Lipids Liquid

Quantity Gel phase (19°C, 12 water molecules/lipid) Liquid crystal phase (50°C, 28 water molecules/lipid) ... 

Esterification of fatty acids is not random C12-C16 are esterified principally at the sn-2 position while C4 and C6 are esterified principally at the sn-3 position (Table 3.8). The concentrations of C4 and C18 appear to be rate-limiting because of the need to keep the lipid liquid at body temperature. Some features of the structures are notable ... 

The Singer and Nicholson (13) model for the plasma membrane, which now receives much support, is basically a smectic liquid crystal consisting of one bilayer of phospholipid (Figure 4a). The phospholipid bilayer contains cholesterol at a concentration which depends on cell type. Embedded in the lipid liquid crystal he protein molecules. Some of these protein molecules transverse the entire lipid bilayer and communicate both with the inside and the outside of the cells. Some of these may... 

Of course, nanocomposites are not the only area where mesoscale theories are being used to predict nanostructure and morphology. Other applications include—but are not limited to—block copolymer-based materials, surfactant and lipid liquid crystalline phases, micro-encapsulation of drugs and other actives, and phase behavior of polymer blends and solutions. In all these areas, mesoscale models are utilized to describe—qualitatively and often semi-quantitatively—how the structure of each component and the overall formulation influence the formation of the nanoscale morphology. 

Bomd, J., Nylander, T., and Khan, A. (2002). Effeet of lipase on different lipid liquid crystalline phases formed by oleie aeid-based acylglyeerols in aqueous systems. Langmuir. 18, 8972-8981. 

The propensity of membranes to fuse correlates with the fraction of inverted phase-forming lipids conversely, membrane fusability is reduced with an increase of the lipid fraction that inhibits inverted phase formation. Substantial evidence suggests that the mechanism of lipid membrane fusion is related to the mechanism of lamellar/inverted phase transitions (23). The intermediates that form in membrane fusion seem to be identical to those that form during the transformations between lamellar, bicontinuous inverted cubic and inverted hexagonal lipid liquid-crystalline phases, and these transitions can be used successfully as a model for studying the lipid membrane fusion mechanism and kinetics. 

In general, there are three main types of non-Newtonian lipid liquids and semisolids ... 

M. Almgren, J. Borne, E. Feitosa, A. Khan, B. Lindman, Dispersed lipid liquid crystalline phases stabilized by a hydrophobically modified cellulose. Langmuir 23, 2768-2777 (2007)... 

F.O. Costa-Balogh, E. Sparr, J.J.S. Sousa, A.A.C.C. Pais, Drug release and skin permeation from lipid liquid crystalline phases. Progr. Colloid Polym. Sci. 135, 119-129 (2008)... 

Salad dressings and mayonnaise can be stabilized by ionic surfactants, which provide some electrostatic stabilization as described by DLVO theory, or by nonionic surfactants which provide a viscoelastic surface coating. The protein-covered oil (fat) droplets tend to be mostly stabilized by steric stabilization (rather than electrostatic stabilization) [34,126,129], particularly at very high levels of surface protein adsorption, in which case the adsorption layer can include not just protein molecules but structured protein globules (aggregates). In some cases, lipid liquid crystal layers surround and stabilize the oil droplets, such as the stabilization of O/W droplets by egg-yolk lecithins in salad dressing [34,135]. 

Li M, Chao L. Structural study of lipid liquid crystal droplets in chicken development. 

See alsa Carbohydrates Starch. Derivatization of Analytes. Extraction Solvent Extraction Principles. Fluorescence Food Applications. Gas Chromatography High-Temperature Techniques. Lipids Fatty Acids Polar Lipids. Liquid Chromatography Food Applications. Mass Spectrometry Food Applications. Quality Assurance Quality Control Internal Standards. Sample Handling Comminution of Samples. Sampling Theory. 

In this chapter, a general introduction to the theory and application of fluorescence polarization spectroscopy has been presented. This technique opens up the interesting possibility of studying the hydrodynamic properties of a fluid at the molecular level. With the growing importance of knowledge of the structure of lipid liquid phases (e.g., liquid crystalline phases), this technique may find more widespread application in fats and oils research. 

In self-organising soft matter systems (e.g. lipids, liquid crystals, and certain polymers) EPR spectra of doped spin probes are sensitive to three types of information about liquid and partially ordered states, namely, (i) molecular dynamics, (ii) local order of molecules averaged over a small volume and (iii) global or long range order in a multi-domain system. As has been demonstrated, EPR spectra can be rich in information about the state of molecules in different phases and across phase transition regions. - ° ... 

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