A review. An outline is given on the use of microemulsions and other microcompartmentalized systems as media for chem. reactions. Examples are presented to illustrate the principles of different possible reactions and the used microheterogeneous media. Treated is the prepn. of nanosized inorg. particles from microemulsions, the prepn. of mesoporous inorg. materials from surfactant liq. crystals, and the use of solid foams prepd. from highly concd. emulsions to make meso/macroporous inorg. oxide materials. The use of microheterogeneous systems as media for the prepn. of org. polymers and of microemulsions for bioorg. synthesis is also described. [on SciFinder(R)]

Various industries including food and pharmaceuticals are sharing increasing interest in microemulsions. Also, one can demonstrate that solubilization of active materials within the core or interface of microemulsions may have environmental benefits. In this work, the authors report three examples of new microemulsion formulations specially designed to be capable of solubilizing active materials and protecting the environment from the emission of hazardous matter or protecting sensitive mols. from the detrimental effects of the environment. In the first example, fire-resistant ingredients were incorporated in hydraulic fluids based on water-in-oil (W/O) microemulsions and their typical characteristics were described. In the second example, five-component oil-in-water (O/W) microemulsions were designed to solubilize lycopene and protect it from exposure to light. In the third example, a friendly solvent (Bu lactate) was microemulsified to form nanosized liq. droplets capable of solubilizing bromine-based bactericide formulations of sophisticated wood preservatives. The new vehicles exhibit a very significant solubilization capacity and can be applied in aq. media. In the last example, the active matter may be triggered when demanded and the release will be followed by film formation. [on SciFinder(R)]

The present invention discloses the use of a lycopene coated with a water non-sol. thin film comprising amphiphilic protein polymer for coloring with red color, foods, pharmaceuticals or cosmetics having fat and/or oil contents higher than 5 %. The invention further discloses a process for the prepn. of stable lycopene formulation comprising: (a) treating an isolated protein to form a protein in a mol. form; (b) dispersing lycopene in an aq. soln. comprising an isolated protein in a mol. form; (c) grinding said dispersion to form lycopene particle size of 1 to 10 $μ$m forming an homogenized mixt. comprising fine particles; and optionally (d) drying the homogenized mixt. [on SciFinder(R)]

Anal. of the phenolic constituents of shea (Vitellaria paradoxa) kernels by LC-MS revealed 8 catechin compds.-gallic acid, catechin, epicatechin, epicatechin gallate, gallocatechin, epigallocatechin, gallocatechin gallate, and epigallocatechin gallate-as well as quercetin and trans-cinnamic acid. The mean kernel content of the 8 catechin compds. was 4000 ppm (0.4% of kernel dry wt.), with a 2100-9500 ppm range. Comparison of the profiles of the 6 major catechins from 40 Vitellaria provenances from 10 African countries showed that the relative proportions of these compds. varied from region to region. Gallic acid was the major phenolic compd., comprising an av. of 27% of the measured total phenols and exceeding 70% in some populations. Colorimetric anal. (101 samples) of total polyphenols extd. from shea butter into hexane gave an av. of 97 ppm, with the values for different provenances varying between 62 and 135 ppm of total polyphenols. [on SciFinder(R)]

Microemulsions are of growing interest to the food industry as vehicles for delivering and enhancing solubilization of natural food supplements with nutritional and health benefits. The incorporation of mol. phytosterols, cholesterol-lowering agents, in food products is of great interest to the food industry. The use is demonstrated of water-dilutable food-grade microemulsions consisting of ethoxylated sorbitan ester (Tween 60), water, R-(+)-limonene, ethanol, and propylene glycol as vehicles for enhancing the phytosterols solubilization. Phytosterols were solubilized up to 12 times more than the dissoln. capacity of the oil [R-(+)-limonene] for the same compds. The solubilization capacity of phytosterols and cholesterol along a diln. line in a pseudo-ternary phase diagram [wt. ratio of R-(+)-limonene/ethanol/Tween 60 const. at 1p1:3] was correlated to the microstructure transitions along the diln. line. Structural aspects were studied by self-diffusion NMR spectroscopy. The ability of phytosterols to compete with cholesterol for penetration into bile salt micelles in the gut may be limited to rich aq. systems (O/W microemulsion). [on SciFinder(R)]

The microstructure of an unusual Winsor IV isotropic region of five-component microemulsions based on nonionic surfactants was studied. The microemulsions are composed of R(+)-limonene, water, propylene glycol (PG), ethanol (EtOH), and polyoxyethylene sorbitan monostearate (Tween 60) with a 1:1:3 R(+)-limonene/ethanol/surfactant wt. ratio. The phase diagrams of the system are characterized by an extended single continuous isotropic region starting from an oil-rich soln. contg. no aq. phase (reverse micelles) to the water/propylene glycol (1/1) corner (swollen direct micelles). The microemulsions seem to be attractive for food applications. The microstructure changes gradually, smoothly, and continuously upon increasing the aq. phase content. The microemulsion transforms from a water-in-oil (W/O) microemulsion to a bicontinuous phase and to an oil-in-water (O/W) microemulsion. The microstructure of the microemulsion along a selected diln. line, is probed using pulsed gradient spin-echo NMR, cond., and viscosity. The results are compared with a corresponding non-food-grade system based on C18:1E10 (Brij 96v). The hydrodynamic radius (RH) of O/W microemulsion samples based on Brij 96v and Tween 60, at 90% aq. phase, was detd. to be 5.4 ± 0.2 and 5.2 ± 0.2 nm, resp., and the calcd. values of the area of the polar headgroup (a) are 87 for Brij 96v and 160 \AA2 for Tween 60-based microemulsions. The ratio of the water self-diffusion coeff., DW, to the PG self-diffusion coeff. (DPG) (termed the L ratio) was found to be sensitive to the aq. phase content. In the O/W microemulsions, the water/PG mixt. diffuses as hydrogen bonded entity (mol. diffusion controlled), while in the W/O microemulsions, the PG partitions, in part, at the interface and the dominant diffusion process is neither aggregate nor mol. controlled. [on SciFinder(R)]

An interfacial Maillard reaction between furfural and cysteine in two different food-grade nano-sized self-assembled solns. with two oppositely curved interfaces (W/O and O/W microemulsions) have been studied and compared. These microemulsions are selective microreactors strongly enhancing the generation of sulfur-contg. flavors. The Maillard reactions occur at lower temps. than in water and are much faster. The interfaces of both W/O and O/W microemulsions are capable of enhancing the Maillard reactions in which the selectivity and reactivity are controlled by the compn. of the interface and its curvature. In the W/O microemulsions the Maillard reaction was controlled and enhanced by the interfacial concn. of a co-emulsifier such as butanol and are restricted by the concn. of the core water reservoir. On the other hand, in the O/W microemulsions, where water is the continuous phase, the reaction rates are enhanced by increase in the water content and the microemulsion curvature. The Maillard product internal compn. (regioselectivity and type of products) is dictated by temp., time, pH and mainly by the nature of the interface, and by the surfactant nature and its interfacial compn. [on SciFinder(R)]

Water-in-oil-in-water (W/O/W) double emulsions with improved stability and less polydispersity in droplet size distribution were prepd. using polyglycerol polyricinoleate (PGPR) as emulsifier in the inner aq. phase and replacing the common nonionic hydrophilic monomeric emulsifiers by a "protein-polysaccharide hybrid" in the outer interface. Amphiphilic macromol. hybrids with specific interfacial recognition capabilities to be termed "biomacro-mol.-recognition hybrids" have been prepd. in aq. soln. by interacting whey protein isolate (WPI) with hydrocolloids (xanthan gum, galactomannans) at selected pH and wt. ratios. The binary aq. mixts. do not coacervate or ppt. but form stable mol. adducts. At pH lower than the isoelec. point of the protein (pH 4.6), the yield of encapsulation of glucose (a model marker) in the inner phase of the double emulsion is close to 95%. The emulsion droplets are stabilized by both steric and electrostatic contributions (zeta potential is close to +30 mV). Rheol. measurements indicate that, at low pH, such systems behave as viscous ones with G'' (loss modulus) greater than G' (storage modulus). When the pH is close or greater than the isoelec. point of the protein, the system exhibits a more pronounced elastic behavior (G' \textless G'') that can explain the redn. in emulsification capabilities of such mixts. In this case the yield of encapsulation is less than 10% and the double emulsion droplets are larger than 10 $μ$m. At pH ≤ 2, the adducts can efficiently stabilize double emulsions and serve as an efficient and thick barrier against the release of vitamin B1 entrapped in the core of the W/O/W double emulsions. The release of the vitamin was less than 18% after three weeks of storage at room temp. (against 100% of release at neutral pH). [on SciFinder(R)]

Organo-inorgano nanocomposites with colloidal dimensions have interesting optical, catalytic, and mech. properties, particularly when such hybrids are reinforced with transition metal oxide nanoparticles. Nanoparticles with a mean size of 1.0-2.4 nm are obtained through hydrolysis of aluminum isopropoxide in the L2 phase of amphiphilic (PDMS-POE) polydimethylsiloxane-polyoxyethylene Silwet L-7607-octanol/acetylacetone-water mixts. The particle sizes are related weakly to the microemulsion compn.: 0.8-1.2 nm for 20 wt% Silwet L-7607 and 2.0-2.4 nm for 50 wt% Silwet L-7607. Protection of the particles against aggregation is ensured through their confinement in the intra-aggregate colloidal domains. Factors affecting the hydrolysis-condensation process of acetylacetone-complexed aluminum isopropoxide in copolymer-poor and copolymer-rich regions of PDMS-POE W/O microemulsions are studied by Fourier transform IR spectroscopy, small angle X-ray scattering, and transmission electron microscopy. Prepd. nanoparticulate dispersions possess long-term stability and form clear mixts. in different org. polar and nonpolar solvents. (c) 2002 Academic Press. [on SciFinder(R)]

A review on basic and applied knowledge on protein-polysaccharide interactions in aq. medium and at the oil-water interface in food emulsion systems. [on SciFinder(R)]

The hydration behavior of the system polyoxyethylene (10) oleyl alc. [C18:1(EO)10 or Brij 97]/water/dodecane/butanol (model system B) was investigated along a diln. line for which the resp. wt. ratio of dodecane:butanol:Brij 97 is 3:3:4. Two exptl. methods were applied: time domain dielec. spectroscopy (TDDS) and sub-zero temp. differential scanning calorimetry (SZT-DSC). Two types of bound water (with melting peaks at - 25 and - 11°C) were detected by SZT-DSC (using the endothermic mode), whereas TDDS revealed only one such type. Nevertheless, roughly the same total amt. of bound water was estd. from these two techniques. The av. no. of bound water mols. per ethylene oxide (EO) group, NW/EO, is 2.3 (TDDS data) or 2.5 (SZT-DSC data) in good agreement with the observation that 1-2 water layers are formed in the hydration of ethoxylated surfactants. We have also shown that butanol is involved in the formation of the bound water that melts at - 25°C. We suggest that butanol mols. occupy binding sites within the second hydration shell, thereby reducing the expected total bound water content. [on SciFinder(R)]

The interactions of two groups of hydrated model crystals, CaHPO4.2H2O (DCPD) vs. Ca4(HPO4)(PO4)2 (OCP) and Ca oxalate monohydrate (COM) vs. Ca oxalate dihydrate (COD) with different org. additives are considered. DCPD ppts. as platelet-like crystals with the dominant faces shielded by hydrated layers and charged lateral faces. In the 2nd system COM has charged surfaces, while all faces of COD are covered with layers contg. water mols. The org. mols. tested include neg. charged, flexible and rigid small and macromols. (glutamic and aspartic acid, citrate, hexaammonium polyphosphate, phytate, and polyaspartate) and anionic surfactants (sodium dodecyl sulfate, SDS, sodium diisooctyl sulfosuccinate, AOT, sodium cholate NaC, and disodium oleoamido PEG-2 sulfosuccinate, PEG). Two types of effects were demonstrated: (i) effect on crystal growth morphol.: flexible org. mols. with high charge d. and anionic surfactants affected the growth morphol. of DCPD and COM by selectively interacting with the charged lateral faces while rigid mols. (phytate, polyaspartate) specifically recognized the dominant (010) face of DCPD due to structural and stereochem. compatibility. (ii) effect on phase compn.: anionic surfactants at concns. above the crit. micelle concn. promoted growth of OCP and COD resp. by selectively adsorbing at, and inhibiting growth of nuclei of DCPD and/or COM, which were dominant in the resp. control systems. The effect was esp. pronounced in the Ca oxalate pptn. system, where in some cases complete reversal of the phase compn. occurred. The important role of the hydrated layer, as part of the structure of the investigated crystal hydrates, in the above crystal additive interactions is discussed. [on SciFinder(R)]

A review on trends and progress in the exploration of new emulsifiers extd. from natural or biotechnol. sources and chem. or enzymically modified to fit the needs of new and advanced products in the food industry. [on SciFinder(R)]