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Stable Emulsion (stable + emulsion)
Selected AbstractsCold-triggered/heat-destroyed emulsions composed of phospholipids and triacylglycerols as thermal history indicators for cold-chain distribution systemsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 6 2008Kohdai Nagata Abstract BACKGROUND: Recently, cold-chain distribution systems have come to play important roles in worldwide food processing/storage/transportation networks. To ensure the maintenance of the quality and safety of foods, it is necessary to develop thermal history indicators for products involved in cold-chain distribution systems. To provide a record of the occurrence of a high-temperature event during a cold-chain system, a temperature-related phase change in a material within the indicator is needed to indicate that the high-temperature event occurred. Preferentially, for safety, the materials of the indicators should be edible and easy to handle. It should be possible to store the indicators at ambient temperature before use, and they should be triggered automatically just by cooling at the start of a cold-chain system. Furthermore, if the indicator is heated even once during the cold-chain distribution system, its appearance must be irreversibly altered to provide evidence of the high-temperature experience. RESULTS: Based on the edible materials composed of lyso-lecithin (15 g), lecithin (2 g), triacylglycerol (150 g), and water, we successfully constructed a stable emulsion that could be triggered just by cooling to 4 °C or lower for more than 12 h. After triggering, it was immediately destroyed by heating up to 20 °C or higher. Furthermore, the mechanism of cold-triggering and heat-destruction has been studied by nuclear magnetic resonance. CONCLUSION: The cold-triggered/heat-destroyed emulsion should be applied as a new thermal history indicator that can be automatically triggered just by cooling down and irreversibly change its appearance after a high-temperature experience in cold-chain distribution systems. Copyright © 2008 Society of Chemical Industry [source] Preparation and Biodegradation of Sugar-Containing Poly(vinyl acetate) EmulsionsMACROMOLECULAR BIOSCIENCE, Issue 2 2008Akinori Takasu Abstract To accelerate the biodegradability of poly(vinyl acetate)-based emulsions, emulsion copolymerizations of vinyl sugars, including triacetylated N -acetyl- D -glucosamine (GlcNAc)-substituted 2-hydroxyethyl methacrylate (GlcNAc(Ac)3 -substituted HEMA), glucose-substituted HEMA (GEMA) and 6- O -vinyladipoyl- D -glucose (6- O -VAG) with vinyl acetate (VAc), were carried out using poly(vinyl alcohol) as an emulsifying agent in the presence of poly[(butylene succinate)- co -(butylene adipate)] [poly(BS- co -BA)]. Copolymerization with GEMA produced a stable emulsion and that with 6- O -VAG also produced a homogeneous emulsion. Their biodegradation tests indicated that PVAc main chain scission was accelerated by copolymerization with vinyl sugars. [source] Polyamide-6/high-density polyethylene blend using recycled high-density polyethylene as compatibilizer: Morphology, mechanical properties, and thermal stabilityPOLYMER ENGINEERING & SCIENCE, Issue 10 2009Márcio R. Vallim Blends of polyamide-6 (PA6) or postindustry polyamide-6 (piPA6) and high-density polyethylene (HDPE) or recycled high-density polyethylene (rHDPE) were processed in single and twin-screw extruders. The use of rHDPE in the blends promotes a significant decrease of size domains and improvement in the mechanical properties. The thermal stability was also slightly improved compared with PA6 and HDPE blends. The Molau test exhibited a stable emulsion in formic acid, which can be attributed to the formation of an interfacial copolymer involving polar amino end groups of PA6 and the rHDPE, respectively. These results indicate that recycled polymers can be used in the production of polymer blends with improved properties. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers. [source] In vitro assessment of antimicrobial activity of carvacrol, thymol and cinnamaldehyde towards Salmonella serotype Typhimurium DT104: effects of pig diets and emulsification in hydrocolloidsJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2006W. Si Abstract Aims:, To determine the effect of pig diets in vitro on the antimicrobial activity of carvacrol, thymol and cinnamaldehyde, and to identify an emulsifier/stabilizer that can stabilize the essential oil (EO) components in aqueous solution and retain their antimicrobial activity in the presence of the diets. Methods and Results:, Emulsification of essential oil components with hydrocolloid solution was achieved by blending with a Polytron. Antimicrobial activity was measured through in vitro assays to determine the inhibition of bacterial growth by measuring the optical density at 600 nm or plating on nutrition agar after incubation of the mixtures of an EO component with the culture of Salmonella serotype Typhimurium DT104 in the presence or absence of pig diets. The results generated through the in vitro assays indicated that pig diets were able to abolish the antimicrobial activity of EOs. Xanthan, fenugreek and yellow mustard gums were the best in forming stable emulsions of five different EO components among ten different plant polysaccharides and surfactants examined. Emulsification of all the EO components in the fenugreek gum solution did not alter their antimicrobial activity. However, the antimicrobial activity of geraniol was significantly reduced when emulsified with other polysaccharides and surfactants. Both fenugreek and xanthan gum solutions were unable to protect the antimicrobial activity of carvacrol and thymol when mixed with the diets. Although cinnamaldehyde required no emulsification, but a high concentration (equivalent to at least three times of minimum bactericidal concentration for cinnamon oil) to inhibit Salmonella growth significantly in the presence of the diets, emulsification in fenugreek gum appeared to be essential for cinnamaldehyde solution to retain its antimicrobial activity during storage. Conclusions:, The diets for newly weaned pigs were a significant factor limiting the antimicrobial activity of EOs and their components. Cinnamaldehyde required a high concentration to retain its antimicrobial activity in the diets, in addition to its requirement for emulsification to stabilize its activity during the storage. Significance and Impact of the Study:, The assay with the diets used in this study for measuring the antimicrobial activity can be used in vitro for rapid and effective screening of potential antimicrobials for swine production. This study has identified polysaccharides that are able to stabilize EO component solutions. It has also identified cinnamaldehyde for further in vivo studies that may have potential in future application in controlling Salmonella and possibly other enteric pathogens in swine production. [source] Self-emulsifying O/W formulations of paclitaxel prepared from mixed nonionic surfactantsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 5 2010Jen-Ting Lo Abstract Nonionic self-emulsifying oil-in-water (O/W) formulations free of Cremophore® were developed as drug delivery vehicles for paclitaxel. The surfactants used included phosphatidylcholine purified from egg yolk (EPC), Tween, and Span. Oils phases were either pure components or blends from benzyl alcohol, 2-phenylethanol benzyl benzoate, and tributyrin. Among these surfactants, mixtures of EPC and Tween-80 gave really stable emulsions in proper sizes ranging from 70 to 200,nm, mainly depends on the ratio of EPC to Tween-80 and amount of oils. Paclitaxel could be well preserved without any loss in oily stocks, namely mixtures of oils and paclitaxel as well as surfactants, stored at 4°C for more than 8 months. Only gentle mixing on oily stocks with aqueous diluents is enough to make paclitaxel-contained emulsions. The optimum formulation contains oils from 1 to 3 wt%, Tween-80 and EPC from 0.4 to 1.2 wt%, respectively. Consequently, near 500,ppm of paclitaxel can be contained in emulsions. Moreover, these paclitaxel-containing emulsions are compatible with commonly used injection fluids. No precipitation is observed upon preparation of emulsion from dilution of oily stocks. Negligible cytotoxicity on these emulsions assessed with NIH/3T3 cells implied their good biocompatibility and promising applications as drug delivery carriers. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99: 2320,2332, 2010 [source] Efficient phase separation and product recovery in organic-aqueous bioprocessing using supercritical carbon dioxideBIOTECHNOLOGY & BIOENGINEERING, Issue 4 2010Christoph Brandenbusch Abstract Biphasic hydrocarbon functionalizations catalyzed by recombinant microorganisms have been shown to be one of the most promising approaches for replacing common chemical synthesis routes on an industrial scale. However, the formation of stable emulsions complicates downstream processing, especially phase separation. This fact has turned out to be a major hurdle for industrial implementation. To overcome this limitation, we used supercritical carbon dioxide (scCO2) for both phase separation and product purification. The stable emulsion, originating from a stereospecific epoxidation of styrene to (S)-styrene oxide, a reaction catalyzed by recombinant Escherichia coli, could be destabilized efficiently and irreversibly, enabling complete phase separation within minutes. By further use of scCO2 as extraction agent, the product (S)-styrene oxide could be obtained with a purity of 81% (w/w) in one single extraction step. By combining phase separation and product purification using scCO2, the number of necessary workup steps can be reduced to one. This efficient and easy to use technique is generally applicable for the workup of biphasic biocatalytic hydrocarbon functionalizations and enables a cost effective downstream processing even on a large scale. Biotechnol. Bioeng. 2010;107:642,651. © 2010 Wiley Periodicals, Inc. [source] | ||||||||||||||||