Search results for "Emulsion"

Influence of xanthan gum and locust bean gum upon flow and thixotropic behaviour of food emulsions containing modified starch

2007

Abstract Low oil content mayonnaises are food emulsions which exhibit shear thinning and thixotropic behaviour. They include generally modified starch in their formulation. In this work we study the effect of substituting part of this starch with other natural gums, such as xanthan gum or locust bean gum, upon the consistency and stability of the emulsions in relation to stirring. The gels prior to final emulsification have also been analyzed. Steady flow curves of all systems are well described by the Carreau model. The emulsions containing the greatest percentage of gums presented significantly higher viscosity than the reference emulsion and the emulsions containing the synergistic mixtu…

Extraction of amino acids with emulsion liquid membranes using industrial surfactants and lecithin as stabilisers

2000

Abstract Industrial surfactants (being the mixtures of several individual compounds) were used as stabilisers of emulsion liquid membranes (ELMs). Although, some impurities present in technical formulations of these compounds were extracted to aqueous solutions of amino acids, most of the used surfactants well served to this purpose. In the case of amino acid transport, they do not act as carriers and application of additional carrier (such as D2EHP) was required in order to facilitate the transport. Interestingly, the same properties were found for lecithin, industrially important natural surfactant. Lecithin applied as a chiral discriminator, used either as an emulsion stabiliser or carri…

Phospholipid-based reverse micelles.

1990

Physicochemical investigations on the aggregation of phospholipids (mainly phosphatidylcholines) in organic solvents are reviewed and compared with the aggregation behaviour of phospholipids in aqueous medium. In particular we review the data showing that phosphatidylcholines (lecithins) form reverse micellar structures in certain apolar solvents. In these systems not only low molecular weight compounds but also catalytically active enzymes and entire cells can be solubilized. In addition, highly viscous phosphatidylcholine gels can be obtained in organic solvents upon solubilizing a critical amount of water. Generally, phospholipid-based reverse micelles can be regarded as thermodynamicall…

Structural Investigation of Water/Lecithin/Cyclohexane Microemulsions by FT-IR Spectroscopy

1995

Abstract FT-IR spectra of water/lecithin/deuterated cyclohexane microemulsions as a function of water/lecithin molar ratio R ( R = [water]/[lecithin]) at various volume fractions ( O ) of the micellar phase have been recorded at 25°C. After elimination of the small spectral contributions due to deuterated cyclohexane and normalization, the shape of the C–H stretching band due to lecithin has been found dependent upon R and O whereas that of the O–H stretching band has been found dependent only upon R . The change in shape of the C–H band was interpreted in terms of a modification of the lecithin alkyl chain packing order. The analysis of the O–H band provides evidence that the hydroxylic gr…

Influence of alginate emulsion-based films structure on its barrier properties and on the protection of microencapsulated aroma compound

2009

In recent years the use of natural polymers coming from renewable sources has greatly increased due to the over-solid packaging waste and dwindling petroleum reserves. Biopolymer films, which contain both lipid and polysaccharide ingredients to form complex packaging enable us to obtain edible films with good mechanical and water barrier properties as emulsified alginate edible films. Moreover, these can be considered to encapsulate active molecules as flavours. The aim of this work is to better understand the influence of the composition and the structure of the film matrix on its barrier properties and thus on its capacity to protect encapsulated active substances. Granulometry, Different…

Soluble organosilicon micronetworks with spatially confined reaction sites

1997

1993

A macromonomer was prepared from succinimido methacrylate and poly(N-isopropylacrylamide) (PIPA) with an amino end group. The macronomer (MA-PIPA) obtained shows a temperature-responsive transition phenomenon from coil to globule in water at about 36°C. For the copolymer of MA-PIPA with acrylamide (ratio of monomer residues of N-isopropylacrylamide (IPA) and acrylamide (AAm) 10:3), the transition temperature of the PIPA chain was the same as that of the macromonomer, whereas the transition temperature of a linear copolymer of IPA and AAm (ratio of the monomer residues 10:3) was much higher than that of PIPA (52°C). Microspheres were prepared by emulsion polymerization of the macromonomer an…

Hemiesters and hemiamides of maleic and succinic acid: synthesis and application of surfactants in emulsion polymerization with styrene and butyl acr…

1999

Hemiesters and hemiamides of maleic acid with different chain lengths of the hydrophobic alkyl group (R = C8H17, C10H21, C12H25, C16H33) have been synthesized and used as surfactants in the emulsion polymerization of styrene and butyl acrylate. The same polymerization experiments were also carried out using nonreactive surfactants with an analogous succinic structure. The chemical structure of the surfactants was confirmed by 1H nuclear magnetic resonance. The melting point and critical micelle concentration of the reactive surfactants described herein were measured. All of the surfactants studied provided good stability of styrene/butyl acrylate latexes, when compared with a reference late…

Methacrylic maleic bifunctional stabilizer in emulsion polymerization

1998

Untersuchungen über die emulsionspolymerisation des acroleins. Polymere acroleine. 15. Mitteilung

1959

Die Polymerisation des Acroleins mit verschiedenen Emulgatortypen wird untersucht. Es zeigt sich, das eine Losung von Polyacrolein in wasriger schwefliger Saure ein vorzuglicher Emulgator fur die Emulsionspolymerisation von Acrolein mit Redox-Systemen ist. An diesem System wird der Einflus der Emulgatorkonzentration S, der Initiatorkonzentration ci, der Monomerkonzentration und der Temperatur gepruft. Man findet folgende Beziehungen: VBr ∼ S1/5; VBr ∼ c; und VBr ∼ M. Die experimentellen Ergebnisse werden mit den nach der Theorie von SMITH und EWART zu erwartenden verglichen und diskutiert. The polymerization of acrolein with several types of emulsifiers has been investigated. There is shown…