction time, the content of menthol, and the temperature; the increase of the emulsifier concentration or the ultrasonic power within a certain range contributed to reducing the diameter and improving the dispersion of microcapsules.%采用原位聚合法,结合超声乳化工艺,制备以薄荷脑为囊芯的微胶囊,并研究了反应条件对微胶囊形貌和粒径的影响.利用扫描电镜(SEM)、光学显微镜(OM)、傅里叶红外光谱(FT-IR)、差示扫描量热仪(DSC)、热重分析(TGA)、激光粒度测试等手段对薄荷脑微胶囊进行了结构和性能的表征.结果表明:所制得的薄荷脑微胶囊包覆良好,能够有效延缓薄荷脑的挥发和逸散；通过调节缩聚反应时间、薄荷脑添加量、反应温度可以得到粒径较为均一、分散性良好的微胶囊；在一定范围内,可以通过提高乳化剂质量浓度和超声功率来减小微胶囊粒径及其分布区间.

Extreme emulsification: formation and structure of nanoemulsions

Directory of Open Access Journals (Sweden)

T.G.Mason

2006-01-01

Full Text Available Nanoemulsions are metastable dispersions of nanodroplets of one liquid that have been ruptured by shear in another immiscible liquid. The ruptured droplets are stabilized against subsequent coalescence by a surfactant. Because the nanodroplets do not form spontaneously, as they can in lyotropic ``microemulsion'' phases, the structure of nanoemulsions is primarily dependent on the history of the applied shear stresses relative to the interfacial restoring stresses. By applying extremely high shear rates and controlling the composition of the emulsion, we have been able to rupture microscale droplets down to diameters as small as 30 nm in a microfluidic process that yields bulk quantities suitable for commercial production. Following ultracentrifugal fractionation to make the droplets uniform, we study the structure of these emulsions using small angle neutron scattering (SANS at dilute and concentrated volume fractions. We contrast the structure of a concentrated nanoemulsion with the structure factor of hard spheres at a similar volume fraction.

In vivo postprandial bioavailability of interesterified-lipids in sodium-caseinate or chitosan based O/W emulsions.

Science.gov (United States)

Farfán, M; Villalón, M J; Ortíz, M E; Nieto, S; Bouchon, P

2015-03-15

Recent studies have shown that it should be possible to control lipid bioavailability through food structural approaches. Nevertheless, the gastrointestinal-tract physiological conditions must also be considered. To get a better understanding of this phenomenon, we evaluated the effect of emulsification, as well as the use of sodium caseinate or chitosan, on the postprandial bioavailability of interesterified-lipids in O/W emulsions after oral gastric feeding Sprague-Dawley rats. We verified that emulsification may increase lipid absorption, as determined after feeding sodium-caseinate emulsions. However, this result could not be generalised. Interesterified-lipids that were emulsified with chitosan were equally absorbed as those contained in non-emulsified interesterified-lipids/distilled-water blends. Copyright © 2014. Published by Elsevier Ltd.

Evaluation and functional characterization of a biosurfactant produced by Lactobacillus plantarum CFR 2194.

Science.gov (United States)

Madhu, Arenahalli Ningegowda; Prapulla, Siddalingaiya Gurudutt

2014-02-01

The study details the investigations on the ability of Lactobacillus plantarum CFR 2194, an isolate from kanjika, a rice-based ayurvedic fermented product, to produce biosurfactant. Surfactant production, as a function of fermentation time, indicates that the maximum production occurred at 72 h under stationary conditions. Isolation, partial purification, and characterization of the biosurfactant produced have been carried out, and Fourier transform infrared spectroscopy (FTIR) spectra demonstrated that biosurfactants were constituted by protein and polysaccharide fractions, i.e., possessed the structure typical of glycoprotein, which is affected by the medium composition and the phase of growth of the biosurfactant-synthesizing strain. Critical micelle concentration (cmc) of the biosurfactant was found to be 6 g l(-1). The emulsification index (EI), emulsification activity (EA), and emulsion stability (ES) values of the biosurfactant have confirmed its emulsification property. Aqueous fractions of the produced biosurfactant exhibited a significant antimicrobial activity against the food-borne pathogenic species: Escherichia coli ATCC 31705, E. coli MTCC 108, Salmonella typhi, Yersinia enterocolitica MTCC 859, and Staphylococcus aureus F 722. More importantly, the biosurfactant from L. plantarum showed antiadhesive property against above food-borne pathogens. The results thus indicate the potential for developing strategies to prevent microbial colonization of food contact surfaces and health-care prosthesis using these biosurfactants.

Surfactant-enhanced alkaline flooding for light oil recovery. Annual report, 1992--1993

Energy Technology Data Exchange (ETDEWEB)

Wasan, D.T.

1994-08-01

In this report, the authors present the results of experimental and theoretical studies in surfactant-enhanced alkaline flooding for light oil recovery. The overall objective of this work is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12.0) for ultimate spontaneous emulsification and ultralow interfacial tension. In addition, the authors have (1) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, (2) investigated the mechanisms for spontaneous emulsification, (3) developed a technique to monitor low water content in oil, and (4) developed a technique to study water-in-oil emulsion film properties.

Colloidal Characteristics of Water Systems of Rhamnolipid Biocomplex of Strain Pseudomonas sp. PS-17 with Tween-80 and their Prospects for Biotechnology

Directory of Open Access Journals (Sweden)

Elena V. Karpenko

2017-12-01

Conclusions. The peculiarities of colloid-chemical characteristics of RBC and Tween-80 systems are determined, the prospects of their use for increasing efficiency of emulsification and sunflower growth stimulation are determined.

Formulation and in vitro evaluation of ibuprofen-loaded poly(D,L ...

African Journals Online (AJOL)

co-glycolide) (PLGA) microparticles. Methods: Ibuprofen-loaded microparticles containing PLGA were formulated using a emulsification/solvent evaporation method. Various concentrations of ibuprofen (200, 300, 400 and 0 mg) were loaded ...

Chemical and rheological properties of exopolysaccharides produced by four isolates of rhizobia.

Science.gov (United States)

Moretto, Cristiane; Castellane, Tereza Cristina Luque; Lopes, Erica Mendes; Omori, Wellington Pine; Sacco, Laís Postai; Lemos, Eliana Gertrudes de Macedo

2015-11-01

The rheological, physicochemical properties, emulsification and stability of exopolysaccharides (EPSs) from four rhizobia isolates (LBMP-C01, LBMP-C02, LBMP-C03 and LBMP-C04) were studied. The EPS yields of isolates under these experimental conditions were in the range of 1.5-6.63gL(-1). The LBMP-C04 isolate, which presented the highest EPS production (6.63gL(-1)), was isolated from Arachis pintoi and was identified as a Rhizobium sp. strain that could be explored as a possible potential source for the production of extracellular heteropolysaccharides. All polymers showed a pseudoplastic non-Newtonian fluid behavior or shear thinning property in aqueous solutions. Among the four EPS tested against hydrocarbons, EPS LBMP-C01 was found to be more effective against hexane, olive and soybean oils (89.94%, 82.75% and 81.15%, respectively). Importantly, we found that changes in pH (2-11) and salinity (0-30%) influenced the emulsification of diesel oil by the EPSs. EPSLBMP-C04 presented optimal emulsification capacity at pH 10 (E24=53%) and 30% salinity (E24=27%). These findings contribute to the understanding of the influence of the chemical composition, physical properties and biotechnology applications of rhizobial EPS solutions their bioemulsifying properties. Copyright © 2015 Elsevier B.V. All rights reserved.

Production of crosslinked protein particles through membrane emulsification

CSIR Research Space (South Africa)

Kotzé-Jacobs, L

2010-09-01

Full Text Available In recent years, the drive towards cleaner technologies has made us more aware of the need for green and sustainable methodologies for chemical synthesis. It is here that enzymes are beneficial due to mild reaction conditions, biodegradability...

Studies of emulsification, emulsion prevention and underwater dispersion

Energy Technology Data Exchange (ETDEWEB)

Celius, H.K.; Vassbotn, T.

1985-03-01

This is a report from the work performed under task 2: ''Effect of demulsifiers and despersants injected into a blowing oil stream'' of the research program ''Dispersion of oil on sea''. Three ad hoc experiments have been carried out involving laboratory studies in a small turbulent oil plume, tests with revolving flasks, and a small scale field test with a combined gas/oil plume. The results show that emulsion is formed in plume from underwater blowouts, and that this formation is prevented by small amounts (250 ppM) of demulsifiers or dispersants. Larger concentrations of dispersants (ca 2%) disperse the oil, and the oil is transported to the upper water layer in the gas/oil plume. None of the experiments have been designed as true scale tests, and the results cannot be directly transferred to operational, full scale conditions. The experiments have however narroved the necessary extent of studies, and allows for a simpler experimental procedure in the full scale field test planned for June 1985. 19 references.

Emulsification in novel ultrasonic cavitation intensifying bag reactors

NARCIS (Netherlands)

Zwieten, van Ralph; Verhaagen, Bram; Schroën, Karin; Fernández Rivas, David

2017-01-01

Cavitation Intensifying Bags (CIBs), a novel reactor type for use with ultrasound, have been recently proposed as a scaled-up microreactor with increased energy efficiencies. We now report on the use of the CIBs for the preparation of emulsions out of hexadecane and an SDS aqueous solution. The

Microencapsulation of protein drugs for drug delivery: strategy, preparation, and applications.

Science.gov (United States)

Ma, Guanghui

2014-11-10

Bio-degradable poly(lactide) (PLA)/poly(lactide-glycolide) (PLGA) and chitosan microspheres (or microcapsules) have important applications in Drug Delivery Systems (DDS) of protein/peptide drugs. By encapsulating protein/peptide drugs in the microspheres, the serum drug concentration can be maintained at a higher constant value for a prolonged time, or injection formulation can be changed to orally or mucosally administered formulation. PLA/PLGA and chitosan are most often used in injection formulation and oral formulation. However, in the preparation and applications of PLA/PLGA and chitosan microspheres containing protein/peptide drugs, the problems of broad size distribution and poor reproducibility of microspheres, and deactivation of protein during the preparation, storage and release, are still big challenges. In this article, the techniques for control of the diameter of microspheres and microcapsules will be introduced at first, then the strategies about how to maintain the bioactivity of protein drugs during preparation and drug release will be reviewed and developed in our research group. The membrane emulsification techniques including direct membrane emulsification and rapid membrane emulsification processes were developed to prepare uniform-sized microspheres, the diameter of microspheres can be controlled from submicron to 100μm by these two processes, and the reproducibility of products can be guaranteed. Furthermore, compared with conventional stirring method, the big advantages of membrane emulsification process were that the uniform microspheres with much higher encapsulation efficiency can be obtained, and the release behavior can be adjusted by selecting microsphere size. Mild membrane emulsification condition also can prevent the deactivation of proteins, which frequently occurred under high shear force in mechanical stirring, sonification, and homogenization methods. The strategies for maintaining the bioactivity of protein drug were

Production of biosurfactants for environment remediation contaminated with oil and derivatives; Producao de biossurfactantes para remediacao de ambiente contaminados com petroleo e derivados

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Adriano Henrique Soares de; Guimaraes, Juliana Aguilar; Hiluy Filho, Joao Jose; Lopes, Ada Amelia Sanders [Universidade Federal do Ceara, Fortaleza, CE (Brazil). Dept. de Engenharia Quimica]. E-mail: hiluy@ufc.br

2003-07-01

Biosurfactants are emulsifiers of hydrocarbons produced by bacteria, yeast and fungi. They are polymers that form micelles and stay at the interface between liquid of different polarities. This work aim to study the development of the biosurfactant production process and its application related to oil sludge. This research has been done in three different steps: the Acinetobacter iwoffii inoculation, its growth in a nutritive broth and the fermentation under specific conditions. It was used three different kind of substrates: ethanol, glycerol and kerosene for comparison. The surfactant potential was evaluated by the emulsification indexes with suspension biomass and efficiency tests with oil sludge. Preliminary results show that biosurfactant production by Acinetobacter iwoffii can be a feasible process due to the satisfactory emulsification indexes that have been obtained. (author)

Fabrication and Properties of Micro-Nanoencapsulated Phase Change Materials for Internally-Cooled Liquid Desiccant Dehumidification

Directory of Open Access Journals (Sweden)

Xiaofeng Niu

2017-04-01

Full Text Available Micro-nanoencapsulated phase change materials (M-NEPCMs are proposed to be useful in liquid desiccant dehumidification by restraining the temperature rise in the moisture-removal process and improving the dehumidification efficiency. In this paper, the n-octadecane M-NEPCMs with desirable thermal properties for internally-cooled dehumidification were fabricated by using compound emulsifiers through the in-situ polymerization method. Melamine-formaldehyde resin was used as the shell material. The effects of the mixing ratio, emulsification methods and amount of the compound emulsifiers on the morphology, size and thermal properties of the M-NEPCMs were investigated experimentally. The optimum weight mixing ratio of the compound emulsifiers is SDS (sodium dodecyl sulfate:Tween80 (polyoxyethylene sorbitan monooleate:Span80 (sorbitan monooleate = 0.1:0.6:0.3, which achieves the best stability of the n-octadecane emulsion. When the compound emulsifiers are 10 wt. % of the core material, the melting enthalpy of M-NEPCMs reaches its maximum of 145.26 J/g of capsules, with an encapsulation efficiency of 62.88% and a mean diameter of 636 nm. The sub-cooling of the prepared M-NEPCMs is lower than 3 °C, with an acceptable thermal reliability after the thermal cycling test. A pre-emulsification prior to the addition of deionized water in the emulsification is beneficial to the morphology of the capsules, as the phase change enthalpy can be increased by 123.7%.

Fabrication and Properties of Micro-Nanoencapsulated Phase Change Materials for Internally-Cooled Liquid Desiccant Dehumidification.

Science.gov (United States)

Niu, Xiaofeng; Xu, Qing; Zhang, Yi; Zhang, Yue; Yan, Yufeng; Liu, Tao

2017-04-29

Micro-nanoencapsulated phase change materials (M-NEPCMs) are proposed to be useful in liquid desiccant dehumidification by restraining the temperature rise in the moisture-removal process and improving the dehumidification efficiency. In this paper, the n -octadecane M-NEPCMs with desirable thermal properties for internally-cooled dehumidification were fabricated by using compound emulsifiers through the in-situ polymerization method. Melamine-formaldehyde resin was used as the shell material. The effects of the mixing ratio, emulsification methods and amount of the compound emulsifiers on the morphology, size and thermal properties of the M-NEPCMs were investigated experimentally. The optimum weight mixing ratio of the compound emulsifiers is SDS (sodium dodecyl sulfate):Tween80 (polyoxyethylene sorbitan monooleate):Span80 (sorbitan monooleate) = 0.1:0.6:0.3, which achieves the best stability of the n -octadecane emulsion. When the compound emulsifiers are 10 wt. % of the core material, the melting enthalpy of M-NEPCMs reaches its maximum of 145.26 J/g of capsules, with an encapsulation efficiency of 62.88% and a mean diameter of 636 nm. The sub-cooling of the prepared M-NEPCMs is lower than 3 °C, with an acceptable thermal reliability after the thermal cycling test. A pre-emulsification prior to the addition of deionized water in the emulsification is beneficial to the morphology of the capsules, as the phase change enthalpy can be increased by 123.7%.

STUDY ON ULTRASONIC DEGREASING OF SHEEPSKIN WASTE

Directory of Open Access Journals (Sweden)

BĂLĂU MÎNDRU Tudorel

2014-05-01

Full Text Available Leather industry is a relatively large source of waste from raw material, so skin waste recovery is a goal of clean technologies. Capitalization of skin waste aims to obtain: chemical auxiliaries, technical articles, hydrolyzed protein, artificial leather, composite building materials, heat sources and collagen biomaterials with applications in medicine, cosmetics, etc. A first step in the recovery of skin waste is the degreasing operation. Ultrasound is an effective tool to improve the efficiency of the conventional degreasing affecting the chemical substances as well as the treated skin. In addition, the processing time is reduced. Ultrasound is known to enhance the emulsification and dispersion of oils/fat. The usual degreasing methods requires more emulsifier/solvent ratio and process time for emulsification and additional solvent for washing out the emulsified fat. This paper investigates the possibility of recovery through ecological processes of leather waste from finishing operations for further capitalization. The present study aims emulsification and subsequent removal of the fat present in the chamois powder waste from polishing operation with the aid of ultrasound by an aqueous ecofriendly method. The study also took into account the ultrasonic treatment of the leather waste using trichlorethylene as a medium of propagation-degreasing, and realized a comparative analysis of efficiency of fat extraction by Soxhlet method and via ultrasonication. IR-ATR and optical microscopy highlight both morphological and chemical-structural changes of treated materials by different degreasing methods

Food Engineering at Multiple Scales: Case Studies, Challenges and the Future—A European Perspective

NARCIS (Netherlands)

Roos, Y.; Fryer, P.J.; Knorr, D.; Schuchmann, H.P.; Schroën, C.G.P.H.; Schutyser, M.A.I.; Trystram, G.; Windhab, E.J.

2016-01-01

A selection of Food Engineering research including food structure engineering, novel emulsification processes, liquid and dry fractionation, Food Engineering challenges and research with comments on European Food Engineering education is covered. Food structure engineering is discussed by using

Physical, rheological, functional and film properties of a novel emulsifier: Frost grape polysaccharide (FGP) from Vitis riparia Michx

Science.gov (United States)

A novel emulsifier, Frost grape polysaccharide (FGP), isolated from natural exudate of the species Vitis riparia Michx, was physically and rheologically characterized. The determination of the physical, structural, thermodynamic, emulsification, film, and rheological properties of FGP provide essent...

Microspheres for protein delivery prepared from amphiphilic multiblock copolymers. 1. influence of preparation techniques on particle characteristics and protein delivery

NARCIS (Netherlands)

Bezemer, J.M.; Radersma, R.; Grijpma, Dirk W.; Dijkstra, Pieter J.; van Blitterswijk, Clemens; Feijen, Jan

2000-01-01

The entrapment of lysozyme in amphiphilic multiblock copolymer microspheres by emulsification and subsequent solvent removal processes was studied. The copolymers are composed of hydrophilic poly(ethylene glycol) (PEG) blocks and hydrophobic poly(butylene terephthalate) (PBT) blocks. Direct solvent

Mechanism of oil-pulling therapy -In vitro study

Directory of Open Access Journals (Sweden)

Sharath Asokan

2011-01-01

Conclusion: The myth that the effect of oil-pulling therapy on oral health was just a placebo effect has been broken and there are clear indications of possible saponification and emulsification process, which enhances its mechanical cleaning action.

Uji produksi biosurfaktan oleh Pseudomonas sp. pada substrat yang berbeda

Directory of Open Access Journals (Sweden)

Fatimah Fatimah

2012-02-01

Full Text Available Biosurfactant, microbial metabolite whose properties like surfactant, was suggested to replace chemically synthesized surfactant for take in hand environtmental pollution by petroleum hydrocarbon. This work was done to examine potency of Pseudomonas sp. isolated from Tanjung Perak Harbor to produce biosurfactant. Also, to know the effect of different substrates (glucose + yeast extract, lubricating oil and hexadecane toward biosurfactant production. Pseudomonas sp. grown in mineral synthetic water and biosurfactant production was measured on stationary phase. Biosurfactant production based on emulsification activity and surface tension reduction of supernatant (using Du Nouy tensiometer. Solar, lubricating oil, and hexadecane were used to examine emulsification activity. Results indicated that Pseudomonas sp. have a potency to produce biosurfactant. Surface tension of supernatant decreased up to 20 dyne/cm, when grown on hexadecane substrate. Hexadecane is the best growing substrate for biosurfactant production than others.

Effects of fish oil type, lipid antioxidants and presence of rapeseed oil on oxidative flavour stability of fish oil enriched milk

DEFF Research Database (Denmark)

Bruni Let, Mette; Jacobsen, Charlotte; Meyer, Anne S.

2004-01-01

As a part of our ongoing experiments on optimization of the oxidative stability of fish oils in genuine food systems, this study investigated the oxidative deterioration of fish oil enriched milk emulsions during cold storage. The experimental data showed that addition of rapeseed oil to fish oil...... (1:1) prior to emulsification into milk significantly protected the emulsions against oxidative deterioration. Addition of propyl gallate and a citric acid ester to the fish oil prior to emulsification also protected the fish oil enriched milk during storage. Emulsions containing a rapeseed:fish oil...... mixture were oxidatively stable during 11 d at 2 øC. Thus, no additional inhibitory effect of the added antioxidants was observed. The peroxide value and concentrations of five selected volatiles derived from n- 3 PUFA degradation in rapeseed:fish oil mixture emulsions were not significantly different...

Preparation and characterization of poly (urea-formaldehyde) walled dicyclopentadiene microcapsules

NARCIS (Netherlands)

Xiong, W.; Zhu, G.; Tang, J.; Dong, B.; Han, N.; Xing, F.; Schlangen, H.E.J.G.

2013-01-01

Poly (urea-formaldehyde) (PUF) shelled dicyclopentadiene (DCPD) microcapsules were prepared by in-situ polymerization technology for self-healing concrete applications. It’s found, during the process, sodium dodecyl benzene sulfonate (SDBS) behaves better in emulsification of DCPD than other

Influence of shear during enzymatic gelation of caseinate-water and caseinate-water-fat systems

NARCIS (Netherlands)

Manski, J.M.; Goot, van der A.J.; Boom, R.M.

2007-01-01

Solidification, emulsification and application of shear were combined to induce diversity and heterogeneity in the micro- and macrostructure of concentrated caseinate-based food matrices containing a dispersed fat phase. The products were evaluated with selected parameters from small-scale and

Aqueous polymer emulsions by chemical modifications of thermosetting alternating polyketones

NARCIS (Netherlands)

Zhang, Youchun; Broekhuis, A. A.; Picchioni, F.

2007-01-01

Aqueous polymer emulsions were prepared by chemical modifications of thermosetting alternating polyketones in a one-pot reaction. Polymeric amines derived from the polyketones can act as polymeric surfactants for the self-emulsification of polyketones. The stability and structure of the emulsions

In vitro and in vivo study to the biocompatibility and biodegradation of hydroxyapatite/poly(vinyl alcohol)/gelatin composite.

NARCIS (Netherlands)

Wang, M.; Li, Y.; Wu, J.; Xu, F.; Zuo, Y.; Jansen, J.A.

2008-01-01

A novel porous composite material composed of hydroxyapatite, poly(vinyl alcohol) (PVA), and gelatin (Gel) was fabricated by emulsification. Scanning electron microscopy showed that the material had a well-interconnected porous structure including many macropores (100-500 microm) and micropores

Strategies for encapsulation of small hydrophilic and amphiphilic drugs in PLGA microspheres: State-of-the-art and challenges

NARCIS (Netherlands)

Ramazani, F.; Chen, Weiluan; van Nostrum, C.F.; Storm, Gerrit; Kiessling, F.; Lammers, Twan Gerardus Gertudis Maria; Hennink, W.E.; Kok, R.J.

2016-01-01

Poly(lactide-co-glycolide) (PLGA) microspheres are efficient delivery systems for controlled release of low molecular weight drugs as well as therapeutic macromolecules. The most common microencapsulation methods are based on emulsification procedures, in which emulsified droplets of polymer and

Scenario for equilibrium solid-stabilized emulsions

NARCIS (Netherlands)

Kegel, W.K.; Groenewold, J.

2009-01-01

We show theoretically that under certain conditions colloidal particles can give rise to spontaneous emulsification of oil/water systems. The capillary penalty to create a large interface is compensated by entropic contributions connected to ionic dissociation on the colloid surfaces. The colloids

Multi-responsive ionic liquid emulsions stabilized by microgels

NARCIS (Netherlands)

Monteillet, H.; Workamp, M.; Li, X.; Schuur, Boelo; Kleijn, J.M.; Leermakers, F.; Sprakel, J.

2014-01-01

We present a complete toolbox to use responsive ionic liquid (IL) emulsions for extraction purposes. IL emulsions stabilized by responsive microgels are shown to allow rapid extraction and reversible breaking and re-emulsification. Moreover, by using a paramagnetic ionic liquid, droplets can be

Microcapsules with a pH responsive polymer: Influence of the encapsulated oil on the capsule morphology

NARCIS (Netherlands)

Wagdare, N.A.; Marcelis, A.T.M.; Boom, R.M.; Rijn, van C.J.M.

2011-01-01

Microcapsules were prepared by microsieve membrane cross flow emulsification of Eudragit FS 30D/dichloromethane/edible oil mixtures in water, and subsequent phase separation induced by extraction of the dichloromethane through an aqueous phase. For long-chain triglycerides and jojoba oil, core–shell

Optimization of cholesterol oxidase production by Brevibacterium sp ...

African Journals Online (AJOL)

An ultrasound-assisted emulsification as a pretreatment for cholesterol oxidase production by submerge fermentation using Brevibacterium sp. in a batch system was studied. Medium improvement for the production employing response surface methodology (RSM) was optimized in this paper. The concentration of ...

Study on mechanisms of biosurfactant-enhanced composting technology for waste management

Energy Technology Data Exchange (ETDEWEB)

Zhang, B.Y.; Huang, G.H.; Chen, B.; Xi, B.D.; Maqsood, I. [Regina Univ., SK (Canada)

2003-07-01

Composting is increasingly being used for solid waste treatment. The efficiency of solid waste composting might be enhanced using biosurfactants produced by microbial activities. This study was conducted to characterize the effect of biosurfactant on solid waste biodegradation throughout the composting process. The method employed involves shredding solid waste, followed by a treatment in an 8-litre (L) batch reactor. Biosurfactant production was monitored daily along with characteristics and maturity degree. Surface tension and emulsification capacity were of particular concern. The measurement of indices such as humic acid carbon (CHA) and fulvic acid carbon (CFA) were used to evaluate the maturity degree. The results indicated that the highest level of biosurfactant concentration was achieved on the third day, and within two days, related emulsification capacity reached its peak. This study confirmed the presence of biosurfactants and their function during the composting process. 16 refs., 2 tabs., 4 figs.

New bioemulsifiers produced by Candida lipolytica using D-glucose and babassu oil as carbon sources

Directory of Open Access Journals (Sweden)

Vance-Harrop Mabel H.

2003-01-01

Full Text Available Candida lipolytica IA 1055 produced extracellular biosurfactants with emulsification activity by fermentation using babassu oil and D-glucose as carbon sources. Natural seawater diluted at 50% supplemented with urea, ammonium sulfate, and phosphate was used as economic basal medium. The best results were achieved with the YSW-B2 medium, which contained urea, ammonium sulfate, and babassu oil and with YSW-B3 medium, which contained urea, ammonium sulfate, phosphate, and babassu oil, kept under fed batch fermentation for 60 hours with 5% of babassu oil. For the two media, the maximum specific growth rates were 0.02 h-1 and 0.04 h-1; the generation times were 34.6 h-1 and 17.3 h-1, and the emulsification activities were 0.666 and 0.158 units, respectively. The molecules of these new bioemulsifiers were contituted of carbohydrates, proteins and lipids.

Stabilization and fabrication of microbubbles: applications for medical purposes and functional materials.

Science.gov (United States)

Lee, Mina; Lee, Eun Yeol; Lee, Daeyeon; Park, Bum Jun

2015-03-21

Microbubbles with diameters ranging from a few micrometers to tens of micrometers have garnered significant attention in various applications including food processing, water treatment, enhanced oil recovery, surface cleaning, medical purposes, and material preparation fields with versatile functionalities. A variety of techniques have been developed to prepare microbubbles, such as ultrasonication, excimer laser ablation, high shear emulsification, membrane emulsification, an inkjet printing method, electrohydrodynamic atomization, template layer-by-layer deposition, and microfluidics. Generated bubbles should be immediately stabilized via the adsorption of stabilizing materials (e.g., surfactants, lipids, proteins, and solid particles) onto the gas-liquid interface to lower the interfacial tension. Such adsorption of stabilizers prevents coalescence between the microbubbles and also suppresses gas dissolution and resulting disproportionation caused by the presence of the Laplace overpressure across the gas-liquid interface. Herein, we comprehensively review three important topics of microbubbles: stabilization, fabrication, and applications.

Mechanism of oil-pulling therapy - in vitro study.

Science.gov (United States)

Asokan, Sharath; Rathinasamy, T K; Inbamani, N; Menon, Thangam; Kumar, S Senthil; Emmadi, Pamela; Raghuraman, R

2011-01-01

Oil pulling has been used extensively as a traditional Indian folk remedy without scientific proof for many years for strengthening teeth, gums and jaws and to prevent decay, oral malodor, bleeding gums and dryness of throat and cracked lips. The aim of this study was to evaluate the antibacterial activity of sesame oil and lignans isolated from sesame oil on oral microorganisms and to check whether saponification or emulsification occurs during oil-pulling therapy. The in vitro study was carried out in three different phases: (1) Antibacterial activity of the lignans and sesame oil were tested by minimum inhibitory concentration assay by agar dilution method and agar well diffusion method, respectively. (2) Increase in free fatty acid level of oil and the quantity of sodium hydroxide (NaOH) used up in the titration are good indicators of saponification process. This was assessed using analytical tests for vegetable oils. (3) Swished oil was observed under light microscope to assess the status of the oil, presence of microorganisms, oral debris and foreign bodies. Sesamin and sesamolin isolated from sesame oil did not have any antibacterial effect against oral microorganisms like Streptococcus mutans, Streptococcus mitis and Streptococcus viridans. Emulsification of sesame oil occurs during oil-pulling therapy. Increased consumption of NaOH in titration is a definite indication of a possible saponification process. The myth that the effect of oil-pulling therapy on oral health was just a placebo effect has been broken and there are clear indications of possible saponification and emulsification process, which enhances its mechanical cleaning action.

Functionality of whey proteins covalently modified by allyl isothiocyanate. Part 1 physicochemical and antibacterial properties of native and modified whey proteins at pH 2 to 7

NARCIS (Netherlands)

Keppler, Julia Katharina; Martin, Dierk; Garamus, Vasil M.; Berton-Carabin, Claire; Nipoti, Elia; Coenye, Tom; Schwarz, Karin

2017-01-01

Whey protein isolate (WPI) (∼75% β-lactoglobulin (β-LG)) is frequently used in foods as a natural emulsifying agent. However, at an acidic pH value, its emulsification capacity is greatly reduced. The covalent attachment of natural electrophilic hydrophobic molecules to WPI proteins is a

Production of surfactants by bacteria that were collected in three marine substrates; Producao de surfactante por bacterias coletadas em tres substratos marinhos

Energy Technology Data Exchange (ETDEWEB)

Silva, Frederico Sobrinho da; Crapez, Mirian A.C.; Bispo, Maria das Gracas S.; Krepsky, Natascha; Fontana, L.F.; Pimenta, Alessandro L.; Savergnini, Fernanda; Vasconcelos, Marcelo A.; Teixeira, Valeria L. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Programa de Pos-graduacao em Biologia Marinha]. E-mail: mirian@vm.uff.br

2003-07-01

Micro-organisms, because of their large surface-to-volume ratio and diverse synthetic capabilities are promising candidates for widening the present range of surfactants. Biosurfactants are those chemicals which are produced by micro-organisms. They are produced by bacteria, yeasts and fungi, and particularly by bacteria which are in a state of growth on water-immiscible substrate which is a source of food for example crude oil spillage treated with selected micro-organisms. Three strains were isolated from water column (B-AM), the algae Grateloupia sp. (B-AR), and mid coast sediment (B-SML) of Boa Viagem beach, RJ. The aerobic rods isolated produced yellow-orange pigments. The presence of biosurfactants was analysed by the oil drop collapse test. Emulsification index (E{sub 24}), emulsification index at non-aqueous phase (A) and aqueous phase (B), were assayed with gasoline, kerosene and Arabian light. The highest index was observed within fifteen days of incubation, when biomass were lower. (author)

Synthesis of biosurfactants and their advantages to microorganisms and mankind.

Science.gov (United States)

Cameotra, Swaranjit Singh; Makkar, Randhir S; Kaur, Jasminder; Mehta, S K

2010-01-01

Biosurfactants are surface-active compounds synthesized by a wide variety of microorganisms. They are molecules that have both hydrophobic and hydrophilic domains and are capable of lowering the surface tension and the interfacial tension of the growth medium. Biosurfactants possess different chemical structures--lipopeptides, glycolipids, neutral lipids and fatty acids. They are nontoxic biomolecules that are biodegradable. Biosurfactants also exhibit strong emulsification of hydrophobic compounds and form stable emulsions. The low water solubility of these hydrophobic compounds limits their availability to microorganisms, which is a potential problem for bioremediation of contaminated sites. Microbially produced surfactants enhance the bioavailability of these hydrophobic compounds for bioremediation. Therefore, biosurfactant-enhanced solubility of pollutants has potential applications in bioremediation. Not only are the biosurfactants useful in a variety of industrial processes, they are also of vital importance to the microbes in adhesion, emulsification, bioavailability, desorption and defense strategy. These interesting facts are discussed in this chapter.

Preparation and in vitro-in vivo evaluation of Witepsol H35 based self-nanoemulsifying drug delivery systems (SNEDDS) of coenzyme Q(10).

Science.gov (United States)

Nepal, Pushp R; Han, Hyo-Kyung; Choi, Hoo-Kyun

2010-02-19

Coenzyme Q(10) (CoQ(10)) was formulated into self-nanoemulsifying drug delivery systems (SNEDDS) to overcome low bioavailability attributed to hydrophobic nature of the drug. Screening of oil phase, surfactants and co-surfactants were performed to select Witepsol H35, Solutol HS15 and Lauroglycol FCC, respectively. Ternary phase diagrams were drawn to identify nanoemulsifying region followed by optimization of SNEDDS formulation. The optimized formulation, CoQ(10), Witepsol H35, Solutol HS15 and Lauroglycol FCC in the weight ratio of 1:0.7:4:2, respectively, emulsified readily at 37 degrees C with mean emulsion droplet size of 32.4 nm. The stability test of the optimized formulation in pH 1.2 and 6.8 buffers confirmed no pH effect on emulsion droplet size. In vitro dissolution (emulsification) test and in vivo animal study of the formulation elucidated the complete emulsification of drug and improved oral bioavailability of poorly soluble CoQ(10). 2009 Elsevier B.V. All rights reserved.

Preparation of fluidized catalytic cracking slurry oil-in-water emulsion as anti-collapse agent for drilling fluids

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Zhengqiang Xiong

2016-12-01

Full Text Available Fluidized catalytic cracking slurry oil-in-water emulsion (FCCSE was prepared by using interfacial complexes generation method that was simple and versatile. The critical factors influencing the sample preparation process were optimized, for instance, the optimum value of the mixed hydrophile-lipophile balance of compound emulsifier was 11.36, the content of compound emulsifier was 4 wt%, the emulsification temperature was 75 °C, the agitation speed was 200 rpm, and the emulsification time was 30–45 min. The performance as a drilling fluid additive was also investigated with respect to rheological properties, filtration loss and inhibition of FCCSE. Experimental results showed that FCCSE was favorable to inhibiting clay expansion and dispersion and reducing fluid loss. Furthermore, it had good compatibility with other additives and did not affect the rheological properties of drilling fluids. FCCSE exhibited better performance than the available emulsified asphalt. It has a promising application as anti-collapse agent in petroleum and natural gas drilling.

Comparison of a novel spray congealing procedure with emulsion-based methods for the micro-encapsulation of water-soluble drugs in low melting point triglycerides.

Science.gov (United States)

McCarron, Paul A; Donnelly, Ryan F; Al-Kassas, Rasil

2008-09-01

The particle size characteristics and encapsulation efficiency of microparticles prepared using triglyceride materials and loaded with two model water-soluble drugs were evaluated. Two emulsification procedures based on o/w and w/o/w methodologies were compared to a novel spray congealing procedure. After extensive modification of both emulsification methods, encapsulation efficiencies of 13.04% tetracycline HCl and 11.27% lidocaine HCl were achievable in a Witepsol-based microparticle. This compares to much improved encapsulation efficiencies close to 100% for the spray congealing method, which was shown to produce spherical particles of approximately 58 microm. Drug release studies from a Witepsol formulation loaded with lidocaine HCl showed a temperature-dependent release mechanism, which displayed diffusion-controlled kinetics at temperatures approximately 25 degrees C, but exhibited almost immediate release when triggered using temperatures close to that of skin. Therefore, such a system may find application in topical semi-solid formulations, where a temperature-induced burst release is preferred.

Lithocholic acid controls adaptive immune responses by inhibition of Th1 activation through the Vitamin D receptor

NARCIS (Netherlands)

Pols, Thijs W. H.; Puchner, Teresa; Korkmaz, H. Inci; Vos, Mariska; Soeters, Maarten R.; de Vries, Carlie J. M.

2017-01-01

Bile acids are established signaling molecules next to their role in the intestinal emulsification and uptake of lipids. We here aimed to identify a potential interaction between bile acids and CD4+ Th cells, which are central in adaptive immune responses. We screened distinct bile acid species for

Evaluating the toxicity of permeability enhanchers of polyethylene ...

African Journals Online (AJOL)

The aim of this study is to evaluate the effect of polyethylene glycol brij ethers surfactants group on red blood cells as a model for biological membranes. Also in this study, physicochemical properties including emulsification index (E24), foam producing activity (Fh) and critical micelle concentration (cmc) were studied.

Production and characterization of a group of bioemulsifiers from the marine Bacillus velezensis strain H3.

Science.gov (United States)

Liu, Xiangyang; Ren, Biao; Chen, Ming; Wang, Haibin; Kokare, Chandrakant R; Zhou, Xianlong; Wang, Jidong; Dai, Huanqin; Song, Fuhang; Liu, Mei; Wang, Jian; Wang, Shujin; Zhang, Lixin

2010-08-01

Marine microbes are a rich source of bioactive compounds, such as drugs, enzymes, and biosurfactants. To explore the bioactive compounds from our marine natural product library, an oil emulsification assay was applied to discover biosurfactants and bioemulsifiers. A spore-forming bacterial strain from sea mud was found to produce bioemulsifiers with good biosurfactant activity and a broad spectrum of antimicrobial properties. It was identified as Bacillus velezensis H3 using genomic and phenotypic data analysis. This strain was able to produce biosurfactants with an optimum emulsification activity at pH 6.0 and 2% NaCl by using starch as the carbon source and ammonium sulfate as the nitrogen source. The emulsification-guided isolation and purification procedure led to the discovery of the biosurfactant components, which were mainly composed of nC(14)-surfactin and anteisoC(15)-surfactin as determined by NMR and MS spectra. These compounds can reduce the surface tension of phosphate-buffered saline (PBS) from 71.8 to 24.8 mN/m. The critical micelle concentrations (CMCs) of C(14)-surfactin and C(15)-surfactin in 0.1 M PBS (pH 8.0) were determined to be 3.06 x 10(-5) and 2.03 x 10(-5) mol/L, respectively. The surface tension values at CMCs for C(14)-surfactin and C(15)-surfactin were 25.7 and 27.0 mM/m, respectively. In addition, the H3 biosurfactant exhibited antimicrobial activities against Staphyloccocus aureus, Mycobacterium, Klebsiella peneumoniae, Pseudomonas aeruginosa, and Candida albicans. Thus B. velezensis H3 is an alternative surfactin producer with potential application as an industrial strain for the lipopeptide production.

Fabrication of lipidic nanocarriers of loratadine for facilitated intestinal permeation using multivariate design approach.

Science.gov (United States)

Verma, Samridhi; Singh, Sandeep Kumar; Verma, Priya Ranjan Prasad

2016-01-01

In this investigation, multivariate design approach was employed to develop self-nanoemulsifying drug delivery system (SNEDDS) of loratadine and to exploit its potential for intestinal permeability. Drug solubility was determined in various vehicles and existence of self-nanoemulsifying region was evaluated by phase diagram studies. The influence of formulation variables X1 (Capmul MCM C8) and X2 (Solutol HS15) on SNEDDS was assessed for mean globule sizes in different media (Y1-Y3), emulsification time (Y4) and drug-release parameters (Y5-Y6), to improve quality attributes of SNEDDS. Significant models were generated, statistically analyzed by analysis of variance and validated using the residual and leverage plots. The interaction, contour and response plots explicitly demonstrated the influence of one factor on the other and displayed trend of factor-effect on responses. The pH-independent optimized formulation was obtained with appreciable global desirability (0.9266). The strenuous act of determining emulsification time is innovatively replaced by the use of oil-soluble dye to produce visibly distinct globules that otherwise may be deceiving. TEM images displayed non-aggregated state of spherical globules (size < 25 nm) and also revealed the structural transitions occurring during emulsification. Optimized formulation exhibited non-Newtonian flow justified by the model-fit and also presented the stability to dilution effects and thermodynamic stress testing. The ex vivo permeation study using confocal laser scanning microscopy indicate strong potential of rhodamine 123-loaded loratadine-SNEDDS to inhibit P-gp efflux and facilitate intestinal permeation. To conclude, the effectiveness of design yields a stable optimized SNEDDS with enhanced permeation potential, which is expected to improve oral bioavailability of loratadine.

Phase behavior and phase inversion for dispersant systems

International Nuclear Information System (INIS)

Solheim, A.; Brandvik, P.J.

1991-06-01

This report describes some preliminary phase behavior studies and phase inversion temperature measurements in seawater, bunker oil and dispersant. The objectives have been to find new ways of characterizing dispersants for dispersing oil spill at sea and, perhaps, to throw new lights on the mechanism of dispersion formation (oil-in-water emulsification). The work has been focussed on the relation to phase behavior and the existence of microemulsion in equilibrium with excess oil and water phases. The dispersing process is also compared to the recommended conditions for emulsion formation. When forming an oil-in-water emulsion in an industrial process, it is recommended to choose an emulsifier which gives a phase inversion temperature (PIT) which is 20 - 60 o C higher than the actual temperature for use. The emulsification process must take place close to the PIT which is the temperature at which the emulsion change from oil-in-water emulsion to water-in-oil emulsion when the system is stirred. This condition corresponds to the temperature where the phase behavior change character. The purpose has been to find out if the composition of the dispersants corresponds to the recommendations for oil-in-water emulsification. The amount of experimental work has been limited. Two kinds of experiments have been carried out. Phase behavior studies have been done for seawater, bunker oil and four different dispersants where one had an optimal composition. The phase behavior was hard to interpret and is not recommended for standard dispersants test. The other experimental technique was PIT-measurements by conductivity measurements versus temperature. 4 figs., 1 tab., 4 refs

Effect of different concentrations of olive oil and oleic acid on the ...

African Journals Online (AJOL)

The main objective of this study was to investigate the effect of olive oil and oleic acid addition to albumin (egg white) through emulsification to produce films on mechanical properties. Plasticizer was necessary to maintain film and coating integrity and to avoid pores cracks. Edible composite films were prepared from ...

Exploiting the aerobic endospore-forming bacterial diversity in saline and hypersaline environments for biosurfactant production.

Science.gov (United States)

de Almeida Couto, Camila Rattes; Alvarez, Vanessa Marques; Marques, Joana Montezano; de Azevedo Jurelevicius, Diogo; Seldin, Lucy

2015-10-28

Biosurfactants are surface-active biomolecules with great applicability in the food, pharmaceutical and oil industries. Endospore-forming bacteria, which survive for long periods in harsh environments, are described as biosurfactant producers. Although the ubiquity of endospore-forming bacteria in saline and hypersaline environments is well known, studies on the diversity of the endospore-forming and biosurfactant-producing bacterial genera/species in these habitats are underrepresented. In this study, the structure of endospore-forming bacterial communities in sediment/mud samples from Vermelha Lagoon, Massambaba, Dois Rios and Abraão Beaches (saline environments), as well as the Praia Seca salterns (hypersaline environments) was determined via denaturing gradient gel electrophoresis. Bacterial strains were isolated from these environmental samples and further identified using 16S rRNA gene sequencing. Strains presenting emulsification values higher than 30 % were grouped via BOX-PCR, and the culture supernatants of representative strains were subjected to high temperatures and to the presence of up to 20 % NaCl to test their emulsifying activities in these extreme conditions. Mass spectrometry analysis was used to demonstrate the presence of surfactin. A diverse endospore-forming bacterial community was observed in all environments. The 110 bacterial strains isolated from these environmental samples were molecularly identified as belonging to the genera Bacillus, Thalassobacillus, Halobacillus, Paenibacillus, Fictibacillus and Paenisporosarcina. Fifty-two strains showed emulsification values of at least 30%, and they were grouped into 18 BOX groups. The stability of the emulsification values varied when the culture supernatants of representative strains were subjected to high temperatures and to the presence of up to 20% NaCl. The presence of surfactin was demonstrated in one of the most promising strains. The environments studied can harbor endospore

The comparison of oxidative thermokinetics between emulsion and microemulsion diesel fuel

International Nuclear Information System (INIS)

Leng, Lijian; Yuan, Xingzhong; Zeng, Guangming; Wang, Hou; Huang, Huajun; Chen, Xiaohong

2015-01-01

Highlights: • Microemulsion fuel (>90 days) was much more stable than emulsion (≈2 days). • Microemulsification decreased activation energy of the fuel system by 5 kJ mol −1 . • Emulsification increased activation energy of the fuel system by 15 kJ mol −1 . • Microemulsification was more competitive for fuel upgrading than emulsification. - Abstract: Water fuel emulsion has been widely studied with the advantages of saving energy, enhancing engine torque, improving engine performance, and reducing the pollutant emissions. However, it has unfavorable disadvantages such as phase separation and long ignition delay. Water fuel microemulsion with rhamnolipid as the surfactant was formed in this study and characterized in comparison to water fuel emulsion. Water fuel microemulsion was thermodynamically stable without phase separation after 90 days vs. the milky-white emulsion fuel, separated within 2 days. In the thermogravimetric analysis, the TG and DTG curves were shifted to higher temperatures as the increment of heating rate. However, the shift for emulsion at 40 K min −1 was inconspicuous, which implies the reduction in heat transfer, mass transfer, and vaporization rates and further the lengthened ignition delay upon combustion in diesel engine. The activation energies (E a ) predicted by Ozawa–Flynn–Wall (OFW), Kissinger–Akhira–Sunose (KAS), and Starink’s methods indicate that the formation of microemulsion could decrease the activation energy of the fuel by about 5 kJ mol −1 , while the formation of emulsion would increase by 15 kJ mol −1 . The lower activation energy of microemulsion fuel is an indication of easy ignition or shortened ignition delay. Thus, microemulsification may be a more competitive technique for fuel upgrading compared to emulsification

Characterization of Celecoxib-Loaded Solid Lipid Nanoparticles ...

African Journals Online (AJOL)

system with several advantages, including enhanced physical stability, dual loading ability for lipophilic and .... where kp is the release rate constant at the elapsed time t, n is a constant, where the value of n ≤ 0.45 indicates .... CXB and the hydrocarbon chain of the esterified fatty acids in the lipids. Upon emulsification CXB.

Assessing Bacillus subtilis biosurfactant effects on the biodegradation of petroleum products.

Science.gov (United States)

Montagnolli, Renato Nallin; Lopes, Paulo Renato Matos; Bidoia, Ederio Dino

2015-01-01

Microbial pollutant removal capabilities can be determined and exploited to accomplish bioremediation of hydrocarbon-polluted environments. Thus, increasing knowledge on environmental behavior of different petroleum products can lead to better bioremediation strategies. Biodegradation can be enhanced by adding biosurfactants to hydrocarbon-degrading microorganism consortia. This work aimed to improve petroleum products biodegradation by using a biosurfactant produced by Bacillus subtilis. The produced biosurfactant was added to biodegradation assays containing crude oil, diesel, and kerosene. Biodegradation was monitored by a respirometric technique capable of evaluating CO₂ production in an aerobic simulated wastewater environment. The biosurfactant yielded optimal surface tension reduction (30.9 mN m(-1)) and emulsification results (46.90% with kerosene). Biodegradation successfully occurred and different profiles were observed for each substance. Precise mathematical modeling of biosurfactant effects on petroleum degradation profile was designed, hence allowing long-term kinetics prediction. Assays containing biosurfactant yielded a higher overall CO₂ output. Higher emulsification and an enhanced CO2 production dataset on assays containing biosurfactants was observed, especially in crude oil and kerosene.

The potential for hydrocarbon biodegradation and production of extracellular polymeric substances by aerobic bacteria isolated from a Brazilian petroleum reservoir.

Science.gov (United States)

Vasconcellos, S P; Dellagnezze, B M; Wieland, A; Klock, J-H; Santos Neto, E V; Marsaioli, A J; Oliveira, V M; Michaelis, W

2011-06-01

Extracellular polymeric substances (EPS) can contribute to the cellular degradation of hydrocarbons and have a huge potential for application in biotechnological processes, such as bioremediation and microbial enhanced oil recovery (MEOR). Four bacterial strains from a Brazilian petroleum reservoir were investigated for EPS production, emulsification ability and biodegradation activity when hydrocarbons were supplied as substrates for microbial growth. Two strains of Bacillus species had the highest EPS production when phenanthrene and n-octadecane were offered as carbon sources, either individually or in a mixture. While Pseudomonas sp. and Dietzia sp., the other two evaluated strains, had the highest hydrocarbon biodegradation indices, EPS production was not detected. Low EPS production may not necessarily be indicative of an absence of emulsifier activity, as indicated by the results of a surface tension reduction assay and emulsification indices for the strain of Dietzia sp. The combined results gathered in this work suggest that a microbial consortium consisting of bacteria with interdependent metabolisms could thrive in petroleum reservoirs, thus overcoming the limitations imposed on each individual species by the harsh conditions found in such environments.

Alternative methodology for isolation of biosurfactant-producing bacteria.

Science.gov (United States)

Krepsky, N; Da Silva, F S; Fontana, L F; Crapez, M A C

2007-02-01

Wide biosurfactant application on biorremediation is limited by its high production cost. The search for cheaper biossurfactant production alternatives has guided our study. The use of selective media containing sucrose (10 g x L(-1)) and Arabian Light oil (2 g x L(-1)) as carbon sources showed to be effective to screen and maintain biosurfactant-producing consortia isolated from mangrove hydrocarbon-contaminated sediment. The biosurfactant production was assayed by kerosene, gasoline and Arabian Light Emulsification activity and the bacterial growth curve was determined by bacterial quantification. The parameters analyzed for biosurfactant production were the growth curve, salinity concentration, flask shape and oxygenation. All bacteria consortia screened were able to emulsify the petroleum derivatives tested. Biosurfactant production increased according to the incubation time; however the type of emulsification (non-aqueous phase or aqueous phase) did not change with time but with the compound tested. The methodology was able to isolate biosurfactant-producing consortia from superficial mangrove sediment contaminated by petroleum hydrocarbons and was recommended for selection of biosurfactant producing bacteria in tropical countries with low financial resources.

Alternative methodology for isolation of biosurfactant-producing bacteria

Directory of Open Access Journals (Sweden)

N. Krepsky

Full Text Available Wide biosurfactant application on biorremediation is limited by its high production cost. The search for cheaper biossurfactant production alternatives has guided our study. The use of selective media containing sucrose (10 g.L-1 and Arabian Light oil (2 g.L-1 as carbon sources showed to be effective to screen and maintain biosurfactant-producing consortia isolated from mangrove hydrocarbon-contaminated sediment. The biosurfactant production was assayed by kerosene, gasoline and Arabian Light Emulsification activity and the bacterial growth curve was determined by bacterial quantification. The parameters analyzed for biosurfactant production were the growth curve, salinity concentration, flask shape and oxygenation. All bacteria consortia screened were able to emulsify the petroleum derivatives tested. Biosurfactant production increased according to the incubation time; however the type of emulsification (non-aqueous phase or aqueous phase did not change with time but with the compound tested. The methodology was able to isolate biosurfactant-producing consortia from superficial mangrove sediment contaminated by petroleum hydrocarbons and was recommended for selection of biosurfactant producing bacteria in tropical countries with low financial resources.

Encapsulation of vitamin E: effect of physicochemical properties of wall material on retention and stability.

Science.gov (United States)

Hategekimana, Joseph; Masamba, Kingsley George; Ma, Jianguo; Zhong, Fang

2015-06-25

Spray drying technique was used to fabricate Vitamin E loaded nanocapsules using Octenyl Succinic Anhydride (OSA) modified starches as emulsifiers and wall materials. Several physicochemical properties of modified starches that are expected to influence emulsification capacity, retention and storage stability of Vitamin E in nanocapsules were investigated. High Degree of Substitution (DS), low Molecular Weight (Mw) and low interfacial tension improved emulsification properties while Oxygen Permeability (OP) and Water Vapor Permeability (WVP) affected the film forming properties. The degradation profile of Vitamin E fitted well with the Weibull model. Nanocapsules from OSA modified starches MS-A and MS-B retained around 50% of Vitamin E after a period of 60 days at 4-35°C. Reduced retention and short half-life (35 days) in nanocapsules fabricated using MS-C at 35°C were attributed to autoxidation reaction occurred due to poor film forming capacity. These results indicated that low molecular weights OSA modified starches were effective at forming stable Vitamin E nanocapsules that could be used in drug and beverage applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microorganism selection and performance in bioslurry reactors treating PAH-contaminated soil.

Science.gov (United States)

Cassidy, D P; Hudak, A J

2002-09-01

A continuous-flow reactor (CSTR) and a soil slurry-sequencing batch reactor (SS-SBR) were operated in 81 vessels for 200 days to treat a soil contaminated with polycyclic aromatic hydrocarbons (PAH). Filtered slurry samples were used to quantify bulk biosurfactant concentrations and PAH emulsification. Concentrations of Corynebacterium aquaticum, Flavobacterium mizutaii, Mycobacterium gastri, Pseudomonas aeruginosa, and Pseudomonas putida were determined using fatty acid methyl ester (FAME) analysis. The CSTR and SS-SBR selected microbial consortia with markedly different surfactant-producing and PAH-degrading abilities. Biosurfactant levels in the SS-SBR reached 4 times the critical micelle concentration (CMC) that resulted in considerable emulsification of PAH. In contrast, CSTR operation resulted in nomeasurable biosurfactant production. Total PAH removal efficiency was 93% in the SS-SBR, compared with only 66% in the CSTR, and stripping of PAH was 3 times less in the SS-SBR. Reversing the mode of operation on day 100 caused a complete reversal in microbial consortia and in reactor performance by day 140. These results show that bioslurry reactor operation can be manipulated to control overall reactor performance.

Screening of novel microorganisms for biosurfactant and biocontrol activity against Phytophthora infestans.

Science.gov (United States)

Tomar, Sonica; Singh, B P; Lal, Mehi; Ma, Khan; Hussain, Touseef; Sharma, Sanjeev; Kaushik, S K; Kumar, Satish

2014-09-01

In the present study, 95 isolates of bacteria were tested for their biosurfactant as well as biocontrol activity against Phytophthora infestans. The results revealed that only 15.8% isolates showed biosurfactant activity. The emulsification index ranged from 0-68% and 24.2% isolates showed positive reaction for biosurfactant properties. In emulsification assay and oil spreading test, 18.95% and 5.26% isolates, respectively scored positive for biosurfactant production. Among all, only five isolates were found effective against P. infestans, for biocontrol properties. Pseudomonas aeruginosa-1 showed 62.22% inhibition zone after 72 hrs while P. aeruginosa-3 showed 46.42%. Forty-eight hrs old culture supernatants were highly effective in food-poisoning test, tuber slice test and detached leaf method against P. infestans. In whole potato plant test, bacterial cell based formulation, culture supernatant and bacterial cell suspension of P. aeruginosa-1 showed 10.42%, 9.94% and 17.96% diseases severity respectively, as against 53.96% in control. This isolate holds promise as biological control agent against P. infestans in field.

A novel ionic amphiphilic chitosan derivative as a stabilizer of nanoemulsions: Improvement of antimicrobial activity of Cymbopogon citratus essential oil.

Science.gov (United States)

Bonferoni, Maria Cristina; Sandri, Giuseppina; Rossi, Silvia; Usai, Donatella; Liakos, Ioannis; Garzoni, Alice; Fiamma, Maura; Zanetti, Stefania; Athanassiou, Athanassia; Caramella, Carla; Ferrari, Franca

2017-04-01

Amphiphilic chitosans have been recently proposed to improve delivery of poorly soluble drugs. In the present paper a derivative obtained by ionic interaction between chitosan and oleic acid was for the first time studied to physically stabilize o/w nanoemulsions of an antimicrobial essential oil, Cymbopogon citratus (Lemongrass), in a low energy and mild conditions emulsification process. The novel combination of spontaneous emulsification process with chitosan oleate amphiphilic properties resulted in a stable dispersion of a few hundred nanometer droplets. Positive zeta potential confirmed the presence of a chitosan shell around the oil droplets, which is responsible for the nanoemulsion physical stabilization and for the maintenance of chitosan bioactive properties, such as mucoadhesion. Cytotoxicity test was performed on four different cell lines (HEp-2, Caco-2, WKD and McCoy cells) showing biocompatibility of the system. The maintenance and in some cases even a clear improvement in the essential oil antimicrobial activity towards nine bacterial and ten fungal strains, all of clinical relevance was verified for Lemongrass nanoemulsion. Copyright © 2017. Published by Elsevier B.V.

The influence of asphaltenes of the petroleum on the rheology of O/W (Oil/Water) emulsions; Influencia de asfaltenos do petroleo sobre a reologia de emulsoes O/A (Oleo/Agua)

Energy Technology Data Exchange (ETDEWEB)

Santos, Ronaldo Goncalves dos; Mohamed, Rahoma Sadeg; Loh, Watson; Bannwart, Antonio Carlos [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil)

2004-07-01

Heavy oils represent a large fraction of the Brazilian petroleum reserves and display a great potential for application as substitute to the conventional oils, provided a suitable technology for their transportation is available. The high viscosity of these heavy oils leads to high flow resistance and increase in the recovery and transportation costs. Methodologies employed to reduce these problems involve application of heat of addition of diluents or lighter oils, but are associated with high costs. Formation of low viscosity oil-in-water emulsions has been proposed as an alternative for the transportation of heavy oils, as investigated in this work. Preliminary results indicate significant viscosity decreases upon emulsification of heavy oils (viscosities greater than 1,000 cP) forming o/w emulsions with high oil content (between 50-65 vol. %), which display viscosities within 4-25 cP. Additionally, the effect of different surfactants, methodology of preparation and oil asphaltene content on the emulsion stability was also evaluated. These results confirm the potential of emulsification as a viable methodology for heavy oil transportation. (author)

A comparison of various modes of liquid-liquid based microextraction techniques: determination of picric acid.

Science.gov (United States)

Burdel, Martin; Šandrejová, Jana; Balogh, Ioseph S; Vishnikin, Andriy; Andruch, Vasil

2013-03-01

Three modes of liquid-liquid based microextraction techniques--namely auxiliary solvent-assisted dispersive liquid-liquid microextraction, auxiliary solvent-assisted dispersive liquid-liquid microextraction with low-solvent consumption, and ultrasound-assisted emulsification microextraction--were compared. Picric acid was used as the model analyte. The determination is based on the reaction of picric acid with Astra Phloxine reagent to produce an ion associate easily extractable by various organic solvents, followed by spectrophotometric detection at 558 nm. Each of the compared procedures has both advantages and disadvantages. The main benefit of ultrasound-assisted emulsification microextraction is that no hazardous chlorinated extraction solvents and no dispersive solvent are necessary. Therefore, this procedure was selected for validation. Under optimized experimental conditions (pH 3, 7 × 10(-5) mol/L of Astra Phloxine, and 100 μL of toluene), the calibration plot was linear in the range of 0.02-0.14 mg/L and the LOD was 7 μg/L of picric acid. The developed procedure was applied to the analysis of spiked water samples. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Three-Dimensional-Moldable Nanofiber-Reinforced Transparent Composites with a Hierarchically Self-Assembled "Reverse" Nacre-like Architecture.

Science.gov (United States)

Biswas, Subir K; Sano, Hironari; Shams, Md Iftekhar; Yano, Hiroyuki

2017-09-06

Achieving a structural hierarchy and a uniform nanofiller dispersion simultaneously remains highly challenging for obtaining a robust polymer nanocomposite of immiscible components. In this study, a remarkably facile Pickering emulsification approach is developed to fabricate hierarchical composites of immiscible acrylic polymer and native cellulose nanofibers by taking advantage of the dual role of the nanofibers as both emulsion stabilizer and polymer reinforcement. The composites feature a unique "reverse" nacre-like microstructure reinforced with a well-dispersed two-tier hierarchical nanofiber network, leading to a synergistic high strength, modulus, and toughness (20, 50, and 53 times that of neat polymer, respectively), high optical transparency (89%), high flexibility, and a drastically low thermal expansion (13 ppm K -1 , 1/15th of the neat polymer). The nanocomposites have a three-dimensional-shape moldability, also their surface can be patterned with micro/nanoscale features with high fidelity by in situ compression molding, making them attractive as the substrate for flexible displays, smart contact lens devices, and photovoltaics. The Pickering emulsification approach should be broadly applicable for the fabrication of novel functional materials of various immiscible components.

Preparation and characterization of monodisperse microcapsules with alginate and bentonite via external gelation technique encapsulating Pseudomonas putida Rs-198.

Science.gov (United States)

Li, Xuan; Wu, Zhansheng; He, Yanhui; Ye, Bang-Ce; Wang, Jun

2017-10-01

This paper evaluated the external gelation technique for preparing microcapsules. The microcapsules were consisted of Pseudomonas putida Rs-198 (Rs-198) core and sodium alginate (NaAlg)-bentonite (Bent) shell. Different emulsification rotation speeds and core/shell ratios were used to prepare the microcapsules of each formulation. The near-spherical microcapsules were monodisperse with a mean diameter of 25-100 μm and wrinkled surfaces. Fourier transform infrared spectrophotometry (FTIR) and thermogravimetric analysis (TGA) revealed the physical mixture of the wall material and the superior thermal stability of the microcapsules. Percentage yield, water content, and encapsulation efficiency were evaluated and correlated with the changes in emulsification rotation speed and core/shell ratio. In vitro release experiments demonstrated that 60% of the bacteria were released from the NaAlg-Bent microcapsules within three days. Considerably better survival was observed for encapsulated cells compared to free cells, especially in pH 4.0 and 10.0. In summary, the desired properties of microcapsules can be obtained by external gelation technique and the microcapsules on the bacteria had a good protective effect.

Surfactant-enhanced alkaline flooding for light oil recovery. Final report 1994--1995

Energy Technology Data Exchange (ETDEWEB)

Wasan, D.T.

1995-12-01

In this report, the authors present the results of their experimental and theoretical studies in surfactant-enhanced alkaline flooding for light oil recovery. The overall objective of this work is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12.0) for ultimate spontaneous emulsification and ultralow interfacial tension. In addition, the authors have (1) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, (2) investigated the mechanisms for spontaneous emulsification, (3) developed a technique to monitor low water content in oil, and (4) developed a technique to study water-in-oil emulsion film properties, (5) investigated the effect of surfactant on the equilibrium and transient interfacial tension, (6) investigated the kinetics of oil removal from a silica surface, and (7) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, accounting for added surfactant. The results of the studies conducted during the course of this project are summarized.

Surfactant-enhanced alkaline flooding for light oil recovery. Final report

Energy Technology Data Exchange (ETDEWEB)

Wasan, D.T.

1996-05-01

In this report, we present the results of our experimental and theoretical studies in surfactant-enhanced alkaline flooding for light oil recovery. The overall objective of this work is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12. 0) for ultimate spontaneous emulsification and ultralow interfacial tension. In addition, we have (1) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, (2) investigated the mechanisms for spontaneous emulsification, (3) developed a technique to monitor low water content in oil and (4) developed a technique to study water-in-oil emulsion film properties, (5) investigated the effect of surfactant on the equilibrium and transient interfacial tension, (6) investigated the kinetics of oil removal from a silica surface, and (7) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, accounting for added surfactant. The results of the studies conducted during the course of this project are discussed.

How relevant are assembled equilibrium samples in understanding structure formation during lipid digestion?

Science.gov (United States)

Phan, Stephanie; Salentinig, Stefan; Hawley, Adrian; Boyd, Ben J

2015-10-01

Lipid-based formulations are gaining interest for use as drug delivery systems for poorly water-soluble drug compounds. During digestion, the lipolysis products self-assemble with endogenous surfactants in the gastrointestinal tract to form colloidal structures, enabling enhanced drug solubilisation. Although earlier studies in the literature focus on assembled equilibrium systems, little is known about structure formation under dynamic lipolysis conditions. The purpose of this study was to investigate the likely colloidal structure formation in the small intestine after the ingestion of lipids, under equilibrium and dynamic conditions. The structural aspects were studied using small angle X-ray scattering and dynamic light scattering, and were found to depend on lipid composition, lipid chain length, prandial state and emulsification. Incorporation of phospholipids and lipolysis products into bile salt micelles resulted in swelling of the structure. At insufficient bile salt concentrations, a co-existing lamellar phase was observed, due to a reduction in the solubilisation capacity for lipolysis products. Emulsification accelerated the rate of lipolysis and structure formation. Copyright © 2015 Elsevier B.V. All rights reserved.

Preparation and characterisation of ethylcellulose microparticles containing propolis

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G. B. AVANçO

2009-02-01

Full Text Available

Ethylcellulose microparticles containing propolis ethanolic extract (PE were prepared by the emulsification and solvent evaporation method. Three ratios of ethylcellulose to PE dry residue value (DR were tested (1:0.25, 1:4 and 1:10. Moreover, polysorbate 80 was used as emulsifier in the external phase (1.0 or 1.5% w/w. Regular particle morphology without amorphous and/or sticking characteristics was achieved only when an ethylcellulose:DR ratio of 1:0.25 and 1.0% polysorbate 80 were used. Microparticles had a mean diameter of 85.83 µm. The entrapment efficiency for propolis of the microparticles was 62.99 ± 0.52%. These ethylcellulose microparticles containing propolis would be useful for developing propolis aqueous dosage forms without the strong and unpleasant taste, aromatic odour and high ethanol concentration of PE. Keywords: Brazilian propolis; ethylcellulose; emulsification and solvent evaporation; microparticle characterisation; optimisation.

Physical and functional properties of breakfast cereals from maize ...

African Journals Online (AJOL)

The results revealed the following ranges of physical and functional properties; pH (4.70- 6.56), bulk density (0.29 - 0.71g/ml), water absorption capacity (68.31- 76.39%), oil absorption capacity (0.87- 1.32%), foam capacity (2.48- 3.49%), viscosity (19.73-31.08%), gelation temperature (121-157°C), emulsification capacity ...

Electrochemical monitoring of the co-extraction of water with hydrated ions into an organic solvent

Czech Academy of Sciences Publication Activity Database

Mareček, Vladimír

2018-01-01

Roč. 88, MAR 2018 (2018), s. 57-60 ISSN 1388-2481 R&D Projects: GA ČR(CZ) GA17-09980S Institutional support: RVO:61388955 Keywords : Liquid/liquid interface * Water co-extraction dynamics * Emulsification Subject RIV: CG - Electrochemistry OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) Impact factor: 4.396, year: 2016

Drilling fluid base oil biodegradation potential of a soil ...

African Journals Online (AJOL)

Staphylococcus sp. isolated from oil-contaminated soil was grown in 1% drilling fluid base oil, HDF- 2000, as a sole source of carbon and energy. The organism has strong affinity for the substrate, growing at the rate of 0.16 h-1. It uses adherence and emulsification as mechanisms for oil uptake. In a nutrient-rich marine ...

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

This is not caused by the dissociative effect of CTAB-SDS with low surface activity at low temperature, as seen from the fact that almost all oxidative products can be retrieved for different toluene derivatives and surfactants by mimicking the conditions of reaction. In the emulsifications of toluene derivatives at 90°C, the time ...

Ultraviolet spectra of CeO2 nano-particles

International Nuclear Information System (INIS)

Tsunekawa, S.; Sivamohan, R.; Ohsuna, T.; Kasuya, A.; Takahashi, H.; Tohji, K.

1998-01-01

Full text: Quantum size effect is generally expected in nanometer size materials. The effect has been observed in many metal clusters and semiconducting nano-particles, but seldom in oxides, because the size control of crystalline oxides is generally difficult due to the ionic bond character. CeO 2 (ceria) is one of the rare-earth oxides and the size effect is worth studying from the viewpoint of an ultraviolet (u.v.) spectroscopy and applications. This report describes the first observation of a blue shift of u.v. spectra in ceria nano-particles of 2-5 nm in diameter with its deviation within 20%. A ceria aqueous sol (pH ≅ 2.5) having particle sizes under 6 nm in diameter was produced by ultrafiltration with a polyether sulfone membrane (SIP-1013, Asahi Chemical Industry Co.) from an original ceria aqueous sol (pH ≅ 1.5) having particle sizes extending over a wide range. Obtained sol contains a high concentration of Ce 3+ ions because of the high acidity. In order to separate ceria particles from Ce 3+ ions and fractionate the particle size, two kinds of anion-type surfactants were used in microemulsification process with toluene and water. One is sodium dodecylbenzene sulfonate (SD-BS) which is 2 nm in length and another is sodium octyl sulfonate (SOS) which is 1.2 nm in length. U.v. spectroscopic measurements and high resolution transmission electron microscopic (HRTEM) observations were performed for (SOS) t , (SOS+SOS) t , and (SDBS+SOS+SDBS) t , where (SOS) t is a ceria suspension in toluene obtained by an emulsification with SOS surfactant, (SOS+SOS) t indicates the same product obtained by the further emulsification with SOS for an aqueous phase of the emulsion with SOS, and (SDBS+SOS+SDBS) t means that obtained by an additional emulsification with SDBS for an aqueous phase obtained by two successive emulsifications with SDBS and SOS. Optical density data for (SOS) t , (SOS+SOS) t , and (SDBS+SOS+SDBS) t show absorption edges at 4076 Angstroms, 3997

Development of flurbiprofen-loaded nanoparticles with a narrow size distribution using sucrose.

Science.gov (United States)

Oh, Dong Hoon; Yan, Yi-Dong; Kim, Dong Wuk; Kim, Jong Oh; Yong, Chul Soon; Choi, Han-Gon

2014-02-01

A novel flurbiprofen-loaded nanoemulsion which gave uniform emulsion droplets with a narrow size distribution was previously reported to be prepared using membrane emulsification method. The purpose of this study is to develop a novel flurbiprofen-loaded nanoparticle with a narrow size distribution and improved bioavailability. The nanoparticle was prepared by solidifying nanoemulsion using sucrose as a carrier via spray drying method. Its physicochemical properties were investigated using SEM, DSC and PXRD. Furthermore, dissolution and bioavailability in rats were evaluated compared to a flurbiprofen-loaded commercial product. The flurbiprofen-loaded nanoparticles with flurbiprofen/sucrose/surfactant mixture (1/20/2, weight ratio) gave good solidification and no stickiness. They associated with about 70,000-fold improved drug solubility and had a mean size of about 300 nm with a narrow size distribution. Flurbiprofen was present in a changed amorphous state in these nanoparticles. Moreover, the nanoparticles gave significantly shorter Tmax, and higher AUC and Cmax of the drug compared to the commercial product (p flurbiprofen-loaded nanoparticles prepared with sucrose by the membrane emulsification and spray drying method would be a potential candidate for orally delivering poorly water-soluble flurbiprofen with enhanced bioavailability.

Optimization of environmental factors for improved production of rhamnolipid biosurfactant by Pseudomonas aeruginosa RS29 on glycerol.

Science.gov (United States)

Saikia, Rashmi Rekha; Deka, Suresh; Deka, Manab; Sarma, Hemen

2012-08-01

A biosurfactant producing Pseudomonas aeruginosa RS29 (identified on the basis of 16S rDNA analysis) with good foaming and emulsification properties has been isolated from crude oil contaminated sites. Optimization of different environmental factors was carried out with an objective to achieve maximum production of biosurfactant. Production of biosurfactant was estimated in terms of surface tension reduction and emulsification (E24) index. It was recorded that the isolated strain produced highest biosurfactant after 48 h of incubation at 37.5 °C, with a pH range of 7-8 and at salinity biosurfactant (Surface tension, 26.3 and 26.4 mN/m and E24 index, 80 and 79% respectively). The CMC of the biosurfactant was 90 mg/l. Maximum biomass (6.30 g/l) and biosurfactant production (0.80 g/l) were recorded at an optimal C/N ratio of 12.5. Biochemical analysis and FTIR spectra confirmed that the biosurfactant was rhamnolipid in nature. GC-MS analysis revealed the presence of C(8) and C(10) fatty acid components in the purified biosurfactant. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Furosemide self nano emulsifying drug delivery system (SNEDDS formulation comprising of capryol-90, polysorbate-80, and peg-400 with simplex-lattice-design

Directory of Open Access Journals (Sweden)

Najma Annuria Fithri

2017-10-01

Full Text Available Preparation of SNEDDS aims to improve solubility and absorption of furosemide in the body to reduce the dosage and minimize the side effects of drugs. Ternary diagram constructed from composition mixture produced nanoemulsion in the range of 20-40% of capryol-90, 20-40% polysorbate-80 and 40-60% PEG-400. Formulations of SNEDDS using Design-Expert®10 with simplex-lattice-design method in the study was aimed to investigate the effect of SNEDDS each component's proportions towards test responses. Emulsification time, drug content and viscosity were best demonstrated by run-7 with consecutive values of 131.68±2.14 seconds, 99.89±2.68% and 0.87±0.0043 mm2/s. The optimum formula was obtained through entering test response parameter data of all thirteen formula. Drug content and emulsification time was 107.0 ± 1.44% and 155.59±1.56 seconds with viscosity value 0.91±0.00 mm2/s. From the physical stability studies, SNEDDS formulas were stable and did not show phase separation when exposed to temparature stress testing.

Manual small incision extracapsular cataract surgery in Australia.

Science.gov (United States)

van Zyl, Lourens; Kahawita, Shyalle; Goggin, Michael

2014-11-01

Examination of the results and describing the technique of manual small incision extracapsular cataract extraction on patients with advanced cataracts in urban Australia. A descriptive case series. Thirty-eight patients at three public hospitals, one tertiary and two secondary ophthalmic units in urban Australia. Forty eyes with dense mature cataracts with hand movement vision or worse underwent a planned manual small incision extracapsular cataract extraction instead of traditional phaco-emulsification. Postoperative visual aquity, surgically induced astigmatism and complications. Seventy-eight per cent of patients had an uncorrected visual acuity of 6/12 or better on the first postoperative day. Eighty-three per cent of patients had a distance corrected visual acuity of 6/9 or better 3 months postoperatively. One case was complicated by a posterior capsule rupture. No cases of endophthalmitis were reported. The summated vector mean of the surgically induced astigmatism was 0.089D at 93°. Manual small incision extracapsular cataract extraction is an efficacious cataract surgery technique with good visual outcome and is a safe alternative to phaco-emulsification in suitable cases in a first-world setting. © 2014 Royal Australian and New Zealand College of Ophthalmologists.

Temperature-controlled continuous production of all-trans retinoic acid-loaded solid lipid nanoparticles using static mixers

Science.gov (United States)

Shao, Wenyao; Yan, Mengwen; Chen, Tingting; Chen, Yuqing; Xiao, Zongyuan

2017-04-01

This work aims to develop a temperature-controlled continuous solvent emulsification-diffusion process to synthesize all-trans retinoic acid (ATRA)-loaded solid lipid nanoparticles (SLNs) using static mixers. ATRA-loaded SLNs of around 200 nm were obtained when the flow rates of the organic and aqueous phases were 50 ml min-1 and 500 ml min-1, respectively. It was found that the lipid concentration played a dominant role in the size of the obtained SLNs, and higher drug concentration resulted in relatively low entrapment efficiency. The encapsulation of ATRA in the SLNs was effective in improving its stability according to the photo-degradation test. The in vitro release of SLN was slow without an initial burst. This study demonstrates that the solvent emulsification-diffusion technique with static mixing is an effective method of producing SLNs, and could easily be scaled up for industrial applications. Highlights Higher lipid concentration leads to larger SLNs. SLN transformation occurs due to Ostwald ripening. The ATRA-loaded SLNs around 200 nm were successfully produced with static mixers. ATRA-loaded SLNs show better stability towards sunlight. ATRA in SLNs exhibited a relatively slow release rate without a significant initial burst.

Production of biosurfactant from Bacillus licheniformis for microbial enhanced oil recovery and inhibition the growth of sulfate reducing bacteria

Directory of Open Access Journals (Sweden)

H.S. El-Sheshtawy

2015-06-01

Full Text Available In this study, the bacterium Bacillus licheniformis has been isolated from oil reservoir; the ability of this bacterium to produce a biosurfactant was detected. Surface properties of the produced biosurfactant were confirmed by determining the emulsification power as well as surface and interfacial tension. The crude biosurfactant has been extracted from supernatant culture growth, and the yield of crude biosurfactant was about 1 g/l. Also, chemical structure of the produced biosurfactant was confirmed using FTIR analysis. Results revealed that, the emulsification power has been increased up to 96% and the surface tension decreased from 72 of distilled water to 36 mN/m after 72 h of incubation. The potential application of this bacterial species in microbial-enhanced oil recovery (MEOR was investigated. The percent of oil recovery was 16.6% upon application in a sand pack column designed to stimulate an oil recovery. It also showed antimicrobial activity against the growth of different strains of SRB (sulfate reducing bacteria. Results revealed that a complete inhibition of SRB growth using 1.0% crude biosurfactant is achieved after 3 h.

Improved Functional Characteristics of Whey Protein Hydrolysates in Food Industry

Science.gov (United States)

Jeewanthi, Renda Kankanamge Chaturika; Lee, Na-Kyoung; Paik, Hyun-Dong

2015-01-01

This review focuses on the enhanced functional characteristics of enzymatic hydrolysates of whey proteins (WPHs) in food applications compared to intact whey proteins (WPs). WPs are applied in foods as whey protein concentrates (WPCs), whey protein isolates (WPIs), and WPHs. WPs are byproducts of cheese production, used in a wide range of food applications due to their nutritional validity, functional activities, and cost effectiveness. Enzymatic hydrolysis yields improved functional and nutritional benefits in contrast to heat denaturation or native applications. WPHs improve solubility over a wide range of pH, create viscosity through water binding, and promote cohesion, adhesion, and elasticity. WPHs form stronger but more flexible edible films than WPC or WPI. WPHs enhance emulsification, bind fat, and facilitate whipping, compared to intact WPs. Extensive hydrolyzed WPHs with proper heat applications are the best emulsifiers and addition of polysaccharides improves the emulsification ability of WPHs. Also, WPHs improve the sensorial properties like color, flavor, and texture but impart a bitter taste in case where extensive hydrolysis (degree of hydrolysis greater than 8%). It is important to consider the type of enzyme, hydrolysis conditions, and WPHs production method based on the nature of food application. PMID:26761849

Eucalyptus oil nanoemulsion-impregnated chitosan film: antibacterial effects against a clinical pathogen, Staphylococcus aureus, in vitro

Directory of Open Access Journals (Sweden)

Sugumar S

2015-10-01

Full Text Available Saranya Sugumar, Amitava Mukherjee, Natarajan Chandrasekaran Centre for Nanobiotechnology, VIT University, Vellore, India Abstract: Eucalyptus oil (Eucalyptus globulus nanoemulsion was formulated using low- and high-energy emulsification methods. Development of nanoemulsion was optimized for system parameters such as emulsifier type, emulsifier concentration, and emulsification methods to obtain a lower droplet size with greater stability. The minimized droplet diameter was achieved using the high-energy method of ultrasonication. Tween 80 was more effective in reducing droplet size and emulsion appearance when compared to Tween 20. Stable nanoemulsion was formulated with Tween 80 as a surfactant, and the particle size was found to be 9.4 nm (1:2 v/v. The eucalyptus oil nanoemulsion was impregnated into chitosan (1% as a biopolymer in varying concentrations. Further, the film was characterized by moisture content, microscopic study, X-ray diffraction, and Fourier transform infrared spectroscopy. Also, the film with and without nanoemulsion was evaluated against Staphylococcus aureus. The nanoemulsion-impregnated chitosan film showed higher antibacterial activity than chitosan film. These results support the inclusion of nanoemulsion-impregnated chitosan film in wound management studies. Keywords: essential oil, emulsion, biopolymer, impregnation, thin film, wound isolate

Effect of medium components on the production of a biosurfactant from Candida tropicalis applied to the removal of hydrophobic contaminants in soil.

Science.gov (United States)

Batista, Ranielly M; Rufino, Raquel D; Luna, Juliana M; de Souza, José Edson G; Sarubbo, Leonie A

2010-05-01

The influence of medium constituents on the production of biosurfactants by Candida tropicalis cultivated in waste frying oil was investigated according to a fractional factorial 2(5-1) design. The combined effect of the C/N(inorganic), C/Fe, C/Mg, and C/P ratios and yeast extract on surface tension reduction, biosurfactant yield, emulsification activity, and biomass were studied. The highest biosurfactant yield was reached when low C/Mg and low C/P ratio variables were combined, while the cell growth was favored by increasing the nitrogen concentration. The highest surface tension net decrease, on the other hand, was observed at low yeast extract concentration, low C/Fe, and high C/P ratios. Emulsification indices against lubrication and automobile waste oil of approximately 65 to 95% were observed. The crude biosurfactant produced in the medium--formulated with 2% waste frying oil, 0.067% NH4Cl, 0.025% MgSO4.7H2O, 0.067% KH2PO4, and 0.0026% FeCl3.6H2O--removed approximately 78 to 97% of the petroleum and motor oil adsorbed in sand samples.

Microencapsulation by Membrane Emulsification of Biophenols Recovered from Olive Mill Wastewaters

Directory of Open Access Journals (Sweden)

Emma Piacentini

2016-05-01

Full Text Available Biophenols are highly prized for their free radical scavenging and antioxidant activities. Olive mill wastewaters (OMWWs are rich in biophenols. For this reason, there is a growing interest in the recovery and valorization of these compounds. Applications for the encapsulation have increased in the food industry as well as the pharmaceutical and cosmetic fields, among others. Advancements in micro-fabrication methods are needed to design new functional particles with target properties in terms of size, size distribution, and functional activity. This paper describes the use of the membrane emulsification method for the fine-tuning of microparticle production with biofunctional activity. In particular, in this pioneering work, membrane emulsification has been used as an advanced method for biophenols encapsulation. Catechol has been used as a biophenol model, while a biophenols mixture recovered from OMWWs were used as a real matrix. Water-in-oil emulsions with droplet sizes approximately 2.3 times the membrane pore diameter, a distribution span of 0.33, and high encapsulation efficiency (98% ± 1% and 92% ± 3%, for catechol and biophenols, respectively were produced. The release of biophenols was also investigated.

The Logistics of Oil Spill Dispersant Application. Volume I. Logistics-Related Properties of Oil Spill Dispersants.

Science.gov (United States)

1982-11-01

time of application. Such designs were probably influenced by the ready availabilit " 51 of fire-fighting hoses on ships and tugs; the water stream not...8217 I I1 ---- i . . .. . IIII . . . I I PREFACE The use of chemicals for the dispersal of oil spilled on water has been the subject of discussion (and of...20 Oil Type, Weathering and Emulsification.. 20 Slick Thickness .......................... 28 Water Temperature

Emulsification technique affects oxidative stability of fish oil-in-water emulsion

DEFF Research Database (Denmark)

Horn, Anna Frisenfeldt; Nielsen, Nina Skall; Jensen, Louise Helene Søgaard

of this study was therefore to compare lipid oxidation in 10% fish oil-in-water emulsions prepared by two different kinds of high pressure homogenizers i.e. a microfluidizer and a two valve high pressure homogenizer. Emulsions were made with equal droplet sizes, and with either 1% sodium caseinate or 1% whey...

Emulsification technique affects oxidative stability of fish oil-in-water emulsions

DEFF Research Database (Denmark)

Horn, Anna Frisenfeldt; Nielsen, Nina Skall; Jensen, Louise Helene Søgaard

of this study was to compare lipid oxidation in 10% fish oil-in-water emulsions prepared by two different kinds of high pressure homogenizers i.e. a microfluidizer and a two valve high pressure homogenizer. Emulsions were made with equal droplet sizes, and with either 1% sodium caseinate or 1% whey protein...

Microbial advanced biofuels production: overcoming emulsification challenges for large-scale operation.

Science.gov (United States)

Heeres, Arjan S; Picone, Carolina S F; van der Wielen, Luuk A M; Cunha, Rosiane L; Cuellar, Maria C

2014-04-01

Isoprenoids and alkanes produced and secreted by microorganisms are emerging as an alternative biofuel for diesel and jet fuel replacements. In a similar way as for other bioprocesses comprising an organic liquid phase, the presence of microorganisms, medium composition, and process conditions may result in emulsion formation during fermentation, hindering product recovery. At the same time, a low-cost production process overcoming this challenge is required to make these advanced biofuels a feasible alternative. We review the main mechanisms and causes of emulsion formation during fermentation, because a better understanding on the microscale can give insights into how to improve large-scale processes and the process technology options that can address these challenges. Copyright © 2014 Elsevier Ltd. All rights reserved.

Modelling of slag emulsification and slag reduction in CAS-OB process

OpenAIRE

Sulasalmi, P. (Petri)

2016-01-01

Abstract Composition Adjustment by Sealed argon bubbling – Oxygen Blowing (CAS-OB) process is a ladle treatment process that was developed for chemical heating and alloying of steel. The main stages of the process are heating, (possible) alloying and reduction of slag. The CAS-OB process aims for homogenization and control of the composition and temperature of steel. In this dissertation, a mathematical reaction model was developed for the slag reduction stage of the CAS-OB process. Sl...

Microfluidic emulsification at cross-junction: experimental and numerical study using Blue

Science.gov (United States)

Roumpea, Evangelia; Kovalchuk, Nina M.; Kahouadji, Lyes; Xie, Zhihua; Chinaud, Maxime; Simmons, Mark J. H.; Matar, Omar K.; Angeli, Panagiota

2017-11-01

Liquid-liquid drop formation in a cross-junction device is investigated both experimentally and numerically. Experiments are performed using 5 cSt silicone oil as the continuous phase and 52% glycerol/ 48% water mixture containing surfactants as the dispersed phase. Both a high-speed camera and a two-colour micro-PIV technique were used to obtain the different flow regimes i.e. squeezing, dripping, jetting and threading and to study the velocity fields of the two phases simultaneously. The dependence of the drop size on flow rate follows a power law with different exponents for small and large drops. Numerical simulations using the code Blue, a massive parallel solver for simulations of fully three-dimensional multiphase flows, were also performed taking into account the properties of the liquids used in the experiments and the precise geometry of the microfluidic chips. The simulation results agreed very well with the surfactant-free solution. The numerical simulations taking into account the surfactant are ongoing. EPSRC, UK, MEMPHIS program Grant (EP/K003976/1), RAEng Research Chair (OKM).

Diversity of biosurfactant producing microorganisms isolated from soils contaminated with diesel oil.

Science.gov (United States)

Menezes Bento, Fátima; de Oliveira Camargo, Flavio A; Okeke, Benedict C; Frankenberger, William T

2005-01-01

Biosurfactant production is a desirable property of hydrocarbon-degrading microorganisms (HDM). We characterized biosurfactant producing microbial populations from a Long Beach soil, California (USA) and a Hong Kong soil (China), contaminated with diesel oil. A total of 33 hydrocarbon-utilizing microorganisms were isolated from the soils. Twelve isolates and three defined consortia were tested for biosurfactant production and emulsification activity. The highest reduction of surface tension was achieved with a consortium of L1, L2 and L3 isolates from a Long Beach soil (41.4mN m(-1)). Isolate L1 (Acinetobacter junii) displayed the highest reduction of surface tension (46.5 mN m(-1)). The emulsifying capacity evaluated by the E24 emulsification index was highest in the culture of isolate L5 (74%). No substantial emulsification was achieved with the cell-free extracts, indicating that the emulsifying activity was not extracellular. Based on surface tension and the E24 index results, isolates F1, F2, F3, F4, L1, L2, L3 and L4 were identified by 16S rRNA gene sequencing as Bacillus cereus, Bacillus sphaericus, B. fusiformis, Acinetobacter junii, a non-cultured bacterium, Pseudomonas sp. and B. pumilus, respectively. Cluster analyses of 16S rRNA gene sequences of the bacterial isolates revealed 70% similarity amongst hydrocarbon-degrading bacterial community present in both soils. Five isolates (isolates F1, F2, F3, F4 and L4) belong to the Firmicutes order, two isolates (L1 and L3) belong to the Proteobacteria order and one isolate (L2) is an Actinomyces sp. Simpson's index (1 - D) and the Shannon-Weaver index (H) revealed more diversity of HDM in the Hong Kong soil, while evenness (E) and the equitability (J) data indicated that there was not a dominant population. Bacterial isolates displaying substantial potential for production of biosurfactants can be applied in the bioremediation of soils contaminated with petroleum hydrocarbons.

Ultrasound assisted synthesis of stable oil in milk emulsion: Study of operating parameters and scale-up aspects.

Science.gov (United States)

Patil, Leena; Gogate, Parag R

2018-01-01

In the present work, application of ultrasound and stirring individually or in combination for improved emulsification of turmeric oil in skimmed milk has been investigated. The effect of different operating parameters/strategies such as addition of surfactant, sodium dodecyl sulfate (SDS), at different concentrations, quantity of oil phase, applied power, sonication time and duty cycle on the droplet size have been investigated. The stability of emulsion was analyzed in terms of the fraction of the emulsion that remains stable for a period of 28days. Optimized set of major emulsification process variables has been used at higher emulsion volumes. The effectiveness of treatment approach was analyzed based on oil droplet size, energy density and the time required for the formation of stable emulsion. It was observed that the stable emulsion at 50mL capacity with mean droplet diameter of about 235.4nm was obtained with the surfactant concentration of 5mg/mL, 11% of rated power (power density: 0.31W/mL) and irradiation time of 5min. The emulsion stability was higher in the case of ultrasound assisted approach as compared to the stirring. For the preparation of stable emulsion at 300mL capacity, it was observed that the sequential approach, i.e., stirring followed by ultrasound, gave lower mean droplet diameter (232.6nm) than the simultaneous approach, i.e., ultrasound and stirring together (257.9nm). However, the study also revealed that the simultaneous approach required very less time (15min) to synthesize stable emulsion as compared to the sequential approach (30min stirring and 60min ultrasound). It was successfully demonstrated that the ultrasound-assisted emulsification in the presence of SDS could be used for the preparation of stable turmeric oil-dairy emulsions, also providing insights into the role of SDS in increasing the stability of emulsions and of ultrasound in giving lower droplet sizes. Copyright © 2017 Elsevier B.V. All rights reserved.

Hydrocarbonoclastic bacteria isolated from petroleum contaminated sites in Tunisia: isolation, identification and characterization of the biotechnological potential.

Science.gov (United States)

Mahjoubi, Mouna; Jaouani, Atef; Guesmi, Amel; Ben Amor, Sonia; Jouini, Ahlem; Cherif, Hanen; Najjari, Afef; Boudabous, Abdellatif; Koubaa, Nedra; Cherif, Ameur

2013-09-25

Petroleum hydrocarbons are important energy resources used by industry and in our daily life, whose production contributes highly to environmental pollution. To control such risk, bioremediation constitutes an environmentally friendly alternative technology that has been established and applied. It constitutes the primary mechanism for the elimination of hydrocarbons from contaminated sites by natural existing populations of microorganisms. In this work, a collection of 125 strains, adapted to grow on minimal medium supplemented with crude oil, was obtained from contaminated sediments and seawater from a refinery harbor of the Bizerte coast in the North of Tunisia. The diversity of the bacterial collection was analyzed by amplification of the internal transcribed spacers between the 16S and the 23S rRNA genes (ITS-PCR) and by 16S rRNA sequencing. A total of 36 distinct ITS haplotypes were detected on agarose matrix. Partial 16S rRNA gene sequencing performed on 50 isolates showed high level of identity with known sequences. Strains were affiliated to Ochrabactrum, Sphingobium, Acinetobacter, Gordonia, Microbacterium, Brevundimonas, Novosphingobium, Stenotrophomonas, Luteibacter, Rhodococcus, Agrobacterium, Achromobacter, Bacilllus, Kocuria and Pseudomonas genera. Acinetobacter and Stenotrophomons were found to be the most abundant species characterized by a marked microdiversity as shown through ITS typing. Culture-independent approach (DGGE) showed high diversity in the microbial community in all the studied samples with a clear correlation with the hydrocarbon pollution rate. Sequencing of the DGGE bands revealed a high proportion of Proteobacteria represented by the Alpha and Gamma subclasses. The predominant bacterial detected by both dependent and independent approaches were the Proteobacteria. The biotechnological potential of the isolates revealed a significant production of biosurfactants with important emulsification activities useful in bioremediation

Production of biosurfactant by Pseudomonas spp. isolated from industrial waste in Turkey

OpenAIRE

KAYA, Tayfun; ASLIM, Belma; KARİPTAŞ, Ergin

2014-01-01

In this study, 26 Pseudomonas spp. were isolated from a stream polluted by factory waste and from petroleum-contaminated soil. The surface tension (ST) of the cultures was used as a criterion for the primary isolation of biosurfactant-producing bacteria. Biosurfactant production was quantified by ST reduction, critical micelle concentration (CMC), emulsification capacity (EC), and cell surface hydrophobicity (CSH). Two of the isolates, P. aeruginosa 78 and 99, produced rhamnolipid biosurfacta...

Emulsiones alimentarias aceite-en-agua estabilizadas con proteínas de atún

OpenAIRE

Ruiz Márquez, Dolores; Partal López, Pedro; Franco Gómez, José María; Gallegos Montes, Críspulo

2010-01-01

This work is focused on the development of o/w salad dressing-type emulsions stabilized by tuna proteins. The influence of protein conservation methods after the extraction process (freezing or liofilization) on the rheological properties and microstructure of these emulsions was analyzed. Processing variables during emulsification were also evaluated. Stable emulsions with adequate rheological and microstructural characteristics were prepared using 70% oil and 0.50% tuna proteins. From the e...

Research of the complex of functional and technological properties of animal protein

Directory of Open Access Journals (Sweden)

Олена Борисівна Дроменко

2016-12-01

Full Text Available The analysis of the results of analytical and practical research of the complex of functional and technological properties of animal protein Gelexcel A-95 as the basis for creation of complex functional additives is shown. The regularities of their changes are determined depending on technological factors. Rational parameters of animal protein rehydration, gelation conditions, emulsification for further use in the process of production of meat products are identified

Nutritional and functional properties of whey proteins concentrate and isolate

OpenAIRE

Zoran Herceg; Anet Režek

2006-01-01

Whey protein fractions represent 18 - 20 % of total milk nitrogen content. Nutritional value in addition to diverse physico - chemical and functional properties make whey proteins highly suitable for application in foodstuffs. In the most cases, whey proteins are used because of their functional properties. Whey proteins possess favourable functional characteristics such as gelling, water binding, emulsification and foaming ability. Due to application of new process techniques (membrane fract...

Lipid Based Formulations of Biopharmaceutics Classification System (BCS Class II Drugs: Strategy, Formulations, Methods and Saturation

Directory of Open Access Journals (Sweden)

Šoltýsová I.

2016-12-01

Full Text Available Active ingredients in pharmaceuticals differ by their physico-chemical properties and their bioavailability therefore varies. The most frequently used and most convenient way of administration of medicines is oral, however many drugs are little soluble in water. Thus they are not sufficiently effective and suitable for such administration. For this reason a system of lipid based formulations (LBF was developed. Series of formulations were prepared and tested in water and biorelevant media. On the basis of selection criteria, there were selected formulations with the best emulsification potential, good dispersion in the environment and physical stability. Samples of structurally different drugs included in the Class II of the Biopharmaceutics classification system (BCS were obtained, namely Griseofulvin, Glibenclamide, Carbamazepine, Haloperidol, Itraconazol, Triclosan, Praziquantel and Rifaximin, for testing of maximal saturation in formulations prepared from commercially available excipients. Methods were developed for preparation of formulations, observation of emulsification and its description, determination of maximum solubility of drug samples in the respective formulation and subsequent analysis. Saturation of formulations with drugs showed that formulations 80 % XA and 20 % Xh, 35 % XF and 65 % Xh were best able to dissolve the drugs which supports the hypothesis that it is desirable to identify limited series of formulations which could be generally applied for this purpose.

Increasing sodium pantoprazole photostability by microencapsulation: effect of the polymer and the preparation technique.

Science.gov (United States)

Raffin, R P; Colomé, L M; Schapoval, E E S; Pohlmann, A R; Guterres, S S

2008-08-01

Pantoprazole sodium is a proton pump inhibitor, used in acid-related disorders, like peptic ulcers and gastroesophageal reflux. This drug is unstable in acid solution and in the presence of salts. The aim of this work was to study the photostability under UVC radiation of pantoprazole and to determine its kinetics. A methanol solution and the solid pantoprazole were evaluated by HPLC within 120 min and 10 days, respectively. The work was also dedicated to evaluate and compare the ability of microencapsulation in stabilizing pantoprazole after UVC radiation. Pantoprazole-loaded microparticles prepared by emulsification/solvent evaporation or spray drying were compared. Pantoprazole was encapsulated using Eudragit S100 or its blend with poly(epsilon-caprolactone) or HPMC. In methanol solution, pantoprazole was completely degraded after 120 min and presented zero-order kinetics with t1/2 of 6.48 min. In the solid form, after 10 days, pantoprazole concentration was reduced to 27% following zero-order kinetic. The microparticles prepared only with Eudragit S100 demonstrated an increase of the drug photostability. After 10 days of irradiation, 56 and 44% of the drug was stable when encapsulated by emulsification/solvent evaporation and spray drying, respectively. The use of polymer blends did not improve the pantoprazole photostability.

Effect of interfacial composition and crumbliness on aroma release in soy protein/sugar beet pectin mixed emulsion gels.

Science.gov (United States)

Hou, Jun-Jie; Guo, Jian; Wang, Jin-Mei; Yang, Xiao-Quan

2016-10-01

In this study, soy protein isolate/sugar beet pectin (SPI/SBP) emulsion gels were prepared through an enzymatic gelation process. The effects of emulsifier (SBP, SPI or SPI/SBP complex) and emulsification process on the microstructure, texture, breakdown properties and aroma release behavior of resulting emulsion gels were investigated. Oil emulsification by SBP/SPI complex resulted in a higher amount of emulsifier absorbing on the oil-water interface than by SBP and SPI alone, indicating that a more compact interfacial network was formed. Flocculation of oil droplets was observed and corresponding emulsion gels exhibited lower fracture force and strain when the oil was emulsified by SPI and SBP/SPI complex. Moreover, emulsion gels with small droplets produced a greater quantity of small fragments after mastication. However, microstructure did not have a significant effect on breakdown properties of emulsion gels. Headspace gas chromatography analysis showed that the release rate of ethyl butyrate before and after mastication was significantly lower in emulsion gel with more compact network, but the release of aroma compounds with higher hydrophobicity did not show a significant influence of the microstructure and texture of emulsion gel. This finding provides a useful application for designing semi-solid foods with desirable flavor perception. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Micro/Nanospheres Generation by Fluid-Fluid Interaction Technology: A Literature Review.

Science.gov (United States)

Lei, Lei; Bergstrom, Don; Zhang, Bing; Zhang, Hongbo; Yin, Ruixue; Song, Ki-Young; Zhang, Wenjun

2017-01-01

This review focuses on the fundamental fluid mechanics which governs the generation of micro/nanospheres. The micro/nanosphere generation process has gathered significant attention in the past two decades, since micro/nanospheres are widely used in drug delivery, food science, cosmetics, and other application areas. Many methods have been developed based on different operating principles, such as microfluidic methods, electrospray methods, chemical methods, and so forth. This paper focuses on microfluidic methods. Although the structure of the microfluidic devices may be different, the operating principles behind them are often very similar. Following an initial discussion of the fluid mechanics related to the generation of microspheres, various design approaches are discussed, including T-junction, flow focusing, membrane emulsification, modified T-junction, and double emulsification methods. The advantages and problems associated with each method are also discussed. Next, the most commonly used computational fluid dynamics (CFD) methods are reviewed at three different levels: microscopic, mesoscopic, and macroscopic. Finally, the issues identified in the current literature are discussed, and some suggestions are offered regarding the future direction of technology development related to micro/nanosphere generation. Few relevant patents to the topic have been reviewed and cited. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Effect of ultrasound treatment on the wet heating Maillard reaction between mung bean [Vigna radiate (L.)] protein isolates and glucose and on structural and physico-chemical properties of conjugates.

Science.gov (United States)

Wang, Zhongjiang; Han, Feifei; Sui, Xiaonan; Qi, Baokun; Yang, Yong; Zhang, Hui; Wang, Rui; Li, Yang; Jiang, Lianzhou

2016-03-30

The objective of this study was to determine the effect of ultrasound treatment on the wet heating Maillard reaction between mung bean protein isolates (MBPIs) and glucose, and on structural and physico-chemical properties of the conjugates. The degree of glycosylation of MBPI-glucose conjugates treated by ultrasound treatment and wet heating (MBPI-GUH) was higher than that of MBPI-glucose conjugates only treated by wet heating (MBPI-GH). Solubility, emulsification activity, emulsification stability and surface hydrophobicity of MBPI-GUH were higher than that of MBPI-GH. Grafted MBPIs had a lower content of α-helix and unordered coil, but a higher content of β-sheet and β-turn structure than MBPIs. No significant structural changes were observed in β-turn and random coil structure of MBPI-GUH, while α-helix content increased with ultrasonic time, and decreased at 300 W ultrasonic power with the increase of β-sheet. MBPI-GUH had a less compact tertiary structure compared to MBPI-GH and MBPI. Grafting MBPIs with glucose formed conjugates of higher molecular weight, while no significant changes were observed in electrophoresis profiles of MBPI-GUH. Ultrasound-assisted wet heating Maillard reaction between MBPIs and glucose could be a promising way to improve functional properties of MBPIs. © 2015 Society of Chemical Industry.

Sintering of wax for controlling release from pellets

OpenAIRE

Singh, Reena; Poddar, S. S.; Chivate, Amit

2007-01-01

The purpose of the present study was to investigate incorporation of hydrophobic (ie, waxy) material into pellets using a thermal sintering technique and to evaluate the pellets in vitro for controlled release. Pellets prepared by extrusion-spheronization technology were formulated with a water-soluble drug, microcrystalline cellulose, and carnauba wax. Powdered carnauba wax (4%–20%) prepared by grinding or by emulsification was studied with an attempt to retard the drug release. The inclusio...

Effect of polyoxyethylene sorbitan esters and sodium caseinate on physicochemical properties of palm-based functional lipid nanodispersions.

Science.gov (United States)

Cheong, Jean Ne; Mirhosseini, Hamed; Tan, Chin Ping

2010-06-01

The main objective of the present study was to investigate the effect of polyoxyethylene sorbitan esters and sodium caseinate on physicochemical properties of palm-based functional lipid nanodispersions prepared by the emulsification-evaporation technique. The results indicated that the average droplet size increased significantly (P sodium caseinate-stabilized nanodispersions containing carotenoids had the largest average droplet size (386 nm), thus indicating a greater emulsifying role for Polysorbate 20 compared with sodium caseinate.

Penggunaan Eudragit L 100 dalam Formulasi Mikrokapsul Natrium Diklofenak dengan Teknik Emulsifikasi-Penguapan Pelarut

OpenAIRE

Rahmadevi, Rahmadevi; Zaini, Erizal; Halim, Auzal

2013-01-01

It has been research about formulation diclofenac sodium that used Eudragit L100. To prepare, using emulsification-solvent evaporation technique, diclofenac sodium-Eudragit L100 microparticles with modified drug sustained release properties and span 80 is emulgator. Methode research is microcapsules were prepared by solvent evaporation method with ratio diclofenac sodium-Eudragit L100 (1:1,125;1:1,25;1:1,5;1:1,75) and characterized by micromeritics, Scanning Electron Microscopy (SEM), Fourier...

Controlled interfacial assembly of 2D curved colloidal crystals and jammed shells

OpenAIRE

Subramaniam, Anand Bala; Abkarian, Manouk; Stone, Howard A.

2006-01-01

Assembly of colloidal particles on fluid interfaces is a promising technique for synthesizing two-dimensional micro-crystalline materials useful in fields as diverse as biomedicine1, materials science2, mineral flotation3 and food processing4. Current approaches rely on bulk emulsification methods, require further chemical and thermal treatments, and are restrictive with respect to the materials employed5-9. The development of methods that exploit the great potential of interfacial assembly f...

Functional liquid structures by emulsification of graphene and other two-dimensional nanomaterials.

Science.gov (United States)

Large, Matthew J; Ogilvie, Sean P; Meloni, Manuela; Amorim Graf, Aline; Fratta, Giuseppe; Salvage, Jonathan; King, Alice A K; Dalton, Alan B

2018-01-25

Pickering emulsions stabilised with nanomaterials provide routes to a range of functional macroscopic assemblies. We demonstrate the formation and properties of water-in-oil emulsions prepared through liquid-phase exfoliation of graphene. Due to the functional nature of the stabiliser, the emulsions exhibit conductivity due to inter-particle tunnelling. We demonstrate a strain sensing application with a large gauge factor of ∼40; the highest reported in a liquid. Our methodology can be applied to other two-dimensional layered materials opening up applications such as energy storage materials, and flexible and printable electronics.

Characterization and emulsification properties of rhamnolipid and sophorolipid biosurfactants and their applications.

Science.gov (United States)

Nguyen, Thu T; Sabatini, David A

2011-02-18

Due to their non-toxic nature, biodegradability and production from renewable resources, research has shown an increasing interest in the use of biosurfactants in a wide variety of applications. This paper reviews the characterization of rhamnolipid and sophorolipid biosurfactants based on their hydrophilicity/hydrophobicity and their ability to form microemulsions with a range of oils without additives. The use of the biosurfactants in applications such as detergency and vegetable oil extraction for biodiesel application is also discussed. Rhamnolipid was found to be a hydrophilic surfactant while sophorolipid was found to be very hydrophobic. Therefore, rhamnolipid and sophorolipid biosurfactants in mixtures showed robust performance in these applications.

The Science of Chocolate: Interactive Activities on Phase Transitions, Emulsification, and Nucleation

Science.gov (United States)

Rowat, Amy C.; Hollar, Kathryn A.; Stone, Howard A.; Rosenberg, Daniel

2011-01-01

Nearly everyone loves chocolate, which makes this an excellent topic for communicating scientific concepts to the general public and to students in the classroom. Here we present the outline and activities for an interactive presentation on the science of chocolate for nonspecialists and their children ages 6 and up. We design the presentation…

Legume Protein Isolates for Stable Acidic Emulsions Prepared by Premix Membrane Emulsification

NARCIS (Netherlands)

Ladjal Ettoumi, Yakoub; Berton-Carabin, Claire; Chibane, Mohamed; Schroën, Karin

2017-01-01

Proteins originating from dry legumes are not that much used in food formulations, yet, they are interesting components from a sustainability point of view, and could have interesting functional properties, e.g. for emulsion preparation. Therefore, this work focuses on the potential of the water

Adsorption of polyelectrolytes at liquid-liquid interfaces and its effect on emulsification

NARCIS (Netherlands)

Böhm, J.T.C.

1974-01-01

In this study we have investigated the adsorption behaviour of a number of synthetic polyelectrolytes at the paraffin oil-water interface and the properties of paraffin oil-in-water emulsions stabilized by these polyelectrolytes.

Polyacrylic acid (PAA), polymethacrylic acid (PMA)

Characterization and Emulsification Properties of Rhamnolipid and Sophorolipid Biosurfactants and Their Applications

Directory of Open Access Journals (Sweden)

Thu T. Nguyen

2011-02-01

Full Text Available Due to their non-toxic nature, biodegradability and production from renewable resources, research has shown an increasing interest in the use of biosurfactants in a wide variety of applications. This paper reviews the characterization of rhamnolipid and sophorolipid biosurfactants based on their hydrophilicity/hydrophobicity and their ability to form microemulsions with a range of oils without additives. The use of the biosurfactants in applications such as detergency and vegetable oil extraction for biodiesel application is also discussed. Rhamnolipid was found to be a hydrophilic surfactant while sophorolipid was found to be very hydrophobic. Therefore, rhamnolipid and sophorolipid biosurfactants in mixtures showed robust performance in these applications.

Combined 30-degree bevel up and down technique against 0-degree phaco tip for phacoemulsification surgery of hard cataracts

Directory of Open Access Journals (Sweden)

Joshi RS

2017-06-01

Full Text Available Rajesh Subhash Joshi, Sonal Jayant Muley Department of Ophthalmology, Vasantrao Naik Government Medical College, Yavatmal, Maharashtra, India Purpose: To evaluate the effective phaco time (EPT, cumulative dissipated energy (CDE and nucleus emulsification time (NET as phaco parameters with 0- and 30-degree phaco tip. Patients and methods: This prospective, interventional and observational case series included 294 patients scheduled for cataract removal by phacoemulsification technique. Patients with nuclear cataracts of grade 4 and 5 nuclear opalescence of Lens Opacities Classification System III were included in the study. Patients were consecutively allocated to phaco chop technique with 0-degree (0-degree group, n=147 and combined bevel up and down position using 30-degree phaco tip (combined bevel up/down group, n=147. The 0-degree group had phacoemulsification with 0-degree phaco tip, while the 30-degree group had chopping of the nucleus with bevel down phaco tip and emulsification of nuclear fragments was accomplished with bevel up tip. EPT, CDE, NET and intraoperative complications were noted and compared between the groups using analysis of variance. Results: Average EPT, CDE and NET were lower in the 30-degree group than in the 0-degree group. However, no statistically significant difference was found in EPT (P=0.0733, CDE (P=0.0663 and NET (P=0.0633 between the two groups. No serious intraoperative complications were noted. The anterior chamber was maintained throughout the procedure in both groups. No patients had wound burn and miosis during the procedure. None of the patients developed bullous keratopathy, uveitis and cystoid macular edema during the follow-up period. Conclusion: Combined bevel up and down 30-degree tip can yield effective hard nucleus phacoemulsification. Bevel down tip of 30-degree helps in effective chopping and bevel up tip assists in emulsification of the nuclear fragments. Although combined bevel up and down 30

Oceanographic Effects on Maritime Threats: Mines and Oil Spills in the Strait of Hormuz

Science.gov (United States)

2007-03-01

from the U.S. Naval Oceanographic Office’s Master Oceanographic Observations Data Set ( MOODS )). The numbers on the x-axis of the cross-sections...several years (from the 1940s to the 1990s) obtained from the U.S. Naval Oceanographic Office’s Master Oceanographic Observations Data Set ( MOODS ...weathering can turn a light crude oil into a viscous material or even a semi-solid. Wave action can cause water-in-oil emulsifications called “ chocolate

Radiation processing and functional properties of soybean (Glycine max)

International Nuclear Information System (INIS)

Pednekar, Mrinal; Das, Amit K.; Rajalakshmi, V; Sharma, Arun

2010-01-01

Effect of radiation processing (10, 20 and 30 kGy) on soybean for better utilization was studied. Radiation processing reduced the cooking time of soybean and increased the oil absorption capacity of soy flour without affecting its proximate composition. Irradiation improved the functional properties like solubility, emulsification activity and foam stability of soybean protein isolate. The value addition effect of radiation processing has been discussed for the products (soy milk, tofu and tofu fortified patties) prepared from soybean.

Microfluidic methods to study emulsion formation

OpenAIRE

Muijlwijk, Kelly

2017-01-01

Emulsions are dispersions of one liquid in another that are commonly used in various products, and methods such as high-pressure homogenisers and colloid mills are used to form emulsions. The size and size distribution of emulsion droplets are important for the final product properties and thus need to be controlled. Rapid coalescence of droplets during emulsification increases droplet size and widens the size distribution, and therefore needs to be prevented. To increase stability of emulsio...

Isolation and characterization of a biosurfactant-producing heavy metal resistant Rahnella sp. RM isolated from chromium-contaminated soil

OpenAIRE

GOVARTHANAN, Muthusamy; MYTHILI, R.; SELVANKUMAR, Thangasamy; KAMALA-KANNAN, S.; CHOI, DuBok; CHANG, Young-Cheol

2017-01-01

Objective of the study was to isolate heavy metal resistant bacteria from chromium-contaminated subsurface soil and investigate biosurfactant production and heavy metal bioremediation. Based on 16S rRNA gene sequence and phylogenetic analysis, the isolate was identified as Rahnella sp. RM. The biosurfactant production by heavy metal resistant Rahnella sp. RM was optimized using Box- Behnken design (BBD). The maximum emulsification activity was obtained 66% at 6% soybean meal in pH 7.0 and 33....

Operational forecast of oil spill trajectory and assessment of impacts on intertidal macrobenthos in the Dahanu region, west coast of India

Digital Repository Service at National Institute of Oceanography (India)

Naidu, V.S.; Sukumaran, S.; Dubbewar, O.; Reddy, G.S.

due to current and wind, (b) horizontal spreading of the surface slick due to both turbulent diffusion and gravitational, inertia, viscous, and surface tension forces, (c) emulsification (d) mass transfer and change in physicochemical properties... processes in the early stage of the oil slick transformation. The spreading of an oil slick is determined by the balance between gravitational, viscous and surface tension forces. The spreading of an oil slick passes through the following three phases: (i...

Pickering emulsion stabilized by cashew gum- poly-l-lactide copolymer nanoparticles: Synthesis, characterization and amphotericin B encapsulation.

Science.gov (United States)

Richter, A R; Feitosa, J P A; Paula, H C B; Goycoolea, F M; de Paula, R C M

2018-04-01

In this work, we provide proof-of-concept of formation, physical characteristics and potential use as a drug delivery formulation of Pickering emulsions (PE) obtained by a novel method that combines nanoprecipitation with subsequent spontaneous emulsification process. To this end, pre-formed ultra-small (d.∼10 nm) nanoprecipitated nanoparticles of hydrophobic derivatives of cashew tree gum grafted with polylactide (CGPLAP), were conceived to stabilize Pickering emulsions obtained by spontaneous emulsification. These were also loaded with Amphotericin B (AmB), a drug of low oral bioavailability used in the therapy of neglected diseases such as leishmaniasis. The graft reaction was performed in two CG/PLA molar ratio conditions (1:1 and 1:10). Emulsions were prepared by adding the organic phase (Miglyol 812 ® ) in the aqueous phase (nanoprecipitated CGPLAP), resulting the immediate emulsion formation. The isolation by centrifugation does not destabilize or separate the nanoparticles from oil droplets of the PE emulsion. Emulsions with CGPLAP 1:1 presented unimodal distributions at different CGPLA concentration, lower values in size and PDI and the best stability over time. The AmB was incorporated in the emulsions with a process efficiency of 21-47%, as determined by UV-vis. AmB in CGPLAP emulsions is in less aggregated state than observed in commercial AmB formulation. Copyright © 2018 Elsevier B.V. All rights reserved.

Biosurfactant produced from Actinomycetes nocardiopsis A17: Characterization and its biological evaluation.

Science.gov (United States)

Chakraborty, Samrat; Ghosh, Mandakini; Chakraborti, Srijita; Jana, Sougata; Sen, Kalyan Kumar; Kokare, Chandrakant; Zhang, Lixin

2015-08-01

This investigation aims to isolate an Actinomycetes strain producing a biosurfactant from the unexplored region of industrial and coal mine areas. Actinomycetes are selected for this study as their novel chemistry was not exhausted and they have tremendous potential to produce bioactive secondary metabolites. The biosurfactant was characterized and further needed to be utilized for pharmaceutical dosage form. Isolation, purification, screening, and characterization of the Actinomycetes A17 were done followed by its fermentation in optimized conditions. The cell-free supernatant was used for the extraction of the biosurfactant and precipitated by cold acetone. The dried precipitate was purified by TLC and the emulsification index, surface tension and CMC were determined. The isolated strain with preferred results was identified as Actinomycetes nocardiopsis A17 with high foam-forming properties. It gives lipase, amylase, gelatinase, and protease activity. The emulsification index was found to be 93±0.8 with surface tension 66.67 dyne/cm at the lowest concentration and cmc 0.6 μg/ml. These biosurfactants were characterized by Fourier transform infra red (FT-IR) spectroscopy and liquid chromatography-mass spectrometry (LC-MS). Therefore, it can be concluded that the biosurfactant produced by Actinomycetes nocardiopsis sp. strain A17 was found to have satisfactory results with high surface activity and emulsion-forming ability. Copyright © 2015 Elsevier B.V. All rights reserved.

Bilayers at High pH in the Fatty Acid Soap Systems and the Applications for the Formation of Foams and Emulsions.

Science.gov (United States)

Xu, Wenlong; Zhang, Heng; Zhong, Yingping; Jiang, Liwen; Xu, Mengxin; Zhu, Xionglu; Hao, Jingcheng

2015-08-20

In our previous work, we reported bilayers at high pH in the stearic acid/CsOH/H2O system, which was against the traditional viewpoint that fatty acid (FA) bilayers must be formed at the pKa of the fatty acid. Herein, the microstructures at high pH of several fatty acid soap systems were investigated systematically. We found that palmitic acid/KOH/H2O, palmitic acid/CsOH/H2O, stearic acid/KOH/H2O, and stearic acid/CsOH/H2O systems can form bilayers at high pH. The bilayer structure was demonstrated by cryogenic transmission electron microscopy (cryo-TEM) and deuterium nuclear magnetic resonance ((2)H NMR), and molecular dynamics simulation was used to confirm the formation of bilayers. The influence of fatty acids with different chain lengths (n = 10, 12, 14, 16, and 18) and different counterions including Li(+), Na(+), K(+), Cs(+), (CH3)4N(+), (C2H5)4N(+), (C3H7)4N(+), and (C4H9)4N(+) on the formation of bilayers was discussed. The stability of foam and emulsification properties were compared between bilayers and micelles, drawing the conclusion that bilayer structures possess a much stronger ability to foam and stronger emulsification properties than micelles do.

Algorithm and interface modifications of the NOAA oil spill behavior model

International Nuclear Information System (INIS)

Lehr, W.; Wesley, D.; Simecek-Beatty, D.; Jones, R.; Kachook, G.; Lankford, J.

2000-01-01

The oil spill weathering program called ADIOS (Automated Data Inquiry for Oil Spills) which is widely used by the National Ocean and Atmospheric Administration (NOAA) has been completely upgraded to include modified algorithms for evaporation, spreading, dispersion and emulsification. This paper was divided into three parts to outlined the changes in the existing algorithms implemented in the new version and to discuss the new algorithms for additional weathering processes and cleanup activities. The paper also described the new interface, which is the result of the NOAA/HAZMAT research in software usability and uncertainty. In the new model, evaporation uses a pseudo-component approach and dispersion includes the effects of sedimentation. Droplet size distribution and water content were considered as factors for new estimates for wave breaking and emulsification. Numerical techniques that allow non-uniformity in slick thickness have been used to determine spreading. The inhalation hazard resulting from benzene evaporation from oil spill surfaces can be calculated using new sub models which can also record the effects of cleanup. The submodels also provide options regarding the initial spill release. Users of the ADIOS 2 can enter ranges of selected input parameters that are likely to be uncertain during a spill. The ADIOS 2 program is also equipped with a library of more than a thousand oils and refined products. 34 refs., 1 fig

Biodegradation of dimethyl phthalate, diethyl phthalate and di-n-butyl phthalate by Rhodococcus sp. L4 isolated from activated sludge.

Science.gov (United States)

Lu, Yi; Tang, Fei; Wang, Ying; Zhao, Jinhui; Zeng, Xin; Luo, Qifang; Wang, Lin

2009-09-15

In this study, an aerobic bacterial strain capable of utilizing dimethyl phthalate (DMP), diethyl phthalate (DEP) and di-n-butyl phthalate (DBP) as sole carbon source and energy was isolated from activated sludge collected from a dyeing plant. According to its morphology, physiochemical characteristics and 16S rDNA sequence, the strain was identified as Rhodococcus ruber. The biodegradation batch tests of DMP, DEP and DBP by the Rhodococcus sp. L4 showed the optimal pH value, temperature and substrate concentration: pH 7.0-8.0, 30-37 degrees C and PAEs concentration Kinetics of degradation have also been performed at different initial concentrations. The results show that the degradation can be described with exponential model. The half-life of degradation was about 1.30 days when the concentration of PAEs mixture was lower than 300 mg/L. PAEs contaminated water samples (300 mg/L) with non-emulsification and completed emulsification were prepared to investigate the effect on PAEs degradation rate. Little difference between the above two sample preparations was observed in terms of ultimate degradation rate. Rhodococcus sp. L4 can also grow on phenol, sodium benzoate or naphthalene solution as sole carbon source and energy which suggests its ability in resisting environmental toxicants. This work provides some new evidence for the possibility of applying Rhodococcus for contaminated water remediation in the area of industry.

Effect of fish gelatin-gum arabic interactions on structural and functional properties of concentrated emulsions.

Science.gov (United States)

Anvari, Mohammad; Joyner Melito, Helen S

2017-12-01

Concentrated emulsions containing both proteins and polysaccharides are the basis for many commercial products; however, the effects of protein-polysaccharide interactions on the functional properties of these complex systems are often poorly understood from a fundamental standpoint. Hence, the objective of this study was to determine the effects of fish gelatin (FG)-gum arabic (GA) complexation at different aqueous phase pH (3.6, 5.0, and 9.0) on concentrated emulsion structure-function relationships. Concentrated emulsions were prepared using FG-GA mixtures and characterized by rheometry and confocal scanning laser microscopy (CSLM). CSLM images showed that all samples were O/W emulsions; emulsions with lower pH showed smaller oil droplets, greater homogeneity in size distribution, and higher stability. This was attributed to an increased number of FG-GA complexes in the emulsification. Electrostatic attractive interactions and charge neutralization created biopolymer associations with increased emulsification capacity. Samples with FG-GA mixtures at lower pH showed higher elastic moduli under small deformation and exhibited greater deviation between apparent and complex viscosities under the Cox-Merz rule, indicating increased gel network extension and greater intermolecular connectivity between adsorbed layers of adjacent oil droplets. These results can be used to incorporate protein-polysaccharide complexes as a suitable emulsifier in materials comprising concentrated emulsions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Novel approaches to microbial enhancement of oil recovery.

Science.gov (United States)

Kryachko, Yuriy

2018-01-20

Microbially enhanced oil recovery (MEOR) was shown to be feasible in a number of laboratory experiments and field trials. However, it has not been widely used in the oil industry because necessary conditions cannot always be easily established in an oil reservoir. Novel approaches to MEOR, which are based on newly discovered biosurfactant-mediated MEOR-mechanisms, are discussed in this review. Particularly, the possibility of combining MEOR with chemical enhancement of oil recovery in heterogeneous oil reservoirs, which involves rock surface wettability shifts and emulsion inversions, is discussed. In wider (centimeter/millimeter-scale) rock pores, the activity of (bio)surfactants and microbial cells attached to oil may allow releasing trapped oil blobs through oil-in-water emulsification. After no more oil can be emulsified, the addition of alkali or surfactants, which turn rock surface oil-wet, may help release oil droplets trapped in narrow (micrometer-scale) pores through coalescence of the droplets and water-in-oil emulsification. Experiments demonstrating the possibility of (bio)surfactant-mediated enhancement of immiscible gas-driven oil recovery are also reviewed. Interestingly, very low (bio)surfactant concentrations were shown to be needed for enhancement of immiscible gas-driven oil recovery. Some possible side effects of MEOR, such as unintended bioplugging and microbially influenced corrosion (MIC), are discussed as well. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Preparation of biodiesel with the help of ultrasonic and hydrodynamic cavitation.

Science.gov (United States)

Ji, Jianbing; Wang, Jianli; Li, Yongchao; Yu, Yunliang; Xu, Zhichao

2006-12-22

An alkali-catalyzed biodiesel production method with power ultrasonic (19.7 kHz) has been developed that allows a short reaction time and high yield because of emulsification and cavitation of the liquid-liquid immiscible system. Orthogonality experiments were employed to evaluate the effects of synthesis parameters. Furthermore, hydrodynamic cavitation was used for biodiesel production in comparison to ultrasonic method. Both methods were proved to be efficient, and time and energy saving for the preparation of biodiesel by transesterification of soybean oil.

Absorption mechanism of three curcumin constituents through in situ intestinal perfusion method

Directory of Open Access Journals (Sweden)

Y.-H. Wang

2017-09-01

Full Text Available This study aimed to investigate the absorption mechanism of three curcumin constituents in rat small intestines. Self-emulsification was used to solubilize the three curcumin constituents, and the rat in situ intestinal perfusion method was used to study factors on drug absorption, including drug mass concentration, absorption site, and the different types and concentrations of absorption inhibitors. Within the scope of experimental concentrations, three curcumin constituents were absorbed in rat small intestines through the active transport mechanism.

PENGEMBANGAN SISTEM NANOSTRUCTURED LIPID CARRIERS (NLC) MELOXICAM DENGAN LIPID MONOSTEARIN DAN MIGLYOL 808 MENGGUNAKAN METODE EMULSIFIKASI

OpenAIRE

Rahmi Annisa; Esti Hendradi; Dewi Melani

2016-01-01

The aim this study was to determine the effect of Monostearin and Miglyol 808 lipid ratio in NLC system formulation resulting in physicochemical characteristics, release rate, and penetration rate. The NLC making was done by using emulsification method. In the formulation of NLC meloxicam, 3 different lipid ratios were used, including ratios of 6:4, 7:3, 8:2.  Meloxicam served as active ingredient, monostearin served as solid lipid, miglyol 808 served as a liquid lipid, and tween 80 was surfa...

Self-Propelled Motion of Monodisperse Underwater Oil Droplets Formed by a Microfluidic Device.

Science.gov (United States)

Ueno, Naoko; Banno, Taisuke; Asami, Arisa; Kazayama, Yuki; Morimoto, Yuya; Osaki, Toshihisa; Takeuchi, Shoji; Kitahata, Hiroyuki; Toyota, Taro

2017-06-06

We evaluated the speed profile of self-propelled underwater oil droplets comprising a hydrophobic aldehyde derivative in terms of their diameter and the surrounding surfactant concentration using a microfluidic device. We found that the speed of the oil droplets is dependent on not only the surfactant concentration but also the droplet size in a certain range of the surfactant concentration. This tendency is interpreted in terms of combination of the oil and surfactant affording spontaneous emulsification in addition to the Marangoni effect.

The effect of adhesion on survival and growth of microorganisms

International Nuclear Information System (INIS)

Bar-Or, Y.

1990-01-01

Adhesion of microorganisms to solid surfaces or water/air interfaces can significantly influence cellular metabolic activity, development and viability. Attachment is of advantage particularly for organisms growing under oligotrophic or otherwise extreme conditions. However, the ability to detach and migrate is of vital importance when prevailing conditions become too harsh or in situations of population explosion. Adhesion can cause alterations in the physical and chemical properties of substratum surfaces as well, by means of degradation, aggregation, emulsification etc. (author) 48 refs

Preparation and Characterization of Keratin/Alginate Blend Microparticles

OpenAIRE

Srisuwan, Yaowalak; Srihanam, Prasong

2018-01-01

The water-in-oil (W/O) emulsification-diffusion method was used for construction of keratin (Ker), alginate (Alg), and Ker/Alg blend microparticles. The Ker, Alg, and Ker/Alg blend solutions were used as the water phase, while ethyl acetate was used as the oil phase. Firstly, different concentrations of Ker solution was used to find suitable content. 1.6% w/v Ker solution was blended with the same concentration of the Alg solution for further microparticle construction. Results from scanning ...

Surface analysis of PEGylated nano-shields on nanoparticles installed by hydrophobic anchors

DEFF Research Database (Denmark)

Ebbesen, M F; Whitehead, Bradley Joseph; Gonzalez, Borja Ballarin

2013-01-01

and cellular interactions. Methods: Poly(lactic-co-glycolic acid) (PLGA) nanoparticles were prepared with a hydrophilic PEGylated "nano-shield" inserted at different levels by hydrophobic anchoring using either a phospholipid-PEG conjugate or the copolymer PLGA-block-PEG by an emulsification/diffusion method....... Surface and bulk analysis was performed including X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance spectroscopy (NMR) and zeta potential. Cellular uptake was investigated in RAW 264.7 macrophages by flow cytometry. Results: Sub-micron nanoparticles were formed and the combination of (NMR...

Mixing of immiscible fluids in chaotic flows and related issues

International Nuclear Information System (INIS)

Ottino, J.M.

1993-01-01

The basis goal of this work was to obtain a basic understanding of mixing of immiscible fluids leading to the determination of flow conditions which result in efficient breakup and dispersion of one mass of fluid in the bulk of another. Related issues were the prediction of the morphological structures and drop size distribution for a given set of operating conditions. The primary motivation for these investigations was to produce basic knowledge leading to increased understanding of industrial processes involving blending, agitation, emulsification, and dissolution

Reversible aggregation of lysozyme in a biodegradable amphiphilic multiblock copolymer.

Science.gov (United States)

van de Weert, Marco; van Dijkhuizen-Radersma, Riemke; Bezemer, Jeroen M; Hennink, Wim E; Crommelin, Daan J A

2002-07-01

Lysozyme-loaded poly(ethylene glycol terephthalate)-poly(butylene terephthalate) (PEGT/PBT) films were prepared using a water-in-oil emulsification solvent evaporation method. Infrared spectroscopic analysis of the dried films indicated the presence of non-covalent lysozyme aggregates in the polymer matrix. The use of methanol to enhance the drying rate of the films increased the relative amount of aggregates. Surprisingly, quantitative in-vitro release of fully active, non-aggregated lysozyme was observed, indicating that lysozyme forms reversible aggregates during encapsulation in PEGT/PBT films.

Editorial - International Journal of Sustainable Energy Planning and Management Vol 9

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Poul Alberg Østergaard

2016-06-01

Full Text Available This editorial introduces the ninth volume of the International Journal of Sustainable Energy Planning and Management. The volume addresses alternative ways of providing diesel fuel through emulsification ow waste cooking oil and fat, estimation of global solar energy potentials based on publically available data, and a large review of global grid connected electricity storage systems. Finally, an article applies stochastic programming to analyse optimal district heating expansion scenarios with particular focus on the phasing issue of investments in district heating grids.

De-emulsifiers for water-in-crude oil-emulsions

Energy Technology Data Exchange (ETDEWEB)

Zaki, N. [Egyptian Petroleum Research Inst. (EPRI), Cairo (Egypt); Al-Sabagh, A. [Egyptian Petroleum Research Inst. (EPRI), Cairo (Egypt)

1997-01-01

The efficiency of 18 different polyalkylphenols-polyalkylene-polyamines-formaldehyde ethoxylates (PAPAFE) in the deemulsification of water-in-crude oil-emulsion were studied. In this respect, two naturally occurring Egyptian water-in-curde oil-emulsions were used to test the investigated de-emulsifiers. The effect of the variation in the molecular structure of the (PAPAFE) on their de-emulsification potency is investigated. The investigation reveals that de-emulsifiers containing nonyl phenol reduce crude oil-water interfacial tension (IFT) and are more efficient than those containing dodecyl phenol. PAPAFE containing more amino groups are found to have better emulsion breaking ability. This is attributed to their enhanced ability to solubilize asphaltenes, which are the prime motivators for crude oil-water emulsion stability. They drag asphaltenes crosslinked at the water-crude oil interface and consequently, resulting in a substantial decrease in emulsion stability. There exists an optimum hydrophilic-lipophilic balance (HLB) for the investigated PAPAFE, ranging from 12 to 13.5 at which their maximum de-emulsification ability is attained. All studied PAPAFE showed increased de-emulsification performance by increasing the temperature from 50 to 70 C. Increasing the temperature reduces the viscosity of the crude oil continuous phase and increases the rate of diffusion of both the surfactant molecules and the dispersed water droplets. This will cause an increase in the rate of coalescence of the water droplets. (orig.) [Deutsch] Es wurde die Wirkung von 18 verschiedenen Polyalkylphenolpolyalkylenpolyamine-formaldehydethoxylaten (PAPAFE) bei der Demulgierung von Wasser-in-Rohoel-Emulsionen untersucht. Zwei in Aegypten natuerlich vorkommende Wasser-in-Rohoel-Emulsionen wurden fuer die Versuche eingesetzt, dabei wurde der Einfluss der molekularen Struktur der PAPAFEs auf das Demulgiervermoegen untersucht. Es zeigte sich, dass Demulgatoren mit Nonylphenol die

Efficiency of emulsifier-free emulsions and emulsions containing rapeseed lecithin as delivery systems for vectorization and release of coenzyme Q10: physico-chemical properties and in vitro evaluation.

Science.gov (United States)

Kaci, M; Arab-Tehrany, E; Dostert, G; Desjardins, I; Velot, E; Desobry, S

2016-11-01

To improve the encapsulation and release of coenzyme Q10 (CoQ10), emulsifier-free-emulsions were developed with a new emulsification process using high-frequency ultrasound (HFU) at 1.7MHz. Nano-emulsions containing CoQ10 were prepared with or without rapeseed lecithin as an emulsifier. The emulsions prepared with HFU were compared with an emulsion of CoQ10 containing emulsifier prepared with the same emulsification technique as well as with emulsions prepared with low-frequency ultrasound coupled with high-pressure homogenization (LFU+HPH). The physico-chemical properties of the emulsions were determined by average droplet size measurement with nano-droplet tracking analysis, droplet surface charge with ζ potential measurement, surface tension and rheological behaviour. Emulsions made by LFU+HPH with an emulsifier showed lower droplet sizes due to cavitation generated by the HFU process. Surface tension results showed that there was no significant difference between emulsions containing lecithin emulsifier regardless of the preparation process or the inclusion of CoQ10. In vitro biocompatibility tests were performed on human mesenchymal stem cells in order to show the cytotoxicity of various formulations and the efficiency of CoQ10-loaded emulsions. In vitro tests proved that the vectors were not toxic. Furthermore, CoQ10 facilitated a high rate of cell proliferation and metabolic activity especially when in an emulsifier-free formulation. Copyright © 2016 Elsevier B.V. All rights reserved.

Degradation of Polycyclic Aromatic Hydrocarbon Pyrene by Biosurfactant-Producing Bacteria Gordonia cholesterolivorans AMP 10

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Tri Handayani Kurniati

2016-12-01

Full Text Available Pyrene degradation and biosurfactant activity by a new strain identified as Gordonia cholesterolivorans AMP 10 were studied. The strain grew well and produced effective biosurfactants in the presence of glucose, sucrose, and crude oil. The biosurfactants production was detected by the decreased surface tension of the medium and emulsification activity.  Analysis of microbial growth parameters showed that AMP10 grew best at 50 µg mL-1 pyrene concentration, leading to 96 % degradation of pyrene within 7 days. The result of nested PCR analysis revealed that this isolate possessed the nahAc gene which encodes dioxygenase enzyme for initial degradation of Polycyclic Aromatic Hydrocarbon (PAH. Observation of both tensio-active and emulsifying activities indicated that biosurfactants which produced by AMP 10 when grown on glucose could lower the surface tension of medium from 71.3 mN/m to 24.7 mN/m and formed a stable emulsion in used lubricant oil with an emulsification index (E24 of 74%. According to the results, it is suggested that the bacterial isolates G. cholesterolivorans AMP10 are suitable candidates for bioremediation of PAH-contaminated environments.How to CiteKurniati, T. H.,  Rusmana, I. Suryani, A. & Mubarik, N. R. (2016. Degradation of Polycyclic Aromatic Hydrocarbon Pyrene by Biosurfactant-Producing Bacteria Gordonia cholesterolivorans AMP 10. Biosaintifika: Journal of Biology & Biology Education, 8(3, 336-343. 

Biosurfactant production by the crude oil degrading Stenotrophomonas sp. B-2: chemical characterization, biological activities and environmental applications.

Science.gov (United States)

Gargouri, Boutheina; Contreras, María Del Mar; Ammar, Sonda; Segura-Carretero, Antonio; Bouaziz, Mohamed

2017-02-01

In this work, biosurfactant-producing microorganisms were isolated from hydrocarbon-contaminated water collected from Tunisian oilfield. After enrichment and isolation, different bacterial strains were preliminary studied for their biosurfactant/bioemulsifier properties when using crude oil as the unique carbon source. In particular, the isolate strain B-2, a Gram-negative, rod-shaped bacterium, efficiently emulsified crude oil. The extracellular biosurfactant product from this strain presented an emulsification activity above 70% and a hydrophobicity of 71%. In addition, a diameter of 6 cm was observed in the oil displacement test. The characterization of B-2 strain using 16S rDNA sequencing enables us to find a high degree of similarity with various members of the genus Stenotrophomonas (with a percentage of similarity of 99%). The emulsification activity of Stenotrophomonas biosurfactant B-2 was maintained in a wide range of pH (2 to 6), temperature (4 to 55 °C), and salinity (0 to 50 g L -1 ) conditions. It also enhanced the solubility of phenanthrene in water and could be used in the re-mobilization of hydrocarbon-contaminated environment. In addition, this biosurfactant exhibited antimicrobial and antioxidant properties. Infrared spectroscopy suggested potential lipidic and peptidic moieties, and mass spectrometry-based analyses showed that the biosurfactant contains mainly cyclic peptidic structures belonging to the class of diketopiperazines. Therefore, the B-2 strain is a promising biosurfactant-producing microorganism and its derived biosurfactant presents a wide range of industrial applications.

Isolation and characterization of biosurfactant producing bacteria from Persian Gulf (Bushehr provenance).

Science.gov (United States)

Hassanshahian, Mehdi

2014-09-15

Biosurfactants are surface active materials that are produced by some microorganisms. These molecules increase biodegradation of insoluble pollutants. In this study sediments and seawater samples were collected from the coastline of Bushehr provenance in the Persian Gulf and their biosurfactant producing bacteria were isolated. Biosurfactant producing bacteria were isolated by using an enrichment method in Bushnell-Hass medium with diesel oil as the sole carbon source. Five screening tests were used for selection of Biosurfactant producing bacteria: hemolysis in blood agar, oil spreading, drop collapse, emulsification activity and Bacterial Adhesion to Hydrocarbon test (BATH). These bacteria were identified using biochemical and molecular methods. Eighty different colonies were isolated from the collected samples. The most biosurfactant producing isolates related to petrochemical plants of Khark Island. Fourteen biosurfactant producing bacteria were selected between these isolates and 7 isolates were screened as these were predominant producers that belong to Shewanella alga, Shewanella upenei, Vibrio furnissii, Gallaecimonas pentaromativorans, Brevibacterium epidermidis, Psychrobacter namhaensis and Pseudomonas fluorescens. The largest clear zone diameters in oil spreading were observed for G. pentaromativorans strain O15. Also, this strain has the best emulsification activity and reduction of surface tension, suggesting it is the best of thee isolated strains. The results of this study confirmed that there is high diversity of biosurfactant producing bacteria in marine ecosystem of Iran and by application of these bacteria in petrochemical waste water environmental problems can be assisted. Copyright © 2014 Elsevier Ltd. All rights reserved.

Isolation and characterization of exopolysaccharide produced by Vibrio harveyi strain VB23.

Science.gov (United States)

Bramhachari, P V; Dubey, S K

2006-11-01

The aim of the study was to isolate and characterize exopolysaccharide (EPS) produced by Vibrio harveyi strain VB23. Growth and EPS production by V. harveyi strain VB23, was studied in mineral salts medium supplemented with NaCl (1.5%) and glucose (0.2%). The rate of EPS production in batch cultures was highest during the late log phase of growth when compared with stationary growth phase. The exopolymer was recovered from the culture supernatant by using a cold ethanol precipitation-dialysis procedure. Chemical analyses of EPS revealed that it is primarily composed of neutral sugars, uronic acids, proteins and sulfates. The purified EPS revealed prominent functional reactive groups, such as hydroxyl, carboxylic and amides, which correspond to a typical heteropolymeric polysaccharide and the EPS, also possessed good emulsification activity. The gas chromatographic analysis of an alditol acetate-derivatized sample of EPS revealed that it is composed primarily of galactose and glucose. Minor components found were rhamnose, fucose, ribose, arabinose, xylose and mannose. The EPS produced by V. harveyi strain VB23 is a heteropolysaccharide possessing good emulsification activity. EPS was readily isolated from culture supernatants, which suggests that the EPS was a slime-like EPS. This is the first report of EPS characterization in luminous V. harveyi bacteria, which describes the isolation and characterization of an EPS expressed by V. harveyi. The results of the study contributes significantly towards an understanding of the chemical composition and applications of the EPS in environmental biotechnology and bioremediation.

Production and characterisation of glycolipid biosurfactant by Halomonas sp. MB-30 for potential application in enhanced oil recovery.

Science.gov (United States)

Dhasayan, Asha; Kiran, G Seghal; Selvin, Joseph

2014-12-01

Biosurfactant-producing Halomonas sp. MB-30 was isolated from a marine sponge Callyspongia diffusa, and its potency in crude oil recovery from sand pack column was investigated. The biosurfactant produced by the strain MB-30 reduced the surface tension to 30 mN m(-1) in both glucose and hydrocarbon-supplemented minimal media. The critical micelle concentration of biosurfactant obtained from glucose-based medium was at 0.25 mg ml(-1) at critical micelle dilution 1:10. The chemical structure of glycolipid biosurfactant was characterised by infrared spectroscopy and proton magnetic resonance spectroscopy. The emulsification activity of MB-30 biosurfactant was tested with different hydrocarbons, and 93.1 % emulsification activity was exhibited with crude oil followed by kerosene (86.6 %). The formed emulsion was stable for up to 1 month. To identify the effectiveness of biosurfactant for enhanced oil recovery in extreme environments, the interactive effect of pH, temperature and salinity on emulsion stability with crude oil and kerosene was evaluated. The stable emulsion was formed at and above pH 7, temperature >80 °C and NaCl concentration up to 10 % in response surface central composite orthogonal design model. The partially purified biosurfactant recovered 62 % of residual crude oil from sand pack column. Thus, the stable emulsifying biosurfactant produced by Halomonas sp. MB-30 could be used for in situ biosurfactant-mediated enhanced oil recovery process and hydrocarbon bioremediation in extreme environments.

Microspheres for protein delivery prepared from amphiphilic multiblock copolymers. 1. Influence of preparation techniques on particle characteristics and protein delivery.

Science.gov (United States)

Bezemer, J M; Radersma, R; Grijpma, D W; Dijkstra, P J; van Blitterswijk, C A; Feijen, J

2000-07-03

The entrapment of lysozyme in amphiphilic multiblock copolymer microspheres by emulsification and subsequent solvent removal processes was studied. The copolymers are composed of hydrophilic poly(ethylene glycol) (PEG) blocks and hydrophobic poly(butylene terephthalate) (PBT) blocks. Direct solvent extraction from a water-in-oil (w/o) emulsion in ethanol or methanol did not result in the formation of microspheres, due to massive polymer precipitation caused by rapid solvent extraction in these non-solvents. In a second process, microspheres were first prepared by a water-in-oil-in-water (w/o/w) emulsion system with 4% poly(vinyl alcohol) (PVA) as stabilizer in the external phase, followed by extraction of the remaining solvent. As non-solvents ethanol, methanol and mixtures of methanol and water were employed. However, the use of alcohols in the extraction medium resulted in microspheres which gave an incomplete lysozyme release at a non-constant rate. Complete lysozyme release was obtained from microspheres prepared by an emulsification-solvent evaporation method in PBS containing poly(vinyl pyrrolidone) (PVP) or PVA as stabilizer. PVA was most effective in stabilizing the w/o/w emulsion. Perfectly spherical microspheres were produced, with high protein entrapment efficiencies. These microspheres released lysozyme at an almost constant rate for approximately 28 days. The reproducibility of the w/o/w emulsion process was demonstrated by comparing particle characteristics and release profiles of three batches, prepared under similar conditions.

The emulsifying effect of biosurfactants produced by food spoilage organisms in Nigeria

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Christianah O. Ogunmola

2016-04-01

Full Text Available Food spoilage organisms were isolated using standard procedures on Nutrient Agar, Cetrimide Agar and Pseudomonas Agar Base (supplemented with CFC. The samples were categorized as animal products (raw fish, egg, raw chicken, corned beef, pasteurized milk and plant products (vegetable salad, water leaf (Talinium triangulare, boiled rice, tomatoes and pumpkin leaf (Teifairia occidentalis.They were characterised as Pseudomonas putida, Pseudomonas aeruginosa, Pseudomonas stutzeri, Burkholderia pseudomallei, Serratia rubidaea, Corynebacterium pilosum, Bacillus subtilis, Bacillus mycoides, Bacillus laterosporus, Bacillus laterosporus, Serratia marcescens, Bacillus cereus, Bacillus macerans, Alcaligenes faecalis and Alcaligenes eutrophus. Preliminary screening for biosurfactant production was done using red blood haemolysis test and confirmed by slide test, drop collapse and oil spreading assay. The biosurfactant produced was purified using acetone and the composition determined initially using Molisch’s test, thin layer chromatography and gas chromatography mass spectrometry. The components were found to be ethanol, amino acids, butoxyacetic acid, hexadecanoic acid, oleic acid, lauryl peroxide, octadecanoic acid and phthalic acid. The producing organisms grew readily on several hydrocarbons such as crude oil, diesel oil and aviation fuel when used as sole carbon sources.  The purified biosurfactants produced were able to cause emulsification of kerosene (19.71-27.14% as well as vegetable oil (16.91-28.12% based on the emulsification index. This result suggests that the isolates can be an asset and further work can exploit their optimal potential in industries.

Quality-by-design based development of a self-microemulsifying drug delivery system to reduce the effect of food on Nelfinavir mesylate.

Science.gov (United States)

Kamboj, Sunil; Rana, Vikas

2016-03-30

Poor aqueous solubility and moderate permeability of Nelfinavir mesylate (NFM) leads to high variability in absorption after oral administration. To improve the solubility and bioavailability of NFM, the self microemulsifying drug delivery system (SMEDDS) was developed. For this purpose, Quality by design (QbD) approach employing D-optimal mixture design was used to prepare SMEDDS of NFM. Further, the software generated numerically optimized SMEDDS were developed by utilizing desirability function. Maisine 35-1, Tween 80, and Transcutol HP were identified as oil, surfactant, and co-surfactant that had best solubility for NFM. Ternary phase diagrams were plotted to identify the self-emulsification region. Dissolution of putative NFM in simulated fasted or fed small intestinal conditions, respectively, predicted that there is a positive food effect. However, NFM loaded SMEDDS showed absence of food effect with no significant difference in dissolution performance either in Fasted or fed state simulated intestinal fluid (FaSSIF or FeSSIF) biorelevent dissolution media. The prepared SMEDDS were thermodynamically stable with droplet size (121 nm), poly dispersity index (PDI) (0.198) and emulsification time (food effect on pure NFM suspension. However, absence of food effect and 3.5-3.6 fold enhancement in the oral bioavailability was observed when NFM was formulated into SMEDDS. Thus, it could be envisaged that development of SMEDDS formulation of NFM could be one of the best alternative to enhance oral bioavailability of NFM. Copyright © 2016 Elsevier B.V. All rights reserved.

Emulsions from Aerosol Sprays

Science.gov (United States)

Hengelmolen; Vincent; Hassall

1997-12-01

An electrostatic emulsification apparatus has been designed for the purpose of studying diffusion from oil droplets which have a mean size in the range of approximately 1.5-3.5 &mgr;m, with standard deviations of 40-50%. The emulsification technique involves the collection of a spray of electrically charged oil droplets onto a rotating water film which is sustained from a reservoir. In this way, emulsions with volume fractions of approximately 10(-3) are produced within several minutes at oil flow rates of around 10(-2) ml min-1. Phase-Doppler anemometry (PDA) was used to assess droplet size distributions for the sprays and emulsions. Results show that the mean emulsion droplet size was smaller than the mean spray droplet size by several orders of magnitude. At flow rates around 10(-2) ml min-1, the spray droplet size distribution was little affected by the applied potential between about -4.20 and -4.65 kV (mean droplet size between approximately 7.6 and 7.8 &mgr;m, with standard deviations of approximately 20%), whereas the mean droplet size of the corresponding emulsion decreased more rapidly with applied potential. Above an applied potential of approximately -4.30 kV, which corresponded to an emulsion droplet size below approximately 2 &mgr;m, the measured volume fraction of the emulsion decreased with respect to the volume fraction as calculated on the basis of total amount of injected oil. Copyright 1997 Academic Press. Copyright 1997Academic Press

Techniques for nanoencapsulation of food ingredients

CERN Document Server

Anandharamakrishnan, C

2014-01-01

Nanoencapsulation has the potential to improve human health through its capacity to both protect bioactive compounds and release them at a specific time and location into various substances, including food. Numerous nanoencapsulation technologies have emerged in recent years, each with its own advantages and disadvantages. The goal of this Brief is to discuss the various nanoencapsulation technologies, such as emulsification, coacervation, inclusion encapsulation, anti-solvent precipitation, nanoprecipitation, freeze drying, and spray drying, including their limitations. Recent safety and regulatory issues concerning the various nanoencapsulation technologies will also be covered.

High internal phase agar hydrogel dispersions in cocoa butter and chocolate as a route towards reducing fat content.

Science.gov (United States)

Skelhon, Thomas S; Olsson, Patrik K A; Morgan, Adam R; Bon, Stefan A F

2013-09-01

Reducing the fat content of chocolate formulations is a major challenge for the confectionery industry. We report the suspension of aqueous microgel agar particles of up to 80% v/v within sunflower oil, cocoa butter, and ultimately chocolate. The optimised emulsification process involves a shear-cooling step. We demonstrate the versatility of our method when applied to white, milk, and dark chocolate formulations, whilst preserving the desired polymorph V of the cocoa butter matrix. In addition, we show that this technology can be used as a strategy to disperse alcoholic beverages into chocolate confectionery.

Incorporation of fluconazole in copolymer PMMA-g-PEG derivatives

International Nuclear Information System (INIS)

Silveira, B.M.; Santos, V.M.R. dos; Novack, K.M.; Lopes, S.A.

2014-01-01

The graft copolymer PMMA-g-PEG went through chemical transformations in its chain through acetylation, halogenation, methylation and esterification followed by hydrolysis reactions. Subsequently, the copolymer PMMA-g-PEG derivatives passed through the process of emulsification and incorporation of the drug fluconazole. Derivatives copolymers were characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) after incorporation in order to evaluate their effectiveness. The efficiency of incorporation was observed and it was also verified that the complexity of polymer chain influence in the incorporated fluconazole content. (author)

The choice of homogenisation equipment affects lipid oxidation in emulsions

DEFF Research Database (Denmark)

Horn, Anna Frisenfeldt; Nielsen, Nina Skall; Jensen, Louise Helene Søgaard

2012-01-01

in emulsions has been shown to be affected by the emulsification conditions. The objective of this study was to investigate the influence of homogenisation equipment (microfluidizer vs. two-stage valve homogeniser) on lipid oxidation in 10% fish oil-in-water emulsions prepared with two different milk proteins....... Emulsions were prepared at pH 7 with similar droplet sizes. Results showed that the oxidative stability of emulsions prepared with sodium caseinate was not influenced by the type of homogeniser used. In contrast, the type of homogenisation equipment significantly influenced lipid oxidation when whey protein...

[done no pages] An overview on applications of guar gum in food systems to modify structural properties

Directory of Open Access Journals (Sweden)

Biljana B. Popova

2017-01-01

Full Text Available Polysaccharides define as complex polymers composed of units interlinked with glycosidic bonds originated naturally. Polysaccharides are categorizing in several groups and among them, Gums are those with critical roles in food systems. Guar Gum is imparting softness, emulsification, stabilizing via its addition to formulas. This Gum is a fast soluble in cold water and can be active in a wide range of pH. The aim of this overview is giving an initial concept about guar gum and then convey to an introduction of its applications in food industries.

Biopolymeric nanoparticles

International Nuclear Information System (INIS)

Sundar, Sushmitha; Kundu, Joydip; Kundu, Subhas C

2010-01-01

This review on nanoparticles highlights the various biopolymers (proteins and polysaccharides) which have recently revolutionized the world of biocompatible and degradable natural biological materials. The methods of their fabrication, including emulsification, desolvation, coacervation and electrospray drying are described. The characterization of different parameters for a given nanoparticle, such as particle size, surface charge, morphology, stability, structure, cellular uptake, cytotoxicity, drug loading and drug release, is outlined together with the relevant measurement techniques. Applications in the fields of medicine and biotechnology are discussed along with a promising future scope. (topical review)

Effective Biosurfactants Production by Pseudomonas aeruginosa and its Efficacy on Different Oils

Directory of Open Access Journals (Sweden)

Sarita Kumari

2010-07-01

Full Text Available A rhamnolipid producing bacterium, Pseudomonas aeruginosa was isolated from contaminated soil with oily wastes. The Pseudomonas aeruginosa grown with glucose and corn oil as a carbon source produced bio-surfactant. This biosurfactant was purified by procedures that included chloroform-ethanol extraction and 0.05M bicarbonate treatments. The active compound was identified as rhamnolipid by using thin layer chromatography. The emulsification activity of bio-surfactant, the coconut oil responded better than the olive oil, groundnut oil and sunflower oil and gave a maximum level of 1 cm.

A comparative study on the emulsifying properties of various species of gum tragacanth.

Science.gov (United States)

Farzi, Mina; Emam-Djomeh, Zahra; Mohammadifar, Mohammad Amin

2013-06-01

Emulsification activities of three different species of gum tragacanth containing Astragalus gossypinus, A. compactus and A. rahensis were investigated. Emulsion stability indexes, particle size distributions, steady and unsteady rheological properties and some other physicochemical attributes including the surface tensions and uronic acid contents were taken into consideration. It was revealed that A. gossypinus created the most stable emulsions although having lower viscosity than A. compactus. It is believed that higher insoluble fraction and higher uronic content made this species a good steric and electrostatic emulsifier. Copyright © 2013 Elsevier B.V. All rights reserved.

Incorporation of fluconazole in copolymer PMMA-g-PEG derivatives; Incorporacao de fluconazol em ineditos derivados do copolimero PMMA-g-PEG

Energy Technology Data Exchange (ETDEWEB)

Silveira, B.M.; Santos, V.M.R. dos; Novack, K.M.; Lopes, S.A., E-mail: vmrebello@yahoo.com.br [Universidade Federal de Ouro Preto (UFOP), MG (Brazil)

2014-07-01

The graft copolymer PMMA-g-PEG went through chemical transformations in its chain through acetylation, halogenation, methylation and esterification followed by hydrolysis reactions. Subsequently, the copolymer PMMA-g-PEG derivatives passed through the process of emulsification and incorporation of the drug fluconazole. Derivatives copolymers were characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) after incorporation in order to evaluate their effectiveness. The efficiency of incorporation was observed and it was also verified that the complexity of polymer chain influence in the incorporated fluconazole content. (author)

Lipid hydrolysis products affect the composition of microbiota isolated from infant fecal samples after in vitro fermentation

DEFF Research Database (Denmark)

Bennike, Rikke Mette Guldhammer; Licht, Tine Rask; Hellgren, Lars

ileum and in colon can be expected to selectively modulate the growth rate and hereby the composition of the microbiota. In earlier studies, we have shown that this concentration is dependent on the type of emulsification of the triglycerides, which deviates between breast milk and formula milk. Here......, we have determined effects of selected combinations of FFA and MAG on microbial composition during a 24-hour anaerobic in vitro fermentation in microbiota obtained from infant fecal samples (age 2-5 months). PCR-based quantification of 11 different bacterial taxa revealed that the growth...

Characterization of fasted human gastric fluid for relevant rheological parameters and gastric lipase activities

DEFF Research Database (Denmark)

Pedersen, Pernille Barbre; Vilmann, Peter; Bar-Shalom, Daniel

2013-01-01

be considered important during development of gastric simulated media. Further, the activity of the HGL is active even under fasted gastric conditions and might contribute to the digestion and emulsification of lipid-based drug delivery systems in the entire gastrointestinal tract. HGL should therefore......PURPOSE: To characterize human gastric fluid with regard to rheological properties and gastric lipase activity. In addition, traditional physicochemical properties were determined. METHODS: Fasted HGA were collected from 19 healthy volunteers during a gastroscopic examination. Rheological...... be considered in gastric evaluation of lipid-based drug delivery systems....

PENGARUH KOMPOSOSI LAPISAN PADA PERMUKAAN GLOBULA MINYAK EMULSI SEBELUM PENGERINGAN SEMPROT TERHADAP SIFAT-SIFAT MIKROKAMSUL TRIGLISERIDA KAYA ASAM LEMAK W-3 [The Effect of the Composition of Adsorbed Layer at Globule Interface of -3 Fatty Acids Enriched Triglyceride Prior to Spray Drying on its Microcapsule Properties

Directory of Open Access Journals (Sweden)

Moch Adnan2

2005-04-01

Full Text Available Emulsification is the critical factor in microencapsulation by spray drying method. Sodium caseinate is a protein with good emulsifying properties. The properties could be improved by phospholipids addition in the emulsification. Phospholipids addition which stabilized oil globule might change the composition of adsorbed layer.This research was conducted to analyze the changes in composition at oil globule interface by analyzing emulsion systems of triglyceride enriched by -3 fatty acids at 5% (w/v stabilized by sodium caseinate (10% w/v and addition of phospholipids at 0; 0,5; 1,0; 1,5; 2,0; and 2,5% (w/v. The changes in composition of adsorbed layer could be determined from the changes in phospholipids and adsorbed protein concentrations at oil globule interface. Analyses were done to measure the possibility of casein-phospholipids complex, phospholipids and protein adsorption concentration at interface, and adsorbed protein.The increase of phospholipids concentration in the emulsions stabilized by sodium caseinate changed the composition of adsorbed layer at interface. There was phospholipids increase and adsorbed protein decrease at oil globule interface. These changes were caused by casein-phospholipids complex which that decreased surface activity and displacement protein by phospholipids that was adsorbed at oil globule interface.Changes of composition of casein-phospholipids at oil globule prior to microcapsulation process caused changes in the properties of microcapsule produced. The increasing phospholipids and decreasing casein concentrations at oil globule interface decreased the quality of the microcapsule, including decreasing in microencapsulation efficiency, in oxidative stability, and decreasing in EPA+DHA content.

Effect of High Pressure Homogenization on the Physicochemical Properties of Natural Plant-based Model Emulsion Applicable for Dairy Products

Science.gov (United States)

Park, Sung Hee; Min, Sang-Gi; Jo, Yeon-Ji; Chun, Ji-Yeon

2015-01-01

In the dairy industry, natural plant-based powders are widely used to develop flavor and functionality. However, most of these ingredients are water-insoluble; therefore, emulsification is essential. In this study, the efficacy of high pressure homogenization (HPH) on natural plant (chocolate or vanilla)-based model emulsions was investigated. The particle size, electrical conductivity, Brix, pH, and color were analyzed after HPH. HPH significantly decreased the particle size of chocolate-based emulsions as a function of elevated pressures (20-100 MPa). HPH decreased the mean particle size of chocolate-based emulsions from 29.01 μm to 5.12 μm, and that of vanilla-based emulsions from 4.18 μm to 2.44 μm. Electrical conductivity increased as a function of the elevated pressures after HPH, for both chocolate- and vanilla-based model emulsions. HPH at 100 MPa increased the electrical conductivity of chocolate-based model emulsions from 0.570 S/m to 0.680 S/m, and that of vanilla-based model emulsions from 0.573 S/m to 0.601 S/m. Increased electrical conductivity would be attributed to colloidal phase modification and dispersion of oil globules. Brix of both chocolate- and vanilla-based model emulsions gradually increased as a function of the HPH pressure. Thus, HPH increased the solubility of plant-based powders by decreasing the particle size. This study demonstrated the potential use of HPH for enhancing the emulsification process and stability of the natural plant powders for applications with dairy products. PMID:26761891

Thiolated alkyl-modified carbomers: Novel excipients for mucoadhesive emulsions.

Science.gov (United States)

Bonengel, Sonja; Hauptstein, Sabine; Leonaviciute, Gintare; Griessinger, Julia; Bernkop-Schnürch, Andreas

2015-07-30

The aim of this study was the design and evaluation of mucoadhesive emulsifying polymeric excipients. Three thiol bearing ligands with increasing pKa values of their sulfhydryl group, namely 4-aminothiophenol (pKa=6.86), l-cysteine (pKa=8.4) and d/l-homocysteine (pKa=10.0) were coupled to the polymeric backbone of alkyl-modified carbomer (PA1030). Resulting conjugates displayed 818.5μmol 4-aminothiophenol, 698.5μmol cysteine and 651.5μmol homocysteine per gram polymer and were evaluated regarding the reactivity of thiol groups, emulsifying and mucoadhesive properties. In general, the synthesized conjugates showed a pH dependent reactivity, whereby the fastest oxidation occurred in PA1030-cysteine, as almost no free thiol groups could be detected after 120min. Emulsification of medium chain triglycerides was feasible with all synthesized conjugates leading to oil-in-water-emulsions. Emulsions with PA1030-cysteine displayed the highest stability and the smallest droplet size among the tested formulations. Oxidation and consequently cross-linking of the thiomers prior to the emulsification process led to an overall decreased emulsion stability. Evaluating mucosal residence time of thiomer emulsions on porcine buccal mucosa, a 9.2-fold higher amount of formulation based on PA1030-cysteine remained on the mucosal tissue within 3h compared to the unmodified polymer. According to these results, the highest reactive ligand l-cysteine seems to be most promising in order to obtain thiolated polymers for the preparation of mucoadhesive o/w-emulsions. Copyright © 2015 Elsevier B.V. All rights reserved.

Ramizol® encapsulation into extended release PLGA micro- and nanoparticle systems for subcutaneous and intramuscular administration: in vitro and in vivo evaluation.

Science.gov (United States)

Wright, Leah; Rao, Shasha; Thomas, Nicky; Boulos, Ramiz A; Prestidge, Clive A

2018-04-11

Novel antibiotic Ramizol ® is advancing to clinical trials for the treatment of gastrointestinal Clostridium difficile associated disease. Despite this, previous studies have shown a rapid plasma clearance upon intravenous administration and low oral bioavailability indicating pure drug is unsuitable for systemic infection treatment following oral dosing. The current study aims to investigate the development of poly-lactic-(co-glycolic) acid (PLGA) particles to overcome this limitation and increase the systemic half-life following subcutaneous and intramuscular dosing. The development of new antibiotic treatments will help in combatting the rising incidence of antimicrobial resistance. Ramizol ® was encapsulated into PLGA nano and microparticles using nanoprecipitation and emulsification solvent evaporation techniques. Formulations were analyzed for particle size, loading level and encapsulation efficiency as well as in vitro drug release profiles. Final formulation was advanced to in vivo pharmacokinetic studies in Sprague-Dawley rats. Formulation technique showed major influence on particle size and loading levels with optimal loading of 9.4% and encapsulation efficiency of 92.06%, observed using emulsification solvent evaporation. Differences in formulation technique were also linked with subsequent differences in release profiles. Pharmacokinetic studies in Sprague-Dawley rats confirmed extended absorption and enhanced bioavailability following subcutaneous and intramuscular dosing with up to an 8-fold increase in T max and T 1/2 when compared to the oral and IV routes. Subcutaneous and intramuscular dosing of PLGA particles successfully increased systemic half-life and bioavailability of Ramizol ® . This formulation will allow further development of Ramizol ® for systemic infection eradication.

Screening and Optimization of Bio surfactant Production by the Hydrocarbon-Degrading Bacteria

International Nuclear Information System (INIS)

Ainon Hamzah; Noramiza Sabturani; Shahidan Radiman

2013-01-01

Bio surfactants are amphiphilic compounds produced by microorganisms as secondary metabolite. The unique properties of bio surfactants make them possible to replace or to be added to synthetic surfactants which are mainly used in food, cosmetics and pharmaceutical industries and in environmental applications. In this study twenty hydrocarbon-degrading bacteria were screened for bio surfactant production. All of the bacterial isolates were grown in mineral salt medium (MSM) with addition of 1 % (v/v) Tapis crude oil as carbon source. The presence of bio surfactant was determined by the drop-collapse test, microplate analysis, oil spreading technique, emulsification index (%EI24) and surface tension measurement. Only one isolate, Pseudomonas aeruginosa UKMP14T, was found to be positive for all the qualitative tests and reducing the surface tension of the medium to 49.5 dynes/ with emulsification index of 25.29 %. This isolate produced bio surfactant optimally at pH 9.0 and incubation temperature of 37 degree Celsius. Furthermore, P. aeruginosa UKMP14T when grown in MSM with addition of 1 % (v/v) glycerol and 1.3 g/ L ammonium sulphate with C/N ratio 14:1 produced bio surfactant with percentage of surface tension reduction at 55 % or 30.6 dynes/ cm with %EI24 of 43 %. This percentage of surface tension reduction represents an increasing reduction in surface tension of medium by 39 % over the value before optimization. This study showed that P. aeruginosa UKMP14T has the ability to biodegrade hydrocarbon and concurrently produce bio surfactant. (author)

Rhamnolipid produced by Pseudomonas aeruginosa USM-AR2 facilitates crude oil distillation.

Science.gov (United States)

Asshifa Md Noh, Nur; Al-Ashraf Abdullah, Amirul; Nasir Mohamad Ibrahim, Mohamad; Ramli Mohd Yahya, Ahmad

2012-01-01

A biosurfactant-producing and hydrocarbon-utilizing bacterium, Pseudomonas aeruginosa USM-AR2, was used to assist conventional distillation. Batch cultivation in a bioreactor gave a biomass of 9.4 g L(-1) and rhamnolipid concentration of 2.4 g L(-1) achieved after 72 h. Biosurfactant activity (rhamnolipid) was detected by the orcinol assay, emulsification index and drop collapse test. Pretreatment of crude oil TK-1 and AG-2 with a culture of P. aeruginosa USM-AR2 that contains rhamnolipid was proven to facilitate the distillation process by reducing the duration without reducing the quality of petroleum distillate. It showed a potential in reducing the duration of the distillation process, with at least 2- to 3-fold decreases in distillation time. This is supported by GC-MS analysis of the distillate where there was no difference between compounds detected in distillate obtained from treated or untreated crude oil. Calorimetric tests showed the calorie value of the distillate remained the same with or without treatment. These two factors confirmed that the quality of the distillate was not compromised and the incubation process by the microbial culture did not over-degrade the oil. The rhamnolipid produced by this culture was the main factor that enhanced the distillation performance, which is related to the emulsification of hydrocarbon chains in the crude oil. This biotreatment may play an important role to improve the existing conventional refinery and distillation process. Reducing the distillation times by pretreating the crude oil with a natural biosynthetic product translates to energy and cost savings in producing petroleum products.

One-step fabrication of multifunctional micromotors

Science.gov (United States)

Gao, Wenlong; Liu, Mei; Liu, Limei; Zhang, Hui; Dong, Bin; Li, Christopher Y.

2015-08-01

Although artificial micromotors have undergone tremendous progress in recent years, their fabrication normally requires complex steps or expensive equipment. In this paper, we report a facile one-step method based on an emulsion solvent evaporation process to fabricate multifunctional micromotors. By simultaneously incorporating various components into an oil-in-water droplet, upon emulsification and solidification, a sphere-shaped, asymmetric, and multifunctional micromotor is formed. Some of the attractive functions of this model micromotor include autonomous movement in high ionic strength solution, remote control, enzymatic disassembly and sustained release. This one-step, versatile fabrication method can be easily scaled up and therefore may have great potential in mass production of multifunctional micromotors for a wide range of practical applications.Although artificial micromotors have undergone tremendous progress in recent years, their fabrication normally requires complex steps or expensive equipment. In this paper, we report a facile one-step method based on an emulsion solvent evaporation process to fabricate multifunctional micromotors. By simultaneously incorporating various components into an oil-in-water droplet, upon emulsification and solidification, a sphere-shaped, asymmetric, and multifunctional micromotor is formed. Some of the attractive functions of this model micromotor include autonomous movement in high ionic strength solution, remote control, enzymatic disassembly and sustained release. This one-step, versatile fabrication method can be easily scaled up and therefore may have great potential in mass production of multifunctional micromotors for a wide range of practical applications. Electronic supplementary information (ESI) available: Videos S1-S4 and Fig. S1-S3. See DOI: 10.1039/c5nr03574k

Three-factor response surface optimization of nano-emulsion formation using a microfluidizer.

Science.gov (United States)

Sadeghpour Galooyak, Saeed; Dabir, Bahram

2015-05-01

Emulsification of sunflower oil in water by microfluidization was studied. Response surface methodology (RSM) and the central composite design (CCD) were applied to determine the effects of certain process parameters on performance of the apparatus for optimization of nano-emulsion fabrication. Influence of pressure, oil content and number of passes on the disruption of emulsions was studied. Quadratic multiple regression models were chosen for two available responses, namely Sauter mean diameter (SMD) and Polydispersity index (PdI). Analysis of variance (ANOVA) showed a high coefficient of determination (R(2)) value for both responses, confirming adjustment of the models with experimental data. The SMD and the PdI decreased as the pressure of emulsification increased from 408 to 762.3 bar for the oil content of 5 vol% and from 408 to 854.4 bar for the oil content of 13 vol%, and thereafter, increasing the pressure up to 952 bar led to increasing the both responses. The results implied that laminar elongational flow is the alternative disruption mechanism in addition to inertia in turbulence flow, especially at low treatment pressures. Both of responses improved with increase in number of passes from 2 to 4 cycles. The oil content depicted low effect on responses; however, interaction of this parameter with other regressors pointed remarkable impact. Also, the effect of pressure on Kolmogorov micro-scale was studied. The results implied that Kolmogorov equation did not take into account the over-processing and was applicable only for disruption of droplets in the inertial turbulent flow.

Optimization of ultrasonic emulsification conditions for the production of orange peel essential oil nanoemulsions.

Science.gov (United States)

Hashtjin, Adel Mirmajidi; Abbasi, Soleiman

2015-05-01

The aim of the present study was to investigate the influence of emulsifying conditions on some physical and rheological properties of orange peel essential oil (OPEO) in water nanoemulsions. In this regard, using the response surface methodology, the influence of ultrasonication conditions including sonication amplitude (70-100 %), sonication time (90-150 s) and process temperature (5-45 °C) on the mean droplets diameter (Z-average value), polydispersity index (PDI), and viscosity of the OPEO nanoemulsions was evaluated. In addition, the flow behavior and stability of selected nanoemulsions was evaluated during storage (up to 3 months) at different temperatures (5, 25 and 45 °C). Based on the results of the optimization, the optimum conditions for producing OPEO nanoemulsions (Z-average value 18.16 nm) were determined as 94 % (sonication amplitude), 138 s (sonication time) and 37 °C (process temperature). Moreover, analysis of variance (ANOVA) showed high coefficients of determination values (R (2) > 0.95) for the response surface models of the energy input and Z-average. In addition, the flow behavior of produced nanoemulsions was Newtonian, and the effect of time and storage temperature as well as their interactions on the Z-average value was highly significant (P < 0.0001).

Isolation and Characterization of Biosurfactant Producing Bacteria for the Application in Enhanced Oil Recovery

Science.gov (United States)

Prasad, Niraj; Dasgupta, Sumita; Chakraborty, Mousumi; Gupta, Smita

2017-07-01

In the present study, a biosurfactant producing bacterial strain was isolated, screened and identified. Further, various fermentation conditions (such as pH (5-10), incubation period (24-96h) and incubation temperature (20-60 °C) were optimized for maximum production of biosurfactant. The produced biosurfactant was characterized by measuring emulsification index, foaming characteristics, rhamnolipid detection, interfacial tension between water and oil and stability against pH and temperature for its potential application in oil recovery process. The additional oil recovery for two different sand, sand1 and sand2, was found to be 49% and 38%, respectively.

Soy Protein Isolate-Phosphatidylcholine Nanoemulsions Prepared Using High-Pressure Homogenization.

Science.gov (United States)

Li, Yang; Wu, Chang-Ling; Liu, Jun; Zhu, Ying; Zhang, Xiao-Yuan; Jiang, Lian-Zhou; Qi, Bao-Kun; Zhang, Xiao-Nan; Wang, Zhong-Jiang; Teng, Fei

2018-05-07

The nanoemulsions of soy protein isolate-phosphatidylcholine (SPI-PC) with different emulsion conditions were studied. Homogenization pressure and homogenization cycle times were varied, along with SPI and PC concentration. Evaluations included turbidity, particle size, ζ-potential, particle distribution index, and turbiscan stability index (TSI). The nanoemulsions had the best stability when SPI was at 1.5%, PC was at 0.22%, the homogenization pressure was 100 MPa and homogenization was performed 4 times. The average particle size of the SPI-PC nanoemulsions was 217 nm, the TSI was 3.02 and the emulsification yield was 93.4% of nanoemulsions.

An Underwater Superoleophobic Sepiolite Fibrous Membrane (SFM) for Oil­‐in­‐water Emulsion Separation

KAUST Repository

Yao, Pinjiang

2014-12-01

Separating oil/water emulsions is significant for the ecosystem and the petroleum and processing industry. To this end, we prepared an underwater superoleophobic membrane inspired by unique wettability of the fish scales. This membrane was fabricated by a facile vacuum filtration process of sepiolite nanofibers and chitosan, and after the cross-linking via glutaraldehyde, a self-standing membrane was obtained. The as-prepared membrane exhibited excellent capability of separating both the surfactant-free and surfactant-stabilized oil-in-water emulsions with high efficiency. This sepiolite fibrous membrane offers a convenient, reliable and efficient way for the large-scale de-emulsification process.

Deterioration of edible oils during food processing by ultrasound.

Science.gov (United States)

Chemat, F; Grondin, I; Shum Cheong Sing, A; Smadja, J

2004-01-01

During food emulsification and processing of sunflower oil (most used edible oil), a metallic and rancid odour has been detected only for insonated oil and foods. Some off-flavour compounds (hexanal and hept-2-enal) resulting from the sono-degradation of sunflower oil have been identified. A wide variety of analytical techniques (GC determination of fatty acids, UV spectroscopy, free fatty acids and GC/MS) were used to follow the quality of insonated sunflower oil and emulsion. Different edible oils (olive, sunflower, soybean, em leader ) show significant changes in their composition (chemical and flavour) due to ultrasound treatment.

Microbial biodiversity of Tang and Pirgal mud volcanoes and evaluation of bio-emulsifier and bio-demulsifier activities of Capnophile bacteria

Directory of Open Access Journals (Sweden)

Yasaman Parsia

2017-12-01

Full Text Available The data presented in this article is related to the Master thesis; entitled “Survey Aerobic Microbial Diversity Mud Volcanoes in Chabahar and Khash Ports in Southern Iran” by the first author of this article, year 2011, Islamic Azad University, Iran (reference number (Parsia, 2011 [1] of this article. This article shows microbial biodiversity and evaluates bio-emulsifier and bio-demulsifier abilities of capnophile isolates, in order to introduce a superior isolate for the Microbial Enhanced Oil Recovery (MEOR process in the petrochemical industry. Keywords: Mud volcanoes, Biodiversity, Bio-emulsification, Bio-demulsification, Petrochemistry

Diesel engine performance and emission evaluation using emulsified fuels stabilized by conventional and gemini surfactants

Energy Technology Data Exchange (ETDEWEB)

M. Nadeem; C. Rangkuti; K. Anuar; M.R.U. Haq; I.B. Tan; S.S. Shah [Universiti Teknologi PETRONAS, Bandar Seri Iskandar (Malaysia)

2006-10-15

Diesel engines exhausting gaseous emission and particulate matter have long been regarded as one of the major air pollution sources, particularly in metropolitan areas, and have been a source of serious public concern for a long time. The emulsification method is not only motivated by cost reduction but is also one of the potentially effective techniques to reduce exhaust emission from diesel engines. Water/diesel (W/D) emulsified formulations are reported to reduce the emissions of NOx, SOx, CO and particulate matter (PM) without compensating the engine's performance. Emulsion fuels with varying contents of water and diesel were prepared and stabilized by conventional and gemini surfactant, respectively. Surfactant's dosage, emulsification time, stirring intensity, emulsifying temperature and mixing time have been reported. Diesel engine performance and exhaust emission was also measured and analyzed with these indigenously prepared emulsified fuels. The obtained experimental results indicate that the emulsions stabilized by gemini surfactant have much finer and better-distributed water droplets as compared to those stabilized by conventional surfactant. A comparative study involving torque, engine brake mean effective pressure (BMEP), specific fuel consumption (SFC), particulate matter (PM), NOx and CO emissions is also reported for neat diesel and emulsified formulations. It was found that there was an insignificant reduction in engine's efficiency but on the other hand there are significant benefits associated with the incorporation of water contents in diesel regarding environmental hazards. The biggest reduction in PM, NOx, CO and SOx emission was achieved by the emulsion stabilized by gemini surfactant containing 15% water contents. 34 refs., 11 figs., 1 tab.

Production of rhamnolipids and diesel oil degradation by bacteria isolated from soil contaminated by petroleum.

Science.gov (United States)

Leite, Giuseppe G F; Figueirôa, Juciane V; Almeida, Thiago C M; Valões, Jaqueline L; Marques, Walber F; Duarte, Maria D D C; Gorlach-Lira, Krystyna

2016-03-01

Biosurfactants are microbial secondary metabolites. The most studied are rhamnolipids, which decrease the surface tension and have emulsifying capacity. In this study, the production of biosurfactants, with emphasis on rhamnolipids, and diesel oil degradation by 18 strains of bacteria isolated from waste landfill soil contaminated by petroleum was analyzed. Among the studied bacteria, gram-positive endospore forming rods (39%), gram positive rods without endospores (17%), and gram-negative rods (44%) were found. The following methods were used to test for biosurfactant production: oil spreading, emulsification, and hemolytic activity. All strains showed the ability to disperse the diesel oil, while 77% and 44% of the strains showed hemolysis and emulsification of diesel oil, respectively. Rhamnolipids production was observed in four strains that were classified on the basis of the 16S rRNA sequences as Pseudomonas aeruginosa. Only those strains showed the rhlAB gene involved in rhamnolipids synthesis, and antibacterial activity against Escherichia coli, P. aeruginosa, Staphylococcus aureus, Bacillus cereus, Erwinia carotovora, and Ralstonia solanacearum. The highest production of rhamnolipids was 565.7 mg/L observed in mineral medium containing olive oil (pH 8). With regard to the capacity to degrade diesel oil, it was observed that 7 strains were positive in reduction of the dye 2,6-dichlorophenolindophenol (2,6-DCPIP) while 16 had the gene alkane mono-oxygenase (alkB), and the producers of rhamnolipids were positive in both tests. Several bacterial strains have shown high potential to be explored further for bioremediation purposes due to their simultaneous ability to emulsify, disperse, and degrade diesel oil. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 32:262-270, 2016. © 2015 American Institute of Chemical Engineers.

Multivariate optimization of the determination of zinc in diesel oil employing a novel extraction strategy based on emulsion breaking

International Nuclear Information System (INIS)

Cassella, Ricardo J.; Brum, Daniel M.; Lima, Claudio F.; Caldas, Luiz Fernando S.; Paula, Carlos Eduardo R. de

2011-01-01

This paper describes the extraction/pre-concentration of Zn from diesel oil and its determination by Flame Atomic Absorption Spectrometry (FAAS), proposed as a novel approach for these kinds of analyses and the multivariate optimization of the proposed procedure. The extraction of Zn is based on the emulsification of an aqueous solution containing Triton X-114 and HNO 3 with diesel oil samples followed by breaking of the emulsion by heating. The aqueous phase obtained after the emulsion breaking was collected and used for Zn quantification by FAAS. The methodology was optimized using a Doehlert design and the system variables were the concentrations of surfactant and HNO 3 in the solution employed in the emulsification and the temperature used in the emulsion breaking. The ratio between absorbance and the time required to break the emulsions was taken as response. Two sets of experiments, using different emulsifier agents, were run: the first one using Triton X-100 and the second one using Triton X-114. At optimized conditions, the emulsions were prepared by mixing 10 mL of diesel oil with 2 mL of a solution containing 5% w/v of Triton X-114 and 15% v/v of HNO 3 and broken by heating at 80 o C. The proposed analytical procedure was applied in the analysis of six real samples of diesel oil and a recovery test was carried out by spiking the samples with known amounts of Zn (25 and 50 μg L -1 ), added as organometallic oiled standard. Recovery percentages achieved in this test were between 92 and 109%.

Pseudomonas sp. BUP6, a novel isolate from Malabari goat produces an efficient rhamnolipid type biosurfactant.

Science.gov (United States)

Priji, Prakasan; Sajith, Sreedharan; Unni, Kizhakkepowathial Nair; Anderson, Robin C; Benjamin, Sailas

2017-01-01

This study describes the characteristics of a biosurfactant produced by Pseudomonas sp. BUP6, a rumen bacterium, and optimization of parameters required for its production. Initial screening of five parameters (pH, temperature, agitation, incubation, and substrate concentration) was carried out employing Plackett-Burman design, which reduced the number of parameters to 3 (pH, temperature, and incubation) according to their significance on the yield of biosurfactant. A suitable statistical model for the production of biosurfactant by Pseudomonas sp. BUP6 was established according to Box-Behnken design, which resulted in 11% increase (at pH 7, 35 °C, incubation 75 h) in the yield (2070 mg L -1 ) of biosurfactant. The biosurfactant was found stable at a wide range of pH (3-9) with 48 mg L -1 critical micelle concentration; and maintained over 90% of its emulsification ability even after boiling and in presence of sodium chloride (0.5%). The highest cell hydrophobicity (37%) and emulsification (69%) indices were determined with groundnut oil and kerosene, respectively. The biosurfactant was found to inhibit the growth and adhesion of E. coli and S. aureus significantly. From the phytotoxicity studies, the biosurfactant did not show any adverse effect on the germinating seeds of rice and green gram. The structural characterization of biosurfactant employing orcinol method, thin layer chromatography and FT-IR indicated that it is a rhamnolipid (glycolipid). Thus, Pseudomonas sp. BUP6, a novel isolate from Malabari goat is demonstrated as a producer of an efficient rhamnolipid type biosurfactant suitable for application in various industries. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In-situ burning of spilled oil

International Nuclear Information System (INIS)

Tennyson, E.J.

1992-01-01

This presentation provided an overview of results from the Minerals Management Service's (MMS) funded research on in situ burning of spilled oil. The program began in 1983 to determine the limitations of this innovative response strategies. Specific physical variables evaluated were slick thickness, degree of weathering (sparging), sea state, wind velocities, air and water temperatures, degrees of emulsification and degree of ice-coverage. All of the oils tested burned with 50 to 95 percent removal ratios as long as emulsification had not occurred. Slick thickness of 3mm or thicker were required to sustain ignition and extinguishment occurred when the slick reached approximately 1mm thick. The next phase of the research involved quantitative analysis of the pollutants created by in situ burning including chemical composition of the parent oil, burn residue, and airborne constituents. These studies were conducted at the National Institute of Standards and Technology (NIST) with emphasis on particulate, and gaseous components created by the burning process. Research efforts over several years, and a variety of crude oils, yielded data which indicated that aldehydes ketones, dioxans, furans, and polyaromatic compounds (PAHS) were not formed in the burning process. The airborne pollutants reflected similar concentrations of these compounds that were present in the parent oil. Lighter molecular weight PAHs tended to be converted to higher molecular weight compounds. Heavier molecular weight compounds are considered less acutely toxic than lighter molecular weight PAHS. Predominant burn products released into the air were by weight: 75% carbon dioxide, 12% water vapor, 10% soot, 3% carbon monoxide and 0.2% other products including those listed above

Characterization, Cytotoxicity, and Genotoxicity of TiO2 and Folate-Coupled Chitosan Nanoparticles Loading Polyprenol-Based Nanoemulsion.

Science.gov (United States)

Tao, Ran; Wang, Chengzhang; Zhang, Changwei; Li, WenJun; Zhou, Hao; Chen, Hongxia; Ye, Jianzhong

2018-07-01

The structure and bioactivity of Ginkgo biloba leaves polyprenol (GBP) are similar to that of dolichol which widely exists in human and mammalian organs. GBP possesses potential pharmacological activities against cancer. This study involved oil-in-water type nanoemulsion (NE) loading GBP was prepared by dissolving polyprenol in nanoemulsion of sodium tripolyphosphate (TPP)/TiO 2 solution, Triton X-100, and 1-octanol by inversed-phase emulsification (EIP) and ultrasonic emulsification (UE) method. Folic acid (FA)-coupled chitosan (CS) nanoparticles (NPs), GBP-FA-CS-NPs and GBP-TiO 2 -FA-CS-NPs, were fabricated by ionic cross-linking of positively charged FA-CS conjugates and negatively charged nanoemulsion with TPP/TiO 2 . And characterizations of them were investigated by TEM, SEM, FTIR, particle size, and zeta potential. The cytotoxic and genotoxic effects of GBP-TiO 2 -FA-CS-NP treatment were higher than GBP-NE, GBP-FA-CS-NPs, TiO 2 -NE, GBP-TiO 2 -NE, TiO 2 -FA-CS-NPs, and GBP-TiO 2 -FA-CS-NP treatment at the same tested concentrations in HepG2 cells. GBP-TiO 2 -FA-CS-NPs at low TiO 2 concentration (from 1 to 2.5 μg/ml) showed good inhibition capacity on HepG2 cells and low cytotoxic and genotoxic effects on HL-7702 cells. The possible mechanism of cytotoxicity on GBP-TiO 2 -FA-CS-NPs against HepG2 cells is by preventing excessive intracellular Ca 2+ into extracellular spaces via inhibiting Ca 2+ -ATPase and Ca 2+ /Mg 2+ -ATPase.

Impact of process parameters in the generation of novel aspirin nanoemulsions--comparative studies between ultrasound cavitation and microfluidizer.

Science.gov (United States)

Tang, Siah Ying; Shridharan, Parthasarathy; Sivakumar, Manickam

2013-01-01

In the present investigation, the operating efficiency of a bench-top air-driven microfluidizer has been compared to that of a bench-top high power ultrasound horn in the production of pharmaceutical grade nanoemulsions using aspirin as a model drug. The influence of important process variables as well as the pre-homogenization and drug loading on the resultant mean droplet diameter and size distribution of emulsion droplets was studied in an oil-in-water nanoemulsion incorporated with a model drug aspirin. Results obtained show that both the emulsification methods were capable of producing very fine nanoemulsions containing aspirin with the minimum droplet size ranging from 150 to 170 nm. In case of using the microfluidizer, it has been observed that the size of the emulsion droplets obtained was almost independent of the applied microfluidization pressure (200-600 bar) and the number of passes (up to 10 passes) while the pre-homogenization and drug loading had a marginal effect in increasing the droplet size. Whereas, in the case of ultrasound emulsification, the droplet size was generally decreased with an increase in sonication amplitude (50-70%) and period of sonication but the resultant emulsion was found to be dependent on the pre-homogenization and drug loading. The STEM microscopic observations illustrated that the optimized formulations obtained using ultrasound cavitation technique are comparable to microfluidized emulsions. These comparative results demonstrated that ultrasound cavitation is a relatively energy-efficient yet promising method of pharmaceutical nanoemulsions as compared to microfluidizer although the means used to generate the nanoemulsions are different. Copyright © 2012 Elsevier B.V. All rights reserved.

Preparation of O/I1-type Emulsions and S/I1-type Dispersions Encapsulating UV-Absorbing Agents.

Science.gov (United States)

Aramaki, Kenji; Kimura, Minami; Masuda, Kazuki

2015-01-01

Oil-in-cubic phase (O/I1) emulsions encapsulating the cosmetic UV absorbing agents 2-ethylhexyl 4-methoxycinnamate (EHMC), 2-ethylhexyl 2-cyano-3,3-diphenylacrylate (octocrylene, OCR) and 1-(4-tertbutylphenyl)-3-(4-methoxyphenyl)-1,3-propanedione (Avobenzone, TBMP) were prepared by vortex mixing accompanied by a heating-cooling process. A ternary phase diagram in a water/C12EO25/EHMC system at 25°C was constructed and the two-phase equilibrium of an oil phase and an I1 phase, which is necessary to prepare the O/I1-type emulsions, was confirmed. Also, the melting of the I1 phase into a fluid micellar solution phase was confirmed, allowing emulsification by a heating-cooling process. The O/I1-type emulsions were formulated in the ternary system as well as a quaternary system. The four-component system contained an additional cosolvent, isopropyl myristate (IPM). The use of the cosolvent allows the use of reduced amounts of EHMC, which is desirable because EHMC can cause temporary skin irritation. Formulation of the O/I1-type emulsions with other UV absorbing agents (OCR and TBMP) was also possible using the same emulsification method. When IPM was changed to tripalmitin, which has a melting point greater than room temperature, a solid-oil dispersion in I1 phase was formed. We have termed this a "solidin-cubic phase (S/I1) type dispersion". These novel emulsions have not been reported previously. The UV absorbability of the O/I1-type emulsions and S/I1-type dispersions that encapsulate the UV absorbing agents was confirmed by measurement of UV absorption spectra.

Multivariate optimization of the determination of zinc in diesel oil employing a novel extraction strategy based on emulsion breaking

Energy Technology Data Exchange (ETDEWEB)

Cassella, Ricardo J., E-mail: cassella@vm.uff.br [Departamento de Quimica Analitica, Universidade Federal Fluminense, Outeiro de Sao Joao Batista s/n, Centro, Niteroi, RJ 24020-141 (Brazil); Brum, Daniel M.; Lima, Claudio F. [Departamento de Quimica, Universidade Federal de Vicosa, Av. Peter Henry Rolfs s/n, Vicosa, MG 36570-000 (Brazil); Caldas, Luiz Fernando S.; Paula, Carlos Eduardo R. de [Departamento de Quimica Analitica, Universidade Federal Fluminense, Outeiro de Sao Joao Batista s/n, Centro, Niteroi, RJ 24020-141 (Brazil)

2011-03-25

This paper describes the extraction/pre-concentration of Zn from diesel oil and its determination by Flame Atomic Absorption Spectrometry (FAAS), proposed as a novel approach for these kinds of analyses and the multivariate optimization of the proposed procedure. The extraction of Zn is based on the emulsification of an aqueous solution containing Triton X-114 and HNO{sub 3} with diesel oil samples followed by breaking of the emulsion by heating. The aqueous phase obtained after the emulsion breaking was collected and used for Zn quantification by FAAS. The methodology was optimized using a Doehlert design and the system variables were the concentrations of surfactant and HNO{sub 3} in the solution employed in the emulsification and the temperature used in the emulsion breaking. The ratio between absorbance and the time required to break the emulsions was taken as response. Two sets of experiments, using different emulsifier agents, were run: the first one using Triton X-100 and the second one using Triton X-114. At optimized conditions, the emulsions were prepared by mixing 10 mL of diesel oil with 2 mL of a solution containing 5% w/v of Triton X-114 and 15% v/v of HNO{sub 3} and broken by heating at 80 {sup o}C. The proposed analytical procedure was applied in the analysis of six real samples of diesel oil and a recovery test was carried out by spiking the samples with known amounts of Zn (25 and 50 {mu}g L{sup -1}), added as organometallic oiled standard. Recovery percentages achieved in this test were between 92 and 109%.

KARAKTERISTIK MIKROKAPSUL MINYAK KAYA ASAM LEMAK OMEGA-3 DARI HASIL SAMPING PENEPUNGAN LEMURU [Characteristics of Microcapsule of omega-3 Fatty Acids Enriched Oil from Lemuru Meal Processing

Directory of Open Access Journals (Sweden)

Teti Estiasih 1

2008-12-01

Full Text Available Omega-3 fatty acids enriched fish oil from lemuru fishmeal processing met the quality standard of food grade fish oil, but it was susceptible to oxidation. Microencapsulation by spray drying was one method that could protect this oil against oxidation and the microcapsule could be applied more widely and easier to handle. The important factor that affected microencapsulation process by spray drying method was encapsulant to core ratio. The objective of research was to elucidate the effect of encapsulant to core ratio (2:1; 3:1; 4:1; 5:1; and 6:1 (w/w on characteristics of omega-3 fatty acids enriched fish oil microcapsule. The increase of microencapsulation efficiency and the decrease of surface oil proportion were related to better emulsion stability prior to spray drying and film forming ability around oil globule as the sodium caseinate proportion increased. Emulsification and heating during spray drying could induce hydrolysis of triglycerides in fish oil. Therefore, the quantity of free fatty acids relatively unchanged although the proportion of encapsulated oil decreased. The decrease of oxidation degree is caused by better protective effect of sodium caseinate during emulsification and spray drying due to better film forming ability as proportion of encapsulant increased. However, it was followed by the decrease of omega-3 fatty acids content that related to decreasing proportion of fish oil. This phenomenon was supported by unchanging omega-3 fatty acids retention that showed protective effect of sodium caseinate on oxidation during microencapsulation. Different encapsulant to core ratio did not change yield of microcapsule. Different proportion of surface oil did not affect microcapsule recovery.

Comparison of 1000-Centistoke versus 5000-Centistoke Silicone Oil in Complex Retinal Detachment Surgery.

Science.gov (United States)

Zafar, Shakir; Shakir, Munira; Mahmood, Syed Asaad; Amin, Saima; Iqbal, Zafar

2016-01-01

To compare the efficacy and complications of using 1000-centistoke versus 5000-centistoke silicone oil for complex retinal detachment repair. Case series. LRBT Tertiary Eye Hospital, Karachi, from January 2007 to June 2013. Eighty-five eyes (85 patients) presenting with superior rhegmatogenous retinal detachments associated with PVR grades B and C (involving not more than 3 clock hours) were randomized to either 1000 centistokes (n=44) or 5000 centistokes (n=41) silicone oil group. All patients underwent 23-gauge pars plana vitrectomy surgery with silicone oil intraocular tamponade. Patient data was analysed at 18 months post-operatively. IBM SPSS 21 was used for data analysis. There were 52 male and 33 female patients aged between 22 and 70 years (45.2 ±16.2). After the first surgery, successful reattachment of the retina was achieved in 67 eyes (78.8%); of which 35 eyes were in 1000-centistoke and 32 eyes in 5000-centistoke groups. Mean pre-operative Best Corrected Visual Acuity (BCVA) was 1.63 ±0.54 which was improved to a mean post-operative BCVAof 1.46 ±0.78 (1.42 ±0.74 in 1000-centistoke group; 1.49 ±0.78 in 5000 centistoke group). The 1000-centistoke group had a significantly higher frequency of oil emulsification which necessitated early removal of silicone oil. There were 66 eyes (77%) with at least one complication (34 eyes in 1000-centistoke group; 32 eyes in 5000-centistoke group) including cataract, corneal abnormalities, raised IOP, hypotony, vitreous haemorrhage and retinal redetachment. Although visual and anatomical outcomes were comparable between the two groups, the 1000-centistoke silicone oil group developed early oil emulsification necessitating its early removal.

Lipopeptide biosurfactant from Bacillus thuringiensis pak2310: A potential antagonist against Fusarium oxysporum.

Science.gov (United States)

Deepak, R; Jayapradha, R

2015-03-01

The aims of the study were to evaluate the effects of a biosurfactant obtained from a novel Bacillus thuringiensis on Fusarium oxysporum to determine the morphological changes in the structure of the fungi and its biofilm in the presence of the biosurfactant and to evaluate the toxicity of the biosurfactant on HEp-2 human epithelial cell lines. The strain was screened and isolated from petroleum contaminated soil based on the E24 emulsification index. The biosurfactant was produced on glycerol, extracted using chloroform:methanol system and purified using HPLC. The purified fraction showing both surface activity (emulsification and oil-spread activity) and anti-fusarial activity (agar well diffusion method) was studied using FT-IR and MALDI-TOF MS, respectively. The minimum inhibitory concentration (MIC) and the biofilm inhibitory concentration (BIC) were determined using dilution method. The effect of biosurfactant on the morphology of Fusarium oxysporum was monitored using light microscopy and confocal laser scanning microscopy (for biofilm). The purified surfactant showed the presence of functional groups like that of surfactin in the FT-IR spectra and MALDI-TOF MS estimated the molecular weight as 700Da. The MIC and BIC were estimated to be 0.05 and 0.5mg/mL, respectively. The molecule was also non-toxic to HEp-2 cell lines at 10× MIC. A non-toxic and effective anti-Fusarium biosurfactant, that is both safe for human use and to the environment, has been characterized. The growth and metabolite production using glycerol (major byproduct of biodiesel and soap industries) also adds up to the efficiency and ecofriendly nature of this biosurfactant. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

IGF-1 release kinetics from chitosan microparticles fabricated using environmentally benign conditions

Energy Technology Data Exchange (ETDEWEB)

Mantripragada, Venkata P. [Biomedical Engineering Program, The University of Toledo, Toledo, OH 43614-5807 (United States); Jayasuriya, Ambalangodage C., E-mail: a.jayasuriya@utoledo.edu [Biomedical Engineering Program, The University of Toledo, Toledo, OH 43614-5807 (United States); Department of Orthopaedic Surgery, The University of Toledo, Toledo, OH 43614-5807 (United States)

2014-09-01

The main objective of this study is to maximize growth factor encapsulation efficiency into microparticles. The novelty of this study is to maximize the encapsulated growth factors into microparticles by minimizing the use of organic solvents and using relatively low temperatures. The microparticles were fabricated using chitosan biopolymer as a base polymer and cross-linked with tripolyphosphate (TPP). Insulin like-growth factor-1 (IGF-1) was encapsulated into microparticles to study release kinetics and bioactivity. In order to authenticate the harms of using organic solvents like hexane and acetone during microparticle preparation, IGF-1 encapsulated microparticles prepared by the emulsification and coacervation methods were compared. The microparticles fabricated by emulsification method have shown a significant decrease (p < 0.05) in IGF-1 encapsulation efficiency, and cumulative release during the two-week period. The biocompatibility of chitosan microparticles and the bioactivity of the released IGF-1 were determined in vitro by live/dead viability assay. The mineralization data observed with von Kossa assay, was supported by mRNA expression levels of osterix and runx2, which are transcription factors necessary for osteoblasts differentiation. Real time RT-PCR data showed an increased expression of runx2 and a decreased expression of osterix over time, indicating differentiating osteoblasts. Chitosan microparticles prepared in optimum environmental conditions are a promising controlled delivery system for cells to attach, proliferate, differentiate and mineralize, thereby acting as a suitable bone repairing material. - Highlights: • Coacervation chitosan microparticles were biocompatible and biodegradable. • IGF-1 encapsulation efficiency increased with coacervation chitosan microparticles. • Coacervation chitosan microparticles support osteoblast attachment and differentiation. • Coacervation chitosan microparticles support osteoblast mineralization.

Isolation and characterization of biosurfactant producing bacteria from Persian Gulf (Bushehr provenance)

International Nuclear Information System (INIS)

Hassanshahian, Mehdi

2014-01-01

Highlights: • Biosurfactant producing bacteria were isolated from Persian Gulf. • There is high diversity of biosurfactant producing bacteria in the Persian Gulf. • These bacteria are very useful for management of oil pollution in the sea. - Abstract: Biosurfactants are surface active materials that are produced by some microorganisms. These molecules increase biodegradation of insoluble pollutants. In this study sediments and seawater samples were collected from the coastline of Bushehr provenance in the Persian Gulf and their biosurfactant producing bacteria were isolated. Biosurfactant producing bacteria were isolated by using an enrichment method in Bushnell-Hass medium with diesel oil as the sole carbon source. Five screening tests were used for selection of Biosurfactant producing bacteria: hemolysis in blood agar, oil spreading, drop collapse, emulsification activity and Bacterial Adhesion to Hydrocarbon test (BATH). These bacteria were identified using biochemical and molecular methods. Eighty different colonies were isolated from the collected samples. The most biosurfactant producing isolates related to petrochemical plants of Khark Island. Fourteen biosurfactant producing bacteria were selected between these isolates and 7 isolates were screened as these were predominant producers that belong to Shewanella alga, Shewanella upenei, Vibrio furnissii, Gallaecimonas pentaromativorans, Brevibacterium epidermidis, Psychrobacter namhaensis and Pseudomonas fluorescens. The largest clear zone diameters in oil spreading were observed for G. pentaromativorans strain O15. Also, this strain has the best emulsification activity and reduction of surface tension, suggesting it is the best of thee isolated strains. The results of this study confirmed that there is high diversity of biosurfactant producing bacteria in marine ecosystem of Iran and by application of these bacteria in petrochemical waste water environmental problems can be assisted

IGF-1 release kinetics from chitosan microparticles fabricated using environmentally benign conditions

International Nuclear Information System (INIS)

Mantripragada, Venkata P.; Jayasuriya, Ambalangodage C.

2014-01-01

The main objective of this study is to maximize growth factor encapsulation efficiency into microparticles. The novelty of this study is to maximize the encapsulated growth factors into microparticles by minimizing the use of organic solvents and using relatively low temperatures. The microparticles were fabricated using chitosan biopolymer as a base polymer and cross-linked with tripolyphosphate (TPP). Insulin like-growth factor-1 (IGF-1) was encapsulated into microparticles to study release kinetics and bioactivity. In order to authenticate the harms of using organic solvents like hexane and acetone during microparticle preparation, IGF-1 encapsulated microparticles prepared by the emulsification and coacervation methods were compared. The microparticles fabricated by emulsification method have shown a significant decrease (p < 0.05) in IGF-1 encapsulation efficiency, and cumulative release during the two-week period. The biocompatibility of chitosan microparticles and the bioactivity of the released IGF-1 were determined in vitro by live/dead viability assay. The mineralization data observed with von Kossa assay, was supported by mRNA expression levels of osterix and runx2, which are transcription factors necessary for osteoblasts differentiation. Real time RT-PCR data showed an increased expression of runx2 and a decreased expression of osterix over time, indicating differentiating osteoblasts. Chitosan microparticles prepared in optimum environmental conditions are a promising controlled delivery system for cells to attach, proliferate, differentiate and mineralize, thereby acting as a suitable bone repairing material. - Highlights: • Coacervation chitosan microparticles were biocompatible and biodegradable. • IGF-1 encapsulation efficiency increased with coacervation chitosan microparticles. • Coacervation chitosan microparticles support osteoblast attachment and differentiation. • Coacervation chitosan microparticles support osteoblast mineralization

Estudos de biodegradação de óleo diesel por consórcio microbiano coletado em Porto Velho - RO, amazônia

Directory of Open Access Journals (Sweden)

Cleber C. Luz

2011-01-01

Full Text Available The goal of this research was to evaluate the biodegradation of diesel by a microbial consortium collected in a region close to distributors of fuel. The experiments were monitored by SPME-GC-FID and SPME-GC-MS. The consortium showed a high potential for production of biosurfactants, presenting an emulsification index of 53%. The consortium degraded completely n-alkanes, while dimethylnaphtalene, hepthyl-cyclohexane and 2,6,10-trimethyl-undecane were partially degraded and pristane was not degraded. From this consortium five strains were isolated and identified as Acinetobacter baumannii. Based on this initial investigation this consortium appears to be effective for bioremediation in Porto Velho - RO region.

Flavor retention of peppermint (Mentha piperita L.) essential oil spray-dried in modified starches during encapsulation and storage

DEFF Research Database (Denmark)

Baranauskiene, R.; Bylaite, Egle; Zukauskaite, J.

2007-01-01

The effect of different commercial modified food starch carrier materials on the flavor retention of the essential oil (EO) of peppermint (Mentha piperita L.) during spray drying and storage was evaluated. The obtained results revealed that the emulsification and encapsulation efficiencies...... individual compounds were observed. Larger differences in the compositions of surface oils from various encapsulation products were obtained. Flavor components were released at different rates by each of the encapsulated products. The aroma binding capacity of different modified starch matrices to lock EO...... droplets depends on the water activity, and the leakage of aromas from encapsulated powder products during storage increased with increasing water activity....

Pumice stones as potential in-situ burning enhancer

DEFF Research Database (Denmark)

Rojas Alva, U.; Andersen, Bjørn Skjønning; Jomaas, Grunde

2018-01-01

Small-scale and mid-scale experiments were conducted in order to evaluate pumice stones as a potential enhancement for in-situ burning (ISB). Four oil types, several emulsification degrees of one crude oil were studied. In general, it was observed that the pumice stones did not improve the burning...... and after the burn, thus bringing the oil into the water column. Finally, the species production of CO and CO2 was not reduced. Based on the presented results, pumice stones have a negative impact on the efficiency of ISB, and they are ruled out as an ISB enhancer and should not be used in relation to ISB....

Synthesis of mesoscale, crumpled, reduced graphene oxide roses by water-in-oil emulsion approach

Science.gov (United States)

Sharma, Shruti; Pham, Viet H.; Boscoboinik, Jorge A.; Camino, Fernando; Dickerson, James H.; Tannenbaum, Rina

2018-05-01

Mesoscale crumpled graphene oxide roses (GO roses) were synthesized by using colloidal graphene oxide (GO) variants as precursors for a hybrid emulsification-rapid evaporation approach. This process produced rose-like, spherical, reduced mesostructures of colloidal GO sheets, with corrugated surfaces and particle sizes tunable in the range of ∼800 nm to 15 μm. Excellent reproducibility for particle size distribution is shown for each selected speed of homogenizer rotor among different sample batches. The morphology and chemical structure of these produced GO roses was investigated using electron microscopy and spectroscopy techniques. The proposed synthesis route provides control over particle size, morphology and chemical properties of the synthesized GO roses.

Thermal properties and burning efficiency of crude oils and refined fuel oil

DEFF Research Database (Denmark)

van Gelderen, Laurens; Alva, Wilson Ulises Rojas; Mindykowski, Pierrick Anthony

2017-01-01

The thermal properties and burning efficiencies of fresh and weathered crude oils and a refined fuel oil were studied in order to improve the available input data for field ignition systems for the in-situ burning of crude oil on water. The time to ignition, surface temperature upon ignition, heat......-cooled holder for a cone calorimeter under incident heat fluxes of 0, 5, 10, 20, 30, 40 and 50 kW/m2. The results clearly showed that the weathered oils were the hardest to ignite, with increased ignition times and critical heat fluxes of 5-10 kW/m2. Evaporation and emulsification were shown...

Procedures in field systems for collecting and demulsifying crude oils

Energy Technology Data Exchange (ETDEWEB)

Vakhitov, G G; Graifer, V I; Tronov, V P; Zakirov, I G

1969-01-01

This microscopic study of crude oil emulsification and demulsification showed that the sooner an emulsion is chemically treated, the less its stability. This finding led to the practice of adding demulsifiers to the crude oil in pipelines. This method of demulsification is now used in Romashkino, Bablinsk, and Elkhovs fields. By this early addition of a chemical, the tendency of the pipeline to form stable, highly viscous emulsions is reduced. This treatment also facilitates separation of water from oil in storage tanks. Repeated tests have shown that pipeline demulsification is a highly effective and economic process. This method reduces crude oil dewatering costs by several hundred percent.

Alginate submicron beads prepared through w/o emulsification and gelation with CaCl2 nanoparticles

NARCIS (Netherlands)

Paques, J.P.; Linden, van der E.; Rijn, van C.J.M.; Sagis, L.M.C.

2013-01-01

A simple method for preparing gelled alginate beads with a diameter smaller than 5 µm is described. A 1% alginate solution and a medium chain triglyceride (MCT) oil are used to prepare a water-in-oil (w/o) emulsion, stabilized by polyglycerol polyricinoleate. CaCl2 nanoparticles with dimensions in

Biosurfactant production by yeasts isolated from hydrocarbon polluted environments.

Science.gov (United States)

Kaur, Kamalpreet; Sangwan, Seema; Kaur, Harpreet

2017-11-03

Thirty-two yeast isolates were retrieved from four soil samples collected from hydrocarbon-polluted locations of Hisar, Haryana, using enrichment culture technique with 1% (v/v) diesel as carbon source. Total nine isolates showing blood agar haemolysis were screened further for biosurfactant production. Yeast isolate, YK32, gave highest 8.4-cm oil displacement which was found to be significantly higher as compared to positive control, 0.2% (w/v) SDS (6.6 cm), followed by 6.2 and 6.0 cm by isolates YK20 and YK21, respectively. Maximum emulsification index was obtained in case of isolates YK20 and YK21 measuring 53.8%, after 6 days of incubation utilizing glucose as carbon source, whereas isolate YK32 was found to be reducing surface tension up to 93 dynes/cm and presented 99.6% degree of hydrophobicity. Olive oil has supported maximum surface tension reduction in isolates YK32 and YK21 equivalent to 53 and 48 dynes/cm and gave 88.3 and 88.5% degree of hydrophobicity, respectively. Diesel was not preferred as carbon source by most of the isolates except YK28 which generated 5.5-cm oil displacement, 25% emulsification index, reduced surface tension to the level of 38 dynes/cm and presented 89% degree of hydrophobicity. Conclusively, isolates YK20, YK21, YK22 and YK32 were marked as promising biosurfactant producers and were subjected to identification. Based on microscopic examination and biochemical peculiarities, isolates YK21 and YK22 might be identified as Candida spp., whereas, isolates YK20 and YK32 might be identified as Saccharomycopsis spp. and Brettanomyces spp., respectively. Interestingly it is the first report indicating Saccharomycopsis spp. and Brettanomyces spp. as a potential biosurfactant producer.

Isolation and identification of biosurfactant-producing strains from the genus Pseudomonas aeruginosa and antibacterial effects of biosurfactant production in vitro

Directory of Open Access Journals (Sweden)

Salman Ahmady-Asbchin

2013-01-01

Full Text Available Introduction: Biosurfactants are amphiphilic biological compounds produced extracellularly or as part of the cell membranes by a variety of microorganisms. Because of their use in various industries, they are of a particular importance. The aim of this study was to identify a strain of bacteria of the genus Pseudomonas aeruginosa biosurfactant producers. Materials and methods: In this study, different samples of oil, water and soil contaminated with oil were prepared. Hemolytic activity, emulsification activity and measurement of surface tension were used and selected strains were identified by biochemical tests. The nature and effect of antibacterial biosurfactant was evaluated for strain selection.Results: In this study, eighty eight bacterial strains were isolated. Twenty four strains were isolated from the isolated strains with hemolytic activity. Among which, 14 strains have emulsification activity more than 70% and at last four strains reached surface tension to be less than 40 mN/m. Selected strain based on biochemical tests was recognized as a Pseudomonas aeruginosa. The nature of biosurfactant was determined by TLC, and proved to be of glycolipid kind. Therefore, the produced biosurfactant of the selected strain had antibacterial activity against six bacterial infectious. Sensitive bacteria to the effects of biosurfactant extract of Pseudomonas aeruginosa83, was Staphylococcus aureus and the most resistant bacteria to these extract, was the Proteus mirabilis. The results of MIC, MBC showed that MIC of the extract in concentration of 63 and 125 mg/ml on Escherichia coli, Staphylococcus epidermidis and Staphylococcus aureus respectively. Also, the MBC were extract in concentration of 63 and 125mg/ml on Staphylococcus epidermidis and Staphylococcus aureus respectively.Discussion and conclusion: Pseudomonas aeruginosa had high potential in reducing the surface tension and biosurfactant extracted had high antibacterial effects. Therefore, it

Application of power ultrasound in radiochemistry

International Nuclear Information System (INIS)

Moisy, Ph.; Venault, L.; Blanc, P.; Madic, C.; Nikitenko, S.

1998-01-01

The chemical effects of ultrasound are related to cavitation process: nucleation, bubble growth and cavitation collapse. Sono-chemical reactions occur due to the rapid heating of the contents of cavitation bubbles. The shock-waves generated by cavitation collapse cause intense emulsification of the immiscible liquids. The CEA/Marcoule research group investigated the effect of power ultrasound on the homogeneous and heterogeneous (liquid-liquid) actinide reactions, in aqueous nitric acid media. It was found that U(IV), Np(V) and Pu(III) can be rapidly oxidized in HNO 3 solutions by HNO 2 , generated by the effect of power ultrasound on HNO 3 solutions. HNO 2 , formed during HNO 3 sono-lysis, decomposes hydrazinium nitrate within the cavitation bubbles. This makes it possible to the control actinide oxidation states without adding any side chemical reagents (NaNO 2 , for example). The quantitative data on the effect in the ultrasonic field in nitric acid medium are discussed, and sono-chemical mechanisms are proposed for nitrous acid formation and hydrazinium nitrate decomposition. In the presence of anti-nitrous reagents, such as hydrazinium nitrate and sulfamic acid, U(IV) was found to be oxidized and Pu(IV) reduced by H 2 O 2 formed as the result of aqueous nitric acid sono-lysis. The kinetics of H 2 O 2 formation is faster than in water, for the same sono-chemical conditions. Np(V) is rapidly oxidized, by aqueous phase HNO 2 , under the effect of ultrasound on the two-phase system TBP-dodecane/HNO 3 . Intense emulsification of the liquid/liquid system accelerates the mass transfer, of Np(VI) formed, into the organic phase. The quantitative effect of power ultrasound in aqueous nitric acid, with or without anti-nitrous reagents, can be used to predict the behavior of actinides in the ultrasonic field in nitric acid medium. (author)

"Self-Shaping" of Multicomponent Drops.

Science.gov (United States)

Cholakova, Diana; Valkova, Zhulieta; Tcholakova, Slavka; Denkov, Nikolai; Smoukov, Stoyan K

2017-06-13

In our recent study we showed that single-component emulsion drops, stabilized by proper surfactants, can spontaneously break symmetry and transform into various polygonal shapes during cooling [ Denkov Nature 2015 , 528 , 392 - 395 ]. This process involves the formation of a plastic rotator phase of self-assembled oil molecules beneath the drop surface. The plastic phase spontaneously forms a frame of plastic rods at the oil drop perimeter which supports the polygonal shapes. However, most of the common substances used in industry appear as mixtures of molecules rather than pure substances. Here we present a systematic study of the ability of multicomponent emulsion drops to deform upon cooling. The observed trends can be summarized as follows: (1) The general drop-shape evolution for multicomponent drops during cooling is the same as with single-component drops; however, some additional shapes are observed. (2) Preservation of the particle shape upon freezing is possible for alkane mixtures with chain length difference Δn ≤ 4; for greater Δn, phase separation within the droplet is observed. (3) Multicomponent particles prepared from alkanes with Δn ≤ 4 plastify upon cooling due to the formation of a bulk rotator phase within the particles. (4) If a compound, which cannot induce self-shaping when pure, is mixed with a certain amount of a compound which induces self-shaping, then drops prepared from this mixture can also self-shape upon cooling. (5) Self-emulsification phenomena are also observed for multicomponent drops. In addition to the three recently reported mechanisms of self-emulsification [ Tcholakova Nat. Commun. 2017 , ( 8 ), 15012 ], a new (fourth) mechanism is observed upon freezing for alkane mixtures with Δn > 4. It involves disintegration of the particles due to a phase separation of alkanes upon freezing.

Cyclic lipopeptide signature as fingerprinting for the screening of halotolerant Bacillus strains towards microbial enhanced oil recovery.

Science.gov (United States)

Farias, Bárbara C S; Hissa, Denise C; do Nascimento, Camila T M; Oliveira, Samuel A; Zampieri, Davila; Eberlin, Marcos N; Migueleti, Deivid L S; Martins, Luiz F; Sousa, Maíra P; Moyses, Danuza N; Melo, Vânia M M

2018-02-01

Cyclic lipopeptides (CLPs) are non-ribosomal biosurfactants produced by Bacillus species that exhibit outstanding interfacial activity. The synthesis of CLPs is under genetic and environmental influence, and representatives from different families are generally co-produced, generating isoforms that differ in chemical structure and biological activities. This study to evaluate the effect of low and high NaCl concentrations on the composition and surface activity of CLPs produced by Bacillus strains TIM27, TIM49, TIM68, and ICA13 towards microbial enhanced oil recovery (MEOR). The strains were evaluated in mineral medium containing NaCl 2.7, 66, or 100 g L -1 and growth, surface tension and emulsification activity were monitored. Based on the analysis of 16S rDNA, gyrB and rpoB sequences TIM27 and TIM49 were assigned to Bacillus subtilis, TIM68 to Bacillus vallismortis, and ICA13 to Bacillus amyloliquefaciens. All strains tolerated up to 100-g L -1 NaCl, but only TIM49 and TIM68 were able to reduce surface tension at this concentration. TIM49 also showed emulsification activity at concentrations up to 66-g L -1 NaCl. ESI-MS analysis showed that the strains produced a mixture of CLPs, which presented distinct CLP profiles at low and high NaCl concentrations. High NaCl concentration favored the synthesis of surfactins and/or fengycins that correlated with the surface activities of TIM49 and TIM68, whereas low concentration favored the synthesis of iturins. Taken together, these findings suggest that the determination of CLP signatures under the expected condition of oil reservoirs can be useful in the guidance for choosing well-suited strains to MEOR.

PLGA nanoparticles from nano-emulsion templating as imaging agents: Versatile technology to obtain nanoparticles loaded with fluorescent dyes.

Science.gov (United States)

Fornaguera, C; Feiner-Gracia, N; Calderó, G; García-Celma, M J; Solans, C

2016-11-01

The interest in polymeric nanoparticles as imaging systems for biomedical applications has increased notably in the last decades. In this work, PLGA nanoparticles, prepared from nano-emulsion templating, have been used to prepare novel fluorescent imaging agents. Two model fluorescent dyes were chosen and dissolved in the oil phase of the nano-emulsions together with PLGA. Nano-emulsions were prepared by the phase inversion composition (PIC) low-energy method. Fluorescent dye-loaded nanoparticles were obtained by solvent evaporation of nano-emulsion templates. PLGA nanoparticles loaded with the fluorescent dyes showed hydrodynamic radii lower than 40nm; markedly lower than those reported in previous studies. The small nanoparticle size was attributed to the nano-emulsification strategy used. PLGA nanoparticles showed negative surface charge and enough stability to be used for biomedical imaging purposes. Encapsulation efficiencies were higher than 99%, which was also attributed to the nano-emulsification approach as well as to the low solubility of the dyes in the aqueous component. Release kinetics of both fluorescent dyes from the nanoparticle dispersions was pH-independent and sustained. These results indicate that the dyes could remain encapsulated enough time to reach any organ and that the decrease of the pH produced during cell internalization by the endocytic route would not affect their release. Therefore, it can be assumed that these nanoparticles are appropriate as systemic imaging agents. In addition, in vitro toxicity tests showed that nanoparticles are non-cytotoxic. Consequently, it can be concluded that the preparation of PLGA nanoparticles from nano-emulsion templating represents a very versatile technology that enables obtaining biocompatible, biodegradable and safe imaging agents suitable for biomedical purposes. Copyright © 2016 Elsevier B.V. All rights reserved.

Enhanced delivery of PEAL nanoparticles with ultrasound targeted microbubble destruction mediated siRNA transfection in human MCF-7/S and MCF-7/ADR cells in vitro

Directory of Open Access Journals (Sweden)

Teng Y

2015-08-01

Full Text Available Yanwei Teng,1,2,* Min Bai,3,* Ying Sun,2 Qi Wang,1,2 Fan Li,3 Jinfang Xing,3 Lianfang Du,3 Tao Gong,1 Yourong Duan2 1Key Laboratory of Drug Targeting and Novel Drug Delivery Systems, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, People’s Republic of China; 2State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, People’s Republic of China; 3Department of Ultrasound, Shanghai First People’s Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: The gene knockdown activity of small interfering RNA (siRNA has led to their use as potential therapeutics for a variety of diseases. However, successful gene therapy requires safe and efficient delivery systems. In this study, we choose mPEG-PLGA-PLL nanoparticles (PEAL NPs with ultrasound targeted microbubble destruction (UTMD to efficiently deliver siRNA into cells. An emulsification-solvent evaporation method was used to prepare siRNA-loaded PEAL NPs. The NPs possessed an average size of 132.6±10.3 nm (n=5, with a uniform spherical shape, and had an encapsulation efficiency (EE of more than 98%. As demonstrated by MTT assay, neither PEAL NPs nor siRNA-loaded PEAL NPs showed cytotoxicity even at high concentrations. The results of cellular uptake showed, with the assistance of UTMD, the siRNA-loaded PEAL NPs can be effectively internalized and can subsequently release siRNA in cells. Taken together, PEAL NPs with UTMD may be highly promising for siRNA delivery, making it possible to fully exploit the potential of siRNA-based therapeutics. Keywords: gene delivery, mPEG-PLGA-PLL, UTMD, emulsification-solvent evaporation method, orthogonal design

MODEL SYSTEM EVALUATIONS OF MEAT EMULSIONS PREPARED WITH DIFFERENT EDIBLE BEEF BY PRODUCTS AND FATS AND OIL

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Mustafa KARAKAYA

1997-02-01

Full Text Available Emulsion parameters of different meat by-products (beef head-meat, beef heart and liver and animal fats and oil (beef fat, mutton fat, sheep tail-fat and corn oil were studied in a model system. The results of the study showed that the highest emulsion capacity (EC was with the heart meat and beef fat emulsion while the lowest EC was measured in the beef head-meat and sheep tail-fat combination. Corn oil gave the best emulsification with beef head-meat and liver, and beef fat resulted the second best results. Beef head-meat gave the most stable emulsion with all fats, but the emulsions prepared with heart and liver were generally unstable.

OSIS: A Windows 3 Oil Spill Information System

International Nuclear Information System (INIS)

Leech, M.; Walker, M.; Wiltshire, M.; Tyler, A.

1993-01-01

An oil spill modelling and analysis system called the Oil Spill Information System (OSIS) has recently been developed. OSIS uses a model of oceanographic processes to predict three-dimensional spreading and transport of an oil slick under the influence of wind, waves, tide, turbulence, and shear diffusion. Oil weathering and fate processes of emulsification, evaporation, and dispersion are also simulated. The physical models have been tested against data obtained from sea trials and spill incidents. OSIS uses an object-oriented programming technique and presents model output as maps, graphs, and tables in multiple windows and can link to other Windows packages to create a suite of spill information management tools. 15 refs., 12 figs

Lubricant for corrosion protection of the inner chambers of internal combustion engines. Schutzschmiermittel zum Korrosionsschutz der Innenraeume von Verbrennungsmotoren

Energy Technology Data Exchange (ETDEWEB)

Ettig, A.; Ferke, M.; Fueloep, J.; Gal, L.; Gyoengyoessy, L.; Horvath, R.; Keresztessy, Z.; Keresztessy, M.; Papp, I.

1987-09-17

The invention is concerned with lubricants for corrosion protecion in internal combustion engines which contain (a) 85 to 99 weight-% of a base oil and/or engine oil, (b) 0.1 to 1.0 weight-% of a corrosion and simultaneously emulsification inhibitor from a monoester, diester or triester of fatty acids with a double bond, (c) 0.1 to 6.0 weight-% of an additive improving the viscosity index and adhesiveness, from a polyolefin or olefin copolymer or a polyacrylic or polymethacrylic acid ester and also, if necessary (d) 0.1 to 8.0 weight-% of a detergent additive with neutralizing effect. The effect of these protective lubricants is by far better as of those known up to now.

Ecotoxicological testing of performance fluids

International Nuclear Information System (INIS)

Kallqvist, T.

1990-05-01

The report deals with a project comprising the testing of drilling fluids concerning ecotoxicology, biological degradation, and toxicity. Two types of drilling fluids were tested for toxic effects on marine algae and biological degradability. A fluid based on mineral oil was readily degradable (98% DOC removal in 28 days) while an ether based oil degraded more slowly (56% DOC removal in 28 days). The toxicity of both fluids was tested after emulsification of the oils in water and separating the oil and water phase after equilibration. The EC 50 values obtained with this approach were 8.15 g/l for the oil based fluid and 116 g/l for the ether fluid. 9 figs., 8 tabs

LATIS3D The Gold Standard for Laser-Tissue-Interaction Modeling

CERN Document Server

London, R A; Gentile, N A; Kim, B M; Makarewicz, A M; Vincent, L; Yang, Y B

2000-01-01

The goal of this LDRD project has been to create LATIS3D--the world's premier computer program for laser-tissue interaction modeling. The development was based on recent experience with the 2D LATIS code and the ASCI code, KULL. With LATIS3D, important applications in laser medical therapy were researched including dynamical calculations of tissue emulsification and ablation, photothermal therapy, and photon transport for photodynamic therapy. This project also enhanced LLNL's core competency in laser-matter interactions and high-energy-density physics by pushing simulation codes into new parameter regimes and by attracting external expertise. This will benefit both existing LLNL programs such as ICF and SBSS and emerging programs in medical technology and other laser applications.

Encapsulation of Antifouling Organic Biocides in Poly(lactic acid) Nanoparticles.

Science.gov (United States)

Kamtsikakis, Aristotelis; Kavetsou, Eleni; Chronaki, Konstantina; Kiosidou, Evangelia; Pavlatou, Evangelia; Karana, Alexandra; Papaspyrides, Constantine; Detsi, Anastasia; Karantonis, Antonis; Vouyiouka, Stamatina

2017-09-26

The scope of the current research was to assess the feasibility of encapsulating three commercial antifouling compounds, Irgarol 1051, Econea and Zinc pyrithione, in biodegradable poly(lactic acid) (PLA) nanoparticles. The emulsification-solvent evaporation technique was herein utilized to manufacture nanoparticles with a biocide:polymer ratio of 40%. The loaded nanoparticles were analyzed for their size and size distribution, zeta potential, encapsulation efficiency and thermal properties, while the relevant physicochemical characteristics were correlated to biocide-polymer system. In addition, the encapsulation process was scaled up and the prepared nanoparticles were dispersed in a water-based antifouling paint in order to examine the viability of incorporating nanoparticles in such coatings. Metallic specimens were coated with the nanoparticles-containing paint and examined regarding surface morphology.

Experimental use of produced waters for waterflooding fields of Kuibyshev region

Energy Technology Data Exchange (ETDEWEB)

Palii, P A; Gavura, V E; Redkin, I I; Sokolov, A G

1970-01-01

Large volumes of produced waters have been used for waterflooding in the Kuibyshev region. Before underground injection, the water is conditioned by short-term storage. The treated water contains emulsified oil, suspended solids, hydrogen sulfide, and ferrous iron. This water is readily injected into fractured porous formations, even if suspended solids reach 42 mg/liter and emulsifed oil 67 mg/liter. However, better quality water has to be injected into nonfractured formations. In this case, the concentration of emulsified oil and suspended solids needs to be kept below 5 mg/liter. If concentration of suspended material exceeds this limit, water injectivity decreases rapidly. The partially plugged wells can be restored by acid treatment. Water injection has shown large economic gains in this region.

Research on a dispersing solution for burnt crude oils: Aegean Sea oil spill

International Nuclear Information System (INIS)

Bergueiro, J.R.; Morales, N.; Dominguez, F.

1993-01-01

The oil tanker Aegean Sea spilled oil when it grounded during severe storm conditions near La Coruna, Spain. Much of the oil burned after an explosion was caused by the hull breaking apart. Oil which contaminated several beaches was affected by both combustion and weathering. Experiments were conducted on oil sampled from the beaches to investigate dispersion of the oil using Beep Enersperse 1990 at different shaking speeds. Biodegradation experiments were also conducted in the presence of Beep Enersperse 1990 but with seawater absent. Although emulsification of the burnt and weathered oil was very difficult, good dispersion and biodegradation were obtained. After 42 d in a stirred reactor, biodegradation of the oil reached at least 80%. 3 refs., 3 figs., 4 tabs

LATIS3D: The Gold Standard for Laser-Tissue-Interaction Modeling

International Nuclear Information System (INIS)

London, R.A.; Makarewicz, A.M.; Kim, B.M.; Gentile, N.A.; Yang, Y.B.; Brlik, M.; Vincent, L.

2000-01-01

The goal of this LDRD project has been to create LATIS3D--the world's premier computer program for laser-tissue interaction modeling. The development was based on recent experience with the 2D LATIS code and the ASCI code, KULL. With LATIS3D, important applications in laser medical therapy were researched including dynamical calculations of tissue emulsification and ablation, photothermal therapy, and photon transport for photodynamic therapy. This project also enhanced LLNL's core competency in laser-matter interactions and high-energy-density physics by pushing simulation codes into new parameter regimes and by attracting external expertise. This will benefit both existing LLNL programs such as ICF and SBSS and emerging programs in medical technology and other laser applications

Extraction of Uranium with Amin as solvent and HCl as internal phase at membrane emulsion

International Nuclear Information System (INIS)

Ninik Bintarti, A.; Bambang-Edi-HB; Sudibyo, R.

1996-01-01

An extraction process of uranium by Tri-n-Actylamine(TOA) solution with kerosene as thinner and surfactant of Span-80 as emulgator to bend a membrane emulsion. HCI 0.01 N is used as an internal phase uranium in HNO 3 as feed and butanol is used to split the membrane. In the case of membrane, the result was 1 % vol. TOA and 5 % vol. Span-80, emulsification time was 30 minutes and 50 % vol. HCI 0.01 N. The product of an extraction was concentration of HNO 3 is 3 M. The time of extraction 20 minutes and uranium concentration in feed of 600 ppm will give distribution coefficient of membrane extraction was 5.830 and coefficient of stripping was 0.276

Maillard-Reaction-Functionalized Egg Ovalbumin Stabilizes Oil Nanoemulsions.

Science.gov (United States)

Liu, Gang; Yuan, Dan; Wang, Qi; Li, Wanrong; Cai, Jie; Li, Shuyi; Lamikanra, Olusola; Qin, Xinguang

2018-04-25

Egg white proteins are an excellent source of nutrition, with high biological and technological values. However, their limited functional properties prevent their widespread industrial applications. In this study, the ovalbumin functionality was improved via glycation by Maillard reaction with d-lactose. The free amino groups and sodium dodecyl sulfate-polyacrylamide gel electrophoresis profile were determined, confirming that glycation occurred between ovalbumin and lactose. The emulsification of the conjugate was 2.69-fold higher than that of ovalbumin at pH 7.0 after glycation. The thermal stability also improved remarkably. The glycated protein products were used to form an oil-water nanoemulsion for polymethoxyflavone-rich aged orange peel oil. The resulting nanoemulsion showed good pH, thermal, and storage stabilities.

Ultrasonication and food technology: A review

Directory of Open Access Journals (Sweden)

Ishrat Majid

2015-12-01

Full Text Available With increasing consumers demand and tightening of food and environmental regulations, traditional food-processing techniques have lost their optimum performance which gave rise to new and powerful technologies. Ultrasonic is a one of the fast, versatile, emerging, and promising non-destructive green technology used in the food industry from last few years. The ultrasound is being carried out in various areas of food technology namely crystallization, freezing, bleaching, degassing, extraction, drying, filtration, emulsification, sterilization, cutting, etc. Ultrasound is being applied as an effective preservation tool in many food-processing fields viz. vegetables and fruits, cereal products, honey, gels, proteins, enzymes, microbial inactivation, cereal technology, water treatment, diary technology, etc. This review summarizes the latest knowledge on impact and application of ultrasound in food technology.

Micro-emulsification/encapsulation of krill oil by complex coacervation with krill protein isolated using isoelectric solubilization/precipitation.

Science.gov (United States)

Shi, Liu; Beamer, Sarah K; Yang, Hong; Jaczynski, Jacek

2018-04-01

This study determined feasibility of krill protein isolated with isoelectric solubilization/precipitation (ISP) as wall material to microencapsulate krill oil by freeze-drying. Effects of krill oil/krill protein ratio on properties of microcapsules were investigated. With increased ratio, crude protein of microcapsules decreased, while total lipid increased. Although microcapsule oil loading capacity increased, loading and encapsulation efficiencies decreased. Thin layer chromatography (TLC) confirmed abundance of phospholipids, which are amphiphilic; and thus, resulted in stable emulsion (emulsion stability index). Microcapsules contained ω-3 polyunsaturated fatty acids (PUFAs) at 43-60, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) at 28-41 and 9-11 g/100g of total FAs, respectively. SDS-PAGE electrophoresis revealed proteolysis of ISP krill protein, probably causing reduced loading and encapsulation efficiencies. SEM showed that krill oil/krill protein ratio affected surface microstructure. ISP krill protein showed potential as a wall material to microencapsulate krill oil; and thus, expand application of krill oil/protein for human consumption. Copyright © 2017 Elsevier Ltd. All rights reserved.

Emulsification as an approach to the introduction of methanol/gasoline blends as a motor fuel in Canada

Energy Technology Data Exchange (ETDEWEB)

1982-10-29

This report summarizes the work on a phase of a program which concentrates on the utilization of methanol-gasoline mixtures in spark-ignition engines. A fuel system having components for a 2.5 liter engine equipped with an oxygen sensor controlled carburetor, described in another report, was further developed. Extended cold start tests were carried out and the maximum amount of methanol that could be tolerated by the fuel system , without imparing engine operation, was 30% methanol in gasoline on a volume basis. The engine was installed in an automobile and road tests were conducted concentrating on cold starts and warm-up, fuel system performance, fuel economy and materials compatibility of components exposed to the methanol-gasoline blend. A second phase separation control system was developed for a 2.1 liter displacement engine equipped with a mechanical fuel injection system. The proportioning and pick-up components for the tank were incorporated in the existing fuel system. Cold start tests were performed and 20% methanol was found to be the upper limit. The engine was installed and the vehicle were road tested. Minor shortcomings identified during road testing were corrected. Overall performance and driveability of both vehicles were found acceptable. However, testing under low ambient temperature conditions remains to be done. 2 refs., 37 figs., 8 tabs.

Optimization, ex vivo permeation, and stability study of lipid nanocarrier loaded gelatin capsules for treatment of intermittent claudication

Directory of Open Access Journals (Sweden)

Sallam MA

2015-07-01

Full Text Available Marwa Ahmed Sallam,1 María Teresa Marín Boscá21Department of Industrial Pharmacy, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt; 2Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Granada University, Granada, Spain Abstract: In this study, an optimized nanodispersible oral dosage form (containing a lactate ester was developed for cilostazol (CZL. CZL is a phosphodiesterase inhibitor used for intermittent claudication. We aimed to improve the dissolution rate and absorption of CZL giving it a better chance of oral bioavailability, and to evaluate its stability on storage. Suitable compositions of nanoemulsion preconcentrate formulations were screened via solubility and compatibility tests. Response surface methodology and a desirability approach were applied to optimize preconcentrates containing minimum amount of surfactant mixture, maximum amount of lipid, and possessing the smallest globule size, with the highest emulsification and dissolution rates and minimum risk of drug precipitation. As part of the optimization process, the main effect, interaction effects and quadratic effects of amounts of lipid, and surfactant/co-surfactant ratio on % transmittance, globule size, emulsification time, drug precipitation, and drug release were investigated. The optimized formulation consisting of 28.9% butyl lactate, 28.9% Capryol®, 27.82% Solubilisant Gamma® 2429, and 14.18% Transcutol® possessing a globule size of 60 nm was mixed with Aerosil® 200. This gave uniform free flowing granules, which were characterized for surface and powder properties. The self-nanoemulsifying granules (SNEGs filled into hard gelatin capsules showed two- and threefold increase in CZL released compared with conventional tablet and pure drug, respectively. The amount of drug permeated using non-everted sac technique from the SNEGs was twofold higher than that permeated from the tablet suspension. The shelf life was 526 days at

Theoretical and Experimental Studies of Dissimilar Secondary Metallurgy Methods for Improving Steel Cleanliness

Science.gov (United States)

Pitts-Baggett, April

Due to a continual increasing industry demand for clean steels, a multi-depth sampling approach was developed to gain a more detailed depiction of the reactions occurring in the ladle throughout the Ladle Metallurgy Furnace (LMF) processing. This sampling technique allows for the ability for samples to be reached at depths, which have not been able to be captured before, of approximately 1.5 m below the slag layer. These samples were also taken in conjunction with samples taken just under the slag layer as well as in between those samples. Additional samples were also taken during the processing including multi-point slag sampling. The heats were divided in to five key processing steps: Start of heat (S), after Alloying (A), after desulfurization/start of pre-Rinse (R), prior to Ca treatment (C), and End of heat (E). Sampling sets were collected to compare the effects of silicon, desulfurization rates, slag emulsification, slag evolution and inclusion evolution. By gaining the ability to gather multiple depths, it was determined that the slag emulsification has the ability to follow the flow pattern of the ladle deeper into the ladle than previously seen in literature. Inclusion evolution has been shown by numerous researchers; however, this study showed differences in the inclusion grouping and distribution at the different depths of the ladle through Automated Feature Analysis (AFA). Also, the inclusion path was seen to change depending on both the silicon content and the sulfur content of the steel. This method was applied to develop a desulfurization model at Nucor Steel Tuscaloosa, Inc. (NSTI). In addition to a desulfurization model, a calcium (Ca) model was also developed. The Ca model was applied to target a finished inclusion region based on the conditions up to the wire treatment. These conditions included time, silicon content, and sulfur concentration. Due to the inability of this model to handle every process variable, a new procedure was created to

Feasibility Of Coupling Permeable Bio-Barriers And Electrokinetics For The Treatment Of Diesel Hydrocarbons Polluted Soils

International Nuclear Information System (INIS)

Ramírez, Esperanza Mena; Jiménez, Cristina Sáez; Camacho, José Villaseñor; Rodrigo, Manuel A.Rodrigo; Cañizares, Pablo

2015-01-01

Highlights: • Electrokinetics and a biobarrier were combined to remediate of a diesel polluted soil. • pH gradients did not affect the biobarrier activity located in soil central position. • Microorganisms were partially detached from the biobarrier and moved across the soil. • An anionic surfactant helped the contact between pollutant and microorganisms. • A 39% of the diesel biodegradable fraction was homogeneously removed across the soil. - Abstract: In this study, the remediation of a diesel hydrocarbon-polluted clay soil using an electrochemical-biological combined technology is assessed. The polluted soil was subjected to an electrokinetic (EK) treatment with a biological permeable reactive barrier. A lab-scale electrochemical cell for soil treatment was used. The biological barrier placed in the soil was a biofilm reactor previously adapted for diesel degradation. A batch experiment of 336 h was conducted in a synthetic clay soil spiked with 10 g·kg −1 of diesel and a constant voltage gradient of 1.0 V cm −1 . Sodium dodecyl sulphate was used as an anionic surfactant in the cathodic well to allow for hydrocarbon emulsification during the treatment. At the end of the experiment, extreme pH values were observed near the electrodes. However, the pH remained constant at approximately 7.7 in the central biobarrier zone, which allowed for biological processes. Biological growth was observed in the biobarrier, and a part of the biofilm was detached and transported through the soil in both directions. Furthermore, the surfactant was transported across the soil due to electromigration and electroosmosis, which resulted in diesel emulsification. The combination of biological and EK phenomena finally resulted in a homogenous hydrocarbon removal of approximately 27% in the polluted soil, which indicated a 39% removal of the diesel biodegradable fraction. Due to the electroosmotic flow and the biological degradation, some of the water, surfactant and

Sono-leather technology with ultrasound: a boon for unit operations in leather processing - review of our research work at Central Leather Research Institute (CLRI), India.

Science.gov (United States)

Sivakumar, Venkatasubramanian; Swaminathan, Gopalaraman; Rao, Paruchuri Gangadhar; Ramasami, Thirumalachari

2009-01-01

Ultrasound is a sound wave with a frequency above the human audible range of 16 Hz to 16 kHz. In recent years, numerous unit operations involving physical as well as chemical processes are reported to have been enhanced by ultrasonic irradiation. There have been benefits such as improvement in process efficiency, process time reduction, performing the processes under milder conditions and avoiding the use of some toxic chemicals to achieve cleaner processing. These could be a better way of augmentation for the processes as an advanced technique. The important point here is that ultrasonic irradiation is physical method activation rather than using chemical entities. Detailed studies have been made in the unit operations related to leather such as diffusion rate enhancement through porous leather matrix, cleaning, degreasing, tanning, dyeing, fatliquoring, oil-water emulsification process and solid-liquid tannin extraction from vegetable tanning materials as well as in precipitation reaction in wastewater treatment. The fundamental mechanism involved in these processes is ultrasonic cavitation in liquid media. In addition to this there also exist some process specific mechanisms for the enhancement of the processes. For instance, possible real-time reversible pore-size changes during ultrasound propagation through skin/leather matrix could be a reason for diffusion rate enhancement in leather processing as reported for the first time. Exhaustive scientific research work has been carried out in this area by our group working in Chemical Engineering Division of CLRI and most of these benefits have been proven with publications in valued peer-reviewed international journals. The overall results indicate that about 2-5-fold increase in the process efficiency due to ultrasound under the given process conditions for various unit operations with additional benefits. Scale-up studies are underway for converting these concepts in to a real viable larger scale operation. In

Efficacy of Ultrasonic Homogenization in the Separation of Benzene-n-Heptane Mixture by Liquid Membrane

Energy Technology Data Exchange (ETDEWEB)

Kim, B.S.; Chung, T.S. [Department of Chemical Engineering, Sung Kyun Kwan University, Seoul (Korea)

1999-04-01

In the separation of benzene-n-heptane mixture by liquid membrane, the efficacy of ultrasonic homogenization in emulsification was studied with two anionic surfactants. The two anionic surfactants used were triethanolamine lauryl sulfate and sodium polyoxyethylene(2) lauryl ether sulfate. The two anionic surfactants used were triethanolamine lauryl sulfate and sodium polyoxyethylene(2) lauryl ether stifle. The highest value of the separation factor obtained by ultrasonic homogenization was approximately three times as large as that for triethanolamine lauryl sulfate and one and a half times as large as that for sodium polyoxyethylene(2) lauryl sulfate when the mechanical stirring was used on the same operational conditions. The lowest membrane breakup was observed when the highest value of the separation factor was achieved with sodium polyoxyethylene(2) lauryl sulfate. 14 refs., 7 figs., 1 tab.

A Comparison between Use of Spray and Freeze Drying Techniques for Preparation of Solid Self-Microemulsifying Formulation of Valsartan and In Vitro and In Vivo Evaluation

Science.gov (United States)

Singh, Sanjay Kumar; Vuddanda, Parameswara Rao; Singh, Sanjay; Srivastava, Anand Kumar

2013-01-01

The objective of the present study was to develop self micro emulsifying formulation (SMEF) of valsartan to improve its oral bioavailability. The formulations were screened on the basis of solubility, stability, emulsification efficiency, particle size and zeta potential. The optimized liquid SMEF contains valsartan (20% w/w), Capmul MCM C8 (16% w/w), Tween 80 (42.66% w/w) and PEG 400 (21.33% w/w) as drug, oil, surfactant and co-surfactant, respectively. Further, Liquid SMEF was adsorbed on Aerosol 200 by spray and freeze drying methods in the ratio of 2 : 1 and transformed into free flowing powder. Both the optimized liquid and solid SMEF had the particle size valsartan as compared to existing formulations with improved bioavailability. PMID:23971048

Early Decomposition of Retained Heavy Silicone Oil Droplets

Directory of Open Access Journals (Sweden)

Touka Banaee

2012-01-01

Full Text Available Purpose: To report a case of early decomposition of retained heavy silicone oil droplets. Case Report: The single highly myopic eye of a 16-year-old boy with history of scleral buckling and buckle revision developed redetachment due to inferior retinal dialysis. The patient underwent pars plana vitrectomy and injection of heavy silicone oil. Early emulsification of the silicone oil was observed following surgery, which was removed 4 weeks later in another operation. Retained heavy silicone droplets lost their heavier- than-water specific gravity within 2 months together with extensive iris depigmentation, and release of pigment granules into the anterior chamber and vitreous cavity. Conclusion: This case report demonstrates that heavy silicone oil droplets can undergo in vivo chemical decomposition with possible toxic effects on ocular tissues.

[Anti-tumor effects of DDP-PLLA-CNTs on human cholangiocarcinoma cell line in vitro].

Science.gov (United States)

Li, Maolan; Lu, Wei; Zhang, Fei; Ding, Qichen; Wu, Xiangsong; Tan, Zhujun; Wu, Wenguang; Weng, Hao; Wang, Xuefeng; Shi, Weibin; Dong, Ping; Gu, Jun; Liu, Yingbin

2014-11-04

To explore the antitumor effects of DDP-PLLA-CNTs on human cholangiocarcinoma cell line. DDP-PLLA-CNTs were prepared with the method of ultrasound emulsification. The morphology of DDP-PLLA-CNTs was determined by scanning electron microscope (SEM). And its drug loading and drug release curve in vitro was detected by UV-Vis-NIR spectrophotometer. CCK8 was used to test the cytotoxic effects of DDP-PLLA-CNTs at different concentrations on QBC939 cell proliferation.Flow cytometry was employed to measure the changes of apoptotic rate. With excellent controlled-release characteristic of in vitro drug release, DDP-PLLA-CNTs inhibited the proliferation and significantly increased the apoptotic rate of QBC939 cell line. DDP-PLLA-CNTs have drug sustained-release characteristics and can significantly inhibit the proliferation of QBC939 cell line.

Formulation of poorly water-soluble Gemfibrozil applying power ultrasound.

Science.gov (United States)

Ambrus, R; Naghipour Amirzadi, N; Aigner, Z; Szabó-Révész, P

2012-03-01

The dissolution properties of a drug and its release from the dosage form have a basic impact on its bioavailability. Solubility problems are a major challenge for the pharmaceutical industry as concerns the development of new pharmaceutical products. Formulation problems may possibly be overcome by modification of particle size and morphology. The application of power ultrasound is a novel possibility in drug formulation. This article reports on solvent diffusion and melt emulsification, as new methods supplemented with drying in the field of sonocrystallization of poorly water-soluble Gemfibrozil. During thermoanalytical characterization, a modified structure was detected. The specific surface area of the drug was increased following particle size reduction and the poor wettability properties could also be improved. The dissolution rate was therefore significantly increased. Copyright © 2011 Elsevier B.V. All rights reserved.

Microsystems for pharmatechnology manipulation of fluids, particles, droplets, and cells

CERN Document Server

2016-01-01

This book provides a comprehensive, state-of-the-art review of microfluidic approaches and applications in pharmatechnology. It is appropriate for students with an interdisciplinary interest in both the pharmaceutical and engineering fields, as well as process developers and scientists in the pharmaceutical industry. The authors cover new and advanced technologies for screening, production by micro reaction technology and micro bioreactors, small-scale processing of drug formulations, and drug delivery that will meet the need for fast and effective screening methods for drugs in different formulations, as well as the production of drugs in very small volumes. Readers will find detailed chapters on the materials and techniques for fabrication of microfluidic devices, microbioreactors, microsystems for emulsification, on-chip fabrication of drug delivery systems, respiratory drug delivery and delivery through microneedles, organs-on-chip, and more.

Industrial Applications of High Power Ultrasonics

Science.gov (United States)

Patist, Alex; Bates, Darren

Since the change of the millennium, high-power ultrasound has become an alternative food processing technology applicable to large-scale commercial applications such as emulsification, homogenization, extraction, crystallization, dewatering, low-temperature pasteurization, degassing, defoaming, activation and inactivation of enzymes, particle size reduction, extrusion, and viscosity alteration. This new focus can be attributed to significant improvements in equipment design and efficiency during the late 1990 s. Like most innovative food processing technologies, high-power ultrasonics is not an off-the-shelf technology, and thus requires careful development and scale-up for each and every application. The objective of this chapter is to present examples of ultrasonic applications that have been successful at the commercialization stage, advantages, and limitations, as well as key learnings from scaling up an innovative food technology in general.

[Orthogonal experiments for optimizing the formulation and preparation conditions of temozolomide solid lipid nanoparticles].

Science.gov (United States)

Dou, Mingjin; Huang, Guihua; Xi, Yanwei; Zhang, Na

2008-10-01

TMZ-SLN were prepared by emulsification-low temperature solidification method with stearic acid. The formulation and the preparation conditions were optimized by orthogonal experiments using entrapment efficiency as the evaluation index. The morphology was detected by transmission electron microscope. The Zeta potentials and the particle size distribution were evaluated by Laser Doppler Anemometry. The entrapment efficiencies and the drug release characteristics in vitro were assessed. The result showed that TMZ-SLN were concinnous and spherical in shape. The mean diameter (d(av) ) was 65.0 +/- 6.2 nm and the Zeta potential was -37.2 mV. The average entrapment efficiency was 58.9% +/- 1.21 %. The drug release behavior in vitro conformed to Higuchi Equation. The formation of a new material phase was testified by analysis of differential scanning calorimetry.

Microencapsulation of Clostridium acetobutylicum ATCC 824 spores in gellan gum microspheres for the production of biobutanol.

Science.gov (United States)

Rathore, Sweta; Wan Sia Heng, Paul; Chan, Lai Wah

2015-01-01

The purpose of the present study was to provide further insights on the applicability of microencapsulation using emulsification method, to immobilise Clostridium acetobutylicum ATCC 824 spores, for biobutanol production. The encapsulated spores were revived using heat shock treatment and the fermentation efficiency of the resultant encapsulated cells was compared with that of the free (non-encapsulated) cells. The microspheres were easily recovered from the fermentation medium by filtration and reused up to five cycles of fermentation. In contrast, the free (non-encapsulated) cells could be reused for two cycles only. The microspheres remained intact throughout repeated use. Although significant cell leakage was observed during the course of fermentation, the microspheres could be reused with relatively high butanol yield, demonstrating their role as microbial cell nurseries. Both encapsulated and liberated cells contributed to butanol production.

Continuous synthesis of tert.-butyl peroxypivalate using a single channel micro reactor equipped with orifices as emulsification units

NARCIS (Netherlands)

Illg, T.; Hessel, V.; Löb, P.; Schouten, J.C.

2011-01-01

The two-step synthesis of tert-butyl peroxypivalate is performed in a single-channel microreactor. The first step, the deprotonation of tert-butyl hydroperoxide, is done in a simple mixer tube setup. The residence time section for the second reaction step is equipped with orifices for interfacial

Preparation of sucrose fatty acid esters as food emulsifiers and evaluation of their surface active and emulsification properties.

Directory of Open Access Journals (Sweden)

Megahed, Mohamed G.

1999-08-01

Full Text Available A simple method for the preparation of sucrose esters, from fatty acids and the least expensive sucrose, has been conducted. Fatty acids namely lauric, palmitic and oleic were used in their preparation in the absence of any organic solvent. Reasonable yields amounting to 86.5%, 87.3% and 88.6% for sucrose esters of laurate, palmitate and oleate were obtained, respectively. The products were evaluated for their hydrophile-lipophile balance (HLB, surface and interfacial tension properties as well as emulsion stability. The results showed that these sucrose esters exhibit similar properties as those of the commercially prepared compounds.

Se ha llevado a cabo un método simple para la preparación de ésteres de sacarosa a partir de ácidos grasos y sacarosa de bajo coste. Se han usado ácidos laurico, palmítico y oleico en su preparación, en ausencia de solventes orgánicos. Se obtuvieron rendimientos aceptables del 86.5%, 87.3% y 88.6% para los ásteres del láurico, palmítico y oleico respectivamente. En los productos se evaluaron sus balances hidrófilo-lipófilo (HLB, sus propiedades de tensión superficial e interfacial así como su estabilidad en emulsiones. Los resultados mostraron que estos esteres de sacarosa exhiben propiedades similares a las de los compuestos preparados comercialmente.

Preparation and characterization of ketoprofen loaded eudragit RS polymeric nanoparticles for controlled release

International Nuclear Information System (INIS)

Tuan Anh, Nguyen; Tuyen Dao, T P; Nhan Le, N T; Mau Chien, Dang; To Hoai, Nguyen; T Chi, Nguyen; Tran, T Khai

2012-01-01

Nanospheres containing ketoprofen (Keto) and polymer eudragit RS were prepared using an emulsion solvent evaporation method. The ultrasonic probe (VCX500, vibracell) was used as a tool to disperse oil phase into aqueous phase leading to water/oil emulsion. Nanoparticles were successfully prepared and their morphologies and diameters were confirmed by transmission electron microscope (TEM) and dynamic light scattering (DLS), respectively. The result showed that particles were spherical with submicron size. The particle size was dependent on the RS concentration, emulsification tools and the types of organic solvents. For the encapsulation ability, Keto-loaded RS nanoparticle showed 9.8% of Keto in nanoparticle, which was evaluated by high-performance liquid chromatography (HPLC). Moreover, the drug release behavior of Keto-loaded eudragit RS nanoparticle was also investigated in vitro at pH 7.4 and compared to referential profenid. (paper)

The preparation of 3,5-dihydroxy-4-isopropylstilbene nanoemulsion and in vitro release

Science.gov (United States)

Zhang, Yue; Gao, Jungang; Zheng, Hetang; Zhang, Ran; Han, Yucui

2011-01-01

We have reported a novel procedure to prepare 3,5-dihydroxy-4-isopropylstilbene (DHPS) nanoemulsion, using a low-energy emulsification method. Based on the phase diagram, the optimum prescription of nanoemulsion preparation was screened. With polyoxyethylenated castor oil (EL-40) as the surfactant, ethanol as the co-surfactant, and isopropyl myristate (IPM) as the oil phase, the DHPS nanoemulsion was obtained with a transparent appearance, little viscosity, and spherically uniform distribution verified by transmission electron microscopy and laser scattering analyzer. The nanoemulsion was also determined by FT-Raman spectroscopy. The DHPS nanoemulsion demonstrated good stability and stable physical and chemical properties. The nanoemulsion dramatically improved the transdermal release of DHPS (from 8.02 μg · cm−2 to 273.15 μg · cm−2) and could become a favorable new dosage form for DHPS. PMID:21674020

Chemical dispersibility testing of fresh and weathered oils

International Nuclear Information System (INIS)

Brandvik, P.J.; Daling, P.S.; Aareskjold, K.

1991-05-01

This activity in the DIspersants on Weathered Oils-project (DIWO) is a continuation and an extended study of the dispersibility study described in DIWO report No. 3. The main objective has been to study the chemical dispersibility of fresh and weathered oils produced or transported in Norwegian waters. Other important aims of this study have been: To correlate the effectiveness results obtained by three different laboratory methods; to determine the relationship between the dispersant effectiveness and the change in the oils' physico-chemical properties due to weathering (topping, photo-oxidation and w/o-emulsification). This study has been performed with 8 different oil types and 12 different weathering degrees of each oil type. The work performed clearly demonstrates that the oil type and especially the weathering properties are essential for the performance of dispersants at sea. 41 figs., 5 tabs., 16 refs

Chemically emulsified crude oil as substrate for bacterial oxidation : differences in species response

International Nuclear Information System (INIS)

Bruheim, P.; Eimhjellen, K.

1998-01-01

The ability of bacterial species to oxidize alkanes in crude oil in water emulsions was studied. Alkanes in crude oil need specific physiological adaptations to the microorganisms. Synthesis of biosurfactants has been considered as a prerequisite for either specific adhesion mechanisms to large oil drops or emulsification of oil followed by uptake of submicron oil droplets. In this study four bacterial species were tested. Emulsions were prepared by nonionic sorbitan ester and polyoxyethylene ether surfactants. The oxidation rates were measured. Both positive and negative effects of surfactant amendments were observed. The same surfactant affected different bacteria in different ways. The response to the surfactant amendment depended on the physiological state of the bacteria. The results showed that surfactants resulted in decreased cell adhesion to the oil phase for all the bacteria. 19 refs., 3 tabs., 4 figs

Performance of single cylinder, direct injection Diesel engine using water fuel emulsions

International Nuclear Information System (INIS)

Abu-Zaid, M.

2004-01-01

A single cylinder Diesel engine study of water-in-Diesel emulsions was conducted to investigate the effect of water emulsification on the engine performance and gases exhaust temperature. Emulsified Diesel fuels of 0, 5, 10, 15 and 20 water/Diesel ratios by volume, were used in a single cylinder, direct injection Diesel engine, operating at 1200-3300 rpm. The results indicate that the addition of water in the form of emulsion improves combustion efficiency. The engine torque, power and brake thermal efficiency increase as the water percentage in the emulsion increases. The average increase in the brake thermal efficiency for 20% water emulsion is approximately 3.5% over the use of Diesel for the engine speed range studied. The proper brake specific fuel consumption and gases exhaust temperature decrease as the percentage of water in the emulsion increases

OSCAR2000 : a multi-component 3-dimensional oil spill contingency and response model

International Nuclear Information System (INIS)

Reed, M.; Daling, P.S.; Brakstad, O.G.; Singsaas, I.; Faksness, L.-G.; Hetland, B.; Ekrol, N.

2000-01-01

Researchers at SINTEF in Norway have studied the weathering of surface oil. They developed a realistic model to analyze alternative spill response strategies. The model represented the formation and composition of the water-accommodated fraction (WAF) of oil for both treated and untreated oil spills. As many as 25 components, pseudo-components, or metabolites were allowed for the specification of oil. Calculations effected using OSCAR were verified in great detail on numerous occasions. The model made it possible to determine rather realistically the dissolution, transformation, and toxicology of dispersed oil clouds, as well as evaporation, emulsification, and natural dispersion. OSCAR comprised a data-based oil weathering model, a three-dimensional oil trajectory and chemical fates model, an oil spill combat model, exposure models for birds, marine mammals, fish and ichthyoplankton. 17 refs., 1 tab., 11 figs

Results of laboratory tests on the potential for using in situ burning on seventeen crude oils

International Nuclear Information System (INIS)

McCourt, J.; Buist, I.; Buffington, S.

2000-01-01

The past five years at SL Ross (Ottawa) have been spent analysing seventeen crude oils to establish whether each oil could be cleaned up using an in situ burning technique in the event of a spill. The process involved a series of laboratory tests and controlled burns. The authors determined the emulsification characteristics, the limits to ignition imposed by evaporation and emulsion formation using a series of baseline burns, as well as the emulsion breaker burn test on emulsions that could not be ignited with gelled gas in the baseline burn test. They also determined the density, viscosity, and for some oils the interfacial tension, pour point, and flash point. The results obtained provided valuable information to be used in the case of a spill. They also indicated avenues to be followed in future research. 10 refs., 2 tabs

[Recent advances in analysis of petroleum geological samples by comprehensive two-dimensional gas chromatography].

Science.gov (United States)

Gao, Xuanbo; Chang, Zhenyang; Dai, Wei; Tong, Ting; Zhang, Wanfeng; He, Sheng; Zhu, Shukui

2014-10-01

Abundant geochemical information can be acquired by analyzing the chemical compositions of petroleum geological samples. The information obtained from the analysis provides scientifical evidences for petroleum exploration. However, these samples are complicated and can be easily influenced by physical (e. g. evaporation, emulsification, natural dispersion, dissolution and sorption), chemical (photodegradation) and biological (mainly microbial degradation) weathering processes. Therefore, it is very difficult to analyze the petroleum geological samples and they cannot be effectively separated by traditional gas chromatography/mass spectrometry. A newly developed separation technique, comprehensive two-dimensional gas chromatography (GC x GC), has unique advantages in complex sample analysis, and recently it has been applied to petroleum geological samples. This article mainly reviews the research progres- ses in the last five years, the main problems and the future research about GC x GC applied in the area of petroleum geology.

Nutritional and functional properties of whey proteins concentrate and isolate

Directory of Open Access Journals (Sweden)

Zoran Herceg

2006-12-01

Full Text Available Whey protein fractions represent 18 - 20 % of total milk nitrogen content. Nutritional value in addition to diverse physico - chemical and functional properties make whey proteins highly suitable for application in foodstuffs. In the most cases, whey proteins are used because of their functional properties. Whey proteins possess favourable functional characteristics such as gelling, water binding, emulsification and foaming ability. Due to application of new process techniques (membrane fractionation techniques, it is possible to produce various whey - protein based products. The most important products based on the whey proteins are whey protein concentrates (WPC and whey protein isolates (WPI. The aim of this paper was to give comprehensive review of nutritional and functional properties of the most common used whey proteins (whey protein concentrate - WPC and whey protein isolate - WPI in the food industry.

Fluorescent Pluronic nanodots for in vivo two-photon imaging

International Nuclear Information System (INIS)

Maurin, Mathieu; Vurth, Laeticia; Vial, Jean-Claude; Baldeck, Patrice; Stephan, Olivier; Marder, Seth R; Sanden, Boudewijn Van der

2009-01-01

We report the synthesis of new nanosized fluorescent probes based on bio-compatible polyethylene-polypropylene glycol (Pluronic) materials. In aqueous solution, mini-emulsification of Pluronic with a high fluorescent di-stryl benzene-modified derivative, exhibiting a two-photon absorption cross section as high as 2500 Goeppert-Mayer units at 800 nm, leads to nanoparticles exhibiting a hydrodynamic radius below 100 nm. We have demonstrated that these new probes with luminescence located in the spectral region of interest for bio-imaging (the yellow part of the visible spectrum) allow deep (500 μm) bio-imaging of the mice brain vasculature. The dose injected during our experiments is ten times lower when compared to the classical commercial rhodamine-B isothicyanate-Dextran system but gives similar results to homogeneous blood plasma staining. The mean fluorescent signal intensity stayed constant during more than 1 h.

State of the art satellite and airborne marine oil spill remote sensing: Application to the BP Deepwater Horizon oil spill

Science.gov (United States)

Leifer, Ira; Lehr, William J.; Simecek-Beatty, Debra; Bradley, Eliza; Clark, Roger N.; Dennison, Philip E.; Hu, Yongxiang; Matheson, Scott; Jones, Cathleen E; Holt, Benjamin; Reif, Molly; Roberts, Dar A.; Svejkovsky, Jan; Swayze, Gregg A.; Wozencraft, Jennifer M.

2012-01-01

The vast and persistent Deepwater Horizon (DWH) spill challenged response capabilities, which required accurate, quantitative oil assessment at synoptic and operational scales. Although experienced observers are a spill response's mainstay, few trained observers and confounding factors including weather, oil emulsification, and scene illumination geometry present challenges. DWH spill and impact monitoring was aided by extensive airborne and spaceborne passive and active remote sensing.Oil slick thickness and oil-to-water emulsion ratios are key spill response parameters for containment/cleanup and were derived quantitatively for thick (> 0.1 mm) slicks from AVIRIS (Airborne Visible/Infrared Imaging Spectrometer) data using a spectral library approach based on the shape and depth of near infrared spectral absorption features. MODIS (Moderate Resolution Imaging Spectroradiometer) satellite, visible-spectrum broadband data of surface-slick modulation of sunglint reflection allowed extrapolation to the total slick. A multispectral expert system used a neural network approach to provide Rapid Response thickness class maps.Airborne and satellite synthetic aperture radar (SAR) provides synoptic data under all-sky conditions; however, SAR generally cannot discriminate thick (> 100 μm) oil slicks from thin sheens (to 0.1 μm). The UAVSAR's (Uninhabited Aerial Vehicle SAR) significantly greater signal-to-noise ratio and finer spatial resolution allowed successful pattern discrimination related to a combination of oil slick thickness, fractional surface coverage, and emulsification.In situ burning and smoke plumes were studied with AVIRIS and corroborated spaceborne CALIPSO (Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observation) observations of combustion aerosols. CALIPSO and bathymetry lidar data documented shallow subsurface oil, although ancillary data were required for confirmation.Airborne hyperspectral, thermal infrared data have nighttime and

蛇床子乳剂的制备及体外抗阴道滴虫考察%Preparation of Cnidium monnieri Emulsion and Investigation of its in vitro Anti-trichomonas Vaginalis

Institute of Scientific and Technical Information of China (English)

杨婧; 姜霁铭; 王锐

2012-01-01

Objective: To prepare o/w type emulsion with total coumarin from Cnidium monnieri, and investigate its in vitro anti-trichomonas vaginalis activity. Method: Total coumarin from C. monnieri was extracted by ultrasonic method with emulsification time, times and pressure, adding order of emulsifier as factors, single factor test was used to optimize preparation technology of C. monnieri emulsion, and its pharmacodynamic trial of in vitro anti-trichomonas vaginalis was investigated. Result; Preparation technology of C. monnieri emulsion was ascertained as follows; emulsification 3 times at 150 MPa, 15 min each time, adding order of emulsifier with oil phase added to aqueous phase; and this emulsion had good inhibition on trichomonas raginalis. Conclusion; This preparation technology was stable and feasible, minimum drug concentration of this emulsion had good inhibition effect to trichomonas vaginalis was 0. 15-0. 62 g - L-1.%目的:将蛇床子中的总香豆素制成o/w型乳剂,并考察其体外抗阴道滴虫药理活性.方法:采用超声法提取蛇床子中的总香豆素,选取乳化时间、乳化次数、乳化压力及乳化剂加入顺序为考察因素,通过单因素试验优选蛇床子乳剂的制备工艺,并考察其体外抗阴道滴虫药效学试验.结果:确定的蛇床子乳剂制备工艺为乳化时间15 min,乳化压力150 MPa,乳化3次,乳化剂加入顺序为油相加入到水相;确认其对临床分离的阴道滴虫有较好的抑制作用.结论:该制备工艺稳定可行,制备的乳剂对阴道滴虫产生抑制作用的最低药物质量浓度0.15 ～0.62 g·L-1.

Preparation and characterization of uniform-sized chitosan/silver microspheres with antibacterial activities

Energy Technology Data Exchange (ETDEWEB)

An, Jing; Ji, Zhenxing; Wang, Desong, E-mail: dswang06@126.com; Luo, Qingzhi; Li, Xueyan

2014-03-01

The chitosan/silver microspheres (CAgMs), which possess effective inhibitory on microorganisms, were prepared by an inverse-emulsification cross-linking method using CS/Ag sol as dispersed phase, whiteruss as continuous phase, and glutaraldehyde as crosslinking agent. The size and shape of CAgMs, greatly affecting their antibacterial activities, were controlled by varying the concentrations of cross-linking agent, emulsifier and CS/Ag colloid. The preparation conditions for obtaining uniform-sized microspheres were optimized. The morphology of CAgMs was characterized by scanning electron microscopy (SEM) and laser particle size analysis. The spherical CAgMs with smooth surface in the mean size of ca. 5 μm exhibited a narrow particle size distribution. Energy Dispersive X-ray spectroscopy (EDX) revealed the elemental composition of the microspheres. Transmission electron micrographs (TEM) and Fourier transform infrared spectroscopy (FTIR) of the microspheres confirmed the formation of silver nanoparticles (AgNPs). The X-ray diffraction (XRD) patterns and UV–Visible diffuse reflectance spectroscopy (UV–vis DRS) of the sample showed that AgNPs with the diameter no more than 20 nm were face-centered cubic crystallites. X-ray photoelectron spectroscopy (XPS) proved that Ag-O bond existed in the microspheres. Thermogravimetric analysis (TGA) showed that the starting decomposition temperature of CAgMs (ca. 260 °C) was much higher than that of CS (ca. 160 °C), suggesting that the as-prepared CAgMs possessed better thermal stability than original CS did. Antimicrobial assays were performed using typical Gram bacteria and fungi. The inhibitory effect indicated that the as-prepared microspheres exerted a stronger antibacterial activity as the concentration of the AgNPs is increasing, and the microspheres in smaller size had much better antibacterial activity than those in the larger size. The antimicrobial mechanism of CAgMs was discussed. - Highlights: • CAgM was

Isolation and characterization of diesel degrading bacteria, Sphingomonas sp. and Acinetobacter junii from petroleum contaminated soil

Science.gov (United States)

Zhang, Qiuzhuo; Wang, Duanchao; Li, Mengmeng; Xiang, Wei-Ning; Achal, Varenyam

2014-03-01

Two indigenous bacteria of petroleum contaminated soil were characterized to utilize diesel fuel as the sole carbon and energy sources in this work. 16S rRNA gene sequence analysis identified these bacteria as Sphingomonas sp. and Acinetobacter junii. The ability to degrade diesel fuel has been demonstrated for the first time by these isolates. The results of IR analyses showed that Sphingomonas sp. VA1 and A. junii VA2 degraded up to 82.6% and 75.8% of applied diesel over 15 days, respectively. In addition, Sphingomonas sp. VA1 possessed the higher cellular hydrophobicities of 94% for diesel compared to 81% by A. junii VA2. The isolates Sphingomonas sp. VA1 and A. junii VA2 exhibited 24% and 18%, respectively emulsification activity. This study reports two new diesel degrading bacterial species, which can be effectively used for bioremediation of petroleum contaminated sites.

Biosurfactant-enhanced bioremediation of polycyclic aromatic hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Cameotra, S.S.; Bollag, J.M. [Penn State University, University Park, PA (USA). Soil Biochemical Lab.

2003-07-01

Biosurfactants are surface-active compounds synthesized by it wide variety of micro-organisms. They are molecules that have both hydrophobic and hydrophilic domains and are capable of lowering the surface tension and the interfacial tension of the growth medium. Biosurfactants possess different chemical structures - lipopeptides, glycolipids, neutral lipids, and fatty acids. They are nontoxic biomolecules that are biodegradable. Biosurfactants also exhibit strong emulsification of hydrophobic compounds and form stable emulsions. Polycyclic aromatic hydrocarbons (PAHs) can be toxic, mutagenic, and carcinogenic compounds that pollute the environment. They are released to the environment its a result of spillage of oil and byproducts of coal treatment processes. The low water solubility of PAHs limits their availability to microorganisms, which is a potential problem for bioremediation of PAH-contaminated sites. Microbially produced surfactants enhance the bioavailability of these hydrophobic compounds for bioremediation. Therefore, biosurfactant-enhanced solubility of PAHs has potential applications in bioremediation.

Optimization of biosurfactant production by Bacillus brevis using response surface methodology

Directory of Open Access Journals (Sweden)

Foukia E. Mouafi

2016-03-01

Full Text Available The present study aims to evaluate and validate a statistical model for maximizing biosurfactant productivity by Bacillus brevis using response surface methodology. In this respect, twenty bacterial isolates were screened for biosurfactant production using hemolytic activity, oil spreading technique, and emulsification index (E24. The most potent biosurfactant-producing bacterium (B. brevis was used for construction of the statistical response surface model. The optimum conditions for biosurfactant production by B. brevis were: 33 °C incubation temperature at pH 8 for 10 days incubation period and 8.5 g/L glucose concentration as a sole carbon source. The produced biosurfactant (BS (73% exhibited foaming activity, thermal stability in the range 30–80 °C for 30 min., pH stability, from 4 to 9 and antimicrobial activity against (Escherichia coli. The BS gave a good potential application as an emulsifier.

Characteristics of Nano-emulsion for Cold Thermal Storage

Science.gov (United States)

Fumoto, Koji; Kawaji, Masahiro; Kawanami, Tsuyoshi

Phase change emulsion (PCE) is novel kind of heat storage and heat transfer fluids. It has characteristics as follows; greater apparent specific heat and higher heat transfer abilities in the phase change temperature range than conventional single phase heat transfer fluid. In this paper, a phase change emulsion, which has droplet diameter distribution of nanometer, were prepared. The Nano-emulsion was formed by low energy emulsification methods, as known the phase inversion temperature (PIT) method. Physical properties, such as viscosity, diameter and its distribution of emulsion were investigated. Especially, the relationships between preparation method and the concentration of surfactant have been discussed in detail. The results show that the viscosity of the Nano-emulsion is lower than the micro-emulsion, which was made by same mixing ratio of surfactant and concentration of phase change material. In addition, the Nano-emulsion clarified that stability was higher than microemulsions.

Superswollen microemulsions stabilized by shear and trapped by a temperature quench.

Science.gov (United States)

Roger, Kevin; Olsson, Ulf; Zackrisson-Oskolkova, Malin; Lindner, Peter; Cabane, Bernard

2011-09-06

We studied the solubilization of oil in the C(16)E(8)/hexadecane/H(2)O system. Close to the phase inversion temperature (PIT), the system, at equilibrium, can form either homogeneous states (i.e., microemulsions) at high surfactant concentrations or three-phase states at lower concentrations. We show that, under gentle shear, at a line we named the clearing boundary (CB), located a few degrees below the PIT, the system is homogeneous regardless of the surfactant concentration. We relate this shift of the microemulsion boundary to shear-induced disruption of the asymmetric bicontinuous structure. Although this state quickly relaxes to equilibrium when shear is stopped, we show that it is still possible to trap it into a metastable state through a temperature quench. This method is the sub-PIT emulsification that we described in a previous work (Roger Langmuir 2010, 26, 3860-3867). © 2011 American Chemical Society

Foam-oil interaction in porous media: implications for foam assisted enhanced oil recovery.

Science.gov (United States)

Farajzadeh, R; Andrianov, A; Krastev, R; Hirasaki, G J; Rossen, W R

2012-11-15

The efficiency of a foam displacement process in enhanced oil recovery (EOR) depends largely on the stability of foam films in the presence of oil. Experimental studies have demonstrated the detrimental impact of oil on foam stability. This paper reviews the mechanisms and theories (disjoining pressure, coalescence and drainage, entering and spreading of oil, oil emulsification, pinch-off, etc.) suggested in the literature to explain the impact of oil on foam stability in the bulk and porous media. Moreover, we describe the existing approaches to foam modeling in porous media and the ways these models describe the oil effect on foam propagation in porous media. Further, we present various ideas on an improvement of foam stability and longevity in the presence of oil. The outstanding questions regarding foam-oil interactions and modeling of these interactions are pointed out. Copyright © 2012 Elsevier B.V. All rights reserved.

Encapsulating acetaminophen into poly(L-lactide) microcapsules by solvent-evaporation technique in an O/W emulsion.

Science.gov (United States)

Lai, M-K; Tsiang, R C-C

2004-05-01

Microencapsulation of acetaminophen in poly(L-lactide) was studied using the oil-in-water emulsification solvent-evaporation technique. Methylene chloride was used as the dispersed medium and water as the dispersing medium. The thermogravimetric analysis and differential scanning calorimetry data indicated that the acetaminophen was encapsulated and uniformly distributed in the poly(L-lactide) microcapsules. The addition of either gelatin or polyvinyl alcohol as the protective colloid to the emulsion was found to have a significant impact on the resulting microcapsules. Increasing the concentration of either protective colloid in the dispersing medium increased the recovery and the release rate of acetaminophen, but reduced the particle size and loading efficiency of the microcapsules. Scanning electron micrographs manifested that all the microcapsules attained a nearly round shape. While gelatin imparted a smooth topography to the surface of the microcapsules, PVA made the surface of the microcapsules bumpy and humped.

Recent advances in flexible low power cholesteric LCDs

Science.gov (United States)

Khan, Asad; Shiyanovskaya, Irina; Montbach, Erica; Schneider, Tod; Nicholson, Forrest; Miller, Nick; Marhefka, Duane; Ernst, Todd; Doane, J. W.

2006-05-01

Bistable reflective cholesteric displays are a liquid crystal display technology developed to fill a market need for very low power displays. Their unique look, high reflectivity, bistability, and simple structure make them an ideal flat panel display choice for handheld or other portable devices where small lightweight batteries with long lifetimes are important. Applications ranging from low resolution large signs to ultra high resolution electronic books can utilize cholesteric displays to not only benefit from the numerous features, but also create enabling features that other flat panel display technologies cannot. Flexible displays are the focus of attention of numerous research groups and corporations worldwide. Cholesteric displays have been demonstrated to be highly amenable to flexible substrates. This paper will review recent advances in flexible cholesteric displays including both phase separation and emulsification approaches to encapsulation. Both approaches provide unique benefits to various aspects of manufacturability, processes, flexibility, and conformability.

Environmental and Irradiation Effect on the Biosynthesis of Bio surfactant by Some Local Bacterial Isolates

International Nuclear Information System (INIS)

Ghoneimy, E.; Ahmed, S.; Desouki, S.; Rasmy, W.; El-Shahawy, M.

2010-01-01

Twenty eight bacterial isolates were isolated from The Suez Gulf sea water from the coast of the El-Nasr Petroleum Company on Suez Canal and formation water from overhead of an oil well in western desert of Egypt named (M68). Sixteen bacterial isolates were obtained from The Suez Gulf sea water. Twelve bacterial isolates were obtained from formation water (M68). The bacterial isolates were screened for bio surfactant production by using emulsification activity and haemolytic activity. The most potent two isolates N8 and S8 were selected according to three parameters; the ability of isolate to grow and produce surfactant on wide range of ph, temperature and salinity. The most promising bacterial isolates were subjected to different doses of gamma irradiation in a trial to improve their abilities for bio surfactant production which resulted in a passive effect on bio surfactant production

On-Chip generation of polymer microcapsules through droplet coalescence

Science.gov (United States)

Eqbal, Md Danish; Gundabala, Venkat; Gundabala lab Team

Alginate microbeads and microcapsules have numerous applications in drug delivery, tissue engineering and other biomedical areas due to their unique properties. Microcapsules with liquid core are of particular interest in the area of cell encapsulation. Various methods such as coacervation, emulsification, micro-nozzle, etc. exist for the generation of microbeads and microcapsules. However, these methods have several drawbacks like coagulation, non-uniformity, and polydispersity. In this work we present a method for complete on chip generation of alginate microcapsules (single core as well as double core) through the use of droplet merging technique. For this purpose, a combined Coflow and T-junction configuration is implemented in a hybrid glass-PDMS (Polydimethylsiloxane) microfluidic device. Efficient generation is achieved through precise matching of the generation rates of the coalescing drops. Through this approach, microcapsules with intact single and double (liquid) cores surrounded by alginate shell have been successfully generated and characterized.

Synthesis and membrane performance characterization of self-emulsified waterborne nitrocellulose dispersion modified with castor oil

Science.gov (United States)

Su, Xiuxia; Zhao, Qingxiao; Zhang, Dan; Dong, Wei

2015-11-01

Waterborne nitrocellulose dispersion modified with castor oil (CWNC) was designed and successfully synthesized by self emulsification and reaction among isophorone diisocyanate (IPDI) trimer, dimethylol propionic acid (DMPA), nitrocellulose (NC) and castor oil (C.O.). The CWNC was characterized by transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectroscopy and thermal gravimetric analysis (TGA), etc. The particle size of CWNC increased with the increase of mass fraction of castor oil to total reactants, ω (C.O.). The morphology of particles is an approximate core-shell structure indicated by TEM. FTIR confirmed that the reactions (i.e. IPDI trimer and castor oil, IPDI trimer and NC) occurred, the NCO groups of IPDI trimer were consumed totally and the backbone of NC was retained. The water contact angle measurements confirmed that introduced castor oil increased hydrophobicity of the film, thereby increasing the contact angle. TGA revealed that the CWNC film had better thermal resistance.

Nanoprodrugs of NSAIDs: Preparation and Characterization of Flufenamic Acid Nanoprodrugs

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Bong-Seop Lee

2011-01-01

Full Text Available We demonstrated that hydrophobic derivatives of the nonsteroidal anti-inflammatory drug (NSAIDflufenamic acid (FA, can be formed into stable nanometer-sized prodrugs (nanoprodrugs that inhibit the growth of glioma cells, suggesting their potential application as anticancer agent. We synthesized highly hydrophobic monomeric and dimeric prodrugs of FA via esterification and prepared nanoprodrugs using spontaneous emulsification mechanism. The nanoprodrugs were in the size range of 120 to 140 nm and physicochemically stable upon long-term storage as aqueous suspension, which is attributed to the strong hydrophobic interaction between prodrug molecules. Importantly, despite the highly hydrophobic nature and water insolubility, nanoprodrugs could be readily activated into the parent drug by porcine liver esterase, presenting a potential new strategy for novel NSAID prodrug design. The nanoprodrug inhibited the growth of U87-MG glioma cells with IC50 of 20 μM, whereas FA showed IC50 of 100 μM, suggesting that more efficient drug delivery was achieved with nanoprodrugs.

A New Application of Lipid Nanoemulsions as Coating Agent, Providing Zero-Order Hydrophilic Drug Release from Tablets

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Nicolas Anton

2012-01-01

Full Text Available The objective of the present investigation was to evaluate potential of nanoemulsions as a coating material for the tablets. The nanoemulsion of size less than 100 nm was prepared using a simple and low-energy spontaneous emulsification method. Conventional tablets containing theophylline as a model hydrophilic drug were prepared. The theophylline tablets were coated with the nanoemulsion using a fluid bed coater. The effect of different levels of the nanoemulsion coating on the theophylline release was evaluated. The theophylline tablets containing different levels of the nanoemulsion coating could be successfully prepared. Interestingly, the coating of tablet with the nanoemulsion resulted in zero-order release of theophylline from the tablets. The noncoated theophylline tablets release the entire drug in less than 2 minutes, whereas nanoemulsion coating delayed the release of theophylline from tablets. This investigation establishes the proof of concept for the potential of nanoemulsions as a coating material for tablets.

Transglutaminase catalyzed cross-linking of sodium caseinate improves oxidative stability of flaxseed oil emulsion.

Science.gov (United States)

Ma, Hairan; Forssell, Pirkko; Kylli, Petri; Lampi, Anna-Maija; Buchert, Johanna; Boer, Harry; Partanen, Riitta

2012-06-20

Sodium caseinate was modified by transglutaminase catalyzed cross-linking reaction prior to the emulsification process in order to study the effect of cross-linking on the oxidative stability of protein stabilized emulsions. The extent of the cross-linking catalyzed by different dosages of transglutaminase was investigated by following the ammonia production during the reaction and using SDS-PAGE gel. O/W emulsions prepared with the cross-linked and non-cross-linked sodium caseinates were stored for 30 days under the same conditions. Peroxide value measurement, oxygen consumption measurement, and headspace gas chromatography analysis were used to study the oxidative stability of the emulsions. The emulsion made of the cross-linked sodium caseinate showed an improved oxidative stability with reduced formation of fatty acid hydroperoxides and volatiles and a longer period of low rate oxygen consumption. The improving effect of transglutaminase catalyzed cross-linking could be most likely attributed to the enhanced physical stability of the interfacial protein layer against competitive adsorption by oil oxidation products.

PRODUCTION AND CHARACTERIZATION OF BIOSURFACTANT BY Pseudomonas fluorescens USING CASSAVA FLOUR WASTEWATER AS MEDIA

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Venty Suryanti

2013-12-01

Full Text Available Biosurfactant with efficient emulsification properties could be produced by Pseudomonas flourescens using cassava flour wastewater (manipueira as media. The ability of P. flourescens to produce biosurfactant could suggest potential use in industrial and environmental applications. Media containing a mixture of natural manipueira and nutrient broth with 48 h fermentation was the optimum condition for the biosurfactant production. Based on UV-Vis and FT-IR spectra, the biosurfactant was indicated as rhamnolipids containing hydroxyl, ester, carboxylic and aliphatic carbon chain functional groups. Biosurfactant exhibited critical micelle concentration (CMC value of 715 mg/L and reduced the surface tension of the water from 80 mN/m to 59 mN/m. The biosurfactant was able to decrease the interfacial tension about 51-70% when benzyl chloride, palm oil and kerosene were used as water-immiscible compounds. The biosurfactant was able to form stable emulsion until 30 days when paraffin, soybean oil, lubricant oil and kerosene were used as water-immiscible compounds.

Solid lipid nanoparticles mediate non-viral delivery of plasmid DNA to dendritic cells

Science.gov (United States)

Penumarthi, Alekhya; Parashar, Deepti; Abraham, Amanda N.; Dekiwadia, Chaitali; Macreadie, Ian; Shukla, Ravi; Smooker, Peter M.

2017-06-01

There is an increasing demand for novel DNA vaccine delivery systems, mainly for the non-viral type as they are considered relatively safe. Therefore, solid lipid nanoparticles (SLNs) were investigated for their suitability as a non-viral DNA vaccine delivery system. SLNs were synthesised by a modified solvent-emulsification method in order to study their potential to conjugate with plasmid DNA and deliver them in vitro to dendritic cells using eGFP as the reporter plasmid. The DNA-SLN complexes were characterised by electron microscopy, gel retardation assays and dynamic light scattering. The cytotoxicity assay data supported their biocompatibility and was used to estimate safe threshold concentration resulting in high transfection rate. The transfection efficiency of these complexes in a dendritic cell line was shown to increase significantly compared to plasmid alone, and was comparable to that mediated by lipofectamine. Transmission electron microscopy studies delineated the pathway of cellular uptake. Endosomal escape was observed supporting the mechanism of transfection.

Producing a lycopene nanodispersion: Formulation development and the effects of high pressure homogenization.

Science.gov (United States)

Shariffa, Y N; Tan, T B; Uthumporn, U; Abas, F; Mirhosseini, H; Nehdi, I A; Wang, Y-H; Tan, C P

2017-11-01

The aim of this study was to develop formulations to produce lycopene nanodispersions and to investigate the effects of the homogenization pressure on the physicochemical properties of the lycopene nanodispersion. The samples were prepared by using emulsification-evaporation technique. The best formulation was achieved by dispersing an organic phase (0.3% w/v lycopene dissolved in dichloromethane) in an aqueous phase (0.3% w/v Tween 20 dissolved in deionized water) at a ratio of 1:9 by using homogenization process. The increased level of homogenization pressure to 500bar reduced the particle size and lycopene concentration significantly (phomogenization pressure (700-900bar) resulted in large particle sizes with high dispersibility. The zeta potential and turbidity of the lycopene nanodispersion were significantly influenced by the homogenization pressure. The results from this study provided useful information for producing small-sized lycopene nanodispersions with a narrow PDI and good stability for application in beverage products. Copyright © 2017 Elsevier Ltd. All rights reserved.

Milk whey protein modification by coffee-specific phenolics: effect on structural and functional properties.

Science.gov (United States)

Ali, Mostafa; Homann, Thomas; Khalil, Mahmoud; Kruse, Hans-Peter; Rawel, Harshadrai

2013-07-17

A suitable vehicle for integration of bioactive plant constituents is proposed. It involves modification of proteins using phenolics and applying these for protection of labile constituents. It dissects the noncovalent and covalent interactions of β-lactoglobulin with coffee-specific phenolics. Alkaline and polyphenol oxidase modulated covalent reactions were compared. Tryptic digestion combined with MALDI-TOF-MS provided tentative allocation of the modification type and site in the protein, and an in silico modeling of modified β-lactoglobulin is proposed. The modification delivers proteins with enhanced antioxidative properties. Changed structural properties and differences in solubility, surface hydrophobicity, and emulsification were observed. The polyphenol oxidase modulated reaction provides a modified β-lactoglobulin with a high antioxidative power, is thermally more stable, requires less energy to unfold, and, when emulsified with lutein esters, exhibits their higher stability against UV light. Thus, adaptation of this modification provides an innovative approach for functionalizing proteins and their uses in the food industry.

Influence of Food Characteristics and Food Additives on the Antimicrobial Effect of Garlic and Oregano Essential Oils.

Science.gov (United States)

García-Díez, Juan; Alheiro, Joana; Pinto, Ana Luisa; Soares, Luciana; Falco, Virgilio; Fraqueza, Maria João; Patarata, Luis

2017-06-10

Utilization of essential oils (EOs) as antimicrobial agents against foodborne disease has gained importance, for their use as natural preservatives. Since potential interactions between EOs and food characteristics may affect their antimicrobial properties, the present work studies the influence of fat, protein, pH, a w and food additives on the antimicrobial effect of oregano and garlic EOs against Salmonella spp. and Listeria monocytogenes. Results showed that protein, pH, a w , presence of beef extract, sodium lactate and nitrates did not influence their antimicrobial effect. In contrast, the presence of pork fat had a negative effect against both EOs associated with their dilution of the lipid content. The addition of food phosphates also exerts a negative effect against EOs probably associated with their emulsification properties as observed with the addition of fat. The results may help the food industry to select more appropriate challenges to guarantee the food safety of foodstuffs.

Identification of potential local isolated for biosurfactant production

Science.gov (United States)

Shafiei, Zahra; Yusoff, Wan Mohtar Wan; Hamid, Aidil Abdul; Moazami, Nasrin; Hamzah, Ainon; Fooladi, Taybeh

2013-11-01

Biosurfactant are amphiphilic molecule that have received increasing attention in recent years because of their role in the growth of microorganisms on water-insoluble hydrophobic materials such as hydrocarbons as well as their commercial potential in the cosmetics, food, oil recovery and agricultural industries. In this study a potential biosurfactant producing strain was isolated from several soil samples of Terengganu oil refinery, Malaysia and selected during preliminary screening using hemolytic activity, oil spreading and drop collapsed technique. Isolates with at least more than one positive response to these three methods were subjected to complementary screening by measuring surface tension reduction as well as emulsification capacity. The biosurfactant produced by isolated 5M was able to reduced surface tension of culture medium from 60 mN/m to30mN/m. The biochemical and morphological characterization, 16SrRNA gene sequencing showed that the isolated 5M belongs to bacillus groups. The maximum production of biosurfactant by Bacillus 5M was observed after 48 h of incubation.

Improved oral bioavailability of glyburide by a self-nanoemulsifying drug delivery system.

Science.gov (United States)

Liu, Hongzhuo; Shang, Kuimao; Liu, Weina; Leng, Donglei; Li, Ran; Kong, Ying; Zhang, Tianhong

2014-01-01

The present study aimed at the development and characterisation of self-nanoemulsifying drug delivery system (SNEDDS) to improve the oral bioavailability of poorly soluble glyburide. The solubility of glyburide was determined in various oils, surfactants and co-surfactants which were grouped into two different combinations to construct ternary phase diagrams. The formulations were evaluated for emulsification time, droplet size, zeta-potential, electrical conductivity and stability of nanoemulsions. The optimised SNEDDS loading with 5 mg/g glyburide comprised 55% Cremophor® RH 40, 15% propanediol and 30% Miglyol® 812, which rapidly formed fine oil-in-water nanoemulsions with 46 ± 4 nm particle size. Compared with the commercial micronised tablets (Glynase®PresTab®), enhanced in vitro release profiles of SNEDDS were observed, resulting in the 1.5-fold increase of AUC following oral administration of SNEDDS in fasting beagle dogs. These results indicated that SNEDDS is a promising drug delivery system for increasing the oral bioavailability of glyburide.

Hydrodynamics of foam flows for in situ bioremediation of DNAPL-contaminated subsurface

International Nuclear Information System (INIS)

Bouillard, J.X.; Enzien, M.; Peters, R.W.; Frank, J.; Botto, R.E.; Cody, G.

1995-01-01

In situ remediation technologies such as (1) pump-and-treat, (2) soil vacuum extraction, (3) soil flushing/washing, and (4) bioremediation are being promoted for cleanup of contaminated sites. However, these technologies are limited by flow channeling of chemical treatment agents. Argonne National Laboratory (ANL), the Gas Research Institute, and the Institute of Gas Technology are collaboratively investigating a new bioremediation technology using foams. The ability of a foam to block pores and limit flow bypassing makes it ideal for DNAPL remediation. The hydrodynamics of gas/liquid foam flows differ significantly from the hydrodynamics of single and multiphase nonfoaming flows. This is illustrated using a multiphase flow hydrodynamic computer model and a two-dimensional flow visualization cell. A state-of-the-art, nonintrusive, three-dimensional magnetic resonance imaging technique was developed to visualize DNAPL mobilization in three dimensions. Mechanisms to be investigated are in situ DNAPL interactions with the foam, DNAPL emulsification, DNAPL scouring by the foam, and subsequent DNAPL mobilization/redeposition in the porous media

Tri-fuel (diesel-biodiesel-ethanol) emulsion characterization, stability and the corrosion effect

Science.gov (United States)

Low, M. H.; Mukhtar, N. A. M.; Yohaness Hagos, Ftwi; Noor, M. M.

2017-10-01

This paper presents the result of experimenting emulsified tri-fuel in term of stability, physico-chemical properties and corrosion effect on three common metals. The results were interpreted in terms of the impact of five minutes emulsification approach. Tri-fuel emulsions were varied in proportion ratio consist of biodiesel; 0%, 5%, 10%, and ethanol; 5%, 10%, 15%. Fuel characterization includes density, calorific value, flash point, and kinematic viscosity. Flash point of tri-fuel emulsion came with range catalog. Calorific value of tri-fuel emulsion appeared in declining pattern as more ethanol and biodiesel were added. Biodiesel promoted flow resistance while ethanol with opposite effect. 15% ethanol content in tri-fuel emulsion separated faster than 10% ethanol content but ethanol content with 5% yield no phase separation at all. Close cap under static immersion with various ratio of tri-fuel emulsions for over a month, corrosiveness attack was detected via weight loss technique on aluminum, stainless steel and mild steel.

Controlled assembly of jammed colloidal shells on fluid droplets

Science.gov (United States)

Subramaniam, Anand Bala; Abkarian, Manouk; Stone, Howard A.

2005-07-01

Assembly of colloidal particles on fluid interfaces is a promising technique for synthesizing two-dimensional microcrystalline materials useful in fields as diverse as biomedicine, materials science, mineral flotation and food processing. Current approaches rely on bulk emulsification methods, require further chemical and thermal treatments, and are restrictive with respect to the materials used. The development of methods that exploit the great potential of interfacial assembly for producing tailored materials have been hampered by the lack of understanding of the assembly process. Here we report a microfluidic method that allows direct visualization and understanding of the dynamics of colloidal crystal growth on curved interfaces. The crystals are periodically ejected to form stable jammed shells, which we refer to as colloidal armour. We propose that the energetic barriers to interfacial crystal growth and organization can be overcome by targeted delivery of colloidal particles through hydrodynamic flows. Our method allows an unprecedented degree of control over armour composition, size and stability.

Use of adsorption and gas chromatographic techniques in estimating biodegradation of indigenous crude oils

International Nuclear Information System (INIS)

Kokub, D.; Allahi, A.; Shafeeq, M.; Khalid, Z.M.; Malik, K.A.; Hussain, A.

1993-01-01

Indigenous crude oils could be degraded and emulsified upto varying degree by locally isolated bacteria. Degradation and emulsification was found to be dependent upon the chemical composition of the crude oils. Tando Alum and Khashkheli crude oils were emulsified in 27 and 33 days of incubation respectively. While Joyamair crude oil and not emulsify even mainly due to high viscosity of this oil. Using adsorption chromatographic technique, oil from control (uninoculated) and bio degraded flasks was fractioned into the deasphaltened oil containing saturate, aromatic, NSO (nitrogen, sulphur, oxygen) containing hydrocarbons) and soluble asphaltenes. Saturate fractions from control and degraded oil were further analysed by gas liquid chromatography. From these analyses, it was observed that saturate fraction was preferentially utilized and the crude oils having greater contents of saturate fraction were better emulsified than those low in this fraction. Utilization of various fractions of crude oils was in the order saturate> aromatic> NSO. (author)

Effect of surfactant on kinetics of thinning of capillary bridges

Science.gov (United States)

Nowak, Emilia; Kovalchuk, Nina; Simmons, Mark

2015-11-01

Kinetics of thinning of capillary bridges is of great scientific and industrial interest being of vital importance for example in various emulsification and microfluidic processes. It is well known that the rate of bridge thinning is proportional to the interfacial tension. Therefore it is expected that the process should slow down by addition of surfactant. The kinetics of capillary bridges in the presence of surfactant was studied by the dripping of liquid from a capillary tip under conditions of nearly zero flow rate (We personal care products. The viscosity, surfactant activity and adsorption kinetics have been controlled by addition of glycerol and sodium chloride. The study has shown that the kinetics of capillary bridges are determined by dynamic surface tension rather than by its equilibrium value. In particular, the kinetics of the bridge thinning for the 0.1 g L-1 aqueous SLES solution is practically the same as that of pure water despite twice lower equilibrium surface tension. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1.

Microbial biosurfactants as additives for food industries.

Science.gov (United States)

Campos, Jenyffer Medeiros; Stamford, Tânia Lúcia Montenegro; Sarubbo, Leonie Asfora; de Luna, Juliana Moura; Rufino, Raquel Diniz; Banat, Ibrahim M

2013-01-01

Microbial biosurfactants with high ability to reduce surface and interfacial surface tension and conferring important properties such as emulsification, detergency, solubilization, lubrication and phase dispersion have a wide range of potential applications in many industries. Significant interest in these compounds has been demonstrated by environmental, bioremediation, oil, petroleum, food, beverage, cosmetic and pharmaceutical industries attracted by their low toxicity, biodegradability and sustainable production technologies. Despite having significant potentials associated with emulsion formation, stabilization, antiadhesive and antimicrobial activities, significantly less output and applications have been reported in food industry. This has been exacerbated by uneconomical or uncompetitive costing issues for their production when compared to plant or chemical counterparts. In this review, biosurfactants properties, present uses and potential future applications as food additives acting as thickening, emulsifying, dispersing or stabilising agents in addition to the use of sustainable economic processes utilising agro-industrial wastes as alternative substrates for their production are discussed. © 2013 American Institute of Chemical Engineers.

Isolation of Biosurfactant Producing Bacteria from Oil Reservoirs

Directory of Open Access Journals (Sweden)

A Tabatabaee, M Mazaheri Assadi, AA Noohi,VA Sajadian

2005-01-01

Full Text Available Biosurfactants or surface-active compounds are produced by microoaganisms. These molecules reduce surface tension both aqueous solutions and hydrocarbon mixtures. In this study, isolation and identification of biosurfactant producing bacteria were assessed. The potential application of these bacteria in petroleum industry was investigated. Samples (crude oil were collected from oil wells and 45 strains were isolated. To confirm the ability of isolates in biosurfactant production, haemolysis test, emulsification test and measurement of surface tension were conducted. We also evaluated the effect of different pH, salinity concentrations, and temperatures on biosurfactant production. Among importance features of the isolated strains, one of the strains (NO.4: Bacillus.sp showed high salt tolerance and their successful production of biosurfactant in a vast pH and temperature domain and reduced surface tension to value below 40 mN/m. This strain is potential candidate for microbial enhanced oil recovery. The strain4 biosurfactant component was mainly glycolipid in nature.

State-of-the-art and research needs for oil spill impact assessment modelling

Energy Technology Data Exchange (ETDEWEB)

French-McCay, D. [Applied Science Associates Inc., South Kingstown, RI (United States)

2009-07-01

Many oil spill models focus on trajectory and fate in aquatic environments. Models designed to address subsurface oil concentrations typically overlay fates model concentration results on maps or grids of biological distributions to assess impacts. This paper discussed a state-of-the-art biological effects model designed to evaluate the impacts and dose of oil spill hydrocarbons on aquatic biota including birds, mammals, reptiles, fish, invertebrates and plants. The biological effects model was coupled to an oil trajectory and fates spill impact model application package (SIMAP) in order to obtain accurate spatial and temporal quantifications of oil distributions and hydrocarbon component concentrations. Processes simulated in the model included slick spreading, evaporation of volatiles from surface oil, transport on the water surface, and various types of oil dispersion and emulsification. The design of the model was discussed, as well as strategies used for applying the model for hindcasts and risk assessments. 204 refs., 3 tabs., 5 figs.

Physical, Rheological, Functional, and Film Properties of a Novel Emulsifier: Frost Grape Polysaccharide from Vitis riparia Michx.

Science.gov (United States)

Hay, William T; Vaughn, Steven F; Byars, Jeffrey A; Selling, Gordon W; Holthaus, Derek M; Price, Neil P J

2017-10-04

A novel emulsifier, Frost grape polysaccharide (FGP), isolated from natural exudate of the species Vitis riparia Michx, was physically and rheologically characterized. The determination of the physical, structural, thermodynamic, emulsification, film, and rheological properties of FGP provide essential details for the commercial adoption of this novel plant polysaccharide. FGP is capable of producing exceptionally stable emulsions when compared with the industrially ubiquitous gum arabic (GA). The FGP isolate contained a negligible amount of nitrogen (0.03%), indicating that it does not contain an associated glycoprotein, unlike GA. Solutions of FGP have a high degree of thermostability, displaying no loss in viscosity with temperature cycling and no thermal degradation when held at 90 °C. FGP is an excellent film former, producing high tensile strength films which remain intact at temperatures up to 200 °C. This work identified a number of potential food and pharmaceutical applications where FGP is significantly superior to GA.

Generation of shrimp waste-based dispersant for oil spill response.

Science.gov (United States)

Zhang, Kedong; Zhang, Baiyu; Song, Xing; Liu, Bo; Jing, Liang; Chen, Bing

2018-04-01

In this study, shrimp waste was enzymatically hydrolyzed to generate a green dispersant and the product was tested for crude oil dispersion in seawater. The hydrolysis process was first optimized based on the dispersant effectiveness (DE) of the product. The functional properties of the product were identified including stability, critical micelle concentration, and emulsification activity. Water was confirmed as a good solvent for dispersant generation when compared with three chemical solvents. The effects of salinity, mixing energy, and temperature on the dispersion of the Alaska North Slope (ANS) crude oil were examined. Microtox acute toxicity test was also conducted to evaluate the toxicity of the produced dispersant. In addition, DE of the product on three different types of crude oil, including ANS crude oil, Prudhoe Bay crude oil (PBC), and Arabian Light crude oil (ALC) was compared with that of the Corexit 9500, respectively. The research output could lead to a promising green solution to the oil spill problem and might result in many other environmental applications.

Preparation of non-porous microspheres with high entrapment efficiency of proteins by a (water-in-oil)-in-oil emulsion technique.

Science.gov (United States)

Viswanathan, N B; Thomas, P A; Pandit, J K; Kulkarni, M G; Mashelkar, R A

1999-03-08

Emulsification-solvent removal methods have been widely used for encapsulating bioactive macromolecules like proteins and polypeptides in biodegradable polymers. We report, a (water-in-oil)-in-oil emulsion technique wherein proteins and polypeptides differing in molecular weight and shape were encapsulated in polymers of current biomedical interest. When an oil was used as the processing medium in combination with a carefully selected mixed solvent system such that a stable (w/o1/o2 emulsion is formed and solvents are removed by a combination of extraction and evaporation, the entrapment efficiency was high and the product nonporous. The entrapment efficiency of globular proteins exceeded 90% while that of fibrous proteins was around 70%. Fracture studies revealed that the polymer matrix was dense. The mechanism of entrapment involved solvent-induced precipitation of the protein as the microspheres were being formed. The principle of the method will find use in preparation of non-porous polymer microparticles with reduced burst effect.

Microcapsules with a pH responsive polymer: influence of the encapsulated oil on the capsule morphology.

Science.gov (United States)

Wagdare, Nagesh A; Marcelis, Antonius T M; Boom, Remko M; van Rijn, Cees J M

2011-11-01

Microcapsules were prepared by microsieve membrane cross flow emulsification of Eudragit FS 30D/dichloromethane/edible oil mixtures in water, and subsequent phase separation induced by extraction of the dichloromethane through an aqueous phase. For long-chain triglycerides and jojoba oil, core-shell particles were obtained with the oil as core, surrounded by a shell of Eudragit. Medium chain triglyceride (MCT oil) was encapsulated as relatively small droplets in the Eudragit matrix. The morphology of the formed capsules was investigated with optical and SEM microscopy. Extraction of the oil from the core-shell capsules with hexane resulted in hollow Eudragit capsules with porous shells. It was shown that the differences are related to the compatibility of the oils with the shell-forming Eudragit. An oil with poor compatibility yields microcapsules with a dense Eudragit shell on a single oil droplet as the core; oils having better compatibility yield porous Eudragit spheres with several oil droplets trapped inside. Copyright © 2011 Elsevier B.V. All rights reserved.

Study on physico-chemical properties of emulsion type sausage produced with aqueous extract of Biarum carduchcorum tenderizied meat

Directory of Open Access Journals (Sweden)

M. Raeisi

2017-05-01

Full Text Available In order to improve the quality of meat such as tenderness, protein solubility, emulsification and water holding capacity, in the food industries, various methods have been employed. Application of the plant enzymes is considered as one of the most efficient methods for meat tenderization. The purpose of the present study was to evaluate the characteristics of emulsion type sausage made from tenderized cattle meat by hydro extract of Biarum carduchcorum. The proteolytic activity of the extract was determined using bovine milk casein as substrate. Post rigor thigh meat were tenderized by 100 and 150 enzyme units/ kg of the extract before used for production of sausage. Fresh post rigor thigh meat was used as control. Nitrogen solubility index (NSI, stability of sausage emulsion, texture analysis and organoleptic properties of sausages were determined. Our results showed a significant increase in the NSI of the experimental groups compared with the control (P

Determination of humic acid in alkali leaching solution of uranium by spectophotrometry-COD method

International Nuclear Information System (INIS)

Feng Yu; An Wei; Chen Shusen

2014-01-01

It is one of the main causes of extraction emulsification or resin toxicosis during alkali leaching process in uranium metallurgy which organic matters including humic acid exist in lixiviums. In order to study the effect of humic acid in uranium metallurgy, a method for determination of content of humic acid in aqueous solution need to be established. Spectrophotometry is a simple and convenient method in humic acid analysis. However, accuracy of spectrophotometry can be reduced greatly because of interference of uranium and other elements in the humic acid solutions. Although chemical oxygen demand (COD) method is a common analysis way of organic matters in aqueous solutions, the concentration of humic acid cannot be directly measured. In this paper, COD method is related with spectrophotometry to avoid the interference of uranium and ensure the accurate analysis of humic acid. The results showed that the detection limit of the method was 1.78 mg/L and the recovery rate was 101.2%. (authors)

Tuning the Wettability of Halloysite Clay Nanotubes by Surface Carbonization for Optimal Emulsion Stabilization.

Science.gov (United States)

Owoseni, Olasehinde; Zhang, Yueheng; Su, Yang; He, Jibao; McPherson, Gary L; Bose, Arijit; John, Vijay T

2015-12-29

The carbonization of hydrophilic particle surfaces provides an effective route for tuning particle wettability in the preparation of particle-stabilized emulsions. The wettability of naturally occurring halloysite clay nanotubes (HNT) is successfully tuned by the selective carbonization of the negatively charged external HNT surface. The positively charge chitosan biopolymer binds to the negatively charged external HNT surface by electrostatic attraction and hydrogen bonding, yielding carbonized halloysite nanotubes (CHNT) on pyrolysis in an inert atmosphere. Relative to the native HNT, the oil emulsification ability of the CHNT at intermediate levels of carbonization is significantly enhanced due to the thermodynamically more favorable attachment of the particles at the oil-water interface. Cryogenic scanning electron microscopy (cryo-SEM) imaging reveals that networks of CHNT attach to the oil-water interface with the particles in a side-on orientation. The concepts advanced here can be extended to other inorganic solids and carbon sources for the optimal design of particle-stabilized emulsions.

Saponification pretreatment and solids recirculation as a new anaerobic process for the treatment of slaughterhouse waste.

Science.gov (United States)

Affes, R; Palatsi, J; Flotats, X; Carrère, H; Steyer, J P; Battimelli, A

2013-03-01

Different configurations of anaerobic process, adapted to the treatment of solid slaughterhouse fatty waste, were proposed and evaluated in this study. The tested configurations are based on the combination of anaerobic digestion with/without waste saponification pretreatment (70 °C during 60 min) and with/without recirculation of the digestate solid fraction (ratio=20% w/w). After an acclimation period of substrate pulses-feeding cycles, the reactors were operated in a semi-continuous feeding mode, increasing organic loading rates along experimental time. The degradation of the raw substrate was shown to be the bottleneck of the whole process, obtaining the best performance and process yields in the reactor equipped with waste pretreatment and solids recirculation. Saponification promoted the emulsification and bioavailability of solid fatty residues, while recirculation of solids minimized the substrate/biomass wash-out and induced microbial adaptation to the treatment of fatty substrates. Copyright © 2013 Elsevier Ltd. All rights reserved.

Microbial Activation of Bacillus subtilis-Immobilized Microgel Particles for Enhanced Oil Recovery.

Science.gov (United States)

Son, Han Am; Choi, Sang Koo; Jeong, Eun Sook; Kim, Bohyun; Kim, Hyun Tae; Sung, Won Mo; Kim, Jin Woong

2016-09-06

Microbially enhanced oil recovery involves the use of microorganisms to extract oil remaining in reservoirs. Here, we report fabrication of microgel particles with immobilized Bacillus subtilis for application to microbially enhanced oil recovery. Using B. subtilis isolated from oil-contaminated soils in Myanmar, we evaluated the ability of this microbe to reduce the interfacial tension at the oil-water interface via production of biosurfactant molecules, eventually yielding excellent emulsification across a broad range of the medium pH and ionic strength. To safely deliver B. subtilis into a permeable porous medium, in this study, these bacteria were physically immobilized in a hydrogel mesh of microgel particles. In a core flooding experiment, in which the microgel particles were injected into a column packed with silica beads, we found that these particles significantly increased oil recovery in a concentration-dependent manner. This result shows that a mesh of microgel particles encapsulating biosurfactant-producing microorganisms holds promise for recovery of oil from porous media.

The study of stability, combustion characteristics and performance of water in diesel emulsion fuel

Directory of Open Access Journals (Sweden)

Syafiq Zulkifli

2017-01-01

Full Text Available A single cylinder diesel engine study of water in diesel emulsions was conducted to investigate the stability effect of emulsion fuel on three different fuel blends and the water emulsification effect on the engine performance. Emulsified fuels contained 2% of surfactant including Span 80 Tween 80 and tested 10 HLB number. The blends also varied of 5%, 10% and 15% of water in diesel ratios namely as BSW5, BSW10 and BSW15. The fuel blends performance was tested using a single cylinder, direct injection diesel engine, operating at 1860 rpm. The results on stability reveal that high shear homogenizer yields more stability on emulsion fuel than mechanical stirrer and ultrasonic water bath. The engine performance results show that the ignition delay and peak pressure increase with the increment of water percentage up to 15%. However, the results indicate the increment of water percentage is also shows a significant decrease in engine power.

Control of Black Rot Disease in Tomato Fruits by Using Formulated Ginger Essential oil Treated by Gamma Radiation

International Nuclear Information System (INIS)

Helal, I.M.; Abdeldaiem, M.H.

2008-01-01

Ginger essential oil (Zingiber officinale) treated by gamma radiation at dose of 10 kGy was selected as an active ingredient for formulation of the biocide. Liquid formulations (emulsifiable concentrates) were prepared using different emulsifiers (Emulgator B.L.M. and tween 80 or tween 20) and additive oil (soybean oil). Physicochemical properties of the formulated oil (spontaneous emulsification, emulsion stability; cold stability and heat stability, viscosity, surface tension and ph) were measured. The formulated oil was tested in vivo to investigate its efficiency for controlling the growth of Alternaria alternata inoculated into tomato fruits. The results indicated that soaking inoculated tomato fruits in the formulated oil (ginger essential oil + soybean oil + emulgator B.L.M. + tween 80) treatment at concentration of 300 ppm for a period of 12 minute was the most effective for controlling the growth of the tested fungus. In addition, the formulated oil had efficiency for controlling the rot development on tomato fruits when applied as therapeutic and protective agents

Mid-scale tests of in situ burning in a new wave tank at Prudhoe Bay, AK

International Nuclear Information System (INIS)

Buist, I.; McCourt, J.; Mullin, J.; Glover, N.; Hutton, C.; McHale, J.

1998-01-01

A series of mid-scale research burns with weathered Alaska North Slope crude, Milne Pt. crude and emulsion slicks were carried out in the fall of 1997 in Prudhoe Bay, Alaska. A suitable wave tank was developed for the in-situ burning tests. The objective was to determine the effects of oil type, emulsification, temperature and waves on in situ burning in Arctic open water conditions. More than 60 individual burns were conducted under various parameters including varying slick thickness, water content, wave energy, degree of weathering and oil type. Results showed that a spill of 60 per cent water emulsion of weathered Alaska North Slope crude was successfully burned in the highest waves tested, with an oil removal efficiency of 79 per cent, after treatment with emulsion breakers. A slick of 60 per cent water emulsion of weathered Milne Pt. crude was also successfully burned under the same conditions but without the addition of emulsion breakers. 10 refs., 1 tab., 13 figs

Polyelectrolyte Complex Inclusive Biohybrid Microgels for Tailoring Delivery of Copigmented Anthocyanins.

Science.gov (United States)

Tan, Chen; B Celli, Giovana; Lee, Michelle; Licker, Jonathan; Abbaspourrad, Alireza

2018-05-14

This study fabricated a novel biohybrid microgel containing polysaccharide-based polyelectrolyte complexes (PECs) for anthocyanins. Herein, anthocyanins were encapsulated into PECs composed of chondroitin sulfate and chitosan, followed by incorporation into alginate microgels using emulsification/internal gelation method. We demonstrated that PECs incorporation strongly affected the properties of microgels, dependent on the polysaccharide concentration and pH in which they were fabricated. The dense internal network surrounded by an alginate shell was clearly visualized in cross-sectioned PECs-microgels. Stability studies carried out under varying ionic strength and pH conditions demonstrated the stimuli-responsiveness of the PECs-microgels. Additionally, the presence of PECs conferred microgels with high rigidity during freeze-drying and excellent reconstitution capacity upon rehydration. These observations were attributed to the modulation of electrostatic and hydrogen-bonding cross-linking between PECs and the alginate gel matrix and suggest the PECs inclusive microgels hold promise as delivery vehicles for the controlled release of hydrophilic bioactive compounds.

Biosurfactant-enhanced bioremediation of hydrophobic pollutants

Energy Technology Data Exchange (ETDEWEB)

Cameotra, S.S.; Makkar, R.S. [Inst. of Microbial Technology, Chandigarh (India)

2010-01-15

Biosurfactants are surface-active compounds synthesized by a wide variety of microorganisms. They are molecules that have both hydrophobic and - philic domains and are capable of lowering the surface tension and the interfacial tension of the growth medium. Biosurfactants possess different chemical structures-lipopeptides, glycolipids, neutral lipids, and fatty acids. They are nontoxic biomolecules that are biodegradable. Biosurfactants also exhibit strong emulsification of hydrophobic compounds and form stable emulsions. Polycyclic aromatic hydrocarbons (PAHs), crude on sludge, and pesticides call be toxic, mutagenic, and carcinogenic compounds that pollute the environment. They are released into the environment as a result of oil spillage and by-products of coal treatment processes. The low water solubility of these compounds limits their availability to microorganisms, which is a potential problem for bioremediation of contaminated sites. Microbially produced surfactants enhance the bioavailability of these hydrophobic compounds for bioremediation. Therefore, biosurfactant-enhanced solubility of pollutants has potential hioremediation applications.

Microalgae as feedstock for biodiesel production under ultrasound treatment - A review.

Science.gov (United States)

Sivaramakrishnan, Ramachandran; Incharoensakdi, Aran

2018-02-01

The application of ultrasound in biodiesel production has recently emerged as a novel technology. Ultrasound treatment enhances the mass transfer characteristics leading to the increased reaction rate with short reaction time and potentially reduces the production cost. In this review, application of ultrasound-assisted biodiesel production using acid, base and enzyme catalysts is presented. A critical assessment of the current status of ultrasound in biodiesel production was discussed with the emphasis on using ultrasound for efficient microalgae biodiesel production. The ultrasound in the biodiesel production enhances the emulsification of immiscible liquid reactant by microturbulence generated by cavitation bubbles. The major benefit of the ultrasound-assisted biodiesel production is a reduction in reaction time. Several different methods have been discussed to improve the biodiesel production. Overall, this review focuses on the current understanding of the application of ultrasound in biodiesel production from microalgae and to provide insights into future developments. Copyright © 2017 Elsevier Ltd. All rights reserved.

The specific ion effect on emulsions, foam and gels of a seed protein concentrate

International Nuclear Information System (INIS)

Lawal, O.S.

2008-05-01

Protein concentrate was prepared from the seeds of jack bean (Canavalia ensiformis) and the influences of selected Hofmeister salts on some functional properties of the protein concentrate were investigated. The results indicate that kosmotropic salts (Na 2 SO 4 , NaCl, NaBr) had improved water absorption capacities over the chaotropic salts (NaI, NaClO 4 , NaSCN) and generally, the reduction in water absorption capacity followed the Hofmeister trend: Na 2 SO 4 > NaCl > NaBr > NaI > NaClO 4 > NaSCN. However, the reverse was observed for the foaming and emulsification properties. The least gelation concentration (LGC) was used as the index of gelation properties and the results showed that LGC were higher in kosmotropic salts than in chaotropic salts. Generally, increases in salt concentration reduced the water absorption capacity, the surfactant properties as well as the gelation property. The findings would provide insight into the understanding of the structure property relations of the protein concentrate. (author)

Porous Polystyrene Monoliths and Microparticles Prepared from Core Cross-linked Star (CCS) Polymers-Stabilized Emulsions.

Science.gov (United States)

Chen, Qijing; Shi, Ting; Han, Fei; Li, Zihan; Lin, Chao; Zhao, Peng

2017-08-17

A hydrophobic CCS polymer of poly(benzyl methacrylate) (PBzMA) was prepared in toluene by reversible addition-fragmentation chain transfer (RAFT)-mediated dispersion polymerization. The CCS polymer, with poly(benzyl methacrylate) as the arm and crosslinked N, N'-bis(acryloyl)cystamine (BAC) as the core, was confirmed by characterization with gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy. Three kinds of oils (toluene, anisole and styrene) were chosen to study the emulsification properties of PBzMA CCS polymer. The oils can be emulsified by CCS polymer to form water-in-oil (w/o) emulsions. Moreover, w/o high internal phase emulsions (HIPEs) can be obtained with the increase of toluene and styrene volume fractions from 75% to 80%. Porous polystyrene monolith and microparticles were prepared from the emulsion templates and characterized by the scanning electronic microscopy (SEM). With the internal phase volume fraction increased, open-pore porous monolith was obtained.

Creating nanoscale emulsions using condensation.

Science.gov (United States)

Guha, Ingrid F; Anand, Sushant; Varanasi, Kripa K

2017-11-08

Nanoscale emulsions are essential components in numerous products, ranging from processed foods to novel drug delivery systems. Existing emulsification methods rely either on the breakup of larger droplets or solvent exchange/inversion. Here we report a simple, scalable method of creating nanoscale water-in-oil emulsions by condensing water vapor onto a subcooled oil-surfactant solution. Our technique enables a bottom-up approach to forming small-scale emulsions. Nanoscale water droplets nucleate at the oil/air interface and spontaneously disperse within the oil, due to the spreading dynamics of oil on water. Oil-soluble surfactants stabilize the resulting emulsions. We find that the oil-surfactant concentration controls the spreading behavior of oil on water, as well as the peak size, polydispersity, and stability of the resulting emulsions. Using condensation, we form emulsions with peak radii around 100 nm and polydispersities around 10%. This emulsion formation technique may open different routes to creating emulsions, colloidal systems, and emulsion-based materials.

Rheological properties of oil-in-water emulsions prepared with oil and protein isolates from sesame (Sesamum Indicum

Directory of Open Access Journals (Sweden)

David Ramirez BREWER

2016-01-01

Full Text Available In this study, food emulsions of oil in water from sesame (Sesamum indicum protein isolates and their oil were formulated and standardised. The effect of the concentrations of sesame (Sesamum indicum protein isolates and base oil and the speed of the emulsification process for the food emulsion stability was studied. The protein isolates were achieved from the defatted sesame flour (DSF, obtaining a percentage of 80% ± 0.05% of protein. Emulsions were formulated through a factorial design 23. The rheological behaviour of sesame (Sesamum indicum protein isolates-stabilised emulsions and microstructural composition were investigated. Stable emulsions with suitable rheological properties and microstructure were formulated at a concentration of 10% sesame oil and different concentrations of protein isolates, between 1.5% and 2.5%, with the best droplet distribution characteristics being shown for the 2.5% sesame protein isolates. The emulsions showed a non-Newtonian fluid behaviour, adjusting the Sisko model.

Cryo-FIB SEM for Characterization of the Structure of Fish Oil Emulsions

DEFF Research Database (Denmark)

Jensen, Louise Helene Søgaard; Horn, Anna Frisenfeldt; Jacobsen, Charlotte

2011-01-01

Addition of fish oil to food products to improve nutritional quality by the addition of omega-3 fatty acids is attractive both to the consumers and the food industry for reasons such as health benefits and added product value. The long chain omega-3 fatty acids contain a large number of double...... bonds which causes the fish oil to be susceptible to oxidation. The shelf lives of fish oil enriched products are thus limited by fast oxidation rates of the fish oil which causes development of off flavours as well as degeneration of the beneficial health effects of the fish oil. At the present moment...... this is a barrier for their access to the market and it is necessary to develop techniques to protect the oil against oxidation. Emulsification of the oil has been put forward as a strategy for protection against oxidation, but whether that is beneficial seems to depend on the food matrix to which the oil is added...

Retardation Of Lipid Oxidation In Fish Oil-Enriched Fish Pâté- Combination Effects

DEFF Research Database (Denmark)

Nielsen, Nina Skall; Jacobsen, Charlotte

2013-01-01

The oxidative stability during storage of fish pâté made from cod and enriched with 5% oil was investigated. Pâtés were produced with neat fish oil, pre-emulsified fish oil, microencapsulated fish oil, inert medium chain triacylglycerol (MCT) oil or a fish/rapeseed oil mixture. Addition of fish...... stored at 2 or 10C were equally stable. Mixing fish oil with rapeseed oil before emulsification slightly increased the stability of the fish pâtés. Addition of antimicrobial agents, sodium benzoate and potassium sorbate increased oxidative stability. It is recommended to produce enriched fish pâté...... by adding pre-emulsified fish oil or microencapsulated fish oil and store at preferentially 2-10C. Practical Applications: The results from this study can directly be transferred to practical applications in the food industry. Thus, the study showed that fish oil-enriched fish pâté with an acceptable...

Low energy nanoemulsification to design veterinary controlled drug delivery devices

Directory of Open Access Journals (Sweden)

Thierry F Vandamme

2010-10-01

Full Text Available Thierry F Vandamme, Nicolas Anton, University of Strasbourg, Faculty of Pharmacy, Illkirch Cedex, France; UMR CNRS 7199, Laboratoire de Conception et Application de Molécules Bioactives, équipe de Pharmacie Biogalénique, Illkirch Cedex, France,  This work is selected as Controlled Release Society Outstanding Veterinary Paper Award 2010Abstract: The unique properties of nanomaterials related to structural stability and quantum-scale reactive properties open up a world of possibilities that could be exploited to design and to target drug delivery or create truly microscale biological sensors for veterinary applications. We developed cost-saving and solvent-free nanoemulsions. Formulated with a low-energy method, these nanoemulsions can find application in the delivery of controlled amounts of drugs into the beverage of breeding animals (such as poultry, cattle, pigs or be used for the controlled release of injectable poorly water-soluble drugs.Keywords: nanoemulsion, nanomedicine, low-energy emulsification, veterinary, ketoprofen, sulfamethazine

Rapid determination of octanol-water partition coefficient using vortex-assisted liquid-liquid microextraction.

Science.gov (United States)

Román, Iván P; Mastromichali, Anna; Tyrovola, Konstantina; Canals, Antonio; Psillakis, Elefteria

2014-02-21

Vortex-assisted liquid-liquid microextraction (VALLME) coupled with high-performance liquid chromatography (HPLC) is proposed here for the rapid determination of octanol-water partitioning coefficients (Kow). VALLME uses vortex agitation, a mild emulsification procedure, to disperse microvolumes of octanol in the aqueous phase thus increasing the interfacial contact area and ensuring faster partitioning rates. With VALLME, 2min were enough to achieve equilibrium conditions between the octanolic and aqueous phases. Upon equilibration, separation was achieved using centrifugation and the octanolic microdrop was collected and analyzed in a HPLC system. Six model compounds with logKow values ranging between ∼0.5 and 3.5 were used during the present investigations. The proposed method produced logKow values that were consistent with previously published values and the recorded uncertainty was well within the acceptable log unit range. Overall, the key features of the proposed Kow determination procedure comprised speed, reliability, simplicity, low cost and minimal solvent consumption. Copyright © 2014 Elsevier B.V. All rights reserved.

A food additive with prebiotic properties of an α-d-glucan from lactobacillus plantarum DM5.

Science.gov (United States)

Das, Deeplina; Baruah, Rwivoo; Goyal, Arun

2014-08-01

An α-d-glucan produced by Lactobacillus plantarum DM5 was explored for in vitro prebiotic activities. Glucan-DM5 demonstrated 21.6% solubility, 316.9% water holding capacity, 86.2% flocculation activity, 71.4% emulsification activity and a degradation temperature (Td) of 292.2°C. Glucan-DM5 exhibited lowest digestibility of 0.54% by artificial gastric juice, 0.21% by intestinal fluid and 0.32% by α-amylase whereas the standard prebiotic inulin, showed 25.23%, 5.97% and 19.13%, hydrolysis, respectively. Prebiotic activity assay of glucan-DM5 displayed increased growth of probiotic bacteria such as Bifidobacterium infantis and Lactobacillus acidophilus, but did not support the growth of non-probiotic bacteria such as Escherichia coli and Enterobacter aerogenes. The overall findings indicated that glucan from L. plantarum DM5 can serve as a potential prebiotic additive for food products. Copyright © 2014 Elsevier B.V. All rights reserved.

COMPARISON OF PHYSICAL STABILITY PROPERTIES OF POMEGRANATE SEED OIL NANOEMULSION DOSAGE FORMS WITH LONG-CHAIN TRIGLYCERIDE AND MEDIUM-CHAIN TRIGLYCERIDE AS THE OIL PHASE

Directory of Open Access Journals (Sweden)

Sri Hartanti Yuliani

2016-08-01

Full Text Available Pomegranate seed oil has antioxidant, anti-inflammatory, and chemo preventive activities. Pomegranate seed oil is lipophilic substance suitable to be prepared in emulsion dosage forms. Long-chain triglyceride (LCT and medium-chain triglyceride (MCT are commonly used as oil phase in emulsion dosage forms. This research aimed to compare the use of LCT and MCT in the Nano emulsion formula of pomegranate seed oil dosage forms. Formulation of pomegranate seed oil Nano emulsion was conducted using high energy emulsification. Parameters observed were pH, Nano emulsion type, percent transmittance, viscosity, turbidity, and droplet size before and after 3 cycles of freeze-thaw. The result showed that there was no significant difference between physical properties of pomegranate oil Nano emulsion with LCT as oil phase and pomegranate oil Nano emulsion with MCT as oil phase. Moreover, physical stability of pomegranate oil Nano emulsion with LCT as oil phase was better than pomegranate oil Nano emulsion with MCT as oil phase.

State-of-the-art and research needs for oil spill impact assessment modelling

International Nuclear Information System (INIS)

French-McCay, D.

2009-01-01

Many oil spill models focus on trajectory and fate in aquatic environments. Models designed to address subsurface oil concentrations typically overlay fates model concentration results on maps or grids of biological distributions to assess impacts. This paper discussed a state-of-the-art biological effects model designed to evaluate the impacts and dose of oil spill hydrocarbons on aquatic biota including birds, mammals, reptiles, fish, invertebrates and plants. The biological effects model was coupled to an oil trajectory and fates spill impact model application package (SIMAP) in order to obtain accurate spatial and temporal quantifications of oil distributions and hydrocarbon component concentrations. Processes simulated in the model included slick spreading, evaporation of volatiles from surface oil, transport on the water surface, and various types of oil dispersion and emulsification. The design of the model was discussed, as well as strategies used for applying the model for hindcasts and risk assessments. 204 refs., 3 tabs., 5 figs

Encapsulation and delivery of food ingredients using starch based systems.

Science.gov (United States)

Zhu, Fan

2017-08-15

Functional ingredients can be encapsulated by various wall materials for controlled release in food and digestion systems. Starch, as one of the most abundant natural carbohydrate polymers, is non-allergenic, GRAS, and cheap. There has been increasing interest of using starch in native and modified forms to encapsulate food ingredients such as flavours, lipids, polyphenols, carotenoids, vitamins, enzymes, and probiotics. Starches from various botanical sources in granular or amorphous forms are modified by chemical, physical, and/or enzymatic means to obtain the desired properties for targeted encapsulation. Other wall materials are also employed in combination with starch to facilitate some types of encapsulation. Various methods of crafting the starch-based encapsulation such as electrospinning, spray drying, antisolvent, amylose inclusion complexation, and nano-emulsification are introduced in this mini-review. The physicochemical and structural properties of the particles are described. The encapsulation systems can positively influence the controlled release of food ingredients in food and nutritional applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Droplets formation and merging in two-phase flow microfluidics.

Science.gov (United States)

Gu, Hao; Duits, Michel H G; Mugele, Frieder

2011-01-01

Two-phase flow microfluidics is emerging as a popular technology for a wide range of applications involving high throughput such as encapsulation, chemical synthesis and biochemical assays. Within this platform, the formation and merging of droplets inside an immiscible carrier fluid are two key procedures: (i) the emulsification step should lead to a very well controlled drop size (distribution); and (ii) the use of droplet as micro-reactors requires a reliable merging. A novel trend within this field is the use of additional active means of control besides the commonly used hydrodynamic manipulation. Electric fields are especially suitable for this, due to quantitative control over the amplitude and time dependence of the signals, and the flexibility in designing micro-electrode geometries. With this, the formation and merging of droplets can be achieved on-demand and with high precision. In this review on two-phase flow microfluidics, particular emphasis is given on these aspects. Also recent innovations in microfabrication technologies used for this purpose will be discussed.

Interaction of divalent minerals with liposoluble nutrients and phytochemicals during digestion and influences on their bioavailability - a review.

Science.gov (United States)

Corte-Real, Joana; Bohn, Torsten

2018-06-30

Several divalent minerals, including the macroelements calcium and magnesium, are essential nutrients for humans. However, their intake, especially via high-dose supplements, has been suspected to reduce the availability of lipophilic dietary constituents, including lipids, liposoluble vitamins, and several phytochemicals such as carotenoids. These constituents require emulsification in order to be bioavailable, and high divalent mineral concentrations may perturb this process, due to precipitations of free fatty acids or bile salt complexation, both pivotal for mixed micelle formation. Though in part based on in vitro or indirect evidence, it appears likely that high-dose supplements of divalent minerals around or even below their recommended dietary allowance perturb the availability of certain liposoluble miroconstituents, in addition to reducing absorption of dietary lipids/cholesterol. In this review, we investigate possible negative influences of divalent minerals, including trace elements (iron, zinc), on the digestion and intestinal uptake of lipophilic dietary constituents, with a focus on carotenoids. Copyright © 2018 Elsevier Ltd. All rights reserved.

Research on the Influence of an Acoustic Field on Particle Cohesion in Liquid

Directory of Open Access Journals (Sweden)

Ramūnas Vilkišius

2012-12-01

Full Text Available Iron is one of the most common natural elements. When iron concentration in water is more than 0,3 mg/l, it causes the formation of rust drain tag or changes the colour of the fabric during washing. Thus, the use of the acoustic field to improve water quality is a very relevant topic. Acoustic oscillations are currently widely used in various industrial sectors, including water treatment, metallurgy, chemical and food industry, equipment manufacturing and medicine. When materials are affected by acoustic fields, physical-chemical processes begin. Acoustic fields cause material dispersion, emulsification, coagulation and degassing (gas removal as well as influence the crystallization and melting processes. Acoustic vibrations may also cause various chemical transformations such as oxidation, polymerization processes and depolymerisation. The utilization of acoustics to enhance water oxidation and precipitation of coarse impurities further extends the scope of the use of this physical method.Article in Lithuanian

Research on the Influence of an Acoustic Field on Particle Cohesion in Liquid

Directory of Open Access Journals (Sweden)

Ramūnas Vilkišius

2013-02-01

Full Text Available Iron is one of the most common natural elements. When iron concentration in water is more than 0,3 mg/l, it causes the formation of rust drain tag or changes the colour of the fabric during washing. Thus, the use of the acoustic field to improve water quality is a very relevant topic. Acoustic oscillations are currently widely used in various industrial sectors, including water treatment, metallurgy, chemical and food industry, equipment manufacturing and medicine. When materials are affected by acoustic fields, physical-chemical processes begin. Acoustic fields cause material dispersion, emulsification, coagulation and degassing (gas removal as well as influence the crystallization and melting processes. Acoustic vibrations may also cause various chemical transformations such as oxidation, polymerization processes and depolymerisation. The utilization of acoustics to enhance water oxidation and precipitation of coarse impurities further extends the scope of the use of this physical method.Article in Lithuanian

Applications of polymeric nanocapsules in field of drug delivery systems.

Science.gov (United States)

Rong, Xinyu; Xie, Yinghua; Hao, Xiaomei; Chen, Tao; Wang, Yingming; Liu, Yuanyuan

2011-09-01

Drug-loaded polymeric nanocapsules have exhibited potential applications in the field of drug delivery systems in recent years. This article entails the biodegradable polymers generally used for preparing nanocapsules, which include both natural polymers and synthetic polymers. Furthermore, the article presents a general review of the different preparation methods: nanoprecipitation method, emulsion-diffusion method, double emulsification method, emulsion-coacervation method, layer-by-layer assembly method. In addition, the analysis methods of nanocapsule characteristics, such as mean size, morphology, surface characteristics, shell thickness, encapsulation efficiency, active substance release, dispersion stability, are mentioned. Also, the applications of nanocapsules as carriers for use in drug delivery systems are reviewed, which primarily involve targeting drug delivery, controlled/sustained release drug delivery systems, transdermal drug delivery systems and improving stability and bioavailability of drugs. Nanocapsules, prepared with different biodegradable polymers, have received more and more attention and have been regarded as one of the most promising drug delivery systems.

Improved physicochemical properties and hepatic protection of Maillard reaction products derived from fish protein hydrolysates and ribose.

Science.gov (United States)

Yang, Sung-Yong; Lee, Sanghoon; Pyo, Min Cheol; Jeon, Hyeonjin; Kim, Yoonsook; Lee, Kwang-Won

2017-04-15

High amounts of waste products generated from fish-processing need to be disposed of despite their potential nutritional value. A variety of methods, such as enzymatic hydrolysis, have been developed for these byproducts. In the current study, we investigated the physicochemical, biological and antioxidative properties of fish protein hydrolysates (FPH) conjugated with ribose through the Maillard reaction. These glycated conjugates of FPH (GFPH) had more viscous rheological properties than FPH and exhibited higher heat, emulsification and foaming stability. They also protected liver HepG2 cells against t-BHP-induced oxidative stress with enhanced glutathione synthesis in vitro. Furthermore, it was shown that GFPH induced upregulation of phase II enzyme expression, such as that of HO-1 and γ-GCL, via nuclear translocation of Nrf2 and phosphorylation of ERK. Taken together, these results demonstrate the potential of GFPH for use as a functional food ingredient with improved rheological and antioxidative properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

The potential applications in heavy oil EOR with the nanoparticle and surfactant stabilized solvent-based emulsion

Energy Technology Data Exchange (ETDEWEB)

Qiu, F. [Texas A and M Univ., College Station, TX (United States)

2010-07-01

The main challenges in developing the heavy oil reservoirs in the Alaska North Slope (ANS) include technical challenges regarding thermal recovery; sand control and disposal; high asphaltene content; and low in-situ permeability. A chemical enhanced oil recovery method may be possible for these reservoirs. Solvent based emulsion flooding provides mobility control; oil viscosity reduction; and in-situ emulsification of heavy oil. This study evaluated the potential application of nano-particle-stabilized solvent based emulsion injection to enhance heavy oil recovery in the ANS. The optimized micro-emulsion composition was determined using laboratory tests such as phase behaviour scanning, rheology studies and interfacial tension measurements. The optimized nano-emulsions were used in core flooding experiments to verify the recovery efficiency. The study revealed that the potential use of this kind of emulsion flooding is a promising enhanced oil recovery process for some heavy oil reservoirs in Alaska, Canada and Venezuela. 4 refs., 2 tabs., 10 figs.

Improved bioavailability and biodegradation of a model polyaromatic hydrocarbon by a biosurfactant producing bacterium of marine origin.

Science.gov (United States)

Das, Palashpriya; Mukherjee, Soumen; Sen, Ramkrishna

2008-07-01

Polyaromatic hydrocarbons (PAHs) are organic pollutants mostly derived from the processing and combustion of fossil fuels and cause human health hazards. In the present study a marine biosurfactant producing strain of Bacillus circulans was used to increase the bioavailability and consequent degradation of a model polyaromatic hydrocarbon, anthracene. Although the organism could not utilize anthracene as the sole carbon source, it showed better growth and biosurfactant production in an anthracene supplemented glycerol mineral salts medium (AGlyMSM) compared to a normal glycerol mineral salts medium (GlyMSM). The biosurfactant product showed high degree of emulsification of various hydrocarbons. Analysis by gas chromatography (GC), high performance thin layer chromatography (HPTLC) and Fourier transform infrared spectroscopy (FTIR) showed that the biosurfactant could effectively entrap and solubilize PAH. Thin layer chromatographic analysis showed that anthracene was utilized as a carbon substrate for the production of biosurfactant. Thus organic pollutant anthracene was metabolized and converted to biosurfactants facilitating its own bioremediation.

OILMAP: A global approach to spill modeling

International Nuclear Information System (INIS)

Spaulding, M.L.; Howlett, E.; Anderson, E.; Jayko, K.

1992-01-01

OILMAP is an oil spill model system suitable for use in both rapid response mode and long-range contingency planning. It was developed for a personal computer and employs full-color graphics to enter data, set up spill scenarios, and view model predictions. The major components of OILMAP include environmental data entry and viewing capabilities, the oil spill models, and model prediction display capabilities. Graphic routines are provided for entering wind data, currents, and any type of geographically referenced data. Several modes of the spill model are available. The surface trajectory mode is intended for quick spill response. The weathering model includes the spreading, evaporation, entrainment, emulsification, and shoreline interaction of oil. The stochastic and receptor models simulate a large number of trajectories from a single site for generating probability statistics. Each model and the algorithms they use are described. Several additional capabilities are planned for OILMAP, including simulation of tactical spill response and subsurface oil transport. 8 refs

An investigation of chitosan and sodium dodecyl sulfate interactions in acetic media

Directory of Open Access Journals (Sweden)

Petrović Lidija B.

2016-01-01

Full Text Available Polymer/surfactant association is a cooperative phenomenon where surfactant binds to the polymer in the form of aggregates, usually through electrostatic or hydrophobic forces. As already known, polyelectrolytes may interact with oppositely charged surfactants through electrostatic attraction that results in polymer/surfactant complex formation. This behavior could be desirable in wide range of application of polymer/surfactant mixtures, such as improving colloid stability, gelling, emulsification and microencapsulation. In the present study surface tension, turbidity, viscosity and electrophoretic mobility measurements were used to investigate interactions of cationic polyelectrolyte chitosan (Ch and oppositely charged anionic surfactant, sodium dodecyl sulfate (SDS, in buffered water. Obtained results show the presence of interactions that lead to Ch/SDS complexes formation at all investigated pH and for all investigated polymer concentrations. Mechanisms of interaction, as well as characteristics of formed Ch/SDS complexes, are highly dependent on their mass ratio in the mixtures, while pH has no significant influence. [Projekat Ministarstva nauke Republike Srbije, br. II46010

Small-angle neutron scattering and rheological analyses of nanoemulsion for cosmetics

International Nuclear Information System (INIS)

Kume, Takuji

2014-01-01

A stable nanoemulsion consisting of nanometer-sized oil droplets in water having a self-standing capability was prepared by high-pressure emulsification. Rheological measurements show that the nanoemulsion has a high viscosity and a yield stress. Small-angle neutron scattering (SANS) revealed the presence of an ordered crystal-like lattice structure in addition to spherical domains with a diameter of ca. 30 nm. Nonfluidity of nanoemulsion is ascribed to crystal-like lattice structure of nanodroplets. A mixed solution of 2-hydroxyethyl cellulose and the nanoemulsion has shear-thickening behavior (shear-induced gelation). Real-time SANS measurements with a Couette geometry as a function of shear rate (Rheo-SANS) revealed that a possible mechanism of gelation was proposed from the viewpoint of shear-induced percolation transition. Furthermore, mixtures of the nanoemulsion and poly(acrylic acid) solutions were opaque and kept the same interdomain distance and high viscosity. We estimated that it had phase-separated structure between nanoemulsion phase and poly(acrylic acid) solution phase. (author)

Pickering emulsions stabilized by paraffin wax and Laponite clay particles.

Science.gov (United States)

Li, Caifu; Liu, Qian; Mei, Zhen; Wang, Jun; Xu, Jian; Sun, Dejun

2009-08-01

Emulsions containing wax in dispersed droplets stabilized by disc-like Laponite clay particles are prepared. Properties of the emulsions prepared at different temperatures are examined using stability, microscopy and droplet-size analysis. At low temperature, the wax crystals in the oil droplets can protrude through the interface, leading to droplet coalescence. But at higher temperatures, the droplet size decreases with wax concentration. Considering the viscosity of the oil phase and the interfacial tension, we conclude that the wax is liquid-like during the high temperature emulsification process, but during cooling wax crystals appear around the oil/water interface and stabilize the droplets. The oil/water ratio has minimal effect on the emulsions between ratios of 3:7 and 7:3. The Laponite is believed to stabilize the emulsions by increasing the viscosity of the continuous phase and also by adsorbing at the oil/water interface, thus providing a physical barrier to coalescence.

Development and evaluation of a microemulsion formulation for transdermal delivery of terbinafine.

Science.gov (United States)

Baboota, S; Al-Azaki, A; Kohli, K; Ali, J; Dixit, N; Shakeel, F

2007-01-01

The aim of the present study is to develop and evaluate microemulsion formulations for Terbinafine (TB) with a view to enhance its permeability through the skin and provide release for 24 h. Various o/w microemulsions were prepared by the spontaneous emulsification method. Oleic acid was chosen as the oil phase, Caprylo caproyl macrogol-8- glyceride (Labrasol S) and purified diethylene glycol monoethyl ether (Transcutol P) were used as surfactant and cosurfactant, respectively, on the basis of solubility studies. Pseudoternary phase diagrams were constructed to obtain the concentration range of oil, surfactant, cosurfactant, and water for microemulsion formulation. The optimized microemulsion consisted of 2% w/w TB, 8% w/w oleic acid, 31% w/w labrasol S, 31% w/w transcutol P, and 30% w/w distilled water. Permeability parameters like Jss and Kp were found to be significantly higher for formulation F4 as compared to other formulations (P activity against Candida albicans and Aspergillus flavus as compared to marketed product (P < 0.05).

Production of lipopeptides by Bacillus amyloliquefaciens XZ-173 in solid state fermentation using soybean flour and rice straw as the substrate.

Science.gov (United States)

Zhu, Zhen; Zhang, Guoyi; Luo, Yi; Ran, Wei; Shen, Qirong

2012-05-01

This work was aimed to produce lipopeptides by Bacillus amyloliquefaciens XZ-173 in solid state fermentation using agro-industrial byproducts. A central composite design was used to get the highest lipopeptides production. Results revealed that the optimal conditions for maximum lipopeptides production were 1.79% starch and 1.91% yeast extract by employing 5.58 g soybean flour and 3.67 g rice straw as the solid substrate with initial pH 7.5, moisture content 55% and a 10% inoculum level at 30°C for 2 days. Under these conditions, the experimental yield of lipopeptides reached 50.01 mg/gds, which was very close to the predicted value (49.91 mg/gds). At high concentration, the lipopeptides extracted from fermented substrates showed strong antibiotic activity against Rhizoctonia solani and Ralstonia solanacearum and certain emulsification but good emulsion stability. This is the first report on lipopeptides production that uses rice straw as a major substrate. Copyright © 2012 Elsevier Ltd. All rights reserved.

Lipid Nanocapsule-Based Gels for Enhancement of Transdermal Delivery of Ketorolac Tromethamine

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Jaleh Varshosaz

2011-01-01

Full Text Available Previous reports show ineffective transdermal delivery of ketorolac by nanostructured lipid carriers (NLCs. The aim of the present work was enhancement of transdermal delivery of ketorolac by another colloidal carriers, lipid nanocapsules (LNCs. LNCs were prepared by emulsification with phase transition method and mixed in a Carbomer 934P gel base with oleic acid or propylene glycol as penetration enhancers. Permeation studies were performed by Franz diffusion cell using excised rat abdominal skin. Aerosil-induced rat paw edema model was used to investigate the in vivo performance. LNCs containing polyethylene glycol hydroxyl stearate, lecithin in Labrafac as the oily phase, and dilution of the primary emulsion with 3.5-fold volume of cold water produced the optimized nanoparticles. The 1% Carbomer gel base containing 10% oleic acid loaded with nanoparticles enhanced and prolonged the anti-inflammatory effects of this drug to more than 12 h in Aerosil-induced rat paw edema model.

Core/shell PLGA microspheres with controllable in vivo release profile via rational core phase design.

Science.gov (United States)

Yu, Meiling; Yao, Qing; Zhang, Yan; Chen, Huilin; He, Haibing; Zhang, Yu; Yin, Tian; Tang, Xing; Xu, Hui

2018-02-27

Highly soluble drugs tend to release from preparations at high speeds, which make them need to be taken at frequent intervals. Additionally, some drugs need to be controlled to release in vivo at certain periods, so as to achieve therapeutic effects. Thus, the objective of this study is to design injectable microparticulate systems with controllable in vivo release profile. Biodegradable PLGA was used as the matrix material to fabricate microspheres using the traditional double emulsification-solvent evaporation method as well as improved techniques, with gel (5% gelatine or 25% F127) or LP powders as the inner phases. Their physicochemical properties were systemically investigated. Microspheres prepared by modified methods had an increase in drug loading (15.50, 16.72, 15.66%, respectively) and encapsulation efficiencies (73.46, 79.42, 74.40%, respectively) when compared with traditional methods (12.01 and 57.06%). The morphology of the particles was characterized by optical microscope (OM) and scanning electron microscopy (SEM), and the amorphous nature of the encapsulated drug was confirmed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis. To evaluate their release behaviour, the in vitro degradation, in vitro release and in vivo pharmacodynamics were subsequently studied. Traditional microspheres prepared in this study with water as the inner phase had a relatively short release period within 16 d when compared with modified microspheres with 5% gelatine as the inner phase, which resulted in a smooth release profile and appropriate plasma LP concentrations over 21 d. Thus this type of modified microspheres can be better used in drugs requiring sustained release. The other two formulations containing 25% F127 and LP micropowders presented two-stage release profiles, resulting in fluctuant plasma LP concentrations which may be suitable for drugs requiring controlled release. All the results suggested that drug release rates from

From Single Microparticles to Microfluidic Emulsification: Fundamental Properties (Solubility, Density, Phase Separation from Micropipette Manipulation of Solvent, Drug and Polymer Microspheres

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Koji Kinoshita

2016-11-01

Full Text Available The micropipette manipulation technique is capable of making fundamental single particle measurements and analyses. This information is critical for establishing processing parameters in systems such as microfluidics and homogenization. To demonstrate what can be achieved at the single particle level, the micropipette technique was used to form and characterize the encapsulation of Ibuprofen (Ibp into poly(lactic-co-glycolic acid (PLGA microspheres from dichloromethane (DCM solutions, measuring the loading capacity and solubility limits of Ibp in typical PLGA microspheres. Formed in phosphate buffered saline (PBS, pH 7.4, Ibp/PLGA/DCM microdroplets were uniformly solidified into Ibp/PLGA microparticles up to drug loadings (DL of 41%. However, at DL 50 wt% and above, microparticles showed a phase separated pattern. Working with single microparticles, we also estimated the dissolution time of pure Ibp microspheres in the buffer or in detergent micelle solutions, as a function of the microsphere size and compare that to calculated dissolution times using the Epstein-Plesset (EP model. Single, pure Ibp microparticles precipitated as liquid phase microdroplets that then gradually dissolved into the surrounding PBS medium. Analyzing the dissolution profiles of Ibp over time, a diffusion coefficient of 5.5 ± 0.2 × 10−6 cm2/s was obtained by using the EP model, which was in excellent agreement with the literature. Finally, solubilization of Ibp into sodium dodecyl sulfate (SDS micelles was directly visualized microscopically for the first time by the micropipette technique, showing that such micellization could increase the solubility of Ibp from 4 to 80 mM at 100 mM SDS. We also introduce a particular microfluidic device that has recently been used to make PLGA microspheres, showing the importance of optimizing the flow parameters. Using this device, perfectly smooth and size-homogeneous microparticles were formed for flow rates of 0.167 mL/h for the dispersed phase (Qd and 1.67 mL/h for the water phase (Qc, i.e., a flow rate ratio Qd/Qc of 10, based on parameters such as interfacial tension, dissolution rates and final concentrations. Thus, using the micropipette technique to observe the formation, and quantify solvent dissolution, solidification or precipitation of an active pharmaceutical ingredient (API or excipient for single and individual microparticles, represents a very useful tool for understanding microsphere-processes and hence can help to establish process conditions without resorting to expensive and material-consuming bulk particle runs.

New technology for the emulsification of petroleum residuals in water; Nueva tecnologia para la emulsificacion de residuales del petroleo en agua

Energy Technology Data Exchange (ETDEWEB)

Peralta, M. Vita; Arriola, Alejandro M.; Sanchez S, Ramon; Manzanares P, Emilio; Romo M, Cesar A.; Yery de Coss P, R. [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

2001-07-01

It turns out of interest to Comision Federal de Electricidad and Petroleos Mexicanos to reduce costs of fuel oil, reducing the viscosity of the residues petroleum of high vacuum distillation emulsifying these with water. The parameters that define the characteristics of the emulsions are mainly the relation of their components, viscosity, size and drop distribution and its stability. The experimental work began producing emulsions in form of lots, using samples of approximately 500 milliliters of vacuum residue. In this first stage, at different concentrations, were examined eight different surfactants, as well as combinations among them, also seven different stabilizers were used. With these tests it has been managed to identify the concentrations, as well as the most adequate relations of surfactants and stabilizers for the production of emulsions of vacuum residues in water. The size and drop distribution has been determined by means of an optical LEICA microscope, model DMLS, that has adapted a photographic system in which an emulsion photo is obtained and, later, a system of analysis of images is used for obtaining of the values of the diameter of the drops present in the emulsion. Finally, by means of statistical software the average size of the particles is obtained, as well as the drop size distribution. The tests results of emulsions that remain fluid are shown and an example of the microstructure of an emulsion of vacuum residue-in-water is given. As well as an example of histogram of the drop size distribution of an emulsion of vacuum distillation-in-water, and another one of the viscosity in function of temperature at different cut efforts in one emulsion of vacuum distillate residue-in-water. [Spanish] Resulta de interes para la Comision Federal de Electricidad y Petroleos Mexicanos reducir costos del combustoleo, reduciendo la viscosidad de los residuos de vacio emulsionando estos en agua. Los parametros que definen las caracteristicas de las emulsiones son principalmente la relacion de sus componentes, viscosidad, tamano y distribucion de gota y su estabilidad. Los trabajos experimentales se iniciaron produciendo emulsiones en forma de lotes, utilizando muestras de aproximadamente 500 ml de residuo de vacio. En esta primera etapa se examinaron, a diferentes concentraciones, ocho surfactantes distintos, al igual que combinaciones entre ellos, tambien se utilizaron siete diferentes estabilizadores. Como estas pruebas se han logrado identificar las concentraciones, asi como las relaciones mas adecuadas de surfactante y estabilizador para la produccion de emulsiones de residuo de vacio-en agua. El tamano y distribucion de gota se ha determinado mediante un microscopio optico LEICA, modelo DMLS, que tiene acoplado un sistema fotografico en el que se obtiene una foto de emulsion y, posteriormente, se utiliza un sistema de analisis de imagenes para la obtencion de los valores de diametro de las gotas presentes en la emulsion. Finalmente, mediante un software estadistico se obtiene el tamano promedio de la particulas, asi como la distribucion del tamano de las gotas. Se muestran los resultados de pruebas emulsiones que permanecen fluidas y se dan un ejemplo de la microestructura de una emulsion de residuo de vacio-en-agua. Asi como un ejemplo de histograma de la distribucion de tamano de gota de una emulsion de residuo de vacio-en-agua. Se muestran graficas de la viscosidad en funcion del esfuerzo de corte a diferentes temperaturas de una emulsion de residuo de vacio-en-agua y otra de la viscosidad en funcion de la temperatura a diferentes esfuerzos de corte de una emulsion de residuo de vacio-en-agua.

Effect of cross-linking of interfacial sodium caseinate by natural processing on the oxidative stability of oil-in-water (o/w) emulsions.

Science.gov (United States)

Phoon, Pui Yeu; Paul, Lake N; Burgner, John W; San Martin-Gonzalez, M Fernanda; Narsimhan, Ganesan

2014-04-02

This study investigated how enzymatic cross-linking of interfacial sodium caseinate and emulsification, via high-pressure homogenization, influenced the intrinsic oxidative stability of 4% (w/v) menhaden oil-in-water emulsions stabilized by 1% (w/v) caseinate at pH 7. Oil oxidation was monitored by the ferric thiocyanate perioxide value assay. Higher homogenization pressure resulted in improved intrinsic emulsion oxidative stability, which is attributed to increased interfacial cross-linking as indicated by higher weighted average sedimentation coefficients of interfacial protein species (from 11.2 S for 0 kpsi/0.1 MPa to 18 S for 20 kpsi/137.9 MPa). Moderate dosage of transglutaminase at 0.5-1.0 U/mL emulsion enhanced intrinsic emulsion oxidative stability further, despite a contradictory reduction in the antioxidant property of cross-linked caseinate as tested by the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. This implied the prominent role of cross-linked interfacial caseinate as a physical barrier for oxygen transfer, hence its efficacy in retarding oil oxidation.

Isolation of a novel strain of Planomicrobium chinense from diesel contaminated soil of tropical environment.

Science.gov (United States)

Das, Reena; Tiwary, Bhupendra N

2013-09-01

A novel bacterial strain (B6) degrading high concentration of diesel oil [up to 2.5% (v/v)] was isolated from a site contaminated with petroleum hydrocarbons in the state of Chhattisgarh, India. The strain demonstrated efficient degradation for diesel oil range alkanes (C14 to C36 i.e., mostly linear chain alkanes). It was identified to be 99% similar to Planomicrobium chinense on the basis of partial 16S rRNA gene sequencing and biochemical characteristics. The efficiency of degradation was optimized at pH 7.2 and temperature at 32 °C. GC analysis demonstrated complete mineralization of higher chain alkanes into lower chain alkanes within 96 h. The organism also displayed surface tension reduction by producing stable emulsification on the onset of stationary phase. A multidimensional characteristics of the strain to grow at a high temperature range, resistance to various heavy metals as well as tolerance to moderate concentration of NaCl makes it suitable for bioremediation of soil contaminated with diesel oil in tropical environment. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Utilization of banana peel as a novel substrate for biosurfactant production by Halobacteriaceae archaeon AS65.

Science.gov (United States)

Chooklin, Chanika Saenge; Maneerat, Suppasil; Saimmai, Atipan

2014-05-01

In this study, biosurfactant-producing bacteria was evaluated for biosurfactant production by using banana peel as a sole carbon source. From the 71 strains screened, Halobacteriaceae archaeon AS65 produced the highest biosurfactant activity. The highest biosurfactant production (5.30 g/l) was obtained when the cells were grown on a minimal salt medium containing 35 % (w/v) banana peel and 1 g/l commercial monosodium glutamate at 30 °C and 200 rpm after 54 h of cultivation. The biosurfactant obtained by extraction with ethyl acetate showed high surface tension reduction (25.5 mN/m), a small critical micelle concentration value (10 mg/l), thermal and pH stability with respect to surface tension reduction and emulsification activity, and a high level of salt tolerance. The biosurfactant obtained was confirmed as a lipopeptide by using a biochemical test FT-IR, NMR, and mass spectrometry. The crude biosurfactant showed a broad spectrum of antimicrobial activity and had the ability to emulsify oil, enhance PAHs solubility, and oil bioremediation.

One-step derivatization and preconcentration microextraction technique for determination of bisphenol A in beverage samples by gas chromatography-mass spectrometry.

Science.gov (United States)

Fontana, Ariel R; Muñoz de Toro, Mónica; Altamirano, Jorgelina C

2011-04-27

A simple technique based on ultrasound-assisted emulsification microextraction in situ derivatization (USAEME-ISD) is proposed for the one-step derivatization, extraction, and preconcentration of bisphenol A (BPA) in beverage samples prior to gas chromatography-mass spectrometry (GC-MS) analysis. BPA was in situ derivatized with acetic anhydride and simultaneously extracted and preconcentrated by using USAEME. Variables affecting the extraction efficiency of BPA were evaluated. Under optimal experimental conditions, the detection limit (LOD) was 38 ng L(-1) with a relative standard deviation (RSD) value of 11.6%. The linear working range was 100-1250 ng L(-1), and the coefficient of estimation (r(2)) of the calibration curve was ≥0.9971. The robustness of the proposed methodology was probed by developing a recovery study at two concentrations (125 and 500 ng L(-1)) over different beverage samples. This study led to a satisfactory result achieving recoveries of ≥82%, which showed acceptable robustness for determination of nanograms per liter of BPA in samples of food safety interest.

Enhanced biodegradation of Pina Cuban crude oil by a culture of mixed marine bacteria

Energy Technology Data Exchange (ETDEWEB)

Joseph, I.N.; Perigo, E. [Ministry of Science. Inst. of Oceanography, La Habana (Cuba); Bergueiro, J.R.; Pita, A.; Mayol, M.A. [Balearic Island Univ., Palma de Mallorca, Islas Baleares (Spain); Navarro, A. [Ministry of Industry, Oil Research Center, La Habana (Cuba)

1998-09-01

The ability of a mixed marine bacteria culture to degrade Pina Cuban crude oil in the presence of nutrients and sea water was studied. Laboratory experiments were conducted in flasks with 100 ml of saline liquid containing 1 per cent crude. The flasks were inoculated with marine bacteria (IDO-225, IDO-226, and IDO-229) at a final concentration of 10{sup 6} cell/ml. The cultures were grown at 29 degrees C for 21 days. Bacterial growth, and surface and interfacial tension were measured after 5, 13 and 21 days. Results showed that the marine bacteria were effective in accelerating the biodegradation process of Pina Cuban oil. The efficiency of the process increased when nutrients were added to the system. This biopreparation also accelerated emulsification of the oil without any negative effects to the natural microbiota. The biological oxygen demand at five days and at the end of the experiment was determined. The biodegradation constant and the biochemical stabilization constant were also measured. 14 refs., 5 tabs., 4 figs.

Isolation and characterization of biosurfactant production under extreme environmental conditions by alkali-halo-thermophilic bacteria from Saudi Arabia.

Science.gov (United States)

Elazzazy, Ahmed M; Abdelmoneim, T S; Almaghrabi, O A

2015-07-01

Twenty three morphologically distinct microbial colonies were isolated from soil and sea water samples, which were collected from Jeddah region, Saudi Arabia for screening of the most potent biosurfactant strains. The isolated bacteria were selected by using different methods as drop collapse test, oil displacement test, blue agar test, blood hemolysis test, emulsification activity and surface tension. The results showed that the ability of Virgibacillus salarius to grow and reduce surface tension under a wide range of pH, salinities and temperatures gives bacteria isolate an advantage in many applications such as pharmaceutical, cosmetics, food industries and bioremediation in marine environment. The biosurfactant production by V. salarius decreased surface tension and emulsifying activity (30 mN/m and 80%, respectively). In addition to reducing the production cost of biosurfactants by tested several plant-derived oils such as jatropha oil, castor oils, jojoba oil, canola oil and cottonseed oil. In this respect the feasibility to reusing old frying oil of sunflower for production rhamnolipids and sophorolipids, their use that lead to solve many ecological and industrial problems.

Determination of the cavity mode in the water

Directory of Open Access Journals (Sweden)

Vikulin Pavel

2018-01-01

Full Text Available Ultrasonic oscillations find their wide application in various sectors and industries: metallurgy, chemical and food industries, in engineering, in medicine. This is due to physical and chemical changes when exposed to the sound field. Cavitation in ultrasonic field causes the dispersion and emulsification of certain substances and promotes coagulation and degassing affects of crystallization and dissolution. It is known that ultrasonic vibrations also cause a variety of chemical transformations of substances such as oxidation, recovery, polymerization, and depolymerization. Researchers of cavitation action on the matter find the explanation of these phenomena: shock waves and, consequently, acoustic wind. The experiments were conducted in liquid environment (non-distilled water. The volume of the experimental sample amounted to 10 dm3. Method of the magnetostriction was applied to receive ultrasonic vibration, the principle of which consists in transforming electrical oscillations into mechanical. The level of cavitation was checked in two stages to evaluate the cavitation mode according to the degree of erosion of the artificial barriers and to measure the intensity of cavitation noise in the volume.

Characterization of Bacteria Isolation of Bacteria from Pinyon Rhizosphere,

Science.gov (United States)

2016-01-01

Two hundred and fifty bacterial strains were isolated from pinyon rhizosphere and screened for biosurfactants production. Among them, six bacterial strains were selected for their potential to produce biosurfactants using two low cost wastes, crude glycerol and lactoserum, as raw material. Both wastes were useful for producing biosurfactants because of their high content in fat and carbohydrates. The six strains were identified by 16S rDNA with an identity percentage higher than 95%, three strains belonged to Enterobacter sp., Pseudomonas aeruginosa, Bacillus pumilus and Rhizobium sp. All strains assayed were able to grow and showed halos around the colonies as evidence of biosurfactants production on Cetyl Trimethyl Ammonium Bromide agar with crude glycerol and lactoserum as substrate. In a mineral salt liquid medium enriched with both wastes, the biosurfactants were produced and collected from free cell medium after 72 h incubation. The biosurfactants produced reduced the surface tension from 69 to 30 mN/m with an emulsification index of diesel at approximately 60%. The results suggest that biosurfactants produced by rhizosphere bacteria from pinyon have promising environmental applications.

Characterization of biosurfactants from indigenous soil bacteria recovered from oil contaminated sites.

Science.gov (United States)

Kumar, Govind; Kumar, Rajesh; Sharma, Anita

2015-09-01

Three bacterial isolates (G1, G2 and G3) characterized as Pseudomonas plecoglossicida, Lysinibacillus fusiformis and Bacillus safensis were recovered from contaminated soil of oil refinery. These bacterial isolates produced biosurfactants in MSM medium in stationary phase. Biosurfactants were characterized on the basis of their emulsifying properties with petrol, diesel, mobil oil and petrol engine oil. Reduction in surface tension (below 40 mN m(-1)) and blood hemolysis were also included in biosurfactants characterization. Emulsification indices of G1, G2 and G3 were in the range of 98.82, 23.53 and 58.82 for petrol; 29.411,1.05 and 70.588 for diesel; 35.31, 2.93 and 17.60 for mobil oil and 35.284, 58.82 and 17.647 for petrol engine oil respectively. Dry weight of the extracted biosurfactant was 4.6, 1.4 and 2.4 g I(-1) for G1, G2 and G3 respectively. Structural analysis of the biosurfactants by Fourier Transform Infrared Spectroscopy (FTIR) revealed significant differences in the bonding pattern of individual biosurfactant.

Utilization of Paneer Whey Waste for Cost-Effective Production of Rhamnolipid Biosurfactant.

Science.gov (United States)

Patowary, Rupshikha; Patowary, Kaustuvmani; Kalita, Mohan Chandra; Deka, Suresh

2016-10-01

The present study aimed at isolating rhamnolipid biosurfactant-producing bacteria that could utilize paneer whey, an abundant waste source as sole medium for the production purpose. Pseudomonas aeruginosa strain, SR17, was isolated from hydrocarbon-contaminated soil that could efficiently utilize paneer whey for rhamnolipid production and reduce surface tension of the medium from 52 to 26.5 mN/m. The yield of biosurfactant obtained was 2.7 g/l, upgraded to 4.8 g/l when supplemented with 2 % glucose and mineral salts. Biochemical, FTIR, and LC-MS analysis revealed that extracted biosurfactant is a combination of both mono and di-rhamnolipid congeners. The critical micelle concentration (CMC) was measured to be 110 mg/l. Emulsification activity of the biosurfactant against n-hexadecane, olive oil, kerosene, diesel oil, engine oil, and crude oil were found to be 83, 88, 81, 92, 86, and 100 %, respectively. The rhamnolipid was detected to be non-toxic against mouse fibroblastic cell line L292.

An efficient biosurfactant-producing bacterium Selenomonas ruminantium CT2, isolated from mangrove sediment in south of Thailand.

Science.gov (United States)

Saimmai, Atipan; Onlamool, Theerawat; Sobhon, Vorasan; Maneerat, Suppasil

2013-01-01

Biosurfactant-producing bacteria, isolate CT2, was isolated from mangrove sediment in the south of Thailand. The sequence of the 16S rRNA gene from isolate CT2 showed 100 % similarity with Selenomonas ruminantium. The highest biosurfactant production (5.02 g/l) was obtained when the cells were grown on minimal salt medium containing 15 g/l molasses and 1 g/l commercial monosodium glutamate supplemented with 1 g/l NaCl, 0.1 g/l leucine, 5 % (v/v) inoculum size at 30 °C and 150 rpm after 54 h of cultivation. The biosurfactant obtained by extraction with ethyl acetate showed high surface tension reduction (25.5 mN/m), a small CMC value (8 mg/l), thermal and pH stability with respect to surface tension reduction and emulsification activity and a high level of salt tolerance. The biosurfactant obtained was confirmed as a lipopeptide by using a biochemical test, FT-IR, MNR and mass spectrometry. The crude biosurfactant showed a broad spectrum of antimicrobial activity and also had the ability to emulsify oil and enhance PAHs solubility.

Aqueous enzymatic extraction of Moringa oleifera oil.

Science.gov (United States)

Mat Yusoff, Masni; Gordon, Michael H; Ezeh, Onyinye; Niranjan, Keshavan

2016-11-15

This paper reports on the extraction of Moringa oleifera (MO) oil by using aqueous enzymatic extraction (AEE) method. The effect of different process parameters on the oil recovery was discovered by using statistical optimization, besides the effect of selected parameters on the formation of its oil-in-water cream emulsions. Within the pre-determined ranges, the use of pH 4.5, moisture/kernel ratio of 8:1 (w/w), and 300stroke/min shaking speed at 40°C for 1h incubation time resulted in highest oil recovery of approximately 70% (goil/g solvent-extracted oil). These optimized parameters also result in a very thin emulsion layer, indicating minute amount of emulsion formed. Zero oil recovery with thick emulsion were observed when the used aqueous phase was re-utilized for another AEE process. The findings suggest that the critical selection of AEE parameters is key to high oil recovery with minimum emulsion formation thereby lowering the load on the de-emulsification step. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characteristic of sausages as influenced by partial replacement of pork back-fat using pre-emulsified soybean oil stabilized by fish proteins isolate

Directory of Open Access Journals (Sweden)

Nopparat Cheetangdee

2017-08-01

Full Text Available Substitution of animal fat with oils rich in n-3 is a feasible way to improve the nutritive value of comminuted meat product. The effect on the characteristics of sausages was investigated of partial replacement of porcine fat with soybean oil (SBO using a pre-emulsification technique. Fish protein isolate (FPI produced from yellow stripe trevally (Selaroides leptolepis was used as an emulsifier to prepare pre-emulsified SBO (preSBO, and its concentration effect (1%, 2% and 3%, w/v was observed in comparison with soy protein isolate (SPI. Substitution of porcine fat using preSBO enhanced the product stability. SPI exhibited better emulsifying ability than FPI. However, FPI was more effective at reinforcing the protein matrix of the sausages than SPI, as suggested by a lowered cooking loss and the restored textural attributes of the sausages formulated with FPI stabilized preSBO. The effective concentration of FPI to improve the product stability was 2%. This work suggested that FPI was promising in the preparation of emulsified meat products.

In Vivo Osteogenic Potential of Biomimetic Hydroxyapatite/Collagen Microspheres: Comparison with Injectable Cement Pastes

Science.gov (United States)

Manzanares, Maria-Cristina; Ginebra, Maria-Pau; Franch, Jordi

2015-01-01

The osteogenic capacity of biomimetic calcium deficient hydroxyapatite microspheres with and without collagen obtained by emulsification of a calcium phosphate cement paste has been evaluated in an in vivo model, and compared with an injectable calcium phosphate cement with the same composition. The materials were implanted into a 5 mm defect in the femur condyle of rabbits, and bone formation was assessed after 1 and 3 months. The histological analysis revealed that the cements presented cellular activity only in the margins of the material, whereas each one of the individual microspheres was covered with osteogenic cells. Consequently, bone ingrowth was enhanced by the microspheres, with a tenfold increase compared to the cement, which was associated to the higher accessibility for the cells provided by the macroporous network between the microspheres, and the larger surface area available for osteoconduction. No significant differences were found in terms of bone formation associated with the presence of collagen in the materials, although a more extensive erosion of the collagen-containing microspheres was observed. PMID:26132468

Effect of mode of addition of flaxseed oil on the quality characteristics of chicken sausage containing vitamin E and omega 3 fatty acids at levels to support a health claim.

Science.gov (United States)

Bolger, Zara; Brunton, Nigel P; Monahan, Frank J

2017-10-18

Vitamin E and omega-3 fatty acids can be incorporated into meat products at levels supporting health claims of "protecting against oxidative stress" and "maintaining normal blood cholesterol levels", respectively. Chicken sausages were formulated to contain vitamin E (12 mg per 100 g) and flaxseed oil (2 g per 100 g) using different oil incorporation methods. The formulations were: (1) control (no oil); (2) oil; (3) emulsified oil; (4) freeze-dried encapsulated oil; (5) freeze-dried encapsulated oil with cross-linker genipin; (6) spray-dried encapsulated oil. α-Linolenic acid and α-tocopherol were retained in all fortified formulations at levels to meet nutrient and health claims but emulsification or encapsulation had no additional benefit in retention following cooking or on product quality as measured by proximate composition, lipid oxidation, colour, microbial analysis, cook loss and texture profile analysis. While the addition of flaxseed oil had a negative effect on consumer acceptance of flavour (although not when emulsified), overall acceptance of the chicken sausages was only reduced significantly (p ≤ 0.05) when oil was encapsulated.

Isolation and characterization of biosurfactant production under extreme environmental conditions by alkali-halo-thermophilic bacteria from Saudi Arabia

Science.gov (United States)

Elazzazy, Ahmed M.; Abdelmoneim, T.S.; Almaghrabi, O.A.

2014-01-01

Twenty three morphologically distinct microbial colonies were isolated from soil and sea water samples, which were collected from Jeddah region, Saudi Arabia for screening of the most potent biosurfactant strains. The isolated bacteria were selected by using different methods as drop collapse test, oil displacement test, blue agar test, blood hemolysis test, emulsification activity and surface tension. The results showed that the ability of Virgibacillus salarius to grow and reduce surface tension under a wide range of pH, salinities and temperatures gives bacteria isolate an advantage in many applications such as pharmaceutical, cosmetics, food industries and bioremediation in marine environment. The biosurfactant production by V. salarius decreased surface tension and emulsifying activity (30 mN/m and 80%, respectively). In addition to reducing the production cost of biosurfactants by tested several plant-derived oils such as jatropha oil, castor oils, jojoba oil, canola oil and cottonseed oil. In this respect the feasibility to reusing old frying oil of sunflower for production rhamnolipids and sophorolipids, their use that lead to solve many ecological and industrial problems. PMID:26150754

Co-delivery of hydrophobic curcumin and hydrophilic catechin by a water-in-oil-in-water double emulsion.

Science.gov (United States)

Aditya, N P; Aditya, Sheetal; Yang, Hanjoo; Kim, Hye Won; Park, Sung Ook; Ko, Sanghoon

2015-04-15

Curcumin and catechin are naturally occurring phytochemicals with extreme sensitivity to oxidation and low bioavailability. We fabricated a water-in-oil-in-water (W/O/W) double emulsion encapsulating hydrophilic catechin and hydrophobic curcumin simultaneously. The co-loaded emulsion was fabricated using a two-step emulsification method, and its physicochemical properties were characterised. Volume-weighted mean size (d43) of emulsion droplets was ≈3.88 μm for blank emulsions, whereas it decreased to ≈2.8-3.0 μm for curcumin and/or catechin-loaded emulsions, which was attributed to their capacity to act as emulsifiers. High entrapment efficiency was observed for curcumin and/or catechin-loaded emulsions (88-97%). Encapsulation of catechin and curcumin within an emulsion increased their stability significantly in simulated gastrointestinal fluid, which resulted in a four-fold augmentation in their bioaccessibility compared to that of freely suspended curcumin and catechin solutions. Co-loading of curcumin and catechin did not have adverse effects on either compound's stability or bioaccessibility. Copyright © 2014 Elsevier Ltd. All rights reserved.

Characterization of edible emulsified films with low affinity to water based on kefiran and oleic acid.

Science.gov (United States)

Ghasemlou, Mehran; Khodaiyan, Faramarz; Oromiehie, Abdulrasoul; Yarmand, Mohammad Saeid

2011-10-01

New edible composite films based on kefiran and oleic acid (OA) at the ratio of 15, 25, and 35% (w/w) were prepared using emulsification with the aim of improving their water vapour barrier and mechanical properties. Film-forming solutions were characterized in terms of rheological properties and particle-size distribution. The impact of the incorporation of OA into the film matrix was studied by investigating the physical, mechanical, and thermal properties of the films. The water vapour permeability (WVP) of the emulsified films was reduced by approximately 33% by adding OA. The mechanical properties of kefiran films were also affected by adding OA: tensile strength was diminished, and elongation increased considerably. Differential scanning calorimetry showed that the glass transition temperature (T(g)) of the kefiran film was -16°C and was not considerably affected by adding OA. Therefore, OA could be incorporated into these films for some food-technology applications that need a low affinity toward water. Copyright © 2011 Elsevier B.V. All rights reserved.

Preparation of liquid-core nanocapsules from poly[(ethylene oxide)-co-glycidol] with multiple hydrophobic linoleates at an oil-water interface and its encapsulation of pyrene.

Science.gov (United States)

Ren, Yong; Wang, Guowei; Huang, Junlian

2007-06-01

A convenient approach is provided to prepare liquid-core nanocapsules by cross-linking an amphiphilic copolymer at an oil-water interface. The hydrophilic copolymer poly[(ethylene oxide)-co-glycidol] was prepared by anionic polymerization of ethylene oxide and ethoxyethyl glycidyl ether first, then the hydroxyl groups on the backbone were recovered after hydrolysis and partly modified by hydrophobic conjugated linoleic acid. The copolymer with multiple linoleate pendants was absorbed at an oil-water interface and then cross-linked to form stable nanocapsules. The mean diameter of the nanocapsule was below 350 nm, and the size distribution was relatively narrow (<0.2) at low concentrations of oil in acetone (<10 mg/mL). The particle size could be tuned easily by variation of the emulsification conditions. The nanocapsule was stable in water for at least 5 months, and the shell maintained its integrity after removal of the oily core by solvent. Pyrene was encapsulated in these nanocapsules, and a loading efficiency as high as 94% was measured by UV spectroscopy.

Poly(lactic-co-glycolic) Acid/Solutol HS15-Based Nanoparticles for Docetaxel Delivery.

Science.gov (United States)

Cho, Hyun-Jong; Park, Ju-Hwan; Kim, Dae-Duk; Yoon, In-Soo

2016-02-01

Docetaxel (DCT) is one of anti-mitotic chemotherapeutic agents and has been used for the treatment of gastric cancer as well as head and neck cancer, breast cancer and prostate cancer. Poly(lactic- co-glycolic) acid (PLGA) is one of representative biocompatible and biodegradable polymers, and polyoxyl 15 hydroxystearate (Solutol HS15) is a nonionic solubilizer and emulsifying agent. In this investigation, PLGA/Solutol HS15-based nanoparticles (NPs) for DCT delivery were fabricated by a modified emulsification-solvent evaporation method. PLGA/Solutol HS15/DCT NPs with about 169 nm of mean diameter, narrow size distribution, negative zeta potential, and spherical morphology were prepared. The results of solid-state studies revealed the successful dispersion of DCT in PLGA matrix and its amorphization during the preparation process of NPs. According to the result of in vitro release test, emulsifying property of Solutol HS15 seemed to contribute to the enhanced drug release from NPs at physiological pH. All these findings imply that developed PLGA/Solutol HS15-based NP can be a promising local anticancer drug delivery system for cancer therapy.

Chitosan-based nanocarriers for antimalarials

Science.gov (United States)

Dreve, Simina; Kacso, Iren; Popa, Adriana; Raita, Oana; Bende, A.; Borodi, Gh.; Bratu, I.

2012-02-01

The objective of this research was to synthesize and characterize chitosan-based liquid and solid materials with unique absorptive and mechanical properties as carriers for quinine - one of the most used antimalarial drug. The use of chitosan (CTS) as base in polyelectrolyte complex systems, to prepare solid release systems as sponges is presented. The preparation by double emulsification of CTS hydrogels carrying quinine as anti-malarial drug is reported. The concentration of quinine in the CTS hydrogel was 0.08 mmol. Chitosan - drug loaded hydrogel was used to generate solid sponges by freeze-drying at -610°C and 0.09 atm. Structural investigations of the solid formulations were done by Fourier-transformed infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-VIS), spectrofluorimetry, differential scanning calorimetry (DSC) and X-ray diffractometry. The results indicated that the drug molecule is forming temporary chelates in CTS hydrogels and sponges. Electron paramagnetic resonance (EPR) demonstrates the presence of free radicals in a wide range and the antioxidant activity for chitosan - drug supramolecular cross-linked assemblies.

Physicochemical characterization and oxidative stability of fish oil-loaded electrosprayed capsules: Combined use of whey protein and carbohydrates as wall materials

DEFF Research Database (Denmark)

García Moreno, Pedro Jesús; Pelayo, Andres; Yu, Sen

2018-01-01

The encapsulation of fish oil in electrosprayed capsules using whey protein and carbohydrates (pullulan and dextran or glucose syrup) mixtures as glassy wall materials was studied. Capsules with fish oil emulsified by using only a rotor-stator emulsification exhibited higher oxidative stability...... than capsules where the oil was emulsified by high-pressure homogenization. Moreover, glucose syrup capsules (with a peroxide value, PV, of 19.7 ± 4.4 meq/kg oil and a content of 1-penten-3-ol of 751.0 ± 69.8 ng/g oil) were less oxidized than dextran capsules after 21 days of storage at 20 °C (PV of 24.......9 ± 0.4 meq/kg oil and 1-penten-3-ol of 1161.0 ± 222.0 ng/g oil). This finding may be attributed to differences in oxygen permeability between both types of capsules. These results indicated the potential of both combinations of whey protein, pullulan, and dextran or glucose syrup as shell materials...

Electric field induced instabilities in free emulsion films

Energy Technology Data Exchange (ETDEWEB)

Tchoukov, P.; Dabros, T. [Natural Resources Canada, Devon, AB (Canada); Mostowfi, F. [Schlumberger DBR Technology Center, Edmonton, AB (Canada); Panchev, N. [Champion Technologies Inc., Houston, TX (United States); Czarnecki, J. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering

2009-07-01

This presentation reported on a study that investigated the mechanism of electric field-induced breakdown of free emulsion films. Instability patterns were observed on the plane of a water-oil-water film following electric polarization. The length-scales of the instabilities were measured by analyzing images immediately after applying the electric field. Linear stability analysis was used to calculate the theoretical dominant wavelengths. The calculated values were found to be in good agreement with measured values. The films were formed in a thin film apparatus modified so that the oil film separated 2 aqueous phase compartments, each in contact with a platinum electrode. This enabled the measurement of disjoining pressure while applying the electric field to the film. It was concluded that breakdown of thin films induced by electric field has many applications, including electrostatic de-emulsification/desalination of crude oil and emulsion stability measurements. It was concluded that electroporation and dielectric breakdown may be responsible for electric field-induced breakdown. This study also presented evidence of an increase in electric field-induced instabilities in emulsion films resulting in rupture. tabs., figs.

Design and optimization of self-nanoemulsifying formulations for lipophilic drugs

International Nuclear Information System (INIS)

Zhao, Tianjing; Maniglio, Devid; Motta, Antonella; Migliaresi, Claudio; Chen, Jie; Chen, Bin

2015-01-01

The purpose of the current study was to develop and optimize novel self-nanoemulsifying drug delivery systems (SNEDDS) with a high proportion of essential oil as carriers for lipophilic drugs. Solubility and droplet size as a function of the composition were investigated, and a ternary phase diagram was constructed in order to identify the self-emulsification regions. The optimized SNEDDS formulation consisted of lemon essential oil (oil), Cremophor RH40 (surfactant) and Transcutol HP (co-surfactant) in the ratio 50:30:20 (v/v). Ibuprofen was chosen as the model drug. The droplet size, ζ-potential and stability of the drug-loaded optimized formulations were determined. The stability of SNEDDS was proved after triple freezing/thawing cycles and storage at 4 °C and 25 °C for 3 months. In vitro drug release studies of optimized SNEDDS revealed a significant increase of the drug release and release rate in comparison to the Ibuprofen suspension (80% versus approximately 40% in 2 h). The results indicated that these SNEDDS formulations could be used to improve the bioavailability of lipophilic drugs. (paper)

Isolation of biosurfactant producing bacteria from petroleum contaminated sites and their characterization

Directory of Open Access Journals (Sweden)

Rida Batool

2017-05-01

Full Text Available Biosurfactants are microbial amphiphilic compounds which can reduce surface tension between aqueous and hydrocarbon mixtures. Bacterial strains isolated from petroleum contaminated soil of various motor workshops were characterized morphologically and biochemically. Biosurfactant producing ability of the strains was determined and their emulsification activity was screened against different oils. All the selected bacterial strains showed enhanced biosurfactants production with yeast extract as nitrogen source and glucose as carbon source at optimized conditions. These strains also exhibited multiple metal and antibiotics resistance. Isolated biosurfactants of three most promising strains SF-1, SF-4 and SM-1 were extracted by solvent extraction and subjected to TLC technique. The technique indicates the glycolipid nature of the compounds and presence of rhamnose sugar, which was further confirmed by FT-IR analysis. 16srRNA analysis revealed that SF-1 and SM-1 had close resemblance with Pseudomonas sp. while SF-4 showed homology with Enterobacter sp. Isolation and screening of biosurfactant producing strains from petroleum polluted places proved to be a quick and effective means to find bacterial strains with possible industrial uses.

In-situ burning of Alaskan oils and emulsions: preliminary results of laboratory tests with and without waves

International Nuclear Information System (INIS)

Buist, I.; McCourt, J.; Karunakaran, K.; Gierer, C.; Comins, D.; Glover, N.; McKenzie, B.

1996-01-01

The efficiency of in-situ burning (ISB) as a response tool for oils transported in Alaska was studied. ISB can be an effective measure during an oil spill clean-up and has the potential to quickly remove large amounts of oil from the water surface. However, studies have shown that it is important to act quickly before the oil evaporates and before water-in-oil emulsions form, rendering the slick unignitable. Small-scale laboratory tests were conducted to determine the limits to ignition of slicks of four oils, and to determine the effectiveness of chemical emulsion breakers in extending the ignition limits. Results showed that while evaporation and emulsification could curtail ignition of oil slicks, the addition of a chemical emulsion breaker could extend the limits of ignition and burnability. Preliminary results also showed that waves had an effect on the burning of fresh, weathered and slightly emulsified crude oil. Burn efficiency and burn time were found to decrease with increasing wave energy. 14 refs., 18 tabs., 4 figs

Laboratory evaluation of the emulsifying characteristics of pumps. [Bilge and ballast water oily wastes

Energy Technology Data Exchange (ETDEWEB)

Harvey, A.C.; Guzdar, A.R.; Fiswell, D.R.

1973-10-01

The program was devoted to a laboratory investigation of the emulsifying characteristics of different pumps suitable for shipboard pumping of bilge and ballast water oily wastes. The tests were designed to investigate the effect of several parameters, such as oil type, input oil concentration, detergent, pump operating characteristics (pressure and flow rate), and salt versus fresh water, on emulsification. Tests were conducted on the Foster-Miller tests loop. No. 2 fuel oil, lubricating oil and No. 6 fuel oil were the oils tested at concentrations ranging from 1 to 10%. The oils were tested with and without the addition of 10% Gamlen D surfactant. The pumps used were a Parker Diaphragm pump, a Blackmer Sliding Vane pump, an Ingersoll Rand Centrifugal pump and a Deming Centrifugal pump. Pump pressure ranged from 10 to 60 psi and flow rate from 10 to 100 gpm. A total of 270 tests were conducted covering 198 different operating points, 108 concerning pump comparison, 54 concerning oil concentration and surfactant, and 45 concerning salt water.

Laboratory evaluation of the emulsifying characteristics of pumps

Energy Technology Data Exchange (ETDEWEB)

Harvey, A.C.; Guzdar, A.R.; Friswell, D.R.

1973-10-01

The program was devoted to a laboratory investigation of the emulsifying characteristics of different pumps suitable for shipboard pumping of bilge and ballast water oily wastes. The tests were designed to investigate the effect of several parameters, such as oil type, input oil concentration, detergent, pump operating characteristics (pressure and flow rate), and salt vs. fresh water, on emulsification. Tests were conducted on the Foster-Miller test loop. No. 2 fuel oil, lubricating oil and No. 6 fuel oil were the oils tested at concentrations ranging from 1 to 10%. The oils were tested with and without the addition of 10% Gamlen D surfactant. The pumps used were a Parker Diaphragm pump, a Blackmer Sliding Vane pump, an Ingersoll Rand Centrifugal pump, and a Deming Centrifugal pump. Pump pressure ranged from 10 to 60 psi and flow rates from 10 to 100 gpm. A total of 270 tests was conducted covering 198 different operating points, 108 concerning pump comparison, 54 concerning oil concentration and surfactant, and 45 concerning salt water.

Effect of Encapsulation on Viability of Bifidobacterium longum CFR815j and Physiochemical Properties of Ice Cream.

Science.gov (United States)

Kataria, Ankita; Achi, Sajan C; Halami, Prakash M

2018-06-01

The health beneficial attributes of bifidobacteria and its safe association with the host gut has increased its significance as a probiotic. However delivering probiotic bifidobacteria with Minimum Biological Value (MBV) through product has always been a challenge. In the present study, an attempt was made to maintain the viability of native isolate of Bifidobacterium longum CFR 815j and deliver through ice-cream. B. longum CFR815j was microencapsulated in alginate starch capsules by emulsification followed by evaluation of bead stability in simulated gastrointestinal conditions. After incorporation in ice-cream, the effect on chemical properties, sensory parameters and meltdown characteristics of the product were also evaluated. Survival studies of B. longum revealed higher counts than 10 7 in the product which is essential for probiotic bacteria to exhibit beneficial effect. Further, all the properties of this ice-cream were comparable to the regular ice-cream. Our studies conclude that encapsulation was able to maintain the requisite MBV of bifidobacteria in ice-cream without affecting the sensory characteristics.

Enhanced biodegradation of Pina Cuban crude oil by a culture of mixed marine bacteria

International Nuclear Information System (INIS)

Joseph, I.N.; Perigo, E.; Bergueiro, J.R.; Pita, A.; Mayol, M.A.; Navarro, A.

1998-01-01

The ability of a mixed marine bacteria culture to degrade Pina Cuban crude oil in the presence of nutrients and sea water was studied. Laboratory experiments were conducted in flasks with 100 ml of saline liquid containing 1 per cent crude. The flasks were inoculated with marine bacteria (IDO-225, IDO-226, and IDO-229) at a final concentration of 10 6 cell/ml. The cultures were grown at 29 degrees C for 21 days. Bacterial growth, and surface and interfacial tension were measured after 5, 13 and 21 days. Results showed that the marine bacteria were effective in accelerating the biodegradation process of Pina Cuban oil. The efficiency of the process increased when nutrients were added to the system. This biopreparation also accelerated emulsification of the oil without any negative effects to the natural microbiota. The biological oxygen demand at five days and at the end of the experiment was determined. The biodegradation constant and the biochemical stabilization constant were also measured. 14 refs., 5 tabs., 4 figs

Biodegradable nanoparticles for improved kidney bioavailability of rhein: preparation, characterization, plasma, and kidney pharmacokinetics.

Science.gov (United States)

Wei, Yinghui; Luo, Xiaoting; Guan, Jiani; Ma, Jianping; Zhong, Yicong; Luo, Jingwen; Li, Fanzhu

2017-11-01

The aim of this work is to develop biodegradable nanoparticles for improved kidney bioavailability of rhein (RH). RH-loaded nanoparticles were prepared using an emulsification solvent evaporation method and fully characterized by several techniques. Kidney pharmacokinetics was assessed by implanting a microdialysis probe in rat's kidney cortex. Blood samples were simultaneously collected (via femoral artery) for assessing plasma pharmacokinetics. Optimized nanoparticles were small, with a mean particle size of 132.6 ± 5.95 nm, and homogeneously dispersed. The charge on the particles was nearly zero, the encapsulation efficiency was 62.71 ± 3.02%, and the drug loading was 1.56 ± 0.15%. In vitro release of RH from the nanoparticles showed an initial burst release followed by a sustained release. Plasma and kidney pharmacokinetics showed that encapsulation of RH into nanoparticles significantly increased its kidney bioavailability (AUC kidney /AUC plasma  = 0.586 ± 0.072), clearly indicating that nanoparticles are a promising strategy for kidney drug delivery.

Surfactant/oil/water system for the determination of selenium in eggs by graphite furnace atomic absorption spectrometry

Science.gov (United States)

Ieggli, C. V. S.; Bohrer, D.; Noremberg, S.; do Nascimento, P. C.; de Carvalho, L. M.; Vieira, S. L.; Reis, R. N.

2009-06-01

An oil-in-water formulation has been optimized to determine trace levels of selenium in whole hen eggs by graphite furnace atomic absorption spectrometry. This method is simpler and requires fewer reagents when compared with other sample pre-treatment procedures. Graphite furnace atomic absorption spectrometric (GF AAS) measurement was carried out using standard addition calibration and Pd as a modifier. The precision, expressed as relative standard deviation, was better than 5% and the limit of detection was 1 µg L - 1 . The validation of the method was performed against a standard reference material Whole Egg Powder (RM 8415), and the measured Se corresponded to 95.2% of the certified value. The method was used for the determination of the Se level in eggs from hens treated with Se dietary supplements. Inorganic and organic Se sources were added to hen feed. The Se content of eggs was higher when hens were fed with organic Se compared to the other treatments. The proposed method, including sample emulsification for subsequent Se determination by GF AAS has proved to be sensitive, reproducible, simple and economical.

Surfactant/oil/water system for the determination of selenium in eggs by graphite furnace atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Ieggli, C.V.S. [Departamento de Quimica, Avenida Roraima, 1000, Universidade Federal de Santa Maria, CEP 97110-970, Santa Maria, RS (Brazil); Bohrer, D. [Departamento de Quimica, Avenida Roraima, 1000, Universidade Federal de Santa Maria, CEP 97110-970, Santa Maria, RS (Brazil)], E-mail: ndenise@quimica.ufsm.br; Noremberg, S.; Nascimento, P.C. do; Carvalho, L.M. de [Departamento de Quimica, Avenida Roraima, 1000, Universidade Federal de Santa Maria, CEP 97110-970, Santa Maria, RS (Brazil); Vieira, S.L.; Reis, R.N. [Faculdade de Agronomia, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 7712, CEP 90540-000, Porto Alegre (Brazil)

2009-06-15

An oil-in-water formulation has been optimized to determine trace levels of selenium in whole hen eggs by graphite furnace atomic absorption spectrometry. This method is simpler and requires fewer reagents when compared with other sample pre-treatment procedures. Graphite furnace atomic absorption spectrometric (GF AAS) measurement was carried out using standard addition calibration and Pd as a modifier. The precision, expressed as relative standard deviation, was better than 5% and the limit of detection was 1 {mu}g L{sup - 1}. The validation of the method was performed against a standard reference material Whole Egg Powder (RM 8415), and the measured Se corresponded to 95.2% of the certified value. The method was used for the determination of the Se level in eggs from hens treated with Se dietary supplements. Inorganic and organic Se sources were added to hen feed. The Se content of eggs was higher when hens were fed with organic Se compared to the other treatments. The proposed method, including sample emulsification for subsequent Se determination by GF AAS has proved to be sensitive, reproducible, simple and economical.

Fiscal 2000 project of inviting proposals for international joint research - invitation for international proposal (Power generation No.14). Achievement report on joint research for utilizing Russia's now-unused high-viscosity crude oil as fuel for power generation; 2000 nendo kokusai kyodo kenkyu teian kobo jigyo - kokusai teian kobo (hatsuden No.14). Russia miriyo konensei gen'yu no denryoku nenryo riyo kyodo kenkyu chosa seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

The Russkoye high-viscosity oil field is located in the western part of Siberia, Russia. Joint research is under way to develop a technology for reducing the viscosity for the collection of crude oil through the utilization of a gas condensate discharged by a neighboring gas field. This report comprises eight chapters, namely, (1) the background, purpose, and contents of the research, (2) Russia's oil resources and oil industry, (3) high-viscosity oil fields in Russia, (4) analysis of Russkoye crude oil and gas condensates yielded in Russia, (5) methods for viscosity reduction, (6) evaluation of combustibility, (7) scenario for developing the Russkoye oil field, and (8) research results as summarized and future tasks. Studied in chapter (5) are approaches to viscosity reduction, methods for emulsification, and a method for viscosity reduction by use of a gas condensate. These are tested and the results after analysis clearly show that the Russkoye crude oil, when blended with a gas condensate, will turn transportable and will provide a fuel equivalent to fuel oil C. (NEDO)

In vivo tumor-targeted dual-modal fluorescence/CT imaging using a nanoprobe co-loaded with an aggregation-induced emission dye and gold nanoparticles.

Science.gov (United States)

Zhang, Jimei; Li, Chan; Zhang, Xu; Huo, Shuaidong; Jin, Shubin; An, Fei-Fei; Wang, Xiaodan; Xue, Xiangdong; Okeke, C I; Duan, Guiyun; Guo, Fengguang; Zhang, Xiaohong; Hao, Jifu; Wang, Paul C; Zhang, Jinchao; Liang, Xing-Jie

2015-02-01

As an intensely studied computed tomography (CT) contrast agent, gold nanoparticle has been suggested to be combined with fluorescence imaging modality to offset the low sensitivity of CT. However, the strong quenching of gold nanoparticle on fluorescent dyes requires complicated design and shielding to overcome. Herein, we report a unique nanoprobe (M-NPAPF-Au) co-loading an aggregation-induced emission (AIE) red dye and gold nanoparticles into DSPE-PEG(2000) micelles for dual-modal fluorescence/CT imaging. The nanoprobe was prepared based on a facile method of "one-pot ultrasonic emulsification". Surprisingly, in the micelles system, fluorescence dye (NPAPF) efficiently overcame the strong fluorescence quenching of shielding-free gold nanoparticles and retained the crucial AIE feature. In vivo studies demonstrated the nanoprobe had superior tumor-targeting ability, excellent fluorescence and CT imaging effects. The totality of present studies clearly indicates the significant potential application of M-NPAPF-Au as a dual-modal non-invasive fluorescence/X-ray CT nanoprobe for in vivo tumor-targeted imaging and diagnosis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Carrier Mediated Distribution System (CAMDIS): a new approach for the measurement of octanol/water distribution coefficients.

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Wagner, Bjoern; Fischer, Holger; Kansy, Manfred; Seelig, Anna; Assmus, Frauke

2015-02-20

Here we present a miniaturized assay, referred to as Carrier-Mediated Distribution System (CAMDIS) for fast and reliable measurement of octanol/water distribution coefficients, log D(oct). By introducing a filter support for octanol, phase separation from water is facilitated and the tendency of emulsion formation (emulsification) at the interface is reduced. A guideline for the best practice of CAMDIS is given, describing a strategy to manage drug adsorption at the filter-supported octanol/buffer interface. We validated the assay on a set of 52 structurally diverse drugs with known shake flask log D(oct) values. Excellent agreement with literature data (r(2) = 0.996, standard error of estimate, SEE = 0.111), high reproducibility (standard deviation, SD < 0.1 log D(oct) units), minimal sample consumption (10 μL of 100 μM DMSO stock solution) and a broad analytical range (log D(oct) range = -0.5 to 4.2) make CAMDIS a valuable tool for the high-throughput assessment of log D(oc)t. Copyright © 2014 Elsevier B.V. All rights reserved.

Droplets Formation and Merging in Two-Phase Flow Microfluidics

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Hao Gu

2011-04-01

Full Text Available Two-phase flow microfluidics is emerging as a popular technology for a wide range of applications involving high throughput such as encapsulation, chemical synthesis and biochemical assays. Within this platform, the formation and merging of droplets inside an immiscible carrier fluid are two key procedures: (i the emulsification step should lead to a very well controlled drop size (distribution; and (ii the use of droplet as micro-reactors requires a reliable merging. A novel trend within this field is the use of additional active means of control besides the commonly used hydrodynamic manipulation. Electric fields are especially suitable for this, due to quantitative control over the amplitude and time dependence of the signals, and the flexibility in designing micro-electrode geometries. With this, the formation and merging of droplets can be achieved on-demand and with high precision. In this review on two-phase flow microfluidics, particular emphasis is given on these aspects. Also recent innovations in microfabrication technologies used for this purpose will be discussed.

Bioremediation of oil-contaminated soil using Candida catenulata and food waste.

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Joo, Hung-Soo; Ndegwa, Pius M; Shoda, Makoto; Phae, Chae-Gun

2008-12-01

Even though petroleum-degrading microorganisms are widely distributed in soil and water, they may not be present in sufficient numbers to achieve contaminant remediation. In such cases, it may be useful to inoculate the polluted area with highly effective petroleum-degrading microbial strains to augment the exiting ones. In order to identify a microbial strain for bioaugmentation of oil-contaminated soil, we isolated a microbial strain with high emulsification and petroleum hydrocarbon degradation efficiency of diesel fuel in culture. The efficacy of the isolated microbial strain, identified as Candida catenulata CM1, was further evaluated during composting of a mixture containing 23% food waste and 77% diesel-contaminated soil including 2% (w/w) diesel. After 13 days of composting, 84% of the initial petroleum hydrocarbon was degraded in composting mixes containing a powdered form of CM1 (CM1-solid), compared with 48% of removal ratio in control reactor without inoculum. This finding suggests that CM1 is a viable microbial strain for bioremediation of oil-contaminated soil with food waste through composting processes.

Kinetic study of biosurfactant production by Bacillus subtilis LAMI005 grown in clarified cashew apple juice.

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de Oliveira, Darlane Wellen Freitas; França, Italo Waldimiro Lima; Félix, Anne Kamilly Nogueira; Martins, João Jeferson Lima; Giro, Maria Estela Aparecida; Melo, Vânia Maria M; Gonçalves, Luciana Rocha Barros

2013-01-01

In this work a low cost medium for the production of a biosurfactant by Bacillus subtilis LAMI005 and the kinetics of surfactin production considering the effect of initial substrate concentration were investigated. First, cashew apple juice supplementation for optimal production of biosurfactant by B. subtilis LAMI005 was studied. The medium formulated with clarified cashew apple juice and distilled water, supplemented with 1.0 g/L of (NH(4))(2)SO(4), proved to be the best among the nutrients evaluated. The crude biosurfactant had the ability to decrease the surface tension of water to 30 dyne/cm, with a critical micelle concentration (CMC) of 63.0 mg/L. Emulsification experiments indicated that this biosurfactant effectively emulsified kerosene (IE(24)=67%) and soybean oil (IE(24)=64%). Furthermore, the emulsion stability was always very high. It was shown by biochemical analysis, IR spectra, that there is no qualitative differences in the composition of the crude biosurfactant from a standard sample of surfactin from B. subtilis. Copyright © 2012 Elsevier B.V. All rights reserved.

Biosynthesis of Bio surfactant by Egyptian Local Bacterial Isolates Using Different Agricultural Wastes

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El-Shahawy, M.R.

2014-01-01

Fifteen bacterial isolates were isolated from sea water from the coast of the General Petroleum Company on Suez Gulf. They were screened for bio surfactant production using emulsification activity and haemolytic activity. The most potent isolate B11 were selected according to two parameters: The ability to grow and produce surfactant and its haemolytic activity on blood agar plates. The isolate B11 was characterized and identified as Bacillus licheniformis according to API system. The isolate was subjected to different doses of gamma irradiation in a trial to improve its ability for bio surfactant production which resulted in a passive effect on bio surfactant production. Three types of agricultural wastes (Rice straw, Cane Bagasse, Corn straw) were used as fertilizers for bio surfactant biosynthesis by the promising isolate in concentrations of 1, 2, 3, 4, 5 g/l. At five g/l concentration cane bagasse gave high production of bio surfactant with maximum capacity at (32%) flowed by rice straw at 18% and corn straw at 9.8 %.

The Ratios of Pre-emulsified Duck Skin for Optimized Processing of Restructured Ham.

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Shim, Jae-Yun; Kim, Tae-Kyung; Kim, Young-Boong; Jeon, Ki-Hong; Ahn, Kwang-Il; Paik, Hyun-Dong; Choi, Yun-Sang

2018-02-01

The purpose of this study was to investigate the quality of duck ham formulated with duck skin through the pre-emulsification process. The experiments to investigate the quality characteristics of duck ham were carried out to measure proximate composition, cooking loss, emulsion stability, pH, color, texture profile analysis, apparent viscosity, and sensory characteristics. Duck ham was prepared with various ratios of duck skin in pre-emulsion as follows: Control (duct skin 30%), T1 (duck skin 20% + pre-emulsified duck skin 10%), T2 (duck skin 15% + pre-emulsified duck skin 15%), T3 (duck skin 10% + pre-emulsified duck skin 20%), and T4 (pre-emulsified duck skin 30%). As the ratio of duck skin to pre-emulsified skin changed, the quality of duck ham in terms of moisture content, fat content, cooking loss, emulsion stability, lightness, textural analysis, apparent viscosity, and overall acceptability changed. The moisture content of T2 was the highest ( p ham and 1:1 ratio of duck skin and pre-emulsified skin was the proper ratio to improve the quality characteristics of duck ham.

In Vivo Osteogenic Potential of Biomimetic Hydroxyapatite/Collagen Microspheres: Comparison with Injectable Cement Pastes.

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Erika Cuzmar

Full Text Available The osteogenic capacity of biomimetic calcium deficient hydroxyapatite microspheres with and without collagen obtained by emulsification of a calcium phosphate cement paste has been evaluated in an in vivo model, and compared with an injectable calcium phosphate cement with the same composition. The materials were implanted into a 5 mm defect in the femur condyle of rabbits, and bone formation was assessed after 1 and 3 months. The histological analysis revealed that the cements presented cellular activity only in the margins of the material, whereas each one of the individual microspheres was covered with osteogenic cells. Consequently, bone ingrowth was enhanced by the microspheres, with a tenfold increase compared to the cement, which was associated to the higher accessibility for the cells provided by the macroporous network between the microspheres, and the larger surface area available for osteoconduction. No significant differences were found in terms of bone formation associated with the presence of collagen in the materials, although a more extensive erosion of the collagen-containing microspheres was observed.

Experimental study of solvent-based emulsion injection to enhance heavy oil recovery in Alaska North Slope area

Energy Technology Data Exchange (ETDEWEB)

Qiu, F.; Mamora, D. [Texas A and M Univ., College Station, TX (United States)

2010-07-01

This study examined the feasibility of using a chemical enhanced oil recovery method to overcome some of the technical challenges associated with thermal recovery in the Alaska North Slope (ANS). This paper described the second stage research of an experimental study on nano-particle and surfactant-stabilized solvent-based emulsions for the ANS area. Four successful core flood experiments were performed using heavy ANS oil. The runs included water flooding followed by emulsion flooding; and pure emulsion injection core flooding. The injection rate and core flooding temperature remained constant and only 1 PV micro-emulsion was injected after breakthrough under water flooding or emulsion flooding. Oil recovery increased by 26.4 percent from 56.2 percent original oil in place (OOIP) with waterflooding to 82.6 percent OOIP with injection of emulsion following water flooding. Oil recovery was slightly higher with pure emulsion flooding, at 85.8 percent OOIP. The study showed that low permeability generally resulted in a higher shear rate, which is favourable for in-situ emulsification and higher displacement efficiency. 11 refs., 4 tabs., 20 figs.

Microsphere Wetting, Meniscus Structure, and Capillary Interactions on a Curved Liquid Interface

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Kim, Paul; Dinsmore, Anthony; Hoagland, David; Russell, Thomas

A small spherical microparticle on a cylindrically curved liquid interface locally induces a quadrupolar interface deformation to maintain a constant contact angle about its wetted periphery. Measured by optical profilometry, this deformation was compared to a recent theoretical expression, and good agreement was noted for contact line shape, particle vertical position, and deformation vs. (distance, angle, particle size, interfacial curvature). Interface quadrupoles lead to particle capillary interactions in analogy to 2D electrostatic quadrupoles, and as one consequence, spheres on a cylindrical interface assemble tetragonally, i.e., into a square lattice. This assembly was monitored in the optical microscope, with particles interacting as predicted, into a square lattice aligned with the underlying cylindrical axis. These particles and assemblies were driven to the middle of the curved interface by capillary interaction with pinned liquid contact lines on each side of the liquid cylindrical section used in the experiments. These phenomena can inform the directed interfacial assembly of micro-sized spherical objects, with potential application in fabrication of functional devices and materials, encapsulation, and emulsification.

Producing Biosurfactants from Purified Microorganisms Obtained from Oil-contaminated Soil

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Nader Mokhtarian

2010-09-01

Full Text Available Contamination of soil by crude oil can pose serious problems to ecosystems. Soil washing by solutions containing biosurfactants is one of the most efficient methods for the remediation of contaminated soil by crude oil because it removes not only the crude oil but also heavy metals. In this study, five soil samples were taken from fields exposed to oil compounds over the years in order to produce biosurfactants from microorganisms that were capable of degrading oil compounds. Sixteen such microorganisms were isolated. After cultivation, their emulsification strength was examined using E24 test. From among the experimental microorganisms, a gram-negative and rod-shape microorganism called A-12 showed the greatest value of the E24 test index (36%. For each liter of the culture medium containing 365 mg of microorganisms, 3 gr of the biosurfactant compound was produced and separated as dried powder. The purified biosurfactant was used in the soil washing process. Also, the insulated microorganisms were capable of degrading crude oil floating on wastewaters.

Preparation and Characterization of Keratin/Alginate Blend Microparticles

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Yaowalak Srisuwan

2018-01-01

Full Text Available The water-in-oil (W/O emulsification-diffusion method was used for construction of keratin (Ker, alginate (Alg, and Ker/Alg blend microparticles. The Ker, Alg, and Ker/Alg blend solutions were used as the water phase, while ethyl acetate was used as the oil phase. Firstly, different concentrations of Ker solution was used to find suitable content. 1.6% w/v Ker solution was blended with the same concentration of the Alg solution for further microparticle construction. Results from scanning electron microscope analysis show that the microparticles have different shapes: spherical, bowl-like, porous, and hollow, with several sizes depending on the blend ratio. FTIR and TG analyses indicated that the secondary structure and thermal stability of the microparticles were influenced by the Ker/Alg blend ratio. The interaction between functional groups of keratin and alginate was the main factor for both β-sheet structure and Td,max values of the microparticles. The results suggested that Ker/Alg blend microparticles might be applied in many fields by varying the Ker/Alg ratio.

Formulation and cytotoxicity evaluation of new self-emulsifying multiple W/O/W nanoemulsions

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Sigward E

2013-02-01

Full Text Available Estelle Sigward,1 Nathalie Mignet,1 Patrice Rat,2 Mélody Dutot,2 Saleh Muhamed,1 Jean-Michel Guigner,3 Daniel Scherman,1 Denis Brossard,1 Sylvie Crauste-Manciet11Chemical, Genetic and Imaging Pharmacology Laboratory; INSERM U1022, CNRS UMR8151, Chimie ParisTech, Faculty of Pharmacy, Paris Descartes University, Sorbone Paris Cité, Paris, France; 2Chemistry-Cellular and Analytical Toxicology Laboratory (C-TAC, Faculty of Pharmacy, Paris Descartes University, Sorbone Paris Cité, Paris, France; 3Institut de Minéralogie et de Physique des Milieux Condensés IMPMC -IRD-CNRS UMR 7590, Université Paris Pierre et Marie Curie, Paris, FranceAbstract: Three multiple water-in-oil-in-water (W/O/W nanoemulsions have been designed for potential inclusion of either lipophilic or hydrophilic drugs using a two-step emulsification process exclusively based on low-energy self-emulsification. The W/O primary emulsion was constituted by a blend of oil (medium chain triglyceride, a mixture (7:3 of two surfactants, and a 10% water phase. The surfactants were a mixture of Polysorbate-85/Labrasol®, Polysorbate-85/ Cremophor® EL or glycerol/Polysorbate-85. The final W/O/W nanoemulsions were obtained by the addition of water, with a weight ratio nanoemulsion/water of 1:2. The multiple emulsion stability was found to increase from 24 hours to 2 and 6 months with Labrasol, glycerol, and Cremophor, respectively. Cytotoxicity was found for formulations including Labrasol and Cremophor EL. The concentration of emulsion inhibiting 50% cell viability (IC50 was determined using the alamarBlue® test, giving after 24 hours of incubation, IC50 = 10.2 mg/mL for the Labrasol formulation and IC50 = 11.8 mg/mL for the Cremophor EL formulation. Corresponding calculated IC50 values for surfactants were 0.51 mg/mL for Labrasol and 0.59 mg/mL for Cremophor EL. In both cases, cytotoxicity was due to an apoptotic mechanism, evidenced by chromatin condensation and P2X7 cell death

Novel sulpiride-loaded solid lipid nanoparticles with enhanced intestinal permeability

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Ibrahim WM

2013-12-01

Full Text Available Waheed M Ibrahim,1 Abdullah H AlOmrani,2 Alaa Eldeen B Yassin31Drug Sector, Saudi Food and Drug Authority, 2Department of Pharmaceutics, College of Pharmacy, King Saud University, 3Department of Pharmaceutical Sciences, College of Pharmacy, King Saud bin Abdulaziz University for Health Sciences, National Guard Health Affairs, Riyadh, Saudi ArabiaBackground: Solid lipid nanoparticles (SLN, novel drug delivery carriers, can be utilized in enhancing both intestinal permeability and dissolution of poorly absorbed drugs. The aim of this work was to enhance the intestinal permeability of sulpiride by loading into SLN.Methods: A unique ultrasonic melt-emulsification method with minimum stress conditions was used for the preparation of SLN. The mixture of the drug and the melted lipids was simply dispersed in an aqueous solution of a surfactant at a temperature that was 10°C higher than the melting points of the lipids using probe sonication, and was then simultaneously dispersed in cold water. Several formulation parameters were optimized, including the drug-to-lipid ratio, and the types of lipids and surfactants used. The produced SLN were evaluated for their particle size and shape, surface charge, entrapment efficiency, crystallinity of the drug and lipids, and the drug release profile. The rat everted sac intestine model was utilized to evaluate the change in intestinal permeability of sulpiride by loading into SLN.Results: The method adopted allowed successful preparation of SLN with a monodispersed particle size of 147.8–298.8 nm. Both scanning electron microscopic and atomic force microscopic images showed uniform spherical particles and confirmed the sizes determined by the light scattering technique. Combination of triglycerides with stearic acid resulted in a marked increase in zeta potential, entrapment efficiency, and drug loading; however, the particle size was increased. The type of surfactant used was critical for particle size

Effect of Emulsification Method and Particle Size on the Rate of in vivo Oral Bioavailability of Kenaf (Hibiscus cannabinus L.) Seed Oil.

Science.gov (United States)

Cheong, Ai Mun; Tan, Chin Ping; Nyam, Kar Lin

2018-05-26

Kenaf (Hibiscus cannabinus L.) seed oil-in-water nanoemulsions stabilized by complexation of beta-cyclodextrin with sodium caseinate and Tween 20 have been shown to have higher bioaccessibility of vitamin E and total phenolic content than nonemulsified kenaf seed oil in the previous in vitro gastrointestinal digestion study. However, its oral bioavailability was unknown. Therefore, the aim of this study was to evaluate the rate of in vivo oral bioavailability of kenaf seed oil-in-water nanoemulsions in comparison with nonemulsified kenaf seed oil and kenaf seed oil macroemulsions during the 180 min of gastrointestinal digestion. Kenaf seed oil macroemulsions were produced by using conventional method. Kenaf seed oil-in-water nanoemulsions had shown improvement in the rate of absorption. At 180 min of digestion time, the total α-tocopherol bioavailability of kenaf seed oil nanoemulsions was increased by 1.7- and 1.4-fold, compared to kenaf seed oil and macroemulsion, respectively. Kenaf seed oil-in-water nanoemulsions were stable in considerably wide range of pH (>5 and oil-in-water nanoemulsions had provided a delivery system to encapsulate the kenaf seed oil, as well as enhanced the bioaccessibility and bioavailability of kenaf seed oil. Therefore, kenaf seed oil-in-water nanoemulsions exhibit a great potential application in nutraceutical fields. © 2018 Institute of Food Technologists®.

Synthetic Polymers at Interfaces: Monodisperse Emulsions Multiple Emulsions and Liquid Marbles

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Sun, Guanqing

The adsorption of polymeric materials at interfaces is an energetically favorable process which is investigated in much diversified fields, such as emulsions, bubbles, foams, liquid marbles. Pickering emulsion, which is emulsion stabilized by solid particles has been investigated for over one century and preparation of Pickering emulsion with narrow size distribution is crucial for both the theoretical study of the stabilization mechanism and practical application, such as templated fabrication of colloidosomes. The precise control over the size and functionality of polymer latices allows the preparation of monodisperse Pickering emulsions with desired sizes through SPG membrane emulsification at rather rapid rate compared to microfludic production. Double or multiple emulsions have long been investigated but its rapid destabilization has always been a major obstacle in applying them into practical applications. The modern living polymerization techniques allow us to prepare polymers with designed structure of block copolymers which makes it possible to prepare ultra-stable multiple emulsions. The precise tuning of the ratio of hydrophobic part over the hydrophilic can unveil the stabilization mechanism. Liquid marble is a new type of materials of which liquid droplets are coated by dry particles. The coating of an outer layer of dry particles renders the liquid droplets non-sticky at solid surface which is useful in transportation of small amount of liquid without leakage at extreme low friction force. The property of liquid marbles relies largely on the stabilizers and the drying condition of polymeric latices is shown to have great influence on the property of liquid marbles. Firstly, an introduction to the interfacial and colloidal science with special attention to topics on emulsions, multiple emulsion and liquid marbles is given in Chapter 1. The unique features of an interface and a discussion on the definition of colloids are introduced prior to the

Preparation of Astaxanthin Nanodispersions Using Gelatin-Based Stabilizer Systems

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Navideh Anarjan

2014-09-01

Full Text Available The incorporation of lipophilic nutrients, such as astaxanthin (a fat soluble carotenoid in nanodispersion systems can either increase the water solubility, stability and bioavailability or widen their applications in aqueous food and pharmaceutical formulations. In this research, gelatin and its combinations with sucrose oleate as a small molecular emulsifier, sodium caseinate (SC as a protein and gum Arabic as a polysaccharide were used as stabilizer systems in the formation of astaxanthin nanodispersions via an emulsification-evaporation process. The results indicated that the addition of SC to gelatin in the stabilizer system could increase the chemical stability of astaxanthin nanodispersions significantly, while using a mixture of gelatin and sucrose oleate as a stabilizer led to production of nanodispersions with the smallest particle size (121.4 ± 8.6 nm. It was also shown that a combination of gelatin and gum Arabic could produce optimal astaxanthin nanodispersions in terms of physical stability (minimum polydispersity index (PDI and maximum zeta-potential. This study demonstrated that the mixture of surface active compounds showed higher emulsifying and stabilizing functionality compared to using them individually in the preparation of astaxanthin nanodispersions.

Cellular uptake and radiosensitization of SR-2508 loaded PLGA nanoparticles

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Jin Cheng [Fourth Military Medical University, Department of Radiation Medicine (China); Bai Ling [Xi' an Gaoxin Hospital, Department of Clinical Laboratories (China); Wu Hong [Fourth Military Medical University, Department of Pharmacy (China); Teng Zenghui [Fourth Military Medical University, Department of Pharmacology (China); Guo Guozhen, E-mail: guozhengg@tom.co [Fourth Military Medical University, Department of Radiation Medicine (China); Chen Jingyuan, E-mail: jy_chen@fmmu.edu.c [Fourth Military Medical University, Department of Occupational and Environmental Health (China)

2008-08-15

SR-2508 (etanidazole), a hypoxic radiosensitizer, has potential applications in radiotherapy. The poly(d,l-lactide-co-glycolide)(PLGA) nanoparticles containing SR-2508 were prepared by w/o/w emulsification-solvent evaporation method. The physicochemical characteristics of the nanoparticles (i.e. encapsulation efficiency, particle size distribution, morphology, in vitro release) were studied. The cellular uptake of the nanoparticles for the two human tumor cell lines: human breast carcinoma cells (MCF-7) and human carcinoma cervices cells (HeLa), was evaluated by fluorescence microscopy and transmission electronic microscopy. Cell viability was measured by the ability of single cell to form colonies in vitro. The prepared nanoparticles were spherical in shape with size between 90 nm and 190 nm. The encapsulation efficiency was 20.06%. The drug release pattern exhibited an initial burst followed by a plateau for over 24 h. The cellular uptake of nanoparticles was observed. Co-culture of MCF-7 and HeLa cells with SR-2508 loaded nanoparticles showed that released SR-2508 retained its bioactivity and effectively sensitized two hypoxic tumor cell lines to radiation. The radiosensitization of SR-2508 loaded nanoparticles was more significant than that of free drug.

Preparative isolation of a cytotoxic principle of a forest mushroom Suillus luteus by sodium dodecyl sulfate based "salting-in" countercurrent chromatography.

Science.gov (United States)

Yang, Zhi; Hu, Xueqian; Wu, Shihua

2016-02-01

In the course of screening new anticancer natural products, an edible forest mushroom Suillus luteus (L. Ex Franch). Gray was found to have potent cytotoxicity against several human cancer cells. However, the lipophilic sample made some countercurrent chromatography solvent systems emulsify, which caused difficulties in the separation of its cytotoxic components. Here, we found that the addition of an organic salt sodium dodecyl sulfate could efficiently shorten the settling time of the mushroom sample solutions by eliminating the emulsification of two-phase solvent systems. Moreover, we found that sodium dodecyl sulfate could play a new "salting-in" role and made the partition coefficients of the solutes decrease with the increased concentrations. Thus, a sodium dodecyl sulfate based salting-in countercurrent chromatography method has been successfully established for the first time for preparative isolation of a cytotoxic principle of the mushroom. The active component was identified as isosuillin. Whole results indicated that sodium dodecyl sulfate could be used as an efficient salting-in reagent for two-phase solvent system selection and targeted countercurrent chromatography isolation. It is very useful for current natural products isolation and drug discovery. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of SiCN@TiO2 core-shell ceramic microspheres via PDCs method

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Liu, Hongli; Wei, Ning; Li, Jing; Zhang, Haiyuan; Chu, Peng

2018-02-01

A facile and effective polymer-derived ceramics (PDCs) emulsification-crosslinking-pyrolysis method was developed to fabricate SiCN@TiO2 core-shell ceramic microspheres with polyvinylsilazane (PVSZ) and tetrabutyl titanate (TBT) as precursors. The TBT: PVSZ mass ratios, emulsifier concentrations and the pyrolysis temperature were examined as control parameters to tune the size and morphology of microspheres. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) confirmed the synthesized SiCN@TiO2 microspheres to be comprised of SiCN core coated with TiO2 crystals, with an average size of 0.88 μm when pyrolyzed at 1400 °C. The analysis of Fourier transform infrared spectroscopy (FT-IR), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) ensured that SiCN@TiO2 core-shell ceramic microspheres composed of rutile TiO2, β-SiC and Si3N4 crystalline phases, The thermal properties were characterized by thermogravimetric analysis (TGA). The obtained SiCN@TiO2 core-shell ceramic microspheres were the promising candidate of the infrared opacifier in silica aerogels and this technique can be extended to other preceramic polymers.

Technology of stable, prolonged-release eye-drops containing Cyclosporine A, distributed between lipid matrix and surface of the solid lipid microspheres (SLM).

Science.gov (United States)

Wolska, Eliza; Sznitowska, Małgorzata

2013-01-30

The aim of this study was to prepare solid lipid microspheres (SLM) with incorporated Cyclosporine A (Cs), suitable for ocular application. For this purpose, SLM were formulated by using different lipids and three different nonionic surfactants. The SLM were produced using a hot emulsification method. The SLM dispersions contained 10, 20 or 30% of lipid (w/w) and up to 2% (w/w) of Cs. The size of the microspheres with Cs ranged from 1 to 15 μm. Physically stable SLM with Cs were prepared using Compritol, as a lipid matrix, and Tween 80, as a surfactant. In contrast, dispersion with Precirol alone, formed semi-solid gels during storage, while in formulations with Precirol and Miglyol, crystals of Cs were observed. In vitro release profile of Compritol formulations showed that 40% of Cs is released within 1h, while the release of the following 40% takes more time, depending on lipid content in the formulations. The large part of Cs, added to SLM formulations (from 45 to 80%), was found on the surface of microparticles, but no drug crystallization occurred during a long-term storage. Copyright © 2012 Elsevier B.V. All rights reserved.

The effect of a lipid composition and a surfactant on the characteristics of the solid lipid microspheres and nanospheres (SLM and SLN).

Science.gov (United States)

Sznitowska, Malgorzata; Wolska, Eliza; Baranska, Helena; Cal, Krzysztof; Pietkiewicz, Justyna

2017-01-01

Solid lipid microparticles (SLM) were produced by a two-step process that, firstly, involved the emulsification of the molten lipid phase in a heated aqueous phase and, secondly, the system cooling. Compritol 888 ATO and Precirol ATO 5, including their mixtures with Miglyol 812 or Witepsol H15 were used as lipid components (10-30% w/w). The average size of the SLM prepared with Compritol and Tween 80 as an emulsifier was 3-7μm and the influence of lipid concentration and thermal sterilization was not large. Dispersions of SLM with Precirol (10-20% w/w) gellified upon storage. SLM stabilized with another surfactant, Tego Care 450, were larger in size and measured 40μm on average. The use of the sonication step (5-15min) in hot formulations containing 5% w/w of Compritol resulted in the formation of the solid lipid nanoparticles (SLN) with average size 200-300nm. The smallest SLN size (below 100nm on average) was obtained in SLN that contained Tego Care and an antimicrobial agent Euxyl PE 9010; such combination evoked synergism between the surfactant and Euxyl components. Copyright © 2016 Elsevier B.V. All rights reserved.

Optimization of LDL targeted nanostructured lipid carriers of 5-FU by a full factorial design.

Science.gov (United States)

Andalib, Sare; Varshosaz, Jaleh; Hassanzadeh, Farshid; Sadeghi, Hojjat

2012-01-01

Nanostructured lipid carriers (NLC) are a mixture of solid and liquid lipids or oils as colloidal carrier systems that lead to an imperfect matrix structure with high ability for loading water soluble drugs. The aim of this study was to find the best proportion of liquid and solid lipids of different types for optimization of the production of LDL targeted NLCs used in carrying 5-Fu by the emulsification-solvent evaporation method. The influence of the lipid type, cholesterol or cholesteryl stearate for targeting LDL receptors, oil type (oleic acid or octanol), lipid and oil% on particle size, surface charge, drug loading efficiency, and drug released percent from the NLCs were studied by a full factorial design. The NLCs prepared by 54.5% cholesterol and 25% of oleic acid, showed optimum results with particle size of 105.8 nm, relatively high zeta potential of -25 mV, drug loading efficiency of 38% and release efficiency of about 40%. Scanning electron microscopy of nanoparticles confirmed the results of dynamic light scattering method used in measuring the particle size of NLCs. The optimization method by a full factorial statistical design is a useful optimization method for production of nanostructured lipid carriers.

Biosurfactants: Multifunctional Biomolecules of the 21st Century.

Science.gov (United States)

Santos, Danyelle Khadydja F; Rufino, Raquel D; Luna, Juliana M; Santos, Valdemir A; Sarubbo, Leonie A

2016-03-18

In the era of global industrialisation, the exploration of natural resources has served as a source of experimentation for science and advanced technologies, giving rise to the manufacturing of products with high aggregate value in the world market, such as biosurfactants. Biosurfactants are amphiphilic microbial molecules with hydrophilic and hydrophobic moieties that partition at liquid/liquid, liquid/gas or liquid/solid interfaces. Such characteristics allow these biomolecules to play a key role in emulsification, foam formation, detergency and dispersal, which are desirable qualities in different industries. Biosurfactant production is considered one of the key technologies for development in the 21st century. Besides exerting a strong positive impact on the main global problems, biosurfactant production has considerable importance to the implantation of sustainable industrial processes, such as the use of renewable resources and "green" products. Biodegradability and low toxicity have led to the intensification of scientific studies on a wide range of industrial applications for biosurfactants in the field of bioremediation as well as the petroleum, food processing, health, chemical, agricultural and cosmetic industries. In this paper, we offer an extensive review regarding knowledge accumulated over the years and advances achieved in the incorporation of biomolecules in different industries.

Isolation and functional characterization of a biosurfactant produced by a new and promising strain of Oleomonas sagaranensis AT18.

Science.gov (United States)

Saimmai, Atipan; Rukadee, Onkamon; Onlamool, Theerawat; Sobhon, Vorasan; Maneerat, Suppasil

2012-10-01

Biosurfactant-producing bacteria were isolated from mangrove sediment in southern Thailand. Isolates were screened for biosurfactant production by using the surface tension test. The highest reduction of surface tension was achieved with a bacterial strain which was identified by 16S rRNA gene sequencing as Oleomonas sagaranensis AT18. It has also been investigated using different carbon and nitrogen sources. It showed that the strain was able to grow and reduce the surface tension of the culture supernatant to 25 mN/m. In all 5.30 g of biosurfactant yield was obtained after 54 h of cultivation by using molasses and NaNO₃ as carbon and nitrogen sources, respectively. The biosurfactant recovery by chloroform:methanol extraction showed a small critical micelle concentration value (8 mg/l), thermal and pH stability with respect to surface tension reduction. It also showed emulsification activity and a high level of salt concentration. The biosurfactant obtained was confirmed as a glycolipid by using a biochemical test, FT-IR and mass spectra. The crude biosurfactant showed a broad spectrum of antimicrobial activity and also had the ability to emulsify oil and enhance PAHs solubility.

Characterization of a novel biosurfactant produced by Staphylococcus sp. strain 1E with potential application on hydrocarbon bioremediation.

Science.gov (United States)

Eddouaouda, Kamel; Mnif, Sami; Badis, Abdelmalek; Younes, Sonia Ben; Cherif, Slim; Ferhat, Samira; Mhiri, Najla; Chamkha, Mohamed; Sayadi, Sami

2012-08-01

A biosurfactant-producing bacterium (Staphylococcus sp. strain 1E) was isolated from an Algerian crude oil contaminated soil. Biosurfactant production was tested with different carbon sources using the surface tension measurement and the oil displacement test. Olive oil produced the highest reduction in surface tension (25.9 dynes cm(-1)). Crude oil presented the best substrate for 1E biosurfactant emulsification activity. The biosurfactant produced by strain 1E reduced the growth medium surface tension below 30 dynes cm(-1). This reduction was also obtained in cell-free filtrates. Biosurfactant produced by strain 1E showed stability in a wide range of pH (from 2 to 12), temperature (from 4 to 55 °C) and salinity (from 0 to 300 g l(-1)) variations. The biosurfactant produced by strain 1E belonged to lipopeptide group and also constituted an antibacterial activity againt the pathogenic bacteria such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis. Phenanthrene solubility in water was enhanced by biosurfactant addition. Our results suggest that the 1E biosurfactant has interesting properties for its application in bioremediation of hydrocarbons contaminated sites. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimization and characterization of biosurfactant from Streptomyces griseoplanus NRRL-ISP5009 (MS1).

Science.gov (United States)

Elkhawaga, M A

2018-03-01

This work aimed to study, isolate, characterize and stabilize the biosurfactant isolated from actinomycetes found in petroleum contaminated soil. Optimized production of the biosurfactant from Streptomyces griseoplanus NRRL-ISP5009, SM1 was obtained on day 6 at 30°C, pH 7, 150 rev min -1 , in glycerol yeast extract broth medium supplemented with cellulose, yeast extract and 1% NaCl. The stability of the biosurfactant produced was studied at different temperatures, pH and different concentrations of NaCl. The produced biosurfactant was extracted and purified. Streptomyces griseoplanus NRRL-ISP5009, SM1 isolated from oil contaminated soil produced a biosurfactant exhibiting emulsification activity. The produced biosurfactant is a mixture of carbohydrate, lipid and protein. It has promising characteristics, including a higher stability at alkaline pH than at acidic pH, a salinity of 1-3% and stable in the temperature range from 0 and 100°C. Also, the potential antimicrobial activity of the purified biosurfactant was recorded. The research was focused on the isolation of a novel source of biosurfactants that have great importance in the manufacture of food, detergent, pharmaceutical and cosmetics. © 2017 The Society for Applied Microbiology.

Bioremediation of oil-contaminated soil using Candida catenulata and food waste

International Nuclear Information System (INIS)

Joo, Hung-Soo; Ndegwa, Pius M.; Shoda, Makoto; Phae, Chae-Gun

2008-01-01

Even though petroleum-degrading microorganisms are widely distributed in soil and water, they may not be present in sufficient numbers to achieve contaminant remediation. In such cases, it may be useful to inoculate the polluted area with highly effective petroleum-degrading microbial strains to augment the exiting ones. In order to identify a microbial strain for bioaugmentation of oil-contaminated soil, we isolated a microbial strain with high emulsification and petroleum hydrocarbon degradation efficiency of diesel fuel in culture. The efficacy of the isolated microbial strain, identified as Candida catenulata CM1, was further evaluated during composting of a mixture containing 23% food waste and 77% diesel-contaminated soil including 2% (w/w) diesel. After 13 days of composting, 84% of the initial petroleum hydrocarbon was degraded in composting mixes containing a powdered form of CM1 (CM1-solid), compared with 48% of removal ratio in control reactor without inoculum. This finding suggests that CM1 is a viable microbial strain for bioremediation of oil-contaminated soil with food waste through composting processes. - Enhancement on degradation ability of petroleum hydrocarbon by the microbial strain in the composting process with food waste

Innovative formulation of nystatin particulate systems in toothpaste for candidiasis treatment.

Science.gov (United States)

Pinto Reis, Catarina; Vasques Roque, Luís; Baptista, Marina; Rijo, Patrícia

2016-01-01

Oral candidiasis is a mycosis on the mucous membranes of the mouth but not limited to the mouth. Nystatin is one of the most frequently employed antifungal agents to treat infections and may be safely given orally as well as applied topically but its absorption through mucocutaneous membranes such as the gut and the skin is minimal. The purpose of this study is to enhance the effectiveness of nystatin using particulate system such as beads, micro- and nanoparticles of alginate incorporated into toothpaste. Those particulate systems of nystatin were prepared by extrusion/external gelation for beads and emulsification/internal gelation for micro- and nanoparticles and characterized. Small, anionic charged and monodispersed particles were successfully produced. The type of particulate system influenced all previous parameters, being microparticles the most suitable particulate system of nystatin showing the slowest release, the highest inhibitory effect of Candida albicans over a period of one year. Those results allowed the conclusion that alginate exhibits properties that enable the in vitro functionality of encapsulated nystatin and thus may provide the basis for new successful approaches for the treatment of oral antifungal infections such as oral candidiasis.

Evaluation of short-term physical weathering of a heavy fuel oil by use of time warping and PCA

Energy Technology Data Exchange (ETDEWEB)

Malmquist, L.M.V.; Olsen, R.R. [Roskilde Univ., Roskilde (Denmark). Dept. of Life Sciences and Chemistry]|[National Environmental Research Inst., Roskilde (Denmark). Dept. of Environmental Chemistry and Microbiology; Christensen, J.H. [Royal Veterinary and Agricultural Univ., Thorvaldsensvej (Denmark). Dept. of Natural Sciences; Andersen, O. [Roskilde Univ., Roskilde (Denmark). Dept. of Life Sciences and Chemistry

2005-07-01

An estimated 1,140 billion tons of oil was accidentally spilled to the environment during the 1990s. These spills present an ecotoxicologic risk due to the presence of toxic and mutagenic compounds in the oil. Oil is affected by short term and long term weathering processes such as evaporation, dissolution, dispersion, emulsification, photodegradation and biodegradation. Physical weathering processes change the composition of the oil but they do not alter the oil components. Gas chromatography and mass spectrometry can characterize the compositional changes resulting from evaporation. However, the process depends on subjective analysis because it is based on manual interpretation of results and visual inspection. This paper presents a rapid and objective method to compare oil sample compositions. The method is based on automated data preprocessing involving baseline removal, alignment of chromatograms using correlation optimized warping (COW) and normalization. Preprocessed data is analyzed by principal component analysis (PCA) based on the total chromatograms. The method has successfully resolved the effects of evaporation and dissolution processes and showed clear dependence of time, but it did not completely resolve the effect of weathering from the analytical variability because better quality data is required. 21 refs., 3 figs.

Investigations in physical mechanism of the oxidative desulfurization process assisted simultaneously by phase transfer agent and ultrasound.

Science.gov (United States)

Bhasarkar, Jaykumar B; Chakma, Sankar; Moholkar, Vijayanand S

2015-05-01

This paper attempts to discern the physical mechanism of the oxidative desulfurization process simultaneously assisted by ultrasound and phase transfer agent (PTA). With different experimental protocols, an attempt is made to deduce individual beneficial effects of PTA and ultrasound on the oxidative desulfurization system, and also the synergy between the effects of PTA and ultrasound. Effect of PTA is more marked for mechanically stirred system due to mass transfer limitations, while intense emulsification due to ultrasound helps overcome the mass transfer limitations and reduces the extent of enhancement of oxidation by PTA. Despite application of PTA and ultrasound, the intrinsic factors and properties of the reactants such as polarity (and hence partition coefficient) and diffusivity have a crucial effect on the extent of oxidation. The intrinsic reactivity of the oxidant also plays a vital role, as seen from the extent of oxidation achieved with performic acid and peracetic acid. The interfacial transport of oxidant in the form of oxidant-PTA complex reduces the undesired consumption of oxidant by the reducing species formed during transient cavitation in organic medium, which helps effective utilization of oxidant towards desulfurization. Copyright © 2014 Elsevier B.V. All rights reserved.

Polyamide nanocapsules and nano-emulsions containing Parsol® MCX and Parsol® 1789: in vitro release, ex vivo skin penetration and photo-stability studies.

Science.gov (United States)

Hanno, Ibrahim; Anselmi, Cecilia; Bouchemal, Kawthar

2012-02-01

To prepare polyamide nanocapsules for skin photo-protection, encapsulating α-tocopherol, Parsol®MCX (ethylhexyl methoxycinnamate) and/or Parsol®1789 (butyl methoxydibenzoylmethane). Nanocapsules were obtained by combining spontaneous emulsification and interfacial polycondensation reaction between sebacoyl chloride and diethylenetriamine. Nano-emulsions used as control were obtained by the same process without monomers. The influence of carrier on release rate was studied in vitro with a membrane-free model. Epidermal penetration of encapsulated sunscreens was ex vivo evaluated using Franz diffusion cells. Ability of encapsulated sunscreens to improve photo-stability was verified by comparing percentage of degradation after UV radiation exposure. Sunscreen-containing nanocapsules (260-400 nm) were successfully prepared; yield of encapsulation was >98%. Parsol®MCX and Parsol®1789 encapsulation led to decreased release rate by up to 60% in comparison with nano-emulsion and allowed minimum penetration through pig ear epidermis. Presence of polyamide shell protected encapsulated sunscreen filters from photo-degradation without affecting their activity. Encapsulation of Parsol®MCX and Parsol®1789 into oil-core of polyamide nanocapsules allowed protection from photo-degradation, controlled release from nanocapsules, and limited penetration through pig ear epidermis.

Evaluation of short-term physical weathering of a heavy fuel oil by use of time warping and PCA

International Nuclear Information System (INIS)

Malmquist, L.M.V.; Olsen, R.R.; Christensen, J.H.; Andersen, O.

2005-01-01

An estimated 1,140 billion tons of oil was accidentally spilled to the environment during the 1990s. These spills present an ecotoxicologic risk due to the presence of toxic and mutagenic compounds in the oil. Oil is affected by short term and long term weathering processes such as evaporation, dissolution, dispersion, emulsification, photodegradation and biodegradation. Physical weathering processes change the composition of the oil but they do not alter the oil components. Gas chromatography and mass spectrometry can characterize the compositional changes resulting from evaporation. However, the process depends on subjective analysis because it is based on manual interpretation of results and visual inspection. This paper presents a rapid and objective method to compare oil sample compositions. The method is based on automated data preprocessing involving baseline removal, alignment of chromatograms using correlation optimized warping (COW) and normalization. Preprocessed data is analyzed by principal component analysis (PCA) based on the total chromatograms. The method has successfully resolved the effects of evaporation and dissolution processes and showed clear dependence of time, but it did not completely resolve the effect of weathering from the analytical variability because better quality data is required. 21 refs., 3 figs

Transdermal solid delivery of epigallocatechin-3-gallate using self-double-emulsifying drug delivery system as vehicle: Formulation, evaluation and vesicle-skin interaction.

Science.gov (United States)

Hu, Caibiao; Gu, Chengyu; Fang, Qiao; Wang, Qiang; Xia, Qiang

2016-02-01

The present study investigated a self-double-emulsifying drug delivery system loaded with epigallocatechin-3-gallate to improve epigallocatechin-3-gallate skin retention. The long chain solid lipids (cetostearyl alcohol) and macadamia oil were utilized as a carrier to deliver the bioactive ingredient. Response surface methodology was used to optimize the formulation, and the solid lipid to total lipid weight ratio, concentration of epigallocatechin-3-gallate and hydrophilic surfactant on skin retention were found to be the principal factors. The optimum formulation with high encapsulation efficiency (95.75%), self-double-emulsification performance (99.58%) and skin retention (87.24%) were derived from the fitted models and experimentally examined, demonstrating a reasonable agreement between experimental and predicted values. Epigallocatechin-3-gallate-self-double-emulsifying drug delivery system was found to be stable for 3 months. Transdermal studies could explain a higher skin diffusion of epigallocatechin-3-gallate from the self-double-emulsifying drug delivery system compared with EGCG aqueous solution. In vitro cytotoxicity showed that epigallocatechin-3-gallate-self-double-emulsifying drug delivery system did not exert hazardous effect on L929 cells up to 1:10. © The Author(s) 2015.

Effects of gamma irradiation on the protein characteristics and functional properties of sesame (Sesamum indicum L.) seeds

Science.gov (United States)

Hassan, Amro B.; Mahmoud, Nagat S.; Elmamoun, Khalid; Adiamo, Oladipupo Q.; Mohamed Ahmed, Isam A.

2018-03-01

This study was aimed at investigating the effect of gamma irradiation at various doses (0.5, 1.0, 1.5 and 2.0 kGy) on protein characteristics and functional properties of sesame seeds. Gamma radiation at high doses (>1.0 kGy) significantly (P ≤ 0.05) increased globulin and albumin fractions of sesame protein. Concomitant (P ≤ 0.05) increase of in-vitro protein digestibility was noticed in irradiated sesame flour compared to non-radiated sample. Maximum protein solubility was observed in sesame flour irradiated at 1.0 kGy. SDS-PAGE electrophoretic patterns of total sesame protein were not affected by irradiation process. Significant enhancement (P ≤ 0.05) in emulsification capacity (EC) and emulsion stability (ES) was recorded after irradiation at a dose level of 1.0 and 1.5-2.0 kGy, respectively. Foaming capacity reached a significantly maximum value in sesame flour irradiated at 1.0 kGy while foaming stability was not significantly affected by gamma irradiation. It can be concluded that gamma radiation enhances the protein and functional properties of sesame flour and thus can be employed as an effective method of preserving sesame flour and its products.

Coarse sediment oil persistence laboratory studies and model

International Nuclear Information System (INIS)

Humphrey, B.; Harper, J.R.

1993-01-01

To gain understanding of the factors which affect the fate of stranded oil on coarse sediment beaches, a series of oil penetration and tidal flushing experiments was conducted in columns containing sediments of two grain sizes: granules and pebbles. The experiments included changing oil properties by weathering and by emulsification. Factors examined included permeability, effective porosity, and residual capacity of the sediment for oil. The laboratory data provided input to an oil persistence model for coarse sediment beaches, and the model was modified on the basis of the new data. The permeability measurements suggest that the permeability of pebble/granule mixtures is close to that of the smaller component. For low viscosity oils, the permeability in coarse sediments is rapid enough to match the fall and rise of tidal water. Effective porosity of the pebbles was ca 90% of the measured porosity, but for both the granules and a 50-50 pebble/granule mixture, the effective porosity was ca 75% of measured porosity. Results of tidal flushing simulation imply that flushing may be rapid but not efficient. The emulsion completely entered the sediment in the case of pebbles only. 2 refs., 6 figs., 3 tabs

Emulsion characteristics, chemical and textural properties of meat systems produced with double emulsions as beef fat replacers.

Science.gov (United States)

Serdaroğlu, Meltem; Öztürk, Burcu; Urgu, Müge

2016-07-01

In recent years, double emulsions are stated to have a promising potential in low-fat food production, however, there are very few studies on their possible applications in meat matrices. We aimed to investigate the quality of beef emulsion systems in which beef fat was totally replaced by double emulsions (W1/O/W2) prepared with olive oil and sodium caseinate (SC) by two-step emulsification procedure. Incorporation of W1/O/W2 emulsion resulted in reduced lipid, increased protein content, and modified fatty acid composition. W1/O/W2 emulsion treatments had lower jelly and fat separation, higher water-holding capacity and higher emulsion stability than control samples with beef fat. Increased concentrations of W1/O/W2 emulsions resulted in significant changes in texture parameters. TBA values were lower in W1/O/W2 emulsion treatments than control treatment after 60days of storage. In conclusion, our study confirms that double emulsions had promising impacts on modifying fatty acid composition and developing both technologically and oxidatively stable beef emulsion systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

On capillary self-focusing in a microfluidic system

Energy Technology Data Exchange (ETDEWEB)

Hein, M; Seemann, R [Experimental Physics, Saarland University, D-66123 Saarbrücken (Germany); Afkhami, S, E-mail: r.seemann@physik.uni-saarland.de, E-mail: shahriar.afkhami@njit.edu [Department of Mathematical Sciences, New Jersey Institute of Technology, Newark, NJ 07102 (United States)

2016-12-15

A computational framework is developed to address capillary self-focusing in step emulsification. The microfluidic system consists of a single shallow and wide microchannel that merges into a deep reservoir. A continuum approach coupled with a volume of fluid method is used to model the capillary self-focusing effect. The original governing equations are reduced using the Hele-Shaw approximation. We show that the interface between the two fluids takes the shape of a neck narrowing in the flow direction just before entering the reservoir, in agreement with our experimental observations. Our computational model relies on the assumption that the pressure at the boundary, where the fluid exits into the reservoir, is the uniform pressure in the reservoir. We investigate this hypothesis by comparing the numerical results with experimental data. We conjecture that the pressure boundary condition becomes important when the width of the neck is comparable to the depth of the microchannel. A correction to the exit pressure boundary condition is then proposed, which is determined by comparison with experimental data. We also present the experimental observations and the numerical results of the transitions of breakup regimes. (paper)

Development and Evaluation of Liquid and Solid Self-Emulsifying Drug Delivery Systems for Atorvastatin

Directory of Open Access Journals (Sweden)

Anna Czajkowska-Kośnik

2015-11-01

Full Text Available The objective of this work was to design and characterize liquid and solid self-emulsifying drug delivery systems (SEDDS for poorly soluble atorvastatin. To optimize the composition of liquid atorvastatin-SEDDS, solubility tests, pseudoternary phase diagrams, emulsification studies and other in vitro examinations (thermodynamic stability, droplet size and zeta potential analysis were performed. Due to the disadvantages of liquid SEDDS (few choices for dosage forms, low stability and portability during the manufacturing process, attempts were also made to obtain solid SEDDS. Solid SEDDS were successfully obtained using the spray drying technique from two optimized liquid formulations, CF3 and OF2. Despite liquid SEDDS formulation, CF3 was characterized by lower turbidity, higher percentage transmittance and better self-emulsifying properties, and based on the in vitro dissolution study it can be concluded that better solubilization properties were exhibited by solid formulation OF2. Overall, the studies demonstrated the possibility of formulating liquid and solid SEEDS as promising carriers of atorvastatin. SEDDS, with their unique solubilization properties, provide the opportunity to deliver lipophilic drugs to the gastrointestinal tract in a solubilized state, avoiding dissolution—a restricting factor in absorption rate of BCS Class 2 drugs, including atorvastatin.

Eudragit-coated dextran microspheres of 5-fluorouracil for site-specific delivery to colon.

Science.gov (United States)

Rai, Gopal; Yadav, Awesh K; Jain, Narendra K; Agrawal, Govind P

2016-01-01

Objective of the present investigation was to prepare and evaluate the potential of enteric coated dextran microspheres for colon targeting of 5-fluorouracil (5-FU). Dextran microspheres were prepared by emulsification-crosslinking method and the formulation variables studied included different molecular weights of dextran, drug:polymer ratio, volume of crosslinking agent, stirring speed and time. Enteric coating (Eudragit S-100) of dextran microspheres was performed by oil-in-oil solvent evaporation method using different coat:core ratios (4:1 or 8:1). Uncoated and coated dextran microspheres were characterized by particle size, surface morphology, entrapment efficiency, DSC, in vitro drug release in the presence of dextranase and 2% rat cecal contents. The release study of 5-FU from coated dextran microspheres was pH dependent. No release was observed at acidic pH; however, the drug was released quickly where Eudragit starts solublizing there was continuous release of drug from the microspheres. Organ distribution study was suggested that coated dextran microspheres retard the release of drug in gastric and intestinal pH environment and released of drug from microspheres in colon due to the degradation of dextran by colonic enzymes.

Antibody study in canine distemper virus nucleocapsid protein gene-immunized mice.

Science.gov (United States)

Yuan, B; Li, X Y; Zhu, T; Yuan, L; Hu, J P; Chen, J; Gao, W; Ren, W Z

2015-04-10

The gene for the nucleocapsid (N) protein of canine distemper virus was cloned into the pMD-18T vector, and positive recombinant plasmids were obtained by enzyme digestion and sequencing. After digestion by both EcoRI and KpnI, the plasmid was directionally cloned into the eukaryotic expression vector pcDNA; the positive clone pcDNA-N was screened by electrophoresis and then transfected into COS-7 cells. Immunofluorescence analysis results showed that the canine distemper virus N protein was expressed in the cytoplasm of transfected COS-7 cells. After emulsification in Freund's adjuvant, the recombinant plasmid pcDNA-N was injected into the abdominal cavity of 8-week-old BABL/c mice, with the pcDNA original vector used as a negative control. Mice were immunized 3 times every 2 weeks. The blood of immunized mice was drawn 2 weeks after completing the immunizations to measure titer levels. The antibody titer in the pcDNA-N test was 10(1.62 ± 0.164), while in the control group this value was 10(0.52 ± 0.56), indicating that specific humoral immunity was induced in canine distemper virus nucleocapsid protein-immunized mice.

Application of edible paraffin oil for cationic dye removal from water using emulsion liquid membrane.

Science.gov (United States)

Zereshki, Sina; Daraei, Parisa; Shokri, Amin

2018-05-18

Using an emulsion liquid membrane based on edible oils is investigated for removing cationic dyes from aqueous solutions. There is a great potential for using edible oils in food industry extraction processes. The parameters affecting the stability of the emulsion and the extraction rate were studied. These parameters were the emulsification time, the stirring speed, the surfactant concentration, the internal phase concentration, the feed phase concentration, the volume ratio of internal phase to organic phase and the treat ratio. In order to stabilize the emulsion without using a carrier, edible paraffin oil and heptane are used at an 80:20 ratio. The optimum conditions for the extraction of methylene blue (MB), crystal violet and methyl violet (CV and MV) cationic dyes using edible paraffin oil as an environment friendly solvent are represented. A removal percentage of 95% was achieved for a mixture of dyes. The optimum concentration of sodium hydroxide in the internal phase, which results a stabile emulsion with a high stripping efficiency of 96%, was 0.04 M. An excellent membrane recovery was observed and the extraction of dyes did not decrease up to seven run cycles. Copyright © 2018 Elsevier B.V. All rights reserved.

Potential of L-fucose isolated from Brown Seaweeds as Promising Natural Emulsifier compare to Carboxymethyl Cellulose (CMC)

Science.gov (United States)

Al-Baarri, A. N.; Legowo, A. M.; Widayat; Abduh, S. B. M.; Lestari, F. P.; Desnasari, D.; Santoso, I. P. M.

2018-02-01

L-fucose has been understood as sulfated polysaccharides and it could be extracted and fractionated from brown algae. These polysaccharides contains carbohydrate, sulfate, and protein that may be used as emulsifier. This research was aimed to study the emulsification properties of L-fucose through the determination of total dissolved solids (TDS), color CIE L*a*b* and stability of oil-in-water emulsion. As much as 0.5% of high concentrated L-fucose and 0.5% of carboxymethyl cellulose (CMC) were used as emulsifier in a 10% (v/v) oil-in-water (O/W) emulsion. The emulsifier was added to O/W emulsions and then heated at 72°C. Result of stability emulsion and TDS showed that L-fucose was comparable to the CMC but remarkable changed the color of O/W emulsion. Heating process significantly reduced the stability O/W emulsion when L-fucose was applied. As conclusion, L-fucose might be used as natural emulsifier in O/W emulsion but in the low heat treatment of food processing. This study may provide valuable information for utilizing natural emulsifier from abundant resources from nature.

Thiomers: A Blessing to Evaluating Era of Pharmaceuticals

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Muhammad Hanif

2015-01-01

Full Text Available Thiomers are the polymers modified for the mucoadhesive properties and other additive properties by incorporating thiol moieties in the backbone of the unmodified polymeric chain by substitution reactions or simple oxidation reactions. Drugs that are less soluble and permeable can be complexed with thiomers for their increased absorption through the mucosal membranes by increase in contact time and prolonged stay in body due to mucoadhesion. Immobilization of thiol group therefore increases the mucoadhesive properties of the modified polymer by 2–140-folds. The prepared thiomers are characterized and made stable by different techniques. Thiomers also give the controlled delivery of the active pharmaceutical ingredients in the body. Different polymers that are modified by thiolation are chitosan, polyacrylic acid, sodium alginate, sodium carboxy methyl cellulose, guar gum, and so forth. Thiomeric formulations are a challenge to deliver drugs with low therapeutic compatibility. Micro- and nanopreparations containing thiomers can be prepared by different techniques such as covalent crosslinking, in situ gelation, radical emulsion polymerization, and emulsification. Nowadays thiomers have wide range of applications as a promising pharmaceutical excipient in the evaluating era of pharmaceutical technology.

Utilization of agroindustrial waste for biosurfactant production by native bacteria from chiapas

Directory of Open Access Journals (Sweden)

Yañez-Ocampo Gustavo

2017-02-01

Full Text Available In this work, two agro-industrial wastes, namely Waste Cooking Oil (WCO and Coffee Wastewater (CW have been used as the carbon source for the production of biosurfactants, due to their low cost and high availability. Biosurfactant-producing bacterial isolates from the Mexican state of Chiapas were used. The selected biosurfactant-producer strains were evaluated in a liquid medium with 2% (v/v of WCO as the carbon source. The assay was conducted in an Erlenmeyer flask containing 300 mL aliquots of mineral salt media (MSM + residue and incubated at 100 rpm at room temperature for 96 hours. The biosurfactant produced in the samples reduced the surface tension from 50 to 30-29 mN/m. Strains A and 83 showed the maximum emulsification index at 58-59%. Strain A showed the highest biosurfactant yield with a production of 3.7 g/L in comparison with strains B, 83 and Pseudomonas aeruginosa ATCC27853. Our results suggest that the biosurfactant produced by strain A has great potential in the treatment of wastewater with a high content of fatty acids, and of soils contaminated by pesticides or oil hydrocarbons.

Preformulation Studies of Bee Venom for the Preparation of Bee Venom-Loaded PLGA Particles.

Science.gov (United States)

Park, Min-Ho; Kim, Ju-Heon; Jeon, Jong-Woon; Park, Jin-Kyu; Lee, Bong-Joo; Suh, Guk-Hyun; Cho, Cheong-Weon

2015-08-18

It is known that allergic people was potentially vulnerable to bee venom (BV), which can induce an anaphylactic shock, eventually leading to death. Up until recently, this kind of allergy was treated only by venom immunotherapy (VIT) and its efficacy has been recognized worldwide. This treatment is practiced by subcutaneous injections that gradually increase the doses of the allergen. This is inconvenient for patients due to frequent injections. Poly (D,L-lactide-co-glycolide) (PLGA) has been broadly studied as a carrier for drug delivery systems (DDS) of proteins and peptides. PLGA particles usually induce a sustained release. In this study, the physicochemical properties of BV were examined prior to the preparation of BV-loaded PLGA nanoparticles NPs). The content of melittin, the main component of BV, was 53.3%. When protected from the light BV was stable at 4 °C in distilled water, during 8 weeks. BV-loaded PLGA particles were prepared using dichloromethane as the most suitable organic solvent and two min of ultrasonic emulsification time. This study has characterized the physicochemical properties of BV for the preparation BV-loaded PLGA NPs in order to design and optimize a suitable sustained release system in the future.

Encapsulated eucalyptus oil in ionically cross-linked alginate microcapsules and its controlled release.

Science.gov (United States)

Noppakundilograt, Supaporn; Piboon, Phianghathai; Graisuwan, Wilaiporn; Nuisin, Roongkan; Kiatkamjornwong, Suda

2015-10-20

Sodium alginate microcapsules containing eucalyptus oil were prepared by oil-in-water emulsification via Shirasu porous glass (SPG) membrane and cross-linked by calcium chloride (CaCl2). SPG membrane pore size of 5.2μm was used to control the size of eucalyptus oil microdroplets. Effects of sodium alginate, having a mannuronic acid/guluronic acid (M/G) ratio of 1.13, eucalyptus oil and CaCl2 amounts on microdroplet sizes and size distribution were elucidated. Increasing sodium alginate amounts from 0.1 to 0.5% (wv(-1)) sodium alginate, the average droplets size increased from 42.2±2.0 to 48.5±0.6μm, with CVs of 16.5±2.2 and 30.2±4.5%, respectively. CaCl2 successfully gave narrower size distribution of cross-linked eucalyptus oil microcapsules. The optimum conditions for preparing the microcapsules, oil loading efficiency, and controlled release of the encapsulated eucalyptus oil from the microcapsules as a function of time at 40°C were investigated. Release model for the oil from microcapsules fitted Ritger-Peppas model with non-Fickian transport mechanism. Copyright © 2015 Elsevier Ltd. All rights reserved.

An Exogenous Surfactant-Producing Bacillus subtilis Facilitates Indigenous Microbial Enhanced Oil Recovery.

Science.gov (United States)

Gao, Peike; Li, Guoqiang; Li, Yanshu; Li, Yan; Tian, Huimei; Wang, Yansen; Zhou, Jiefang; Ma, Ting

2016-01-01

This study used an exogenous lipopeptide-producing Bacillus subtilis to strengthen the indigenous microbial enhanced oil recovery (IMEOR) process in a water-flooded reservoir in the laboratory. The microbial processes and driving mechanisms were investigated in terms of the changes in oil properties and the interplay between the exogenous B. subtilis and indigenous microbial populations. The exogenous B. subtilis is a lipopeptide producer, with a short growth cycle and no oil-degrading ability. The B. subtilis facilitates the IMEOR process through improving oil emulsification and accelerating microbial growth with oil as the carbon source. Microbial community studies using quantitative PCR and high-throughput sequencing revealed that the exogenous B. subtilis could live together with reservoir microbial populations, and did not exert an observable inhibitory effect on the indigenous microbial populations during nutrient stimulation. Core-flooding tests showed that the combined exogenous and indigenous microbial flooding increased oil displacement efficiency by 16.71%, compared with 7.59% in the control where only nutrients were added, demonstrating the application potential in enhanced oil recovery in water-flooded reservoirs, in particular, for reservoirs where IMEOR treatment cannot effectively improve oil recovery.

Study on the reutilization of clear fracturing flowback fluids in surfactant flooding with additives for Enhanced Oil Recovery (EOR).

Science.gov (United States)

Dai, Caili; Wang, Kai; Liu, Yifei; Fang, Jichao; Zhao, Mingwei

2014-01-01

An investigation was conducted to study the reutilization of clear fracturing flowback fluids composed of viscoelastic surfactants (VES) with additives in surfactant flooding, making the process more efficient and cost-effective. The clear fracturing flowback fluids were used as surfactant flooding system with the addition of α-olefin sulfonate (AOS) for enhanced oil recovery (EOR). The interfacial activity, emulsification activity and oil recovery capability of the recycling system were studied. The interfacial tension (IFT) between recycling system and oil can be reduced by 2 orders of magnitude to 10(-3) mN/m, which satisfies the basic demand of surfactant flooding. The oil can be emulsified and dispersed more easily due to the synergetic effect of VES and AOS. The oil-wet surface of quartz can be easily converted to water-wet through adsorption of surfactants (VES/AOS) on the surface. Thirteen core plug flooding tests were conducted to investigate the effects of AOS concentrations, slug sizes and slug types of the recycling system on the incremental oil recovery. The investigations prove that reclaiming clear fracturing flowback fluids after fracturing operation and reuse it in surfactant flooding might have less impact on environment and be more economical.

Characterization of Exopolysaccharide Produced by Streptococcus thermophilus CC30

Directory of Open Access Journals (Sweden)

Sri Lakshmi Ramya Krishna Kanamarlapudi

2017-01-01

Full Text Available An exopolysaccharide (EPS producing strain CC30 was isolated from raw milk and identified as Streptococcus thermophilus with morphological and 16S sequencing analysis. The strain was shown to produce 1.95 g/L of EPS when grown in skim milk lactose medium at 30°C by increasing the viscosity of the medium. The EPS was isolated and purified, and it was shown to consist of glucose and galactose in 1 : 1 ratio, with molecular weights ranging from 58 to 180 kDa. FTIR spectroscopy indicated the EPS to have amide, hydroxyl, and carboxyl groups. Under Atomic Force Microscopy, EPS showed spike-like lumps of EPS. Scanning Electron Microscopy (SEM studies showed that it had irregular lumps with a coarse surface. The EPS displayed pseudoplastic nature. Thermogravimetric analysis (TGA reported a degradation temperature of 110.84°C. The purified EPS exhibited reducing activity, hydrogen peroxide radical scavenging activity, and emulsification activity. The results of the present study indicated that EPS producing Streptococcus thermophilus could serve as a promising candidate for further exploitation in food industry.

Advantages and disadvantages of high power ultrasound application in the dairy industry

Directory of Open Access Journals (Sweden)

Mislav Muža

2009-12-01

Full Text Available Preservation of food with thermal sterilisation is usually the most common way nowadays. Besides the positive aim of preservation regarding microorganisms’ reduction, elevated temperature in processing simultaneously causes serious changes in nutritive and organoleptical properties of food. Loss of food quality is related to structure and texture deformations, modification of macromolecules and creation of new compounds coming from reactions that are catalised with temperature. One of the new non-thermal processes that can in large scale improve different processes in food industry is ultrasound. In the last five years, new applications of high power ultrasound (HPU include inactivation of enzymes and microorganisms, assistance in membrane processes, improvement of dairy product texture, improvement of functional properties of proteins etc. High power ultrasound application is used in emulsification and milk homogenization, but in these processes the most important thing is to monitor possible negative effect like oxidation of fats, inactivation of valuable enzymes and denaturation of proteins. Controled and optimized application of ultrasound demands application of specific ultrasound frequency and optimal treatment time. Treatments should be performed at lower temperatures to avoid negative side effects on treated materials.

Selection of biosurfactan/bioemulsifier-producing bacteria from hydrocarbon-contaminated soil

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Sabina Viramontes-Ramos

2010-10-01

Full Text Available Petroleum-derived hydrocarbons are among the most persistent soil contaminants, and some hydrocarbon-degrading microorganisms can produce biosurfactants to increase bioavailability and degradation. The aim of this work was to identify biosurfactant-producing bacterial strains isolated from hydrocarbon-contaminated sites, and to evaluate their biosurfactant properties. The drop-collapse method and minimal agar added with a layer of combustoleo were used for screening, and positive strains were grown in liquid medium, and surface tension and emulsification index were determined in cell-free supernantant and cell suspension. A total of 324 bacterial strains were tested, and 17 were positive for the drop-collapse and hydrocarbon-layer agar methods. Most of the strains were Pseudomonas, except for three strains (Acinetobacter, Bacillus, Rhodococcus. Surface tension was similar in cell-free and cell suspension measurements, with values in the range of 58 to 26 (mN/m, and all formed stable emulsions with motor oil (76-93% E24. Considering the variety of molecular structures among microbial biosurfactants, they have different chemical properties that can be exploited commercially, for applications as diverse as bioremediation or degradable detergents.

In situ depot comprising phase-change materials that can sustainably release a gasotransmitter H2S to treat diabetic wounds.

Science.gov (United States)

Lin, Wei-Chih; Huang, Chieh-Cheng; Lin, Shu-Jyuan; Li, Meng-Ju; Chang, Yen; Lin, Yu-Jung; Wan, Wei-Lin; Shih, Po-Chien; Sung, Hsing-Wen

2017-11-01

Patients with diabetes mellitus are prone to develop refractory wounds. They exhibit reduced synthesis and levels of circulating hydrogen sulfide (H 2 S), which is an ephemeral gaseous molecule. Physiologically, H 2 S is an endogenous gasotransmitter with multiple biological functions. An emulsion method is utilized to prepare a microparticle system that comprises phase-change materials with a nearly constant temperature of phase transitions to encapsulate sodium hydrosulfide (NaHS), a highly water-labile H 2 S donor. An emulsion technique that can minimize the loss of water-labile active compounds during emulsification must be developed. The as-prepared microparticles (NaHS@MPs) provide an in situ depot for the sustained release of exogenous H 2 S under physiological conditions. The sustained release of H 2 S promotes several cell behaviors, including epidermal/endothelial cell proliferation and migration, as well as angiogenesis, by extending the activation of cellular ERK1/2 and p38, accelerating the healing of full-thickness wounds in diabetic mice. These experimental results reveal the strong potential of NaHS@MPs for the sustained release of H 2 S for the treatment of diabetic wounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Solubilization of myofibrillar proteins in water or low ionic strength media: Classical techniques, basic principles, and novel functionalities.

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Chen, Xing; Tume, Ron K; Xu, Xinglian; Zhou, Guanghong

2017-10-13

The qualitative characteristics of meat products are closely related to the functionality of muscle proteins. Myofibrillar proteins (MPs), comprising approximately 50% of total muscle proteins, are generally considered to be insoluble in solutions of low ionic strength ( 0.3 M) for solubilization. These soluble proteins are the ones which determine many functional properties of meat products, including emulsification and thermal gelation. In order to increase the utilization of meat and meat products, many studies have investigated the solubilization of MPs in water or low ionic strength media and determining their functionality. However, there still remains a lack of systematic information on the functional properties of MPs solubilized in this manner. Hence, this review will explore some typical techniques that have been used. The main procedures used for their solubilization, the fundamental principles and their functionalities in water (low ionic strength medium) are comprehensively discussed. In addition, advantages and disadvantages of each technique are summarized. Finally, future considerations are presented to facilitate progress in this new area and to enable water soluble muscle MPs to be utilized as novel meat ingredients in the food industry.

Evaluation of cashew apple juice for surfactin production by Bacillus subtilis LAMI008.

Science.gov (United States)

Ponte Rocha, Maria Valderez; Gomes Barreto, Raphaela V; Melo, Vânia Maria M; Barros Gonçalves, Luciana Rocha

2009-05-01

Bacillus subtilis LAMI008 strain isolated from the tank of Chlorination at the Wastewater Treatment Plant on Campus do Pici in Federal University of Ceará, Brazil has been screened for surfactin production in mineral medium containing clarified cashew apple juice (MM-CAJC). Results were compared with the ones obtained using mineral medium with glucose PA as carbon source. The influence on growth and surfactin production of culture medium supplementation with yeast extract was also studied. The substrate concentration analysis indicated that B. subtilis LAMI008 was able to degrade all carbon sources studied and produce biosurfactant. The highest reduction in surface tension was achieved with the fermentation of MM-CAJC, supplemented with yeast extract, which decreased from 58.95 +/- 0.10 to 38.10 +/- 0.81 dyn cm(-1). The biosurfactant produced was capable of emulsifying kerosene, achieving an emulsification index of 65%. Surfactin concentration of 3.5 mg L(-1) was obtained when MM-CAJC, supplemented with yeast extract, was used, thus indicating that it is feasible to produce surfactin from clarified cashew apple juice, a renewable and low-cost carbon source.

Application of Ionizing Radiations to Produce New Polysaccharides and Proteins with Enhanced Functionality

International Nuclear Information System (INIS)

Al Assaf, S.

2006-01-01

Treatment of polysaccharides with ionizing radiation either in the solid state or in aqueous solution leads to degradation, whereas application of radiation to process synthetic polymers to introduce structural changes and special performance characteristics is now a thriving industry. Using a mediating gas associated during the radiation treatment prevents the degradation of natural polymers and enables the introduction of different molecular and functional characteristics, as previously achieved with synthetic polymers. For example, the molecular weight can be increased and standardised, protein distribution reorganised and modified to ensure better emulsification, viscosity and viscoelasticity enhanced, leading when required to hydrogel formation. More than one hydrocolloid can also be integrated into a single matrix using this process. Protein, within demineralised bone, too can be modified to give enhanced osteoinductive capacity. This experience has led to additional patented and proprietary processes, using standard food processing techniques, to promote changes in a wide range of hydrocolloids which emulates and extend those which occur naturally. The lecture will describe these structural changes and their functional role by reference to several hydrocolloids, including acacia gums, pectin, ispaghula and hyaluronan, bone morphogenic protein. Applications in food products, dietary fibre and medical products will be illustrated

Production of a New Emulsifier Material for the Formation Heavy Hydrocarbon/Water Emulsion

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Afshin Farahbakhsh

2011-04-01

Full Text Available Emulsifiers are a unique class of compounds that have proved to have a variety of potential applications in formation of hydrocarbon in water emulsion, in enhancement of oil recovery and in the reduction of heavy oil viscosity. In this paper, a bio emulsifier was synthesized by a strain of Bacillus licheniformis and was separated by an autoclave and centrifugal process; the purification of bio emulsifier and the increase quality of product was done by adding sulfuric acid (H2SO4 (98% to the solution and centrifuging this compound again. This bio emulsifier has the property of emulsification to a wide range of heavy hydrocarbon to form a stable hydrocarbon-water emulsion. This bio emulsifier could reduce Iranian Nuroze high viscosity oil of about 10000 cP down to 250 cP. This means about 97% decreases in the viscosity. The emulsion stable this condition for 48 hr and the viscosity slowly increases to 4000cp until 192 hr. The stability of the oil in water emulsion during 48hr allows the heavy oil to be transported practically over lengthy distances or remain stable for long periods of time prior to utilization.

A rapid and sensitive analytical method for the determination of 14 pyrethroids in water samples.

Science.gov (United States)

Feo, M L; Eljarrat, E; Barceló, D

2010-04-09

A simple, efficient and environmentally friendly analytical methodology is proposed for extracting and preconcentrating pyrethroids from water samples prior to gas chromatography-negative ion chemical ionization mass spectrometry (GC-NCI-MS) analysis. Fourteen pyrethroids were selected for this work: bifenthrin, cyfluthrin, lambda-cyhalothrin, cypermethrin, deltamethrin, esfenvalerate, fenvalerate, fenpropathrin, tau-fluvalinate, permethrin, phenothrin, resmethrin, tetramethrin and tralomethrin. The method is based on ultrasound-assisted emulsification-extraction (UAEE) of a water-immiscible solvent in an aqueous medium. Chloroform was used as extraction solvent in the UAEE technique. Target analytes were quantitatively extracted achieving an enrichment factor of 200 when 20 mL aliquot of pure water spiked with pyrethroid standards was extracted. The method was also evaluated with tap water and river water samples. Method detection limits (MDLs) ranged from 0.03 to 35.8 ng L(-1) with RSDs values or =0.998. Recovery values were in the range of 45-106%, showing satisfactory robustness of the method for analyzing pyrethroids in water samples. The proposed methodology was applied for the analysis of river water samples. Cypermethrin was detected at concentration levels ranging from 4.94 to 30.5 ng L(-1). Copyright 2010 Elsevier B.V. All rights reserved.

Conversion of Uric Acid into Ammonium in Oil-Degrading Marine Microbial Communities: a Possible Role of Halomonads

KAUST Repository

Gertler, Christoph

2015-04-29

Uric acid is a promising hydrophobic nitrogen source for biostimulation of microbial activities in oil-impacted marine environments. This study investigated metabolic processes and microbial community changes in a series of microcosms using sediment from the Mediterranean and the Red Sea amended with ammonium and uric acid. Respiration, emulsification, ammonium and protein concentration measurements suggested a rapid production of ammonium from uric acid accompanied by the development of microbial communities containing hydrocarbonoclastic bacteria after 3 weeks of incubation. About 80 % of uric acid was converted to ammonium within the first few days of the experiment. Microbial population dynamics were investigated by Ribosomal Intergenic Spacer Analysis and Illumina sequencing as well as by culture-based techniques. Resulting data indicated that strains related to Halomonas spp. converted uric acid into ammonium, which stimulated growth of microbial consortia dominated by Alcanivorax spp. and Pseudomonas spp. Several strains of Halomonas spp. were isolated on uric acid as the sole carbon source showed location specificity. These results point towards a possible role of halomonads in the conversion of uric acid to ammonium utilized by hydrocarbonoclastic bacteria. © 2015 Springer Science+Business Media New York

Laboratory tests, experimental oil spills, models, and reality: The Braer oil spill

International Nuclear Information System (INIS)

Reed, M.; Daling, P.S.; Brandvik, P.J.; Singsaas, I.

1993-01-01

The IKU Petroleum Research organization in Norway has accumulated data on the weathering behavior of spilled oils and petroleum products, mainly pertaining to North Sea crudes. Recent weathering research at IKU has been carried out in an elliptical mesoscale flume and in field tests consisting of experimental releases of crude oil. Results of these tests provided information on oil spill dispersion, evaporation, and emulsification. When the tanker Braer grounded in the Shetland Islands in January 1993 in extreme environmental conditions, the imminent release of a load of 84,000 tonnes of North Sea oil confronted response personnel with a variety of issues including the use of dispersants as a response action. Relevant information on the expected behavior of the crude was obtained within a day of the grounding as a result of close relations between IKU and Warren Spring Laboratory. The question is raised whether such information, which could have been spread between several organizations around the world, will be rapidly accessible in the event of another major spill. It is proposed to establish an electronically accessible database on the behavior and fate of specific oils and petroleum products to address this problem. 9 refs., 4 figs

Cellular uptake and radiosensitization of SR-2508 loaded PLGA nanoparticles

International Nuclear Information System (INIS)

Jin Cheng; Bai Ling; Wu Hong; Teng Zenghui; Guo Guozhen; Chen Jingyuan

2008-01-01

SR-2508 (etanidazole), a hypoxic radiosensitizer, has potential applications in radiotherapy. The poly(d,l-lactide-co-glycolide)(PLGA) nanoparticles containing SR-2508 were prepared by w/o/w emulsification-solvent evaporation method. The physicochemical characteristics of the nanoparticles (i.e. encapsulation efficiency, particle size distribution, morphology, in vitro release) were studied. The cellular uptake of the nanoparticles for the two human tumor cell lines: human breast carcinoma cells (MCF-7) and human carcinoma cervices cells (HeLa), was evaluated by fluorescence microscopy and transmission electronic microscopy. Cell viability was measured by the ability of single cell to form colonies in vitro. The prepared nanoparticles were spherical in shape with size between 90 nm and 190 nm. The encapsulation efficiency was 20.06%. The drug release pattern exhibited an initial burst followed by a plateau for over 24 h. The cellular uptake of nanoparticles was observed. Co-culture of MCF-7 and HeLa cells with SR-2508 loaded nanoparticles showed that released SR-2508 retained its bioactivity and effectively sensitized two hypoxic tumor cell lines to radiation. The radiosensitization of SR-2508 loaded nanoparticles was more significant than that of free drug.