1037

ABSTRACTS FROM AOCS JOURNALS

Applications or Milk·F,t F'r.clions in COnrf(liOD~ry Products.Richard W. Hanel. Department of Food Science. Uni~ily of Wisconsin.Madison. Wisconsin 53706.

Incompatibilities between rats limit the use of modified milk ral inconfectionery applications. To further enhance the use of milk-fat frac-lions in chocolates and compound coatings. a better understanding ofmixed crystallization effects between lipids is required. Recent work doc-uments lhal high-melting fractions incorporated into chocolates drasticallyreduce bloom formation and cause less softening than anhydrous milk far.ISOMIlids diagrams for mixtures of cocoa butler and milk-fat fractionsshow that softening occurs due 10 both dilution effects and a slight eurec-lie formation. Incorporation of milk-fat tracuons into palm kernel oil-based coatings shows some differences with results in chocolates. Milk fatand its fractions cause significant bloom formation in these coatings. ascompared to the control. and cause significant softening. However. bothmilk fat and milk-fat fractions are fully compatible with palm kernel oil,based on isesohds diagrams. Softening occurs only because of dilutioneffects, I'lIther than eutectic formation. Funher work is necessary to under-stand the effects of milk-fat fractions on bloom formation in compoundcoatings.IJAOCS 73, 945-953 (1996)1

Contribution oiTrigl,'ceridt'$ from Cocoa Bullt'f to the Pbysial Prop-erttes of MUldat Fractions. Catl'lcrine Simoneau and J. Bruce German.Department of Food Science and Tecbnology, University of California.Davis, California 95616.

Miltfal was separated into major chainlength fractions by solid-phaseutnlCtiOll. 'The effect 011 thermal behavior and texture of replacing bcMbsalUrated and monounsaturated long-cham triglyceride! from milkfat bylong-chain monounsaturated triglyceride! with an unsaturated fally acid inlhe slI-2 position is reponed. Increasing proponions of cocoa buller wereadde.d to fractions of s.OOrt:to me~ium-chain triglycerides (C2:z--C44) andmedium- to long-cham triglycerides (C36-C48) isolated from milkfat.l1Iermal behavior and texture of the mixtures were measured. Resultsindicated thatlong-chain Ol(lnounsaturated triglyceride5 from cocoa bullerenhanced co-crysialtization and co-operative melting and did IKM inducepolymorpbic transitions upon crystallization and melting of the fractions.AI 4OC. they acted as tuture builder if present in proportions of more than3O'l>. whereas below this level. they acted as texture softeners, 'The effectof the long-cllain mcnoonsaturated triglyceride! on the texture of fractionsthat melt at low temperature could not be predicted from the proportion ofsolid fat at that temperature.IJAOCS 73. 955-961 (1996)1

Restructuring 8utterfat Througll Blending and Chemical Interestni-nation. I.Melling 8(>ba\'lor and Triacylgl)'cerol Modincations. ~rickRousseau. Kanne goresuere, Anhur R. Hill. and Alejandro G. Marangoni.Department of rood Science. Uni~ersity of GueJpll. Guelph. Ontario N lG2W I.Canada.

Chemical imeresterification of bcuerfat-cancla oil blends. rangingfrom 100% butterfat 10 lOO'lb canola oil in 10% increments. decreasedsolid fat content (SFC) of all blends in a nonlinear fasbion in the tempera-ture range of 5 to 4O"C excepe for bulterfat and the 90: 10 bullerfatlcanolaoil blend. wt.ose SFC increased between 20 and 4O·C. 1be sharp meltingassociated with butterfat at 1S-2O"C dlsappeered upon interestcrification.Heats of fusion for butterfat to the 60:40 bUllerfat/canola oil blenddecreased fllHll 75 to 60 JIg. Blends with >50% canola oil displayed amocb sbarper drop in t'nthalpy. HealS of fusion .....ere 30-50% jcwer onaverage for intereslcrified blends than for their noninterestcrified ecemer-pans. Bod! noninterestcrified and interestcrified blends deviated substan-tially from ideal solubility. with greater deviation as the proponion ofcanola oil increased. The change in the entropy of melting was consistent-ly higher for noninteresterifled blends than for interesterified blends.Chemical interesterification generated statistically significant differencesfor all triacylglycerol carbon species (C) from C30 10 C56. except forC42' and in SFC at mcst temperatures for all blends.IJAOCS 73. 963-972 (1996)]

Restructuring BUllerfat Througll Blending and Chemicallnteresterl-fication. 2. Micro!itructure and Polymorphism. ~ric.k Rousseau. AnhurR. Hill. and Alejandro G. Marangoni. Department of Food Science. Uni-versity of Guelph. Guelph, Ontario N IG 2W I.Canada,

Blending of bnterfat with canola oil and subsequent chemical inter-esterirlC8tion modified the crystal morphology and X-ray diffraction pat-terns of butterfat. 90:10 (w/w). and 80:20 (111'1111') blends ofoouerfat-canola oil. 1be morphology of 50:~ (wJw) was also greatlyinnucoced by intertSterification.

Polarized lig/\1 microscopy revealed that additioo of canola oil led togradual aggregation of the crystal structure. Scanning electron microscopyrevealed all samples to be mix tures of defined crystalline regions andamorphous areas with greater amorphism as oil content increased. Ml)!;tsamples revealed segregation of solid from liquid, Confocal laser scanningmicroscopy of benerfat revealed complex aggr.:gated structures that werec?mJlOS;ed of out~atdly radiating fillL",M=ntsfrom ~ central nucleus. X-l'lIydIffraction analysts revealed a predommance of ~ and a small proportionof ~ crystals for all samples examined except irueresrerified butterfat.which consisted solely of W crystals.IJAOCS 73. 913-981 (1996)]

Restructuring Butterfat Through Blending and Chemlcat Interestert-ficat]on.3. Rheology. Derick Rousseau. Arthur R. Hill. and Alejandro G.Marangoni. Depanmern of Food Science. University of Guelph, Guelph,Ontario N to 2Wl. Canada.

lnterestenfled and noninteresterified buuerfat-canola oil blends. rang-ing from I()()'A, bulterfatto 60:40 butterflll-canoia oil (w/w) in 10% incre-ments. were evaluated for hardness index (HI). dropping point. viscosity,and viscoelastic propenies at small deformation. Both blending and chem-ical inlueslcrirlCation diminished HI in a noolinear fashion. HI changes ininteresterified blends were more pronounced than in noninleresterifiedblends. Dropping points yielded information on the structure of tileblends. Bunerfet's dropping point (DP) was 34.4"C, whereas that of inter-esterified butterfat was 37.O"C. which is indicative of a more structurednetwork for the latter. DP values of blends with 60-90% butterfat (inter-esterified vs. nonlrueresterified) were not significantly different (P <0.05). lnteresterifled blends had a higber crystallization onset temperaturethan did noninteresterified blends. All blends in the liquid Slate displayedNewtonian behavior. Oscillatory fJ'C(juency sweep measurements at smallamplitude showed thlll interesterirlCd blends generally bad lower stCKagemoduli (G') than their noninteresterified counterparts. Both G' and G"were frequency-dependent. Replacement of 30% buuerfat by canola oilled to notable changes in small deformation measurements. whereasreplacement of 20% butterfat led to big changes in large deformation mea-surements,(JAOCS 73. 983-989 (1996)]

Is 1'llIsllc Flit Rlleology Governed by tile hllctal Nature of the FlitCrystal Network? Alejandro G. Marangoni and ~rict Rousseau, Depan·ment of Food Science. Universny of Guelph. Guelph. Ontario N lG 2WI.Canada.

'The rheological properties of interestcrified and noninteresterified but-terfat-canola oil blends do IKM seem to be strongly related to either solidfat content (SFC) or crystal polymorphic behavior. but rather 10 themicrostructure of the fat crystal network. The microstnlClure of the fatsWD.'l quantified by using fractal geometric relationships between the elaslicmoduli (G') of the falS and their SFC values using the approach of Silih.W.H .. W. Y. Shih. S.I. Kim. J. Liu. and I.A. Aksay (Ph},!. R,,~.A.41:4112-4119 (1990)] for weak-link regimes, Chemical interesu:rificationdecreased the fractal dimension of the fat crystal network from 2.46 102.15. We propose that fat miCTOSlI\ICturt:.as quantified by a fractal dirnen-sionality. could be modified 10 attain specific rheological propenies.[JAOCS 7J, 991-994 (1996)]

Chemlnl Composition and Physical Properties of Soft (rub) Mar·garines Sold In Malaysia. Nor Aini Idrisa. Leny deMaoh. T.S. TangD. andC.L. Chonlf. apalm Oil Researcll. Institute of Malaysia. 50120 KualaLumpur. Malaysia and bDc:Man Food Technology Services Inc .. Guelph.Ontario NIH 685. Canada.

Seven samples of domestic and Imported Malaysian tub margarineswell' analyted for their fatty acid and triglyceride (carbon number) com-position. solid fat content. dropping and wftening points. crystallization

INFORM. Vol. 7. no. 9 (September 1996)

1038

ABSTRACTS FROM AOCS JOURNALS

temperature. polymorphic form, color, and textural attributes. Domesticmlll'garines were formulated from palm oil 01' palm olein and palm kerneloil with. liquid oit bn no hydrogenated oils. Two imported products con-tained hydrogenated palm oil product, which resulted in a high level of~'crystals. whereas the domestic nonhydrogenatcd products contained IJlOI'e

II than II' crystals. Crystal habit was related to the ratty acid and Diglyc-eride ccmposhlce of the high-melting glycerides. Domestic prodocts werefirmer in texture. probably because !hey were formulated to be sold in atropical climale.[JAOCS 73, 995-1001 (1996)1

Rapid intcornlination of the Tohl] trons Content or Neal HydrogenatedOils by Attenuated Total Renedion SpeclmscoPl" Magm M. MOS5Oba<l,Marlin P. Yurawecz'l. and Richard E. McDonald . QFood and Drug Ad-ministration. Center for Food Safety and Applied Nutrition, Washington,OC 20204 and brood and Drug AdminislnUon. National Center for FoodSafety and Technology, Summit-Argo. Illinois 60501.

A Fourier ITaRSform infrared lpectm5COpy peccecure is described forquantitating the ~Is of total trons triglyccrides or their fany acid methylester derivatives in neat fats and oils. It requilU either warming or nopreparation of the laboratory $aJIlple, and about 5 min for speclrOSCOpicmeasurement. band area integration, and calculation of the trons contentfrom a linear regression equation. To eliminate the strongly sloping back-ground of the 966-cm-1 Iron! band, the single-beam spectrum of theImns-containing fat is "ratieed" against that of an unhydrogenated oil or areference matcrialthat contains only cis double bonds. Thus. a symmetricabsorption band on a hori:wntal background is obtained. lbe ~a underthe Irons band can then be accurately integrated between the same limits.990 and 945 ee-t. for all trons levels invesugated. To speed up the analy-sis. an attenuated tOUlI renection liquid celt was used, into which oils.melted fats or their methyl esters were poured without weighing or quanu-tative dilution with the toxic and volatile carbon disulfide solvent. TheIroltS levels determined by attenuated tOl.lI ren~on were closer to thosefound by capillary gas chromatography when the hydrogenated fat wasmeasured against the corresponding unhydrogenated oil than when it wasmeasured against a cts reference material. Small differences were foundbetween Imn.! levels in hydrogenated fat test samples and the correspond-ing methyl ester derivatives (9.3 and 2.2% at about 2 and 41 % mIltS,

respectively). TIle lower limits of identification and quantitation were 0.2and 1'10,respectively.[JAOeS 73.1003-1009 (1996)]

13C NuclC'lIr I\-bgnetic Resonllnct Sp«trosc:opic Allillysis or the Tria-cylglycerol Composition or Some Margarines. Marcel S.F. Lie KenJiell. C.C. Lama, Mohammed Khysar Pasha, Kamen L. Stefenovb, and i.MOlekovb• IlDepartment of Chemistry. The University of Hong Kong.Hong Kong and blnstitute of Organic Chemistry. Bulgarian Academy ofSciences. 1040Sofia. Bulgaria.

The triacylglycerol fraction of three samples of margarine, namely"Flora" (Holland). "Kaliura" (Bulgaria). and "Corona" (Holland), werestudied by 13C nuclear magnetic resonance spectroscopy, By examiningthe various carbon chemical shifts of the IIIturated and unsaturated carbonnuclei. "Flora" margarine was shown to contain a mixture of hydrogenat·ed and unhydrogenated vegetable oils. This technique allowed all majoracyl groups (saturated. oleate. llnojeare. and linolenate) and minor acylcomponents [different positional isomers of long-chain (E)- and (Z)-monocnoic moieties. arising as by-products during catalytic hydrogena·tionJ to be identified. The amount of each fatty add present in the mar-garine was also estimated from the relmive intensities of the correspond-ing signols, "Kuliakra" margarine consisted of a blend of unhydrogenatednatural Iats and oils that contained saturated fatty acids. oleate, andlinolellle. There were no signs in the specmrm of "Kaliakra" of any (E)-isomers. nor signals associated with positional unsaturated acyl groups(othe:r than oleate and liooleate). The sample of "'Corooa~ margarine con-sisted of a mixture of hydrogenated and unhydrogen.ated vegetable oilsand butler (1.3'1.). 1be presence of butter in this $aJIlple was identified by!he chanctcrislic carbon shifts of the C-I to C-4 carbon atoms of butyrate.1be distributtnn of !he fany acids on !he glycerol ''bacl:bone- also wasestimated by this technique.[JAOCS 73. 1011-1017 (1996)]

Interference or Polar Lipids with the Alkalimetric Delermlnalion orFree Fatly Add in Fish LipIds. Shengying Zhou and Roben G. Ackman.Canadian institute of Fisheries Technology. Technical Univcn.ity of NovaScotia, Halifax. Nova Scotia B3J 2X4. Canada.

An examination of the suitability of an alkaflmetric method for thedetermination of free fatty add (FFA) contents in fats, oils. and lipidextracts was conducted by comparing AOCS method Ca 5a-40 with amethod based on a Chromarod-Iatroscan thin- layerchromatogtaphy-flame-ioniution detector (TLC-AD) system. The FFAcontents determined by the alkalimetric II1C'thodwere consistently higherthan the genuine FFA contents obtained by the latmscan TLC-FIDmethod. Phospholipids were found to be the major components that con-tributed to the alkall-titratable. nongenuine FFA in the total FFA deter-mined alkali metrically. Contributions from other polar lipid componentswere smaller. but they dominated 1$ the proportion of phospholipids fell.The other aJkalj.titrntable polar components may include ollidiu(i lipidsand their by-products bound 10 protein fragments. The accurate determi-nation of FFA contents by alk.alimetric methods may only be applicable tothose commercially refined fats and oils that contain negligible amountsof phospholipids. Corrections for the alkalimetrically determined FFAcontents should be made for those fats and oils with relatively high phos_pholipid contents by correlating the nongenuine FFA contents and thephospholipid contents.!JAoes 7J. 1019-1023 (1996)]

EIcOSllpC'ntaenoic AcId (20:5n-3) rrem the Marine Microalga Phaeo·dactyfum lrico,.,,,uum. M. Cartens", E. Molina Grimab. A. RoblesMedinab• A. Gimfnez Gimfnezh. and 1. Ib:iilez GonzalezC'. aDepana_mento de Ingeniena Cfrfmica. Uoiversidad de la Patagonia. Comodoro Ri-vadavia. Argcntina. Dcpanamento de Ingenierfa QuLmica. Facultad deCiencias Eliperimentales. Univcrsidad de AllllC'na. E.()4.()71 Almena.Spain. and COerivados del Etilo S.A. 04618 Villaricos (Cuevas de Alman-lOra). Almeria. Spain.

Elcosapentaenolc acid (EPA. 2O:5n-3) was obtained from the marinemicroalgae Plweodaclylum lricomulum by a three-step process. fany acidextraction by direct saponification of biomass. polyunsaturated fatty acid(PUFA) concentration by formation of urea inclusion compounds, andEPA isolation by sernipreparative high-performance liquid chromatogra-phy (HPLC). Alternatively, EPA was obtained by a similar two-step pro-cess without the PUFA concentration step by the urea method. Directsaponification of biomass was carried out with IWO solvents that containedKOH for lipid saponirlCation. An increase: in yield was obtained becausethe problcms associated with emulsion formation were avoided by sepa-rating the biomass from the soap solution before adding hexane forextraction of insaponifiables. The most efficient solvent. ethanol (96%) at6O"C for I h. extracted 98.3% of EPA. PUFA were concentrated by theurea method with a urea'fany IIcid ratio of 4: I at a crystallization tempera-ture of 28"C and by using methanol and ethanol as urea solvents. An EPAccncemreuon ratio of 1,73 (55.2:31.9) and a recovery yield of 78.6% wereobtained with methanol as the urea solvent. This PUFA concentrate wasused to obtain 93.4% pure EPA by scmipreparative HPLC with a reverse-phase. C18' 10 mm l.d. )( zs-cm column and methanol/water (1<;1.aceticacid), 80:20 w/w, 1$ the mobile phase. Eighty-five percera of EPA loadedwas recovered. and 65.1'10 of EPA preseO! io P. lricomulum biomass wasrecovered in highly pure form by this mree-srep downstream process.Alternatively. 93.6% pure EPA was isolated frnm the fatty acid extract(without the PUFA concentration step) with 100% EPA recovery yield.This two-step process increases the overall EPA yield to 98.3%, but it isonly possible 10 obIain 20% Its much EPA Its that obtained by three-stepdownstream processing.(JAOCS7J.1025-1031 (1996)J

Validation or the Randrnat Trst for IhC' Assessment or the RelatlveSlabUU.r or Fish Oils. Eduardo Mfndezll. Julio Sanhuezab• HerOJinSpeisky". and Alfonso Vale~uclab. aFacultad de Ingeniena. lestiunc deQufmica. Universidad de Uruguay, Montevideo. Uruguay and bunidad deBioqufmica Farmacol6gic1 y Lfpidos. INTA. Universidad de Chi~. Santi-aao. Chile.

The induction periods for the perollidalion of various fish oils at5S-9O"C wen: studied by the Rancimat test. The natural logarithms of theindoction periods varied linearly with respect to temperature. with a meancoefficient of -7.S)( 10-2 -c-r. which was significantly different from

INFORM. Vol. 7. no. 9 (September 1996)

1039

that reponed for vegetable oils. 'The activation energy for me formation ofvolatile acids had II mean value of 38.9 IUlmo! and was independent of thefish oil source. Peroxide formation under Rancimat lest conditions fol-lowed first-order kinetics. The same k.inetics were followed under SchaalOven test conditions (forced-air oven, 6O"C). On the basis of the resultsobtained, the Rancimat ttst appears to be useful in determining the rela-tive "abilities of fish oils without the eMnge in peroxide decompositionkindies!hat may occur at ekvalCd temperatures.!JAOCS 73, 1033-1037 (1996))

Determination of the Oxidative St.bllily of \'~etable Oils by Rand-mal lind Conductivity and ChemliuminHC('lICC' Measul1.'menl$.Bcrtnmd W. Mlllthll.us. 1051ilUIrur Chemic und Physik tier Fene der Bun-desanstall ffir Gctreide-. Kartoffel- und Fettforschung, 0-48006 Milnster,Germany.

TIle oxidative stability of five different oils was detennined by Rand-nmt analY$is with conductivity and chemiluminescence measurements forevalWllion of the indllCtion periods. Samples of oil, Ulli:enat intervals fromthe Rancimat apparatus. ....ere used for chemiluminescence measurements.The chemiluminescence results ....ere plotted vs. time. and the resultingCU1VC$ ....en: evaluated ....ith a graphical tangential procedure in the &arne.

way as the curves of the Rancimat method (conductivity measumnent).Induction periods of the oils assessed by Rancinmt and chemilumiIle5-ceece methods showed a signif\C&llt linear correlation (r'" 0.9865). Thetemperature dependence of the indUC1ioo periods evaluated by chemilumi-nescence and by conductivity ....as investigated ....ith walnut oiL A markedtemperature dependence was observed for both.[JAOCS 7J. 1039-1043 (1996»)

Suybean Llpexygenase-Prcmoted O:ddlltion or Free and EsterifiedLinoleic Acid In the Presence or Decxyeholete. George J. Piazza,Thomas A. Foglia, and Alberlo Nu~e:t, USDA. ARS. ERRC, Wyndmoor.Pennsylvania 19038.

Lipoxygenase (EC 1.13.11.12) catalyzes the reactioo bet ....een oxygenand polyunseusrated Iany acids to give fauy acid hydroperoxides. Recent....ork showed that soybean lipoxygenese I can oxidize diacylglycerol'....hen deoxycholate is present in the reaction medium. Conditions ....ere50Ught 10 maximize 1,3-dilinolein oxidation ....ith B commercial soybeanlipoxygenase preparation. It was found thtll dilinolein ....as oxidized mostropidly in a multicomponent buffer medium that contained 10 10M deoxy-cholate bet ....een pH 8 and 9. When dilinolein oxidation ....as conducted inthe individual components of the ruulticoruponem buffer. the oxidationrate decreased two- to threefold. Addition of 0.2 M NaCI 10 one of thecomponents, Tricine butTer. caused a twofold increase in the oxidationrate, demonstrating that high ionic strength is II major factor promotingropid oxidation in the multicomponent buffer. In the deoxycholate multi-component buffer, the order of reactivity to ....ard oxidation ....as monclt-nclein » methyl linoleate .. linoleic acid> dilinolein. Competition expen-meras in ....hich mixtures of the substnltes ....ere presented simultaneouslyto lipoxygenase in the presence of deoxycholate showed that linoleic acid....as the most reactive substrate. When no surfactant ....as present 01" .... henthe surfactant ....as l'ween 20. linoleic acid ....as the most rapidly oxidizedsubstrate. Overall. the results demonstrate that monolinolein and methylIlnoleate are just as reactive, or more 50. as linoleic acid to oxidation bylipcxygenase under specified reaction conditions. In competition experi-ments. linoleic acid oxidation predominates. probably because its free car-boxyl functionality allo ....s illO be preferentially bound 10 the active sue oflipoxYienase.(JAOCS 7), 1045-1049 (1996))

Crystalll:r.ation Kinetks or the Pure Triacylglycerob GI,.«rol·I,3-Oi·palmltate-2-0leate, Glycerol-I-Palmitate-2-0Ieate-3-Stearate, andGlycerol.I,J..Distearate-2-OIeate. Ph. Rousset and M. Rappaz. Labora·toire de Mttallurgie Physique, Ecole Poly technique RdErale de Lausanne.MX-G. CH·101.5 Lausanne. S ....itzerland.

CrystalliZlllion kinetics of the three main components of cocoa butter.the triacylglycerols POP. POS. and SOS ( ....here P. O. and S stand forpalmitic. oleic. and Stearic acids. respectively) ....ere studied by combineddifferential scanning calorimetry and polarized light microscopy. Themorphologies. nucleation kinetics, gro ....th kinetics. and phases of thegrains formed ....ere identified ....ith this system. 'The experimental data. as....ell 3$ IWO different models to ,imulDte crystalliution and 10 predict

behavior of the pure triecylglycerols. are presented. The first model isbased on 3 macroscopical approach 10 solidification by usinitime-temperarure-transforrneeicn (TIT) diagrams and the additivity prin-ciple. It allows prediction of the proportion of the different phases formedfor pny given thermal path imposed on the sample once the TIT diagramis known fOl"the product. It is illustrated for SOS Pt constant cooling ratesand is compared ....ith experimental results. The second model directlysimulptC$ growth of the spherulites in the sample by using nucleation andgrowth nllCS that are detennined experimentally. It provides a view of thest.ructure as it ....ould be observed ....ith a microscope and shows evolutionof the heat released in the sample. Isothermal 5OIidification of POP at1.5°C is displayed. "The experiment and the model are in good agreement.!JAOCS 7),1051-1051 (1996»)

Enzymatic Modineu.tion 01' E~'enlng PrImrose Oil: Incorporation or n-J Polyunsaturated Fatly Adds. Casimir C. Akoh, Brenda H. Jennings.and Dorris A. Lillard. Department of Food Science and Technology. TheUniversity of Georgia.. Athens. Georgia 30602-1610.

Immobiliud lipase SP43.5 from COlIdidD {In/{lrrlic{l was used as a bio-catalyst for Inc: modification of the fatty acid composition of eveningprimrose oil by incorponu..ing n-3 polyunulIlllUed fatty acid (PUFA) andeicosapentaeooic acid (EPA). Transesterificlllion (ester-ester inten:nangc")WIIS conducted in organic sotvem or ithout 5OIvenl. with EPA ethyl ester(EEPA) as the acyl donor. ProductS ere analyzed by gas-liquid chrc-matognlphy (GLC). After 24-h incubation in hexane, the fany acid com-position of evening primrose oil was l1lIIlitedly changed 10 contain up to43% EPA. The IlIl10IIntof 18:2n-6 PUFA was reduced by 32%, and thesaturoted fOlly acid content ....as also reduced. The effects of incubationtime. molar ratio. enzyme load, und relICtion medium on mol'll EPA Incor-poration ....ere also studied. Geocrolly. as the incubation time (up to 24 h).molM ratio. and enzyme load increased, EPA incorporation also increased.Evening primrose oil. containing EPA and l-linolenic acid (I8:3n-6) inthe same glycerol backbone ..... as successfully produced and may be morebeneficial for certain applications than unmodified oil.[JAOCS 7J, 1059-1062 (1996»)

Alkali-Modifted Soy Prolrlns: ErrKt or SailS and Disullide BondCICllvilge on Adhesion and Viscosily. U. Kalapathyil. N.S.Hettiarachchy". D. Myersb, and K.C. Rheec, DDepanment of Food Sci-ence, University of Arkansas. Fayeueville. Arkansas 12104. bCenter forCrops Utilization Research. Iowa State University of Science and Technol-ogy. Ames.lo ....a 50011. and cFood Protein Research and DevelopmentCenter, Texas A&M University. College Station, Texas 17843.

Soy protein isolates were treated ....ith NaC!. Na2S04. or Na2S03(disulfide bond-cleaving agent) at a pH of 10.0 and 50"C. and the etrecuof these salts on viscosity. adhesive strength on woods. and water rests-ranee of the treated isolates were investigated. Viscosity and adhesivestrength decreased ....ith increasing concentrations of these salts. At a con-centrlltion of 0_1 M. these three salts reduced the viscosity of soy proteinsw ith no significant adverse effects on adhesive strength and water resis-tance. Addition of 0.1 M NaCl. Na2S04, or ND2S03 reduced adhesivestrength insignificantly from 1230 N to 1120, 1060. or 1013 N. respec-tively. The viscosity of protein isolate modified at pH 10.0 and SO·C inthe absence of salts was >30.000 cPo Treatment ....ith NaCI or N02S04resulted in viscosity reductions to 60CXl or 1050 cp, respectively. TheNa2S03 treatment yielded an isolate ....ith the lo....est viscosity of 110 cPand ....hich retained adhesive and ....arer-resjsuve properties. The ....aterresistance of modified 50y proteins with and ....itOOI.II0.1 M N02S03 treat-ment was IlOl significantly different ....ith 3.3 and 6.6% cumulative delami-nations occulTing after four water soaking cycles. Treatment ....ith 0.1 MNB2S03 resulted in an isolate ....ith a 28'10 decrease in disulfide linkages.(JAOeS 7),1063-1066 (1996))

MKhanism or Physical Modi6al11ott of lnsol.ubk Soy Proteln Conan-trait'. Yu Fei Hua. Pel De Ni, Wen Ying Gu, and Bei Ying Shen. School ofFood Science, Wuxi University of Light IndusU)', Wuxi, People'S Republicof China.

'The mechanism for solubilization of alcohol-leached my protein con-centrate (ALSPC) by physical mcdiflcmlon was studied from the stand-point of molecular interactions, ....hich are related 10 the differences in pro-lein JoQlubility under different conditions. 'The low solubility of ALSPC iscaused by beth noncovalent and covatern forces, bill the noncovalent

INFORM, Vol. 7, no. 9 (September 1996)

1040

of 52:48. and incubation at pH 9.8 strongly suppressed producdcn of 5(S)-HPETE and led 10 fonnation of S(S)·HPETE and 15(S}HPETE in a ratioof 3:97. A p+r-oependenr orientation of arachidonic acid at the active sueis proposed \0 explain these firKIings. Rice leaf pathogen-inducible lipoxy-genase [Pengo Y-L.. Shtrano, Y.. OhIO. H.. Hibino. T.. Tanaka. K., andShibata, D. (1994) J. Bioi. Chem. 269. 3755-3761] cat.alyzed 0';Y8eoal;00of arachidonic acid into a single hydropercxjde isomer of high opticalpurity. i.e., IS(S}HPETE (99.S,*, 5),(lipid! 31,803-809 (1996)1

ABSTRACTS FROM AOCS JOURNALS

forces do not affect the solubility of modified soy protein concentrate(MSPC). Gel filtration shows thai the major constituents of soluble pro-Iein from ALSPC and MSPC arc protein molecules and protein aggre-gates. respectively. Physical modification promotes the formation ofaggregates that IIJ'e readily soluble in buffer. Fluorescence spectroscopyfurther proved that the lIydropllobic groups life located in the interior ofthe aggregates. "The reason for the formation of soluble protein aggregatesduring physical modification of ALSPC is discussed.(JAOCS 71.1067-1070(1996)1

Tht Errttt ofTtmptniture on Lipid Classes and Tbeir Fally Acid Pre-filr!I in Lipomyul SllIrktyi. M. Suutari, A. Rintamaki, and S. Laakso,Helsinki University ofTecllnol08Y. Departmenl of Chemical EngiDe1:ring.L..aboratOl')'of Biochemistry and Microbiol08Y. 02150 Espoo. Finland.

The effect of environmental temperature on fally acid contents ofmajor lipid classes was determined in lipomYC~1 sMru)"i at 30. 20. andIO"C. When the temperature was reduced from 30 to 20DC. the linolenicacid content increased in phosphatidylcheltne but fell with further reduc-tion to IO"C. "The relative contribution of pbospbatldytcboline and phos--pllatidylethanolamine that contained the next lowest-melting fany acids.palmito1eM: and linoleic acids. increased on lowering the temperatUJe from20 to IO"C and. concomitantly. the combined pbcspbaudylieositol andpbosph.aUdylserine fraction decretied, and triacylglycerols were eccumu-lated.(JAOCS 71. 1071-1073 (1996)1

Phosphatidate PhosphatastS or Mammals, Ytast., and Hightr Plants.Michael G. Kocsis and Randall J. wesetake. Department of Chemistry.University of Lethbridge. Lethbridge. Alberta Tl K 3M4. Canada.

Phosphatldate phosphatase (EC 3.1,).4) catalyzes the hydrolysis ofphosphatidare to yield sn·I,2-diacylglycerol and inorganic phosphate. Inmammalian systems. forms of phcspharldate phosphatase involved inglycerolipid synthesis and signaltrunseuction have been identified. Formsof the enzyme involved in signnl transduction have been purified and per-tially chnracterized. In yeast. phosphntidate phosphatases associated withthe endoplasmic reticulum lind mitochondria have also been purified andpartially characterized, Information on phosphatidate phosphatases frommammals and yeast is useful in characterizing the enzyme from plant sys-tems. This review examines progress on the characterization of phosphatl-date pbosphatases from mammals, yeast, and higher plants. "The purifica-tion and characterization of the pbesphatldete phosphatase involved inglyceroJipid synthesis in developing oilseeds may lead to the identifica·tion of the encoding gene. Increasing our understanding of the enzymes oflipid synthesis in developing seeds will aid in the development of biotech-nological strategies for seed oil medificarion.{lipids 1/, 78~2 (1996»)

Sp«tncily of T~'o Llpoxygenases from Rice: Ijnusua! Regiosp«tncllyof a Lipcxygeaase Isoenzyme. Llan- Ying Zhang and Mats Hamberg. ])C.partment of Medical Biochemistry and Biophysics, Division of Physiolog-ical Chemistry 11. Karolinska Institutet. S·171 77 Stockholm. Sweden.

The reglo- and st~pecificity of two Jipoxygenases from rice wereinvestigated using arachidonic acid as the substrate. Rice seed lipoxyge·nase--2 (RSL--2) ~t.alyzed oxygenation of arachidonic acid into a mixtW"Cof S(S)-hydroperoxy·6.S.II,14-eicosatetraenoic acid [SCS)-HPETEI andIS(S}·hydroperoxy·S,g,II.13-eieOhtetnlC'noic acid (IS(S)-HPETE). Inaddilion, two double dioxygena.se products. 5(S),15(S}-dihydroperoxy·6,8.11.13-eicosatetraenoic acid and 8(S},IS(S}-dihydroperoxy·5,9,11,13·eicosatetracnoic acid. were obtained in a lower yield. "The regiospecificityof the RSL--2--catalyud oxygenation was pH-dependenl ThIJ.'i. iocubationIt pH 6.7 led to the fonnation of 5(S)-HPETE and l5(S)-HPETE in a ratio

timrr"u Isomtriutlon or UIIISRWnlted Fitly Acids as Possib'" ControlMechlnlsm or Membrlne .'Iuldity in P$~lIdOmOnlUpll/ida P8.Burkhard Loffeld and Heribert Keweloh. Depanment of Microbiology.University of Muenster. 0-48149 Moenster. Germany.

Exponentially growing cells of Pst!rMiomona.J pUlida had an illCreasedratio of saturated to unsaturated fatty acids in response to increasedgrowth temperatures, Resting cells in which fany acid biosynthesis wasstopped reacted to a thermal increase by converting cis-monounsaturatedfauy acids to Irons isomers. cisllro,u Isomerization of up to 60'10 of theunsaturated fatty acids was also activated by alcohols of different chainlength. Their effective concentrations apparently depended on thelipophilic charactCl" of the alcohols. Also, a salt shoe" caused by the addi·tion of NaCl re:su11Cd in the production of trans fatty acids. H"","CVCI".cellsthat were adapted to growth modia of high osmolarity symhesized cyclo-propane fally acids instead of IrofIJ fally acids. Activity of cisllrans·iso-merase was dependent on tnc growth phase and was significantly higherduring logarithmic growth than during the statiooaf)' phase. "The results ofthis study agtet' with the hypothesis that the isomerization of en into IMruunsaturated fatty acids is an emergency action of cells of P. putida toadapt membrane fluidity to drastic changes of environmental conditions,(lipjds 11. 811-815 (1996)]

Alterations In Cell Cholesterol Content Modulate Ca2+.lndueedTight Junction Assembly by MOCK Cells. Michael C. Stankewich".Stacy A. FrancisD, Quynh U. VuQ• Eveline E. Schnecbergerh. and RobertD. Lyncho. QDepanment of Biological Sciences. University of Mas·sachusetts at Lowell, Lowell, MassachUSCIts 01854 and boepanment ofPathology. Massachusetts General Hospital. Boston, Massachusetts02114.

Transepithelial electrical resistance (fER). a measure of tight junction(TJ) barrier function, develops more rapidly and reaches higher valuesafter preincubation of MOCK cells for 24 h with 2 ]It.1 Lovestatin (Iova),un inhibitor of 3·hydro~y·3·methylglutaryl-CoA reductase. While thiseffect was attributed to a 30% fall in cholesterol (CH), possible effects ofleva on the supply of prenyl group precursors could not be excluded. Inlhe current study, str~tegie~ were devised to examine effects on TER ofagents that simultaneously lower CH and increase the flux of intermedi-ates through the CH biosynthetlc pathway. zaragoztc acid. 20 ].1M.aninhibitor of squalene synthase known to increase the synthesis of iso--prenoids and levels of prenylaied proteins. lowered cell CH by 30% after24 h. while accelerating development ofTER in the same manner as lova.TER was also enhanced. despite a 23% increase in the rate of [3H]lICCtateincorporation into CH. when total CH was reduced by 45% during I 2·hincubation with 2 mM methyl jH:yclodextrin (MBCD). an agent that stim-ulates CH efflux from cells. "The fact that the rate of TER developmentwas diminished when cell CH content was elevated by incubation wah acomplex of CH and MBCD is funhcr evidence that this sterol modulatesdevelopment of the epithelial barrier, Cell associated CH derived from thecomplex was sirnllur to endogenous CH with respect to its accessibility tocholesterol oxidase, Leva's effect on TER was diminished when 5 ].IglmLof CH was added to the medium during the last 11 h of incubation withI~.[Upid$ JI. 817-828 (1996)]

t:fTttt or Dittary n.' .Jcosatrk:nok Add on the Fatty Acid Composi·tlon of Plasma Lipid .'ractlOn5 and Tissue Phospholipids. L.G.Deland". M.A. Neumannb• R.A. Gibsorl>. T. Hamazalcic. K. Alr.imotod.and MJ. Jame5I1• QRheumawl08Y Unit. Royal Adelaide Hospital. Ade--laide. SA. Australia, Doepanment or Pediatrics and Child Health. AindersMedical Centre, Bedford Park. SA. Austnlia. 'Fm.t Department of Inter·nal Medicine, Toyama Medkal and Pharmaceutical University. Toyama.Japan. and dlnstitute for Biomedical Research, Suntory Ltd., Mishima·

INFORM. Vol. 7. no. 9 (Seplember 1996)

1041

Guo. Osaka. Japan.n-9 Elcosatriencic add (ETTA), also known as Mead acid. is a miner

fatly acid in essential fany acid (EFA)-sufficient healthy subjects but isfound at increased levels in EFA deficiency. This study examined theinfluence of dietary ETTA from a biological source on plasma and tissueETrA. A synthetic fat-free diet was prepared to which was added MUi 48oil which contains 19% ETTA (wt%) as well as other 0-9 fally acids.Blends of vegetable oils were used 10 achieve overall diets with 5% f31(w\%) and varying amounts of ETTA 31 two different dietary levels oflinoleic acid (LA). approximately 4.4 and [9% of IOIlIi fatty acids. Thesediets were fed to S-week-old Dark Agouti rats for four weeks. Plasmalipid fractions and liver, spleen. and peritoneal exudate (PEl cells wereanalyzed for fatty acid composition. ETrA was present at up to 20% totalfatty acids in plasma triglyceride. cholesrerot ester, and pbospbolipid frac-tions. ETrA also accumulated to substantial levels in phospholipids ofliver and spleen (up to 15% of total fany acids) and PE cells (up to 11%).ETrA was found in plasma and tissue phospholipids in proportion to theamount of ETrA present in the diet. The illCorporation was reduced indiets with higher LA content compared to diets containing similaramounts of ETrA but lower LA. All rats remained apparently healthy, andhistological survey of major organs revealed no abnormality. While thelong-term implications for health of ingestion of diets rich in ETTAremain to be established. rats appear to tolerate bigh levels of dietaryETrA without adverse effects. Dietary enrichment with ETrA warrantsfurther investigation for possible beneficial effects in models of inl1amma-tion and autoimmunity. as well as in other conditions ill which mediatorsderived from n-6 fatty acids C311affect homeostasis adversely.[Lipids 3/. 829-837 (1996»)

Vitamin E Inhibits Fish Oil-Induced Hyperlipidemia and TISSue LipidPcro:ddalion In Hamsters. Stan Kubow", Nathalie Goyette". Sehm Ker-mashab. Jean Stewart-Pbillip". and Kristine G. Koskia. aSchool of Dietet-ics and Human Nutrition, bDepanment of Food Science and AgriculturalChemistry, Macdonald Campus of McGill University. Quebec H9X 3V9,Canada CMontreal General Hospital Research Institute and Department ofMedicine. McGill University. Montreal. Quebec H3G I A4, Canada.

Previous research has linkcd hypertipidemia with increased serumconcentrations of lipid percxidation products: however, a specific associa-tion between diet-induced oxidative stress and hyperlipidemia has notbeen studied. In the present study. the relationship between tissue lipidperoxidation and hyperlipidemia induced by ingestion of fish oil wasexamined. In Experiment I. male Golden Syrian hamsters were fed semi-purified diets composed of 1.6 wt% safflower oil plus 15.0 wt% of eitherbutterfat (BF), saffiower oil (SAFF). or high-cholesterol menhaden oilrMHO(H-CHOL») sernipurifled diets for 27 d. The cholesterol cornems ofthe diets were adjusted to 0.088%. The MHO(H-CHOL)-fed hamstersexhibited higher serum ccecenuancns of total cholesterol. triglycerides.apolipoprotcin 8. and lipid peroxides when compared to the BF andSAFF diet groups. In a further study (Experiment 2). hamsters were fedfor 27 d three dietary treatments: (i) MHO(H-CHOL) with no vitamin Econtent: (ii) a low-cholesterol menhaden oil containing high concentra-tions of vitamin E (2.5 mg tooopherollg oil or dietary concentrations of375 mg!kg) [MHO(L-CHOL) + E): and (iii) the MHO(l.-CHOL + E) withadded cholesterol (595 mg!kg) [MHO(L-CHOL) + CHOL + E) to matchthe cholesterol con tent of the MHO(H-CHOL). TIle MHO(L-CHOL) + Earlll MHO(L-CHOL) + CHOL + E diet groups showed lower concentra-tions of serum cholesterol. triglycerides, and hepatic lipid peroxides thanthe MHO(H-CHOL)-treated group. Moreover. in contrast to the hyperc-holesterolemia caused by the MHO(H-CHOL) feeding. the MHO(L-CHOL)+ E and MHO(L-CHOL) + CHOL + E diets did not show a serumcholesterol-elevating ecncn, This study supports the hypothesis thatoxidative stress in the Syrian hamster could playa causal role in dietary-induced hyperlipidemia which can be inhibited by high vitamin E intake.[Lipids 3/. 839-847 (1996)1

A Diet Containing Myrtstoleic Plus PBlmitoleic Acids Elevates PlasmaCholesterol In Young Growing Swine. Dana R. Smith. Darrell A. Knabe.H. Russell Cross. and Stephen 8. Smith. Department of Animal Science.Texas A&M University. College Station. Texas 77843-2471.

The objective of this study was to test the effect of a novel fatty acidmixture. enriched with myristoleic and palmitoleic acids. on plasmalipoprotein cholesterol coocentrations. Weanling pigs were assigned to

one of six groups and each group received a diet differing in fatty acidcompcsiucn. Diets were fed for 35 days and contained \0 g added com-starch/IOO g (to provide baseline data) or \0 g added fatty acids/IOO g.For those diets containing added fatty acids. extracted lipids contained36% rnyristclelc plus palmholeic acid combined (14:lfI6:l diet). 52%palmitic acid (16:0 diet). 51% stearic acid (lg:O diet). 47% oleic acid(18:1 diet). or 38% linoleic acid (18:2 diet). With the exception of thecornstarch diet. all diets contained approximately 30% myristic acid.There were no significant differences in weight gain across treatmentgroups (P = 0.22). All diets caused a significant increase in triglyceridesand in total. low density lipoprotein, bigh density lipoprotein. and verylow density lipoprotein cholesterol. The increase in total plasma choles-terol from pretreatment values was greatest in pigs fed the 14:lfl6:1 and18: I diets, However. the increase in low density lipoprotein cholesterolfrom the pretreatment concentration was greatest in the l4:lfI6:I-fOOpigs. Increases in very low density lipoprotein cholesterol above pretreat-ment concentrations were lowest in 16:O-fOOpigs and greatest ill 18: l-Iedpigs. Dietary fatty acids elicited ch3llges in plasma fatty acids which gen-erally were reflective of the diets. although the 18:0 diet did IlOlalter plas-ma fatty acid coecemranons and the 16:0 diet iocreased plasma 16:0 onlyat the end of the study. These results demonstrated that the combination ofmyristolelc plus palmitolejc acids increased plasma cholesterol in youngpigs. suggesting that fany acid chain length. rather than degree of unsatu-ration. is primarily responsihle for the effects of fany acids on circulatinglipoprotein cholesterol concencauons.[Lipids 3/. 849-858 (1996)]

Fatly Add Composition or Late Embryonic and Early Postnatal RalBrain. Pnina Green and Ephraim Yavin. Department of Neurobiology, Thewetzmann Institute of Science, 76100 Rehovot. Israel.

The fatty acid (FA) composition and distribution in a variety of phos-pholipids (PL) and neutral lipids (NL) at two discrete stages during theembryonic rat brain development were investigated. Over 96% of the FAwere acylated into fetal brain PL at emhrynnic day 17 after the peak ofneuronal proliferation and ot embryonic day 20. one day prior to delivery.Phosphatidylchollne constituted approximately 60% of the total PL pool,phosphatidylethanolamine (PE) 30%, phosphatidylserine (PS) 6%. andphosphatidylincsitol (PI) 4%. The diacylglycerols and triacylglycerolsconstituted 1-2% of the fetal brain lipids. a-Linolenic acid (18:3n-3) andlinoleic acid (18:2n-6) were found in very low amounts io all fetal brainPL and NL. TIle percentage of the n-6 polyunsaturated FA, consisting ofarachidonic acid (AA). 22:4n-6 and 22:5n-6, remained unchanged in allthe fractions. except ill Pl. in which the proportion of AA increased. TIleconcentration of uocosahexaenotc acid (DHA) illCreased with age in allthe Iracrlons, with the bulk of accumulation accounted for by its increasein PE anti. to a lesser extent, in PS. This finding suggests a "DHA accre-tion spurt" during the last three days of pregnancy.[Lipids 31. 859-865 (1996)]

The Errects or 3-H)'droxy-3-Methylglutary~oA Reductast Inhibitionon 'rtssue Levels or Carnitine and Camitine Acyltransrerast Activityin tht Rabbit. lalaluddin Bhuiyan and David W. Seccombe. Departmentof Pathology. University of British Columbia. Division ofClinicaJ Chem-istry. Department of Pathology and Laboratory Medicine, Vancouver Hos-pital & HSC. Vancouver. V5Z IM9. Canada.

Recently. a new class of lipid lowering agents [3-hydroxy-3-methyl-glutaryl (HMG}-CoA reductase inhibitors) was introduced imo clinicalpractice. TIle use of these agents could lead to a secondary deficiency incamitine. which may manifest clinically as a myalgialmyositis-a sideeffect that is occasionally seen with this class of drogs. In the presentstudy. we examined the effect of an HMG-CoA reductase inhibitor(lovastatin) on serum and tissue levels of camitine and camitine acyltrans-Ierase activities in the rabbit. Rabbits (/I = 6) were fed chow containinglovastatln (30 mg/d) fnr 16 wk. Blood was collected and tissues (liver.bean, and skeletal muscle) harvested at sacrifice. Free and total carnitinewere measured in serum and tissues by a radicenzymatic method. Carni-tine aceryltransferase and carnitine palmitoyltrllnsferase (cvr) activitieswere determined and expressed relative to DNA. Serum free (24.0 :t 2.6vs, 29.4 ± 3.1 11M) and total (35.1 :t 4.7 vs. 52.8 ± 8_8 11M) carnitine lev-els increased significantly with 16 wlr::of treatment. This Increase in totalcarnitine was mainly due to an increase in the levels of !;Crum acylcarni-tine (12.7 ± 3,] vs. 26.5 ± 5.7 11M). TIssue levels of total carntune were

INFORM, Vol. 7, no. 9 <September 1996)

1042

ABSTRACTS FROM AOCS JOURNALS

significantly decreased by the treatment. Camitine acetyltransferase wasunaffected by the treatment. whereas there was a significant increase inthe activity of CPT in the liver and heart.(Lipids J I. 867-870 (1996)]

weeks. At the end of each e.tperimental period. the hamsters were operat-ed on to establish external biliary fistulas. During the depletion of theendogenous bile acid pool (for two hours), the basal bile flow of group 4was significantly smaller than that of group 3. Basal bile acid Output wassignificantly [ower in the methyltestosterone-fed groups 2 and 4 than incontrol groups I and 3. In contrast. groups 2 and 4 secreted more choles-terol than groups I and 3. Group 4 had a higher ratio of cholesterol out-put 10 phospholipid output than group 3. Increasing doses of taurocholatewere infused after the bile acid depletion period. and it was found thatmethyltestosterone did not change the bile acid independent bile flow.The increments in cholesterol or phospholipid output induced per incre_ment of bile acid output (linkage coefficients) were analyzed by linearregression. The methyltestosterone-fed groups (groups 2 and 4) had ahigher linkage coefficient of cholesterol output to bile acid output thanthe control groups (groups I and 3). The linkage coefficients of phospllo+lipid output to bile acid output of groups 2 and 4 were also higher com-pared to groups I and 3. 'The linkage coefficient of cbotesierot output tophospholipid output of group 2 was higher than that of group I. Theseresults suggest that methyltestosterone stimulated the cosecrenon mecha-nism of cholesterol and phospholipid in hil~ associated with an increas-ing ratio of cholesterol to phospholipid. In conclusion. the syntheticandrogen. methyltestosterone, caused a decrease in basal bile flow andbile acid secretion. and an increase in basal cholesterol secretion and thebiliary cholesterol-to-phospholipid ratio. These findings explain, in part.how methyltestosterone intensifies the formation of cholesterol gall-stones in female hamsters.!Lipids 31,879-386 (1996)]

Dietury Sunflower Oil Reduces Plasma and Liver Trlacylglycerols In,,'asting Rllts and Is Associated with Decreased Liver MicrosomlllPhosphatidate Phosphehydrolase Activity, Lucie Premont and Marie-Therese Gozzelino. Laboratoire de Nutrition et S~curit~ Alimentairel.N.R.A .. Jouy-en-roses Ceder. France.

Plasma and liver lipids were studied in male weanling rats fed dietscontaining moderat~ levers of fat (6% by weight) as sunflower oil (SFdiet. rich in linoleic acid). salmon oil (SM diet, rich in long-chain n-3fatty acids). (1Ta blend of peanut and rapeseed oil CPR diet, rich in oleicacid). After nine weeks of feeding. the fasting plasma cholesterol concen-trations were 49 and 24% lower in groups SM and SF. respectively, asoompared to group PRo Botb dietary salmon oil and sunflower oil loweredthe triacylglycerol concentration of plasma and liver but. unexpectedly,the response was higher with sunflower oil. Indeed. in group SM the val-ues were 15 and 30% lower in plasma and liver. whereas in group SF, theywere 24 and 53% lower. respectively, As compared 10 group PR, liver tria-cylglycerols and microsomes contained 2,5- and 2.3-fold less oleic acid,respectively, in group SF. and they were 9.2- and 3.2-fold enriched in n-3fatty acids. respectively, in group SM. The liver triacylglycerol concentra-tions were correlated with changes in the microsomal Mg2+ -dependentphosphatidate phosphohydrolase activity (r = 0.47, P < 0.01). As oleicacid. unlike long-chain n-3 fally acids, is considered to promote the tria-cylglycerol synthesis and secretion. our findings suggest that changes inthe membrane fatty acid composition could affect the triecylglycerol con-tent of liver and plasma. Moreover, the availability within the liver. ofoleic acid. predominantly incorporated into rriacylglyceruls. might limitthe triacylglycerol production in SF-fed rats.ILipids 31. 871-878 (1996)]

Salivary Lipid Profiles of the Leech (Hirudo medieinolis), Joseph L. Ra-binowitz, The Veterans Administration Hospital, and the Department ofBiochemistry School of Dental Medicine. University of Pennsylvania.Philadelphia. Pennsylvania 19104.

Saliva was collected from sixteen leeches (Hirudo medicinlllis). Thesaliva was analyzed for its total lipid content (3.26 :t 0.31 mg of totallipids per 100 mL saliva). The lipids were separated into polar and nonpo-lar by chromatographic techniques. The neutral fraction was approximate-ly 213 of the total, and the polar fraction was appro)(imately 1f3 of thetotal lipids. Thin-layer chromatography was used to obtain the individualprofiles of the polar and nonpolar lipids. Of the identified lipids, phospha-tidic acids and free Iauy acids represented the largest percentage. Theseresults suggest thai the leech contains a unique lipid distribution. and thatsome of these components may be potent phospholipases and hpases thatprobably are present in its saliva for the purpose of preventing plugging (1Thealing of the wound in the attacked organism.ILipids 3/. 887---sB8 (19%)]

Effect of a Synthetic Androgen on Biliary Lipid Secretion In the Fe-male Hamster. Akira Ohshima. Bertram I. Cohen. Nariman Ayyad. andErwin H. Mosbach. Depanment.s of Surgery, Beth Israel Medical Center,New York. New York and the Alben Einstein Coll~g~ of M~dicine. TheBronx, New York.

This study was designed to elucidate the effect of the synthetic andro-gen. methyltestosterone, on bile flow and biliary lipid secretion in femalehamsters. Animals were divided into four groups and fed the followingdiets: group I. lithogenic diet for three weeks; group 2, lithogenic diet +0.05% methyltestosterone for three weeks: group 3. lithogenic diet f(1Tsi~ weeks: group 4. lithogenic diet + 0.05% methyltestosterone for six

AOCS MissIon StalementTo be a forum for the exchange of ideas. information, and experienceamong those with a professional interest in the science and technology offats, oils, and related substances in ways that promote personal excellenceand provide high standards of quality.

eming Board. This prohibition includes the use of the American OilChemists' Society logo or letterhead when making a statement of a tech-nical or economic nature. Members of the Society, or employees of theSociety, speak only for themselves when giving opinion or making state-ments concerning technical mailers and economic mailers.

Declaration by the Governing Board'The American Oil Chemists' Society is organized for charitable. educa-tionat and scientific purposes. It does not have as its purpose the promo-lion of any product. manufacturers. laboratory or busir\CSs. Members ofthe Society. and employees of the Society. do IlOl and may 001 speak f(1Tor on behalf of the Society without the expressed permission of the Ocv-

Use of AOCS Name and Logo~ ~ Individually or in combination. the design of the name

~ and logo of the American Oil Chemists' Society(AOCS) may IIOt be reproduced or used by any person or organi1.lltionother than the AOCS, its elected and appointed officers. sections. or com_minces, except by special permission of the AOCS Governing Board.

INFORM, VOl. 7, no. 9 (September 1996)