Peer Review Publications

B ZAIDMAN, A KISILEV, Y SASSON, and N Garti. 1988. “Double bond oxidation of unsaturated fatty acids.” JAOCS, J. Am. Oil Chem. Soc., 65, 4, Pp. 611–615. Abstract
Different oxidizing agents for performing the cleavage oxidn. of the double bond of the unsatd. fatty acids are presented, and their economic performance is analyzed. Ozone and sodium hypochlorite are the most com. efficient oxidants. Lab. work for the oxidn. of oleic acid to azelaic and pelargonic acids using hypochlorite as oxidant is described. The advantages of working in an emulsion system and using RuCl3 as a catalyst are discussed, and a possible mechanism of the reaction is presented. A flow sheet for an industrial process based on this concept is proposed. A simulation of a plant using this technol. is made by a computerized model, and the economic parameters obtained suggest that sodium hypochlorite can be an interesting reagent for industrial oxidns. of double bonds in fatty acids. [on SciFinder(R)]
Schlichter J Aronhime, Sara Sarig, and N Garti. 1987. “Mechanistic considerations of polymorphic transformations of tristearin in the presence of emulsifiers.” JAOCS, J. Am. Oil Chem. Soc., 64, 4, Pp. 529–533. Abstract
The role of selected emulsifiers on fat polymorphic transformations was studied. Tristearin was heated or aged under controlled conditions using differential scanning calorimetry (DSC) and x-ray techniques, and the extent of transformation was evaluated with respect to the possible pathways of $\alpha$ transforming into $\beta$. The temp. regime controls the extent of mobility of fat mols., the local crystal imperfections and the degree of liquefaction. As a result, it dictates the kinetics of the polymorphic transformation. The surfactant added as an impurity does not have a straightforward effect, as thought previously, but rather varies with the kinetic conditions. During aging some selected solid emulsifiers will retard the $\alpha$-$\beta$ transformation while others still enhance it (during heating, all of them will inhibit $\beta$ form crystn.). Their effect probably is related to different cryst. organizations and the creation of imperfections. Liq. emulsifiers in any case will enhance the $\alpha$-$\beta$ transformation, due probably to their weak structure compatibility with tristearin, which causes a higher mobility of triglyceride mols. [on SciFinder(R)]
O ARKAD, H WIENER, N Garti, and Y SASSON. 1987. “Catalytic transfer hydrogenation of soybean oil methyl ester using inorganic formic acid salts as donors.” JAOCS, J. Am. Oil Chem. Soc., 64, 11, Pp. 1529–1532. Abstract
The hydrogenation of soybean oil Me esters using aq. formic acid salt (esp. K formate) solns. and heterogeneous Pd/C catalyst was investigated. Complete hydrogention of Me ester was achieved by mixing a concd. aq. alkali formate soln. with the Me ester at 80° in the presence of the catalyst (0.2-0.4% Pd). During the initial stages of the reaction, the selectivity was significantly higher than conventional hydrogenation (hydrogenation under pressure) performed with the same catalyst. Cis-trans isomerization was similar to the behavior of conventional techniques. [on SciFinder(R)]
N Garti and O ARKAD. 1987. “Preparation of cloudy coconut oil emulsions containing dispersed titanium dioxide by using atomizer.” Journal of Dispersion Science and Technology, 8, 2, Pp. 125–136. Abstract
The food-grade rutile TiO2, was dispersed in coconut oil with the help of hydrophobic emulsifiers such as sorbitan esters and lecithin. The dispersed mixt. was melted and blended with hydrophilic emulsifiers such as ethoxylated sorbitan esters and the preheated (60°) blend was further sprayed by atomizer into cold water (20°). The oil-in-water emulsions contained encapsulated TiO2 in the internal phase. The technique is simple and allows prepn. of stable emulsions with av. droplet size of 1-10 $μ$. [on SciFinder(R)]
N Garti and A Aserin. 1987. “Brominated, chlorinated and hydroxylated surfactants derived from oleyl chain. Part II. Emulsifying properties.” Journal of Dispersion Science and Technology, 8, 2, Pp. 113–124. Abstract
Bromination, chlorination, and hydroxylation were carried out on the hydrophobic chain of several com. available nonionic surfactants (Brij, Mapeg, and polyglycerol oleates) in order to modify their hydrophobic characteristics without changing their hydrophilic moieties. Paraffinic oil-in-water emulsions could be stabilized using these new surfactants. The derivatization of the nonionic surfactants increased their overall hydrophilicity, and as a result higher HLB values were obtained for the surfactants. In spite of the fact that hydrophilic groups were introduced into the hydrocarbon chain, stable emulsions were prepd. and in some cases even better stabilities were obsd. [on SciFinder(R)]
N Garti, A Romano-Pariente, and A Aserin. 1987. “The effect of additives on release from W/O/W emulsions.” Colloids and Surfaces, 24, 1, Pp. 83–94. Abstract
The effect of additives on the rate of release of a drug (or a marker) from the internal phase of a multiple emulsion (water/oil/water) (w/o/w) without causing a decrease in its stability was studied. Electrolytes were added to the internal and/or external aq. phase in order to equalize osmotic pressures of the two aq. phases. Addn. of electrolytes to the outer phase does not slow the rate of drug migration while incorporation of electrolytes and drug to the inner phase decreases the leaching rate. The electrolytes, both cations and anions, which improve the salting-in effect of the emulsifier are effective in decreasing the drug transport. The drug transport can be controlled by altering the electrolyte-surfactant interaction at both interfaces. The right balance between counter-current flow of electrolytes and water in each direction is crit. for such control. [on SciFinder(R)]
Nissim Garti, Judith Schlichter, Isaac Mayer, and Sara. Sarig. 1987. “Solid emulsifiers and polymorphic transitions - effect of solid emulsifiers as dynamic controllers of polymorphic transitions in triglycerides.” Tenside, Surfactants, Detergents, 24, 1, Pp. 42–45. Abstract
Sorbitan esters and other solid emulsifiers had no effect on the x-ray diffraction patterns of the stable $\beta$ polymorphs of trilaurin [538-24-9] and tristearin [555-43-1]. Plots of heat capacities (C+) of the polymorphs vs. temp. had divergence points with increase of slope at the onset of 2-dimensional melting. Sorbitan esters did not affect the Cp values of tristearin below the divergence point but increased the values for only the $\beta$-form above this point. Acridan [92-81-9] and Dimodan [31566-31-1] increased the Cp of tristearin in both forms through the whole range of temp., up to melting. Phase diagrams of tristearin with 2 sets of emulsifiers were constructed. All solid emulsifiers could be incorporated in tristearin forming one phase, but tristearin could be similarly incorporated only in sorbitan esters. Sorbitan esters increased the value of the heat of fusion of $\alpha$-trilaurin whereas other solid emulsifiers did not. Explanations were suggested by taking into account the degree of structural compatibility between the triglycerides and the solid emulsifiers. [on SciFinder(R)]
Hillel Isaacs, Rosi Schwartz, and Nissim. Garti. 1987. “Microsuspension polymerization of vinyl chloride.” Tenside, Surfactants, Detergents, 24, 4, Pp. 220–226. Abstract
Microsuspension polymn. of vinyl chloride (I) catalyzed by diacetyl peroxydicarbonate in the presence of Shamtonate 333 (a petroleum sulfonate in hydrocarbon oil) and Berol 259 yielded spherical, smooth PVC particles of 1-3 $μ$ diam. The addn. of butylene glycol further improved the stability and particle size distribution in the microsuspension system. Polymn. of I with conventional emulsifying agents such as Na lauryl sulfate, ammonium laurate, Methocel K35, Aerosol AT, and Myrj 49 yielded aggregated PVC particles due to inversion of the emulsion to a water-in-oil system. Stable emulsions were obtained for CH2Cl2 (as model compd. for I) but not for I in the presence of nonionic emulsifiers alone. [on SciFinder(R)]
Abraham Aserin and Nissim. Garti. 1986. “Brominated surfactants. Brominated surfactants as emulsifiers and weighting agents: ethoxylated nonyl phenols.” Tenside, Surfactants, Detergents, 23, 6, Pp. 305–308. Abstract
Bromination of the arom. ring of ethoxylated nonylphenols produced surfactants which were effective emulsifiers for oil-in-water emulsions and which had slightly higher HLB values than their nonbrominated analogs. The bromination increased the sp. gr. to values higher than that of water, allowing formation of oil-in-water emulsions with denser droplets. Initial bromination caused an increase in viscosity while further bromination decreased viscosity. The refractive index increased with increasing oxyethylene chain length and bromination. Crit. micelle concns. for the brominated surfactants were lower than those for the nonbrominated surfactants. Bromination decreased the surface excess concn. values for the compds. [on SciFinder(R)]
O ARKAD, T ARKAD, and N Garti. 1986. “Quantitative determination of creaming in O/W emulsions by use of absorption measurements of oil soluble dyes.” Lebensmittel-Wissenschaft und -Technologie, 19, 2, Pp. 164–166. Abstract
An easy and new method for the quant. evaluation of creaming for oil-in-water emulsions used absorption measurements of a dye dissolved in the oil phase prior to the emulsion prepn. The measurements were carried out by dissolving samples, withdrawn at different intervals from the bottom of the stored emulsions, in Me2CO, to obtain clear colored solns. The technique was suitable to predict the tendency of an emulsion to undergo creaming. The proposed method has been compared to known methods for droplet size evaluation, and a good correlation was obtained. [on SciFinder(R)]

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