257

ABSTRACTS FROM AOCS JOURNALS

Analysis of s/I-1(3)- and sn·2·Short·Chain Acyl Isomers of Triac)'l-glycerols in Butteroil by' Gas-Liquid Chl"OmalogI'llphy. Asmo Kemp-pineou,. and Paavo KalOb, Departments of °Food Technology, and bAp-plied Chemistry and Microbiology. FIN-00014 University of Helsinki,Finland.

The aim of the study was to determine major triacylglycerols (TG),and sn-I(3) and s/I-2 isomers of butyryl and caproyl TG in bulteroii (80)and intcresterified buneroii (lBO) by gas-liquid chromatography (GLC)and silver ion column chromatography. Altogether, 112 molecular speciesof TG were synthesized by interesteriflcation and their retention indiceswere determined. Molar empirical correction factors for TG were deter-mined using linear calibration. Retention indices showed that sn-I(3) andsn·2 isomers of the TG containing one short-chain acyl (butyrate,caproate) and two long-chain acy1s (lauroate, myristate, palmitate,stearate. and oleate) were separated on a phenyl (65%) methylsilicone col-umn. Tbe difference between retention indices of 1(3}- and 2-short-chainacyl Isomers ranged from 14 to 19, and from 9 to 16 for butyrates andceproates. respectively. The proportion of $n·2 isomers of butyraies aver-aged 1.4%, but only traces of $11-2isomers of ceproates were detected inbuueruil. The ratio nf $11-1(3)- to se-z-bnyrates and caproates in illter-esterified butteroil averaged 2.0: I. The most abundant molecular speciesof mono-short-chain TG in butteroil were BPP + BMS (5.6 mol%). BPO+ BSPo (4.8 mol%), BMP + BLaS (3.4 mol%), BMO + BPPo (2.7mol%). BPS (2.5 mol%), and COPP + CoMS (2.3 mol%).JAOeS 75, 91-100 (1998).

Gas Chromatography-Fourier Transrorm Infrared Spectrometry orFatty Adds: New Agplications with a Direct Deposition Interface. E.S~mono,*, S. Ferllf)' ,J. Augert>, and J.L. Le Qu~r&. °Labomtoire deRecherches sur res Aremes. INRA. 21034 Dtjon-Cedex. France. andblBEAS URA CNRS 1298 and SAVIT, Universittl; F. Rabelals, 37200Tours, France.

Infrared spectroscopy is a suitable spectroscopic method to differen-tiate geometric Z and E isomers of unsaturated compounds. A direct-deposition Fourier transform infrared spectrometer (FTIR), coupled to agas chromatograph. was used successfully to analyze with a high sensitiv-ity traces of CI g: I fatty acid methyl ester (FAME) isomers. It could alsoconclusively distinguish between isomers of conjugated diunsaturaredFAME. The achievable sensitivity of this direct-deposition device makespossible accurate FAME mixture analyses that are not currently attainablewith the l1lOI"C conventional light-pipe interface.JAOeS 75, 101-105 (1998).

Determinallon or Sterols, Oxysterots, and Fatty Acids or Phospho-lipids in Cells and Lipo~roteins: A One-Sample Method, D, Blache",·,P. Durand'", F. Girodon , L. Gesqulere". and N. Loreau«. °INSERMU498, Laboratcire de Biocbimie des Lipoproreines. Faculttl; de M6:lecine,Universiltl; de Bourgogne, Dijon. France. and bt..aboratoire d'Hematolo-gie, Centre Hospilalier Regional Universitaire, Dijon, France.

In addition 10 fatly acids. especially polyunsaturated species,cholesterol oxidizes and leads 10 various oxygenated derivatives. namedoxvsrerols. They display a wide range of adverse hiological properties.Monitoring oxysterols is important in the evaluation of the potentialrisks associated with lipid oxidation. In the present study, a quick. andreliable method was developed for analysis of oxysterols, sterols. andfatty acid composition of phospholipids in the same biological sample.Total lipid extraction was determined after addition of several internalstandards (epicoprostanol for sterols. 19-hydroxy-cholesterol for oays-terol and di-heptadecanoyl-phosphatidylcholine for phospholipid fattyacids). Cold acetone-mediated precipitation was then used to fraction-ate sterols from phospholipids. The phospholipid-containing precipitatewas «ansmethytared for fauy acid analysis by gas chromatography, Thesterol- and cxysterol-comainlng phase was saponified under mild con-ditions to avoid anificial oxysrerot generation and was analyzed by gaschromalOgraphy after dcrivatiution into Irimethylsilyl ethers. The

overall procedure was found to be specific with good recovery andreproducibility for sterols, oxysrerots [mean coefficient of variation inpercent (CV), 1l.3%j as well as phospholipid fatty acids (CV. 5.6%).This procedure has been used to document in vitro free radical treated-human low-density lipoproteins and erythrocytes. Results demonstratedIhal this method is a useful tool in assessing qualitative and quantitativedifferences in oxysterots and phospholipid fatty acid patterns attributedto lipid oxidation.JAOCS 75.101-113 (1998).

Determlnatjen of Low trans Levels in Refined Oils by Fourier Trans-form Inrrared Spectroscopy. W. De GreytO,*, A. Kim". M. Kellensb.and A, Huyghebaen", °Depanment of Food Technology and Nutrition,University of Gbent, Belgium. and e», Smet Group N,V .. B-2650Edegem. Belgium.

A Nicolet 410 Fourier (FTIR) spectrophotometer. equipped with aDGTS detector and a sample cell with NaCI windows (nominal pathtength= 50 pm), was used for the development of an FTIR method for routineanalysis of low IrOll5 levels in physically refined oils. The approach of thestudy differed from those previously described in that a separate calibra-tion curve was established for each t~ of oil. Quantitation was estab-lished by use of Basic Quant Software and by measuring the peak heightat 967 cm-I relative to a baseline drawn between 1002 and 932 cm-I.TIle slope of the different calibration curves established in six vegetableoils (soybean, com. sunflower, high-oleic sunflower, low-erucic rapeseed,and high-erucic rapeseed) was close to I (0.9942-1.0041), and correlationcoefficients (,2) were rather good (0.9990--0.9999). FTlR spectra of 20soybean oil samples were collected and quantitated with the different cali-brations. Compared to previous reported literature data, increased accura-cy (mean difference = 0.05%; standard deviation of difference = 0.11%)and reproducibility (,2 = 0.09-0.12%) were obtained when the FfIRspectra were quantitated with a calibration curve based on 10 physicallyrefined soybean oil samples.JAoeS75.115-1I8(l998).

Applicalions of Chromatographic Techniques 10 Evaluate EnzymaticHydrolysis of Oxidiud and Polymeric Triglycerldes by PancreaticLipase in wro, G. M!rquez-Ruiz*. G. Guevel. and M.C. Dobarganes.InstirulO de la Grasa (CSIC). 41012 Sevilla. Spain.

With the aim of studying the suscepdbilhy to enzymatic hydrolysisof oxidized and polymeric triglycerides (TO) that are formed during fry-ing. various chromatographic techniques were applied in combination,l.e., adsorption chromatography. high-performance size-exclusion chro-matography (HPSEC). and thin-layer chromatography-flame ionizationdetection (TLC-RD), Polar fractions. isolated by adsorption chromatog-raphy from theemoxidized trilinolein as model system. and real used fry-ing fats and oils. were analyzed by HPSEC before and after incubationwith pancreatic lipase in viuo. Also. the influence of degradation level ofused frying oils on hydrolysis of intact TG was investigated with the addi-tional aid of TI..C-RD. Results showed the high hydrolysis rate of oxi-dized TG monomers in contrast to the significant discrimination of pan-creatic lipase against TG dlmers and, particularly, TG polymers. On theother hand. hydrolysis of intact TG CHn be affected by the presence ofdimers and polymers in abused frying oils.JAOeS 75. 119-126 (1998).

Application of Headspace Analysis 10 the Study or Aroma Com-pounds-Lipids Interactions. C. Druauxo, M, Le Thanhb, A.-M, Seu-vreol,c. and A. Voilieyo -", °Lah. G.P.A.B .• ENSBANA, Universite deBourgogne. F-21000 Dijon, France. bDl!partement de Technologie Ali-mentaire. Institut National Poly technique de Hanoi. Hanoi. Vietnam, andcl.U.T .. Biologie Appliquee. F-2100 Dijon. France.

Taking into account interactions between aroma compounds andfood components is necessary to better manage the navoring or food prod-ucts. These interactions occur at a molecular level and reflect changes. ata macroscopic level. in thermodynamic equilibria. such as solubility orvolatility. The rate of transfer of an aroma compound from the liquid tothe vapor phase can be affected as well. The behavior of aroma com-pounds in water and lipid solutions was studied in two complementaryways, a thermodynamic and a kinetic approach (headspace analysis). 'TheIJ1UIsferrete of volatiles al the liquid-waler interface does not only dependon the hydrophobicity of the aroma compounds. Vapor-liquid panition

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Sacchl, ltnlc Gludicianni, and Santiago Aubourg. lnstituro de Investiga-ciones Marinas del CSIC. E-36208 vlgc. Spain.

I3C Nuclear magnetic resonance spectroscopy has been applied toelucidate the mechanism of lipid oxidation occurring during thennaI treat-ment of fish. EffectS of temperature and lime of processing have beenstudied by means of • model system of lipids, e.ltJ'acled from salmon(Salmo sa/ar) muscle, to simulate industrial conditions of canning. Unsal-urared fatty acids located alIne sII·2 position of the glycerol moiety werethe most prone 10 oxidative damage. Regarding the mechanism of thereaction. results inferred from olefinic and melhylenic resonances indicat-ed a higher susceptibility of the allylic sites dosest 10 the carbonyl group.followed by those placed ncar the methyl terminal group. Unsaturationslocated in the middle of the carbon chain did IJ()( ~ much damage. Theglyceryl rqion provided an unu5IIa! resonance at 53.4 ppm. whkh couldbe assigned 10. hydroxylic compoond formed during process.JAOeS 75,147-154 (1998).

ABSTRACTS FROM AOCS JOURNALS

IlI1dactivity coefficients show the presence of solute-solvent interactions.The Gibbs free energy values indicate their physicochemical nature.JAOCS 75.121-130(1998).

Interference of 7·Deh)"droc:holesttrolln a·Tocopheroi Dtoluminatiooby Hiab·Perfonn.nce LlquMtChromatography: A Possible ScreeningT~I for the Smilh·Lemli·Opila Syndrome, F. Michela, J.P. Crislola,M.H. vemetl', c. Feine,D, M.-A. Carbonneaua, C.L. UgerD. J. Casldb,and B. I)eSCQmpso"", lILabonlioirc de Biologic 1'1Biochimie des Upides,Facuh~ de Mfdceine, and Dt..aboralOirc de Biochimie A. Hopital Lapey-ronie, Av. G. Giraud. 34000 Monlpcllier. France.

'·Dehydrocholesterol (7-DHe). a normal cholesterol precursor,accumulates in plasma and tissues of patients affected by the Smith-Lemli-Opitz (SLO) syndrome, II recessive autosomic disease character-ized by mental retardation and physical malformations. In thesepatients, we suspected that 7-DHC interfered with u-toccpherol «(l-ndetermination because this steroid could be coetoted with u-rocopherotacetate (a-TA), an internal standard commonly used for a- T determina-tion, and because the conjugated dienic structure of 7-DHC stronSlyabsorbs al 292 nm. The lim of this work was (i) to characterize !beinterfering material and (ii) to evaluate the possibility of a rapid screen-ing test for SLO syndrome identificalion from 7-DHC determination byreverse-phase chromatography high-performance liquid chromatogra-phy (HPLC). Human plasmas (control and SLO syndrome) wereextracted with hexane alter ethanol protein precipitation and addition ofascorbic acid lIS protective agent plus (l-TA or S-tocopherol (6-n asinternal standards. The dry hexane extract was used for HPLC. andtrimethylsilyl ethen derivatives of the extracts were submitted to gaschromatography (GC) and gas chromatography-mass spectrometry(GC-MS). The material interfering in the a- T determination was unam-biguously identified to 7·DHC by retention time (R1) relative 10 stan-dard, RT relative to 6-T. and analysis of the eluted material by GC andby GC-MS. In n-T determination. the interference can be eliminatedby using S-T as internal standard instead of a-TA. Rapid detection andevaluation of 7-DHC in plasma appear to be possible by HPLC underthe conditions described: comparison with the GC reference metbodsuggests that the rapid HPLC determination of 7-DHC in plasma can beused within the 1-40 mgldL range. values commonly found in SLOsyndrome.JAOeS 75,131-135 (1998).

Identification or Conjugated Fally Acids by GasChromatography-Mus Spectrometry or 4-Metbyl-I,2,4-trillollne-3,5·dione Adduct.'J, Oary Dobson. Scottish Crop Research Institute,lnvergowrie. Dundee. Scotland, United Kingdom, DD2 5DA.

4·Methyl·l ,2,4·triu;0Iine-35-dione was reacted with conjugatedfallY acid methyl esters co form Diels-Alder cycloaddition products. Theelectron impact muss spectra of conjugated octadecadienoates and9, 11,l3-octadecatrienoate were simple and informative and allowed thepositions of the double bonds to be determined. The dieoes gave singleadducts whereas the mere formed four products that corresponded to twostereclscmers of the adducts of the 9.II-diene system and two of theI I, 13-dieoe system. The method can be used to complement other meth-ods for identifying conjugated fany acids.JAOeS 75, 137-142 (1998).

Content of trGns·Fally Acids In Edible Margarioes, R. 't'senev-, A.Russeva, T. Riwv, and rv. Dontcheva. National Center of Hygiene. Medi-cal Ecology and Nutrition. 1431 Sofia. Bulgaria.

Fatty acid composition, including tnvu-isorncrs. was determined forfour types of imported margarines consumed by the Bulgarian population.The results were compared with data obtained from a Bulgarian ediblemnrgarine produced under Oerman license. Fatty acid composition andtrails-isomer content were determined by gas chromatography of fanyacid methyl esrers on a packed and capillary column. respectively. Theloul contents of tralll'!somer:s of oleic and linoleic acid were within theranges of 1.9-8.09l> and 0.4-1.4%, respec.:tively. 1be Bulgarian margarinecontained $imi1ar quantitia or IIWIS-isomc:n..JAOCS 7J. 143-145 (1998).

Oxidation in Fish LJplds During Thennal Stress as Studied by IJCNucJCllr MagMtic Resonance SpectfQSCOpy, Isabel Medina·, Raffaele

The Presence or O.ldl"t!na Enzyme ActivitIes In Vlrgio Olive 011,M.D. GeorgaIati, T.G. Sotiroudis·, and A.. Xenakis.lndu.'ilrial Enzymolo-gy Unit, Insnnne of Biological Research and Biotechnology. The NationalHellenic: Rescan:::b Foundation. Athens 11635. creece.

Samples of Greek virgin olive oils were examined for the presenceof proteins and oxidative enzyme activities. All oil samples tested COD-

rained detectable amounts of protein, as well as lipoxygenase andpolyphcnol oxidase activities. Sodium dodecyl sulfate--polyac:rylamide gelelectrophoresis and size-exclusion chromatography of olive oil extnclJrevealed the presence of low·molecular-mass (I{}-40 kDa) silver-stainingand ultraviolet-absorbing components. respectively. Both Iipoxygeo.aseand polyphenol oxidase catalytk activities were heat- and pnxease-sensi-tive, and they upressed Michaelis-Menten kinetiC$.JAOCS 75, 15S-159 (l99g).

Effect or Oil Replenishment During Deep-Fat Frying or Frozen Foodsin Sunnower Oll and HIllh·Olel( Acld SunOower OilL AntonioRomercP, Carmen Cuesta'l,·, and Francisco J. S!ncbez-Muniz". °lnstitu_to de Nutricit'in y Bromatologra (CSIC-UCM). and bDepartarnento deNutricilNt y Bromatologra I (Nutricit'in), Scccit'in Lfpidos, Faculiad de Far-macia, Universidad Complutense. £-28040 Madrid. Spain.

Frying stability of sunflower oil (SO) with 23% oleic acid and 61 %linoleic acid, and of high-oleic acid sunflower oil (HOSO) with 74% oleicacid and 13% linoleic acid was studied during 20 discontinuous deep-fatfryings of various frozen foods. with or without frequent replenishment ofthe used oil with fresh oil. Altel'1ltions of both oils were measured by col-umn, gu-liquid and high-performance size-exclusion chromatography.Total polar content and compounds. related 10 thermoxidauve changes.and diacylglycerides. related to hydrolytic changes, increased in all oilsduring frying but reached higher levels in SO than in HOSO. Neverthe-less, the increased levels of dlacylglycerioes observed may result from thefrozen potatoes prefrted in palm oil. Oleic acid in HOSO and linoleic acidin SO significantly decreased. but the fally acid modifications thDtoccurred during the repeated fryings .....ere not only related to thermo~ida·uve alterotion but also to interactions between the bath oil and the fat inthe fried products. Data from this study also indicated thai HOSO per-formed more satisfactorily than SO in repeated fryings of frozen foods.Moreover, frequent addition of fresh oil throughout the deep-frying pro-cess minimized thermcxldatlve and hydrolytic changes in the frying oilsand extended the frying life of the oils.JAOCS 75,161-167 (1998).

Antloddant Properties of MyricetJn and QuertttJo In Oil and Emul.slons, Andrea Roedig-Penman and Michael H. Gordon·. Hugh SinclairUnit of Human Nutrition. Depanment of Food Science and Technology,The University of Reading, Whiteknights, Reading. R06 6AP. UnitedKingdom.

The effect of queKetin and myricetin on the stability of sunfloweroil and oil·in·water emulsions was studied by storage experiments mooi-tored by measurement or pcro~ide values, conjugaled dienes. andbcadspace volatile analysis. Myricetin showed strong antioxidant activityin oils stored at 60 or we and in oil-in-water emulsions stored al we.whether tocopherols or citric acid were present or not; however. quercetinshowed similar antioxjdant ectivky in stripped sunflower oil but no activi-ty in oils that contained tocopherols and citric acid. This showed that

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259

myricetin is effective owing to strong radical scavenging and metal-chelatieg properties, whereas quercetin has weaker radical scavengingectivhy, although it is also ecnve by metal-cbetatlon. The effects of copperand iron salts on the antio~idunlllClivily of myriceun and quercetin werestudied in sunflower oil and oil-In-water emulsions. Quercetin andmyncetin enhanced the prooxidant effect of cupric chloride in oil-in-wateremulsions (pH 7.4), but this effect was IIOlobserved with cupric stearate.11le addition of myricedn 10 emulsions that contained ferric chloride atpH 5.4 also produced a strong prooxidanl effect, and small prooxidanteffects of flavonols were also IkIeCted in the: peeseece of cupric chlorideunder these conditions. However. myricedn and quercetin reduced theprooxidanl effect of ferric palmitate in oils. Myricetin abo showed astrong antioxidant effect in oil that contained cupric stearate, althoughquercetin had no significant effect on the oxidative stability of this system.It therefore appean that Ilavcnols rnay exert a proo:l:idant effect in thepresence of metal salts, but the nature of the metal salt is important indetermining .....hether I prooxidant effect occurs,JAOCS75,169-18O(l998),

Antio:l:idants rrom a Heated Histidine-Glucose Model System, I:Investigation or the Antio:l:idant Role or Histidine and Isolation orAntlO:l:idanl$ by Hlgh-Perfarmance Liquid Chromatography, P.BCI'5uder"'. M. Hole. and G. Smith, The University of Lincolnshire andHumberside, Food RC5ClII'ChCenIJ'C.. Grimsby DN34 5AA. Uni~ King·-.The ndical-combining activity of Maillard reaction products[MRP(aq)]' produced by heating o-gjuccse and L-hiSlidillC (3:1) in a 0.1M pllosphate buffer for 10 h at 105"C (final pH 6.53). was estimateddirectly by means of a diphenylpicrylhydrazyl radical (DPPH") method.Additionaliy, the indirect methods of peroxide values changes (oven test),hexanal formation. and proIcctiOf1 factOl"!l(Rancimat method) were deter-mined on a lipid model syMem that consisted of sunflower seed oiVwater(1:2). emulsified with 3'l! (w/w) Tween 40. Results from the DPPH"method showed a potential antioxidant activity of MRP(lIII)' which wascon finned by the indirect methods. Surprisingly, histidine in solutionalone (beated 01" not) exhibited an antioxidant activity greater than 01" simi-lar 10 the MRP( ) aclivity in the indirect methods with the lipid modelsystem, in contra'3 10 the results from the DPPH' method. The suitabilityof various solvents for extraction of potential antioxidant compounds fromfreeze-dried MRP(aQl was examined. and ethanol extracts showed thegreatCSt activity by tlie DPPH' method. Consequently. the ethanol extnlCtof freeu-dried MRP(aq) was separated by means of preparative reverse-phase high-performance liquid chromatography (HPLC) with a 0.05 Mphosphate buffer (pH 4.4)1waterfacetoniuile gradient system. The antioxi-dant activity of the eluate was measured through the OPPH' method. anda fraction (Fraction A) with antiradical activity was further purified bypreparative HPLC. Fraction B was collected, lind its freeze-dried residueexhibited potent antiradical activity. significantly greater than that of thesame level of a-propyl gallate.JItOCS 75. 181-187 (1998).

Use or a-Tocopherol Acetate to Improve Fresh Pig Meat Quality orFull·Fat Rapeseed-Fed Pigs, G.E. Onibia.b. J.R. Scaif&·. L Murrayb.and V.R. Fowlerh. aDepanment of Agriculture. University of Aberdeen.and bScOllish Agricultural College, Aberdeen, AB24 SUA, Scotland.

Thirty-two pigs were allocated to one of four diets. FFRDO andFFRD200. containing ruu-ret rapeseed (FFR), 150 glkg 125-50 kghveweight (LW»). and 250 glkg (50-90 kg LW), or COO and C0200, con-tainins equivalent quantities of rapeseed meal and 34 glkg (25-50 kg LW)01" 59.2 gf1:g (50-90 kg LW) coconut oil and lard (0.5:0.5. w/w). DietsFFRD200 and CD200 were supplemented with 200 mgf1:g a-tocopherolacetate (ATA). ATA supplementation significantly (P < 0.(01) reducedmuscle drip loss. The melting point (OC) of subcuianeoos fat was signifi-cantly lowered by FFR (P < 0.(01) but increased by ATA supplementation(P < 0.05). Tissue n-teccpberol (An concentrations were significantlyincreased by ATA supplementation. lmrgi.rsimu.r dorsi AT coocentraUOf1was positively correlated with AT coocentnltion in subcutaneous fat (r '"0.86) and in plasma at 35 (r. 0.6S) and 77 (r '" O.SS) days of feeding (P <0.(01). ln both l... dQrsi and subcutaneous adipose tissue lipids. FFRDcaused a signiflCllllt (P < 0.001) decrease: in the ratio of n-6 to n-3 fattyacids and a significant (P < 0.001) increase in the flllio of polyunsammtedto saturated fatty acids. AT lupplementation 5ignificamly reduced the sus-

ceptibility of l... dorsi and subcutaneous flit to lipid oxidation during stor-age at 4"C for up to 16 d. For all dietllry treatments and storage times.lipid oxidation [mg malcndialdehyde (MDA)fIi:g muscle) was greater inthe surface layer (0-2.5 mm) of L dorsi than below the surface (2.5-5mm). Oxidative stability of L dorsi lipids to iron-induced lipid peroxida-tion was significantly improved (P < 0.00]) by AT supplementation. Meatfrom pigs fed FFRD diets was significantly less stable 10 iron-inducedoUdatioo (emotes MDAfmg prcMein) at the 1000gerincubation periods (100and 200 min). The susceptibility of l... dorsi to iron-induced lipid o:l:ida-tion decrea.sed as the ratio of the tissue concenuatioo of AT 10 unsaturatedfany acid increased.JAOCS 75. 189-198 (1998).

Free Radicals. Oxidati\'e Stress, and Antioxidants in Human Healthand Disease. Okel.ie I. Arooma, OICA International, SainI Lucia, WestIndies. and Pharmacology Group, King's College London. London SW36LX_ Great Britain.

Free radicals and other reactive oxygen species (ROS) are constantlyformed in the human body. Free-radical mechanisms have been implicatedin the pathology of several human diseases, including cancer, atheroscle-rosis, malaria. and rheumatoid anhritis and neurodegenerarive diseases.FQr example. the superoxide radical (Of) and hydrogen peroxide (H2OVare known to be generated in the bnUn and nervous system in \·i\'O. andsever:al areas of the human bntin are rich in iron. which appears to be easi-ly mobilizable in a fonn that can stimulate free-radical reactions. Antioxi-dant defenses to remove ~- and H2~ exist. Superoxide dismutases(SOD) relTlO\'eOf by greatly accelerating its conversion to H20:z. Cala-lases in peroxisomes convert H20:z into water and O:z and help to disposeof H202 generated by the action of the oxidase enzymes that are locatedin these organelles. Other important H2~-removing enzymes in humancells are the glutathione peroxidases. WJw::nproduced in excess, ROS cancause tissue injury. However. tissue injury can itself cause ROS genet1ltion(e.g .. by causing aclivation of phagocytes or releasing transition metalions from damaged cells), which may (01" may not. depending on the situ-ation) conuibute to a wOTKning of the injury. Assessment of oxidativedamage to biomolecules by means of emerging technologies based onproducts of oxidative damage to DNA (e.g., 8-hydro:l:ydeoxyguanosine).lipids (e.g .• isoprostanes). and proteins (altered amino acids) would notonly advance our understanding of the underlying mechanisms but alsofacilitate supplementation and intervention studies designed and ccoduct-ed to test antioxidant efficacy in human lK:alth and disease.JAOeS 75. 199-212 (1998).

The Tocopherol Pattern In Human Serum Is Markedly lnflueneed byIntake or Vitamin": Drugs-Results of the Gennan National HealthSurveys, H.-U. Melchert· and E. Pabet. Robert Koch-Institute, RKI 623(Bereich Tempelhol). 0-12101 Berlin, Germany.

During national and regional health surveys. done from 1984-1995in Germany. consumption data for all drugs used by theparticipants-c-epproxtmately 18.000 persons-in the last 7 d before theexamination were monitored with a detailed drug-usage questionnaire.The groups examined are representative for the national and regional Ger-man inhabitant population aged 25--69 yr. In serum samples of subsam-pies of the study participants. all tocopherols were measured by isocmtichigh-performance liquid cbromatogrephy (Si 60 column. fluorescencedetection). Consumption data for rocopherol-cornaining drugs showed thatup to 5% of females and up to 3'l! of males of the study population usedthose drugs. During the study period. the serum contenl of a·tocopherol(mean values:t SD) rose from 7.5:t 2.6 mgfL serum to 11.8:t 2.8 mgILserum for nonusen and from 11.9:t 4.3 mgIL serum to 15.3:t 4.9 mgILserum in tocopherol-drug users. Throughout all studies, il could be shownthat ~ and y-tocopherol were heavily reduced in those persons takingdaily doses ~ mg u-tocopherol. The reduction of the two rocopherots isdose-dependent and especially pronounced in females using high-dose a-tocopherol drugs. Owing to the emerging evidence of the physiologicalimportanee oonceming the balance of the different locopherols in biologi-cal systems. the possible bellCfits of using natural tocopherol mixturesfrom plant origin instead of pure RRR'(Hocopherol, gained from perme-thylation procedures. as vitamin supplemml5 in human nuuitiOf1 shouldbe considered.JAOCS 75, 21)-216(1998).

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ABSTRACTS FROM AOCS JOURNALS

A Prelimlnllry Study on Plalelet Aggregation in PostmenopausalWomen Consuming txtn.-Vlrgin Olive Oil and High-Oltic Acid Sun-floln'r OU. FJ. S4nchcz·MunizU··, P. Oubii\all~. BeBedrb. S. R6denasc,and C. Cuesurt. 0Departamento de Nutrici6n. "UepartamcnlO de Farma-cologla, cSea:i6n Departamental de Qufmica Analitica. and dlnstitulo deNutrici6n y Bromatclogta (CSIC·UCM). Pacultad de Fannacia, Universi-dad Complutense. 28040 Madrid, Spain.

'The purpose of the present study was 10 examine the effects of twornonounsalumlcd fatty acid-rk:b oils, extra-virgin olive oil (EVOO) andhigh-oleic sunflower oil (HOSO). on platelet aggregation in 14 post-menopausal women (aged 62.9:1: 1.8 yr) with high-fal. dietary habilS. Bothoils contained olek: acid as the major compound (.. 76"l! of total fattyacids). bullhe oonlenl ofp.almitic and linoleic acids and many minor com-pounds was significantly different. 1bese oils were used as the only culi-nary fats during two 28-d periods. and represented -62% of the tOOlllipidintake (..46% of total energy consumption). Other dietary componentswere matched. The daily energy conlrib.llion of saturated. monounsaturnt·ed. and polyull$8tUnited fatty acids to the total enetgy consumption was11.8. 28.5. and 2.8%. respectively. during the EVOO dietary period and10.3.21.8, and 4.6%. respectively. wilb HOSO. Aggtqtation in platelet·rich pluma was meuu~ .fier addition of ADP. Platelet aggregation(expressed as cm15 min) was significantly lower after the EVOO dier thanafter HOSO (2.1 :t 1.1 and 3.0:1: 1.4. respectively: P < O.OS). Althoughmaximalaggregalion time was 40.2% higher in HOSO than in EVOO, thedifference was not significant. Independent of serum cbclesteml level.platelet aggregation teOOed to be different on the EVOO diet when womenwere c1as.sified according to cholesterol level$: <220 mgldL or ;a20mgldL. Resull5 suggest that other compounds present in the oils asidefrom the fauy acids may play an imponant role in modulating plateletag.gn:gation in these postmenopausal women.JAOCS 75, 211-223 (1998).

Influence of Modfrate Amountll of Irons Fatty Acids on the Fonna-lion of PolyuMliturated Fatly Adds, Anette Bysted". Gunhild Holmer.and Pia lAInd, Department of Biochemistry and Nutrition. The TechnicalUniversity of Denmark. DK-2800 Lyngby. Copenhagen. Denmark.

The effect of Irons fatty acids from partially hydrogenated soybeanoil and buuerfat on the formation of polyunsaturnted fally acids was inves-tigated. Five groups of rats were fed diets that contained 20 wt% fat. Thecontent of linoleic acid was adjusted to 10 wt% of the dietary fats in alldiets. whereas the amount of Irons fally acids from partially hydrogenatedsoybean oil (PHSBO) was varied from 4.5 to 15 wt% in three of the fivediets. The fourth group received Irons fatty acids from butterfat (BF).while the control group was fed palm oil without /r.:lns fauy acids. Tronsfatty acids in the diet were proportionally reflected in nit liver and heartpbospbaudylethanolamine (PE). phosphatidylcholine (PC), phosphatidyl-inositol. and phcsphatldylserine. Incorporation in the sn-I position wascompensated by a decrease in saturated fatty acids. Trans fatty acids werenot detected in diphospheudylgjycerol. Compared to the presence in thedietary fats, 81- and 101-18: I were discriminated against in the incorpora-tion in PE and PC from liver and heart, whereas 9/- and 121-18:1 werepreferred. The f()fffill.tion of 20:4n-6 was not influenced by 4.5 wt% Ironsfally acids (from PHSBO) oot apparently was by 10 WI'l> in liver. In con-trast. even a content of 2.5 wt'l> lrans fany acids from BF reduced the for-mation of 20:4n-6. The inhibitOl)' effect of Irans isomers on linoleic acidconversion was reffected less in heart than in liver and less for PE than forPC. Groups with lrans fatty acids showed increased 22:6n-J and 22:5n-3deposition in liver and heart PE and PC.JAOeS 75. 22S-234 (1998).

Impronrm:nt In the Antioxidant Status of Plasma and Low-DensityLipoprotein In Subjects Receiving a Red wjne Pbt'nolia MiIturt'.Marie·Annette Carbonneau<l. Claude L. Uger.:lo·. Bernard Descomp5<l.Francoise Michel.:l. and Louis Monnierb. °Laboratoire de Biologie etBiechimie des Lipldes. Insthut de Biologie. UFR de M4!decine. 34060Montpellter, Frunce. and Laboratoire ees Maladies M~l.Dboliques. HOpilDlLapeyronie. 34295 MOllIpellit'r cedex 9. France.

II is commonly BCCt'"pIed that ollidittd low--density li]lO\Jl1J'l"in(Oll-LOL) plays an importanl role in coronary hean disease (CHO) and etio-logically related atherogenesis. Consump:ion of wine may coecibcre 10the low risk ofCHD in the Mediterranean populatioo.1bese findings raisethe question of the in viI'Q antiOllidanl role of wine phenolic compounds

after a prolonged supplementation period in healthy human volunteers.We found that subjects. receiving 2 gld of an alcohol-free red wine-extracted phenolic compound (RWPC) mixture for 14 d (which wasequivalent to about I Ud of the red wine). exhibited an increase in theplasma antioxidative capacity and in LOL vitamin E by blood samplingunder fasting conditions. The fact that the LDL eu2+ -oxidizability wasnot decreased can be explained by both the lack of phenolic compoundaffinity for the lipoprotein panicle, highlighted by LDL dialysis. and theinsufficient increase in LDL vitamin E. as shown by the relationshipbetween vitamin E content and oxidaLion resistance of LDL evidenced byliterature data. These results support that RWPC could playa coantiolli-ciani role. similar 10 that of vitamin C. possibly ICOOUnting for their LDLvitamin E sparing effect and their beneficial role in lowering CHD riSQ.JAOCS 75. 235-240 (199S).

Dietary Fish on Inhibits t>fi·Desaturase Activity in vivo. AmiramRu.:!'·. Nerit Kamin.Belsky'l. Fiorenza Przedeck;<l, and Mark Obukow-iczb. aDepartment of Biochemistry. George S. Wise Faculty of Life Sci-ences. Tel-Aviv Univcnity. Tel-Aviv 69978. Isnel. and ~ Phar-macology. G.D. Searle, SI. Louis. Missouri 6319S.

Liver 6.6-desaturase aclivity was determined in mice which weremade deficient in (i) n-6 and n-3 polyunseturated fany acids (PUFA). (ii)n-6 PUFA, 01' (iii) arachidonic acid (AA). Initially, the mice were subject-ed to two cycles of a fasting (I dV~feeding (2-3 d) protocol in whichthey were refed an essential fally acid-deficient (EFAD) diet during therefeeding period. This l-wk fastinglrefeeding protocol. referred 10 as FIREFAD. produced a rapid and 5uMWlIiai decline in tissue n-3 and n-6PUFA and a com:spondins increase in n-9 fatty acids. notably oleic acidand Mead acid (20:3n-9). Combined liver 6.6-desalliraselelongaselM-desaturue activities in vtvo were quantified by measuring the conversionof 14C.linoleic acid (LA) to 14C_AA in mouse liver. Although FIR EFADcaused, as expected. a substantial decline in liver AA and LA content, theconversion of 14c_LA to 14C_AA was the same in these mice as in chow-fed controls (approdmately 33-34%). Subseqcera refeeding of FIR EFADmice with an EFAD dtet. supplemented whh com oil. ~ored tissue n-6PUFA levels without altering the conversion of 14C_LA 10 14c_AA. Incontrnsl. refeedinl, with an EFAD diet. supplemented with fish oil. inhibit-ed 14C_LA to I C-AA conversion by 78%. Significantly. inhibition ofconversion of 14C_LA to 14C.AA was maintained in FIR EFAD mice thatwere subsequently fed an EFAD diet supplemented with a 1:1 mixture offish oiVcorn oil. This latter protocol yielded a unique liver fany acid com-position in which AA was selectively depleted. whereas LA and the n·3PUFA were increased. The data suggest that dieUll)' n-J C2o-22 PUFAnegatively regulate !he in 1';1'0 synthesis of n-6 PUFA at the level of these-oeseturase.JAOCS 75. 241-245 (1998).

Long-Chain Polyunsaturated Falty Acids Influence Both 13- lind cr.-Adrenergic Functlnn of Rat Cardiomyocytes. B. Ponsard<l. I. Durotil,A. Fournier', F. OUdotb• P. Athiastl,., and A. Grynbeti', lILabonitoire dePhysiopathologie er Pbarmacclogie Cardiovasculaires Experimentales,Facu1t4!de M4!decine. 21033 Dijon. Fnll1CC.and bI.N.R.A .. Unit4! de Nutri-tion Lipidique. Dijon. France.

Dietary polyunsaturated Ieuy acids (PUFA) have been reported tolower the incidence of cardiovascular diseases. but neither the mecha-nisms that determine these protective effects nor the specific influence ofn-3 YS. n-6 PUFA series has been well established. The purpose of thiswork was 10 demonstrate the influence of the membrane long-chain fattyacid composition on the spontaneous contractile activity and the adrener-gic fUlICtion ofral cardiomyocytes in culture. Cells were grown fOl'24 h in• standard culture medium and then foc 4 d in media that conlDined eithern-3 (eirosapentaenoic acid and docosahexaennK: acid) or n-6 (arachidonicacid) PUFA. The n-61n-3 nltio was 1.2 in n-J cells compared with 20.1 inn-6 cells. The basal contracdle properties of these cardiomyocytes werenOI affected by the PUFA phospholipid composition. However. thesemodifications influeeced the adrenoceptor funclion because the IJ-adren-ergic stimulation by isoproterenol (10-1 M) induced a positivechronotropic response thai was 5igniflClJltly greater in n-] cells. More-over, the c~ response 10 a-adrenoceptor stimulation by phenyl-ephrine (10--6 M) appeared significantly ~ pronounced in the n-3 cellsthan in the n-6 cells. However. the parameters related 10 the inotropicresponse induced by these agonislS did not differ significantly between the

INFORM. VOl. 9, no. 3 (March 1998)

two groups of cells. These results 5Uggested that the membrane long-chainPUFA composition does IJ()( influence the basal cardiac contnlCtility andautomaticity but is able to modulate the chronolropic function of bod! a-and ji.-adreOOCC'plOfS.JAOCS15. 247-254 (1998).

Peroxisomal Metabolism or Adrenle Acid; No;W Desaturasc Detectedin Rat LiVC'r Perexlsomes. T.S. Ha'!Benll. V. Mimoonib• J.1. Pedersena,HJ. GravD. and E.N. Christiansenll. , alnstitute for Nutrition Research,University of Oslo, Oslo. Norway, and bIUT Biologie Appliqufe. Univer-silt du Maine. Laval, Fnux:e.

The existence of a peroxisomal 44 desaturation of 22:4n-6 and22:5n-3 to yjcld. respectively. 22:5n-6 and 22:6n-3 has been questioned.An alternative pathway has been formulated to include microsomal chainelongation and 66 desaturation a.nd peroxisomal chain shortening. Weincubated (I.l4C]adfenic acid (22:4n-6) in a system for desaturation (i.e"in the presence of NADH) with purified rat liver peroxiscmes. The fatlyacids were separated as methyl derivatives by bigh-performance liquidchromatography. Four ultraviolet-absorbing product peaks appeared. threeof which contained radioactivity. which we investigated as methyl.trimelbylsilyl. and oXllOline derivative$ on gas chromatography-massspectrometry, In addition 10 adn:nic and arachidonic acids. the productpeaks were Imns-eooyl. hydroxy. and keto derivatives of adrenic acid: thethree first Steps of f}-oxidation cycle. This indicated that the NAD-depen-dent dehydrogenase step in the peroxisomal IHJxidation cycle of adrenicacid was lnhibned due to a high concentration of added NAOH. Incuba-tion in the presence of NAO instead of NADH reduced radioactivity in thepeaks that corresponded 10 intermediates. while radioactivity in the acid-soluble fraction increased considerably. consistent with a complete f}-oxi-dation cycle of adrenic 10 arachidonic acid. 1beR were 00 indications ofM desaturation in purified peroxisomes incubated in a slllldard desatura-tion system. Instead. adrcnic acid as substrate underwent f}-oxidation.JAOeS 75. 255-259 (1998).

Conjugated Linoleic Acid and OxldaUve Stress. Sebastiano Banni'".Elisabeua AngionL Maria Stefania Comini. Gianfranca Carta. VivianaCasu. Giorgio Amcdeo Iengo, Maria Paola Melis, Monica Deiana, MariaAssunta Dessl, and Francesco P. Corongiu, Dipanimento di BiologiaSperimentale, Sezicee Patologia Sperimcntale. Universita' degli Studi diCagliari. 0904{) Monserrato (Cagliari). Italy.

At the present time. conjugated linoleic acid (CLA) is the subject ofa growing number of studies since it has been demonstrated to possessenucarctnogemc and annmherogenic activities in experimental animalmodels and to increase in some pathological states in humans. In botl1 sit-uations. CLA has been claimed to be involved in oxidative stress. as anantioxidant in the first case and as a primary product of a rree- radicalattack on polyunsaturated fally acids (PUFA) in the otbcT. 'The controver-sial results are due mostly to a lack of a suitable methodology because thepresence of conjugated dienea (CD) in lipid moiety has been taken foryears as evidence of lipid peroxidattcn due to the occurrence of this struc-ture in Iauy acid hydroperoxtdes. We have recently developed a newmethodology that consists of the extraction of fatty acids. including CDfatty acid hydroperoxides. by mild saponification and their separation andidentification by high-performance liquid chromatography with diodearray detector. Fatly acid analyses of liver homogenate. oxidized in \'ilmeither with Fe-ADP or '-butyl hydroperoxide (I-ButyIHP). of lwnb andrats fed CLA at levels known to prevent carcinogenesis. showed that CLAand its metabolites steadily decreased during oxidative stress and that theyarc more prone 10 oxidation than their cOlTC'sponding methylene-interrupt-ed fatty acids. No significant antioxidant effect of CLA was detected inany model tested. However. CD fatty acid hydrcperoxldes increased in theI-ButyIHP model but not in the Fc-ADP model. owing probably to thedegradation of CD fally acid hydroperoxidcs induced by this oxidativeagent. In conclusion. CLA and its metabolites seem 10 behave. UDderoxidative Stress, as regular PUFA. Thus, il is highly unlikely thallhc pecu-liar effects of CLA arc directly related 10 interference in lipopcroxidativeprocesses.JAOCS 75. 261-267 (1998).

Dieta!')' Arachidonic Acid and Hepatic Desaturation of Fally Acids inObese Zucker RalS. Jean Paul Blond". Georges Durandb. and JeanBtzanttI--. IIUnilt de Nutrition Cellulaire et Mttaboliquc. Univcrsiu: de

Bourgogoe, 21011 Oijon Cedex. France. and bLabofatoire de Nutrition erSteurit!! Alimentaire. InstilUt National de la Recherche Agronomique.78352 Jouy en roses, France.

'The effect of low levels of dietary IIl1IChidonic acid (20:4n-6) on 46dcsatunnion of liooleie acid (18:2n-6) and a·lioolenic acid (18:3n-3). andon M desaturation of dihomo-l-lioolenic acid (20:3n-6) wen: studied inliver microsomes of obese Zucker rats. in comparison with their lean lit-termates. Fatty acid composition of serum total lipids and of phospho-lipids from liver microsomes and from total heart and kidney was deter-mined to see whether modifications of desaturation rate. if any, werereflected in the tissue fatty acid profiles. Animals fed fo.- 12 wI!;on a bal-anced diet. containing 2O:4n-6 and 18:211-6. were compared 10 those fed18:2n·6 only. Tbe low amount of dietary 20:40-6 greatly inhibited 46desaturation of 18:211-6and M desaruration of 2O:3n-6. whereas 46 desat-uralion of 18:3n-3 was slightly increased in obese rats. Inhibition of thebiosynthesis of long-chain n-6 fally acids by dietary IIl1IChidonic acid wasonly slightly reflected in the 2O:4n-6 content of llver microsome phospho-lipids. On the contrary. the enrichment of serum total lipids and heart andkidney phospholipids in this fatty acid was pronounced, more in obesethan in lean animals. Our results show that. although the dcsaturation meof the n-6 fatty acids in liver microsomes was greatly decreased by thepresence of arachidonic add in the diet, the tissue phospholipid content inarachidonic acid was not depressed. The potentiality of synthesis ofeicosaooids of the 2 fwnily from this fatty acid is consequently not lower.especially in obese rats. in which certain tissues arc deficient in arachi-donic acid. in comparison with their lean lhtermates.JAOCS 75, 269-274 (1998).

PeroxJsomal Changes During Hibernation of Jerboa (J~Nlus omn·ttllis). M. Kabinel'. M. Cberkaoui-Mallrill. M.-C. CI!!mencctD. M.S. EIK~bbajb. and N. Lalniffell··. aLBMC-Universitf de Bocrgogne. 21011Dijon Cedex. France. and bLBBCM-Universitf Hassan II. Casablanca.Morocco.

As a member of the order of Rodentia, jerboa (Jaculu.r orit!nla/is) isa natural deep hih.crnator and lives in subdesen highland in many parts ofthe world, including Morocco. liS small si:r.e (adult body weigbr -100 g).availability in the wild. tolerance to laboratory conditions, and someunique peroxisomal propenies make it a suitable research subject forexploring peroxisome biogenesis under prehibemating and hibernatingstates. During 3 wk. animals referred to as the prehlbemetor group wereexposed to cold temperature (5 107°C) with food ad libilurn. Pan of theprehibernator group entered deep hibernation 24 to 48 h after starvation.Animals were sacrificed 4 and 6 d after starting hibernation. As 3 control.a third group. consisting of active animals. was maintained at 22°e. Con-cerning hibernation. results from plasma analysis showed an increasedlevel for both ketonemia and ureamia, while triglyceredemia wasdecreased. Liver acyl·CoA oxidase activity. a peroxisomal ~-()xidationenzyme. increased during hlbernatlcn. Liver peroxisomal urate oxidasewas induced only during rhe prehibernaring state and remained at anincreased level until Ihe fourth day of hibernation. The variations wereconcomirara to a decrease in percxlsomal protein yield and 3 differentialchange in peroxisomal protein pattern in sodium dodecyl sulfate-poly-ecrylamide gel electrophoresis during prehibernating ot hih.crnating states.These preliminary results showed that cold exposure and hibernationaffcci biogenesis of liver pero~isomes in jerbna.JAOeS 75. 275-280 (1998).

Isolation of Chemically Induced Mntants in Borage (Baraga affici-nalis L.). A. De Haro-Bnillina .• and M. Del Rioh. alnstituto de Agricul-tura Sosientble (C.S.I.e.). and bCentro de lnvestlgaclon y FormacilinAgraria. 14080 Clirdoba. Spain.

,\,-Linolenic acid (GLA. 18:366.9.12) has been reported to be br:lp-ful in the l!Catmcnt of a wide ran~ of disorders. Borage (Borogo offici-na/is L) is an annual plant of renewed interest because the seeds arc animpoltant source of GLA. The failure 10 l!:tain mature seeds until harvestlimits thc tOIlIIseed and GLA yield per plant and is the major limiting fac-tor for the commercial production of borage. In the course of a mutagene-sis program. an agronomically good line of white-flowered borage (RG-00l) was treated with ethyl methane sulfonate. As a result of this pro-gram. several types of mutanlli were identified in the M2 generation ofplants: I chlorotic mutant (type A); a muUlI1t with increased nwnbr:r ofsepals. petaJs. and ovules hut reduced fcnilily (type B); and mutants with

INFORM, Vol. 9. no. 3 (March 1998)

261

262

ABSTRACTS FROM AOCS JOURNALS

closed flowers (type el) or partially opened flowers (type C2) that hadi~ased seed mention. The type C mutants are the first reported borageplants with a nonshaltering habit. After crossing type B plants with nor-mal plants, a new mutant (type B I) was obtained with higher fertility andhigher seed production per flower than those from normal plants. Thesemutants coold be used 10 develop borage lines that would be superior 10those cum:ntly available as I source ofOLA.jAOCS 75. 281-283 (1998).

Syntbesls and Physicochemical CharacterilaUoll ot Mi:nd macldTriglycerides That Contain E1aldk Acid, P. E1isabeuiniD. G. Logna~_A. Oesmedt'l, C. CUlOla, N. ISlass&. E. Oelfensec, and F. Duran!"'-,°FlICuh6s Universitaires Notre-Dame de la Paix, Laboratoire de ChimieMolttulaire StruclUrale, 8·5000 Namur, Belgium, bfacuh1! Universitairedes Sciences Agronomique5, UER de Chimie CUm!rale et Organique.Oembloox. Belgium. and CFractionnemenl Trrtiaux u....Fleurus, Belgium.

The synthesis of symmefrical and asymmetrical palmho- and stc:aro-elaidk uigiyceridc:s (PEP. SES. EPP. PEE. ESS. and SEE. in .....Itio:h P ::palmitic. S s stearic. and E '"' elaidi<: acid) was undertaken to investigatetheir polymorphism. The chemica] pathways and the purification steps.including ctystalliz.ation and adsorption chromatography. are described.The different chromatognlphic analyses (gas-]iquid chromatogntphy: car-bon number profile and fauy acid methyl ester profile. and high-perfor-mance liquid cltromatogmphy) revealed that the purity of the synthesizedproducts was superior to 99-.. except for SES (>96'9b). The thcnnal behav-ior. 11$ well as the polymorphism of these uiglycerides. has been investi·gated by means of differenti.1 5Canning calorimetry and powder X-nydiffraction specu-oscopy .t variable temperatures. The six compoundsctyswlitc according to I double chainlength packing. TIle most stablepolymorphic fonn of palmito-elaidic triglycerides belongs to the ~' vari-ety, wbereL'! the stearo-elaidic triglycerides are ~ stable,JAOCS 75, 285--291 (1998),

Total Ind Partial Erucate of Pentaerytbritol. Inl'rared Sp«troscopyStudy of RelationshIp Bel .....een Siruclun. RCliclivity. and ThermalProperties, Val&ie Eychenne, UpI'lirin Mouloungui-. and Antoine GI5et.Ecole N.tionale superteure de Chimie de Toulouse, Laboratoire deChimie Agro-industrielle, Unit~ l55OCi~ INRA nO 3]AI010. Toulouse.France.

Esters of neopentylpolyols are an important starting base for syn-thetic lubricants. These bulky esters are generally prepared by an esterifi-cation reaction between a carboltylic acid and a neopentylpolyoL Becauseneopentylpolyols have a number of primary alcohol sites. a variety of per-tial esters is formed before tOlal esters. In the present study, we investigat-ed the reaction between pentaerythrhol and erucic acid. 1be composruoeof the reaction mmure in erucic acid, partial esters, and total esters wasmonitored by thin-layer chromatography, coupled with flame-ionizationdetection. The pure esters and the esters in solution at different concentra-tions in xylene at different temperatures were analyzed by Fourier trans-form infrared spectroscopy. Erucic acld and panial esters in xytene ccexistin the free form and as bound complexes. These findings furthered under-standing of the reactivity and thermal properties of the panial esters,JA.OCS 75, 293-299 (1998).

Pliol 8alch Production or Speclnc-Structured Lipids by Lipase-Cal-alyzed InterHltrilicallon: PrelimInary Study on Incorporation andAcyl Migralion, X. Xu"'-, S. BalchenQ, C.-E. Hllyb, and J. Adler-NissenQ, Departments of UBiotechnology and bBinchcmislry and Nutri-tion, Technical University of Denmark, OK-2800 Lyngby, Denmark.

Effects of water content. reaction time. and their relationships in theproduction of two types of specilic-slnlCrured lipids (slI-MLM- and ,JII-

LML-types: L-Iong chain fally acids; M-medium chain fatty acids) bylipase-c.talyzed interesteriflCation in a solvent-free system were studied.TIle bioca1Dlyst used was Upozyme 1M (COIIIIIICTCialimmobilized lipase).The $ubstrates used for sn-MLM·type were fish oil and capric acid, andmedium chain triacylglycerols and sunflower free fauy acids for sn-LML-type. The observed incorporation with the time course agrees well withthe Michaelis-Menten equation. while the acyl mignuion is proportionalto time within the range of 20 mol'9b acyl nUsr.!tion (MLM-type: Mf::0.222j;T. R2. 0.98: LML-type: MJ: O.}6liT. R2 :: 0.99). As WlII£[ con-tent (wt'9b. 00 the enzyme basis) iiIcrused from 3.0 to l 1.6'l> for MLM-type and from 3.0 to 1.2'l! for LML-type in the solvent-free systems. the

incorporation nileS in the first 5 h increased from 3.34 to 10.3O%/h. andfrom 7.29 to 1l,12~1h, respectively. However, the acyl migration nilesalso increased from 0.22 to 1.12%111and from 0.56 to 1.37%/h. respec-tively, Different effects in the production of two totally position-opposedlipids can be observed. Presumably these II!'e caused by the different chainlength of the fally acids, The relationships between reaction time andwater content are inverse and give a quantitative prediction of incorpora-tion and acyl migration in selected reaction conditions and vice versa. TIleacyl migration can not be totally .voided in present systems, bul can bereduced to a relatively low level. Acyl migration during the downstreamprocessing has also been observed and other facton influencing the acylmigration II!'e briefly discussed.JAOeS 75, 301-308 (1998).

Emcienl Llpast-Catalyud Production of Tallor·Made EmulsiliersU5ing Solvent EngioeerinC Cou~ to ExtJ'Ktlve Proc:emng, CastilloEdmundo, Donat V.I~rie, Combes Didier. and Many Alain'". InstilutNational des Sciences Appliqu~e5, Centre de Bioing~nierie GilbcnDInnd, UMR 5504. LA. INRA. Complexe scientifique de Rangueil. F-3 lOTI Toulouse Cedex 04, France.

Within the framework: of enzymatic biosurfactant synthesis, thedevelopment of reaction processes leading to a selective and efficient pr0-duction is of crucial interest, In this work. we proposed an enzymaticmethod for producing 1(3}-monooleoyl-rw.--glycerol using a commercialimmobilized lipase. the LipozymeCl). To avoid the blockage of the enzymeby the presence of ill501uble glycerol, the latter was adsorbed onto driedsilica gel. The selective ItIO!IOCSICrproduction (83'9b) was obatined using2-methyl-2-butanol amended n-heune (90:10. vol/vol) as reacti.oo medi-um, 1be observed decrease in the substrate conversion, in a medium con-taining 2-methyl-2-butanol. was countered by coopling to the reaction anInline selective recovery method for the produced monoester by ads0rp-tion onto a silica gel column located at the outflow of the reaction vessel,This process leads to an efficient rnoooolcoyl glycerol production with ahigh oleic acid conversion (71%) and to the recovery of a lOO'9bpuremonooleoyl glycerol.JAOCS 75, JC»-313 (1998).

cernnese Eslerincatlon with Fatly Acids and Acetic Anhydride inLithium Chloride/N,N-D1melhylacetamide Medium, C. Vaca-Gan:iaQ,S. Thiebaud", M.E. Borredonll,., and G. Gozzelinob, QENSCT, INPT,Laboratoire de Chimie Agro-lndustriel1e. Unit~ esscctee INRA 31A1010,F-31077 Toulouse Cedex 04, France, and %lite<:nico di 'Iortno, Dip. diScienza dei Materiali e Ina. Chimica. 1-10129 Turin. Itaiy.

Homogeneous esterification of cellulose with saturated fatly acids(n-octanoic to n-octadecanoic) was accomplished with acetic anhydrideco-reactant in lithium chloride/N,N-dimethylacetamide (LiCVDMAc)medium, Cellulose mixed trlesters (CMT) were obtained after 5 h at130°C with an average of 2.2 acetyl groups and 0.8 fauy substituents peranhydroglucose unit. A mixed acetic-fatty anhydride, formed in 5i1U,

accounts for the gmfting of the Iauy moiety. The purified products werecharacterized and compared to the analogous cellulose simple fany tri-esters (CST) that were synthesized from fally acid chlorides in pyridinemedium. Dynamic contact angle with water. glass transition, and storagemoduli were correlated with the length of the fatty substituents. The CMTproved to be highly hydrophobic and more mechanically resistant than theCST,JAOeS 75, 31$-319 (1998).

INFORM. Vol. 9. no. 3 (March 1998)

Arachidonic Acid Supplemenlalion Enhances Synlhesis ofEicosanoids Withoul Suppressing Immune Functions in YoungHealthy Men. Danhan S. KelleyD··. Peler C. Tayi~. Gary 1. Nelsona.and Bruce E. Mack:eyb, United StaleS Department of Agriculture, Agricul-tural Research Service. aWeslern Human Nuuition Research Center, Pre-sidio of San Francisco, California, and Owestern Regional Research Cen-ter, Albany, California.

This study was conducted to determine the effects of arachidonicacid (AA) supplementation on human immune response OR) and on thesecretion of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4). Tenhealthy men (20-38 yr) participated in the study and lived al the Metabol-ic Suite of the Western Human Nuuition Research Center; 11Iey were feda basal diet (57. 27. and 16 energy percentage from carbohydrate. fat, andprotein. respectively, and AA 200 mgld) for the first 15 d of the study.Additional AA (1.5 gld) was added to the diet of six men from day 16to65. while the remaining four subjects remained on the basal diet. Thediets of the two groups were crossed-over from day 66 to liS. In viEr"Q

indices of IR were examined using blood drawn on days 15.58.65. 108,and 115. Influenz.a antibody titers were determined in the sera preparedfrom blood drawn on days 92 and liS (23 d postimmunization). AA sup-plementation caused significant increases in the ill vitro secretion ofLTB4, and PGE2, but it did not alter the in virro secretion of tumor necro-sis factor a; interleukins Iii, 2, 6; and the receptor for imerleukin 2. Nnrdid it change the number of circulating lymphocytes bearing markers forspecific subsets (B. T. helper. suppressor, natural killer) and the serumantibody titers against influenza vaccine. The opposing effects of PGE2and LTB4 may have led to the lack of change in immune functions lested.UpUJs33.125--130(1998).

Effeclll of High[y Purified Eicosapentaenoic Acid and Decusahex-aenofc Acid on Fatly Acid Absorption, Incorporation Into SerumPhospholipids, and Postprandial Triglyceridemia, John-BjarneHansenQ·-. Sameline Grimsgaardb. Hugo Nitsene• Arne Nord0ya. andKaare H. B0naab, QDepartment of Medicine, Institute of Clinical Medicine,bJnstilUle of Community Medicine, University of T~. and <Departmentof Clinical Nutrition, Tromse Uoiversity Hospital. Tromse, Norway.

Fourteen healthy volunteers were randomly allocated to receive 4 ghighly purified ethyl esters of eicosapentaenoic acid (EPA) (95% pure. n =7) or eccossnexeencrc acid (DHA) (90% pure, n '" 7) daily for 5 wk insupplement to their ordinary diet. The n-3 fauy acids were given with astandard high- fat meal at !he beginning and the end of the supplemenre-tion period. EPA and DHA induced a similar incorporalion into chylomi-crons which peaked 6 h after the meal. 11Ie relative uptake of EPA andDHA from the meal was >90% compared with the uptake of oleic acid.During absorption. there was 00 significant elongation or recocoeversionof EPA or DHA in total chylomicron fatty acids. The concentration ofEPA decreased by 13% and DHA by 62% (P < 0.001) between 6 and 8 hafter the meal. During the 5-wk supplementation period. EPA showed amore rapid and comprehensive increase in serum phospholipids than didDHA. DHA was retroconverted to EPA. whereas EPA was elongated 10docosapentaeooic add (DPA). The postprandial triglyceridemia was sup-pressed by 19 arK! 49% after prolonged intake of EPA and DHA. respec-tively, indicating that prolonged intake of DHA is equivalent to or evenmore efficient than !hat of EPA in lowering postprandial trigtyceridemia.This study indicates that there are metabolic differences between EPA andDHA which may have implications for the use of n-3 fauy adds in pre-ventive and clinical medicine.Upids 33.131-138 (1998).

Effect or Apolipoprotein E Pnlymorphism on Serum LipoproteinResponse to Saturated Fatty Acids. lim K. Tso. Sunmin Park. Yu-HwaiTsai. Glenn WtllillDls. and Jean T. SIKlC)le:·.Department of Human Nuui-tion and Food Management. 11Ie Ohio State University, Columbus. Ohio432tO.

This report summarizes two studies which investigated the effects ofapolipoprotein E (apoE) polymorphism on the serum total cholesterol(TC) arK! lipoprotein cho[eslerol responses 10 8:0 + 10:0 and 12:0 diets(Study I) and 14:0, 16:0, and [8:0 diets (Study II). Eighteen healthy pre-menopausal women (3 apoE 3/2, 12 apoE 3D, 3 apoE 4/3) in study I andanother 18 healthy premenopausal women (4 apog 312, 10 apoE 313, 3apoE 413, I apoE 4(2) in study II consumed a baseline diet providing 4{)

en% total Iar. II en'll> 18:2. IS en'll 18:1, 11.5 en% saturated fat for thefirst week: of each 5-wle: period. The experimental diets for beth studiesprovided 40 en% total fat, 13-14 en'll as one of five test saturated fatlyacids (SFA). 14-16 en'll 18: I. and 3-4 en% 18:2. Analysis by apoE phe-notypes showed that both the 8:0 + 10:0 diet and the 12:0 diet in Study Iinduced sigruflcant increases in serum TC in subjects with different apoEphenotypes with the exception of apoE 312 in the medium-chain triglyc-eride group. In contrast, in Study II, individuals with apoE 4/3 consumingthe 14:0 diet showed significant increases in serum TC, high densitylipoprotein-cholesterol (HDL-C), and HDL2-C, but the same subjectsconsuming the 16:0 diet showed significant increases in serum TC andlow density Iipoprotein-chcleseerol. The findings from both studies indi-cated serum lipoprotein responses to SFA were different arK! the variationof responsiveness may be regulated. at [east in part, by apoE polymor-phism, especially when 14:0. 16:0. or 18:0 was consumed.Upids 33, 139-148 (1998).

Low-Fat, Monounsaturate-Rich Diets Reduce Susceptibility of LowDensity Lipoproteins to Peroxidation ex vivo, Dawn J. O'Byme. Sean F.O'Keefe, and Rachel B. Shireman". Department of Food Science andHuman Nuuition at !he University of Rorida. Gainesville. Florida 32611.

0~id3tive modification of low density lipoprotein (LDL) plays animportant role in the process of atherosclerosis. The susceptlbitity ofLDL 10 oxidation and the amount of peroxidation products fonned areinfluenced by the lipoprotein content of 18:ln-9. [8:2n-6, and the18:2n-6118:ln-9 ratio, which is dependent in pan on dietary fatty acids.The purpose of this study was to determine if changing from a typicalAmerican diet to a low-fat, moncunsaturate-rich diet (LFMR) wouldresult in favorable alterations in the fatty acid composition and oxidativeprofite of LDL in hypercholesterolemic individuals. Free-living post-menopausal hypercholesterolemic women who routinely consumed a dielmoderately high in total fat and total saturates (34 and II 'll, respectively)followed an LFMR diet (26% fat, 6% saturated fat. and 14% monounsatu-rated fat) for 6 mono Sixteen postmenopausal hypercholesterolemicwomen already following standard low-fat (LF) diets acted as a controlfor seasonal variations in serum lipids. LDL from randomly selected sub-jeers (LF n '" 6. LFMR n = 5) was evaluated. LFMR diets resulted in LDLwi!h increased concentrations and percentages of 18:In-9. reduced 18:2n-61[8: In-9 ratio, and lower percentages of 18:2n-6. No significant changesin LDL fatty acids occurred in tile LF group. Conjugated otene lag timeincreased in both groups during copper-induced ill vltro oxidation. Onlythe LFMR group experienced an increase in lipid peroxide lag time and adecrease in lipid peroxide formation. The LFMR diet was well toleratedand may be of therapeutic value in the treatment of hypercholesterolemia.Upids 33, [49-157 (1998).

A Comparison or Lycopene and Canthaxanthin Absorption: Usingthe Rat 10 Study the Absorption or Non-Provitamin A Carotenoids.Richard M. Clark", Lili Yeo. Li She. and Harold C. Furr, Department ofNutritional Sciences, University of Connecticut. Storrs, Connecticut06269-40 [7.

The purpose of !his study was to validate the use of the mesemenclymph duel cannulated 1111to study the absorption of caroteooids which donot have provitamin A activity. The absorption of IWO carotenoids, ahydrocarbon carotenoid (Iycopene) and a xanthophyll carotenoid (caruha-xanthin). were investigated. In the first experiment, lipid emulsions con-raining Iycopene (LYC) or canthaxanthin (CTX) were continuouslyinfused into the duodenum. and lymph was collected for analysis at 2-hintervals. The time course for absorption of carotenoids and uiacylglyc-erol (TAG) was similar. Carotenoids and TAG reached steady-state con-centrations in the lymph by 6 h. There was no evidence for a delayedrelease of either carotenoid from the intestine relative to TAG. During asecond experiment, emulsions containing increasing concemranons ofLYC or crx (5, 10, 15,20 "moVL) were infused. Tbe Lyeand crx inthe lymph increased in a dose-dependent manner. The average efficiency

[NFORM, Vol. 9, no. 3 (March 1998)

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Changes In Cultured Arterial Smooth Muscle Cells Isolaled fromChicks upon Cholesterol Feeding, Angel CarucP, M", rose Alejandrea,Ramen Dino, Antonio Rfosb, Mercedes Castillo". and Ana Linareso .• ,Departments ofoSiocbemistry and Molecular Biology, and eceu Biology.Faculty of Sciences. University of Granada. 18011 Granada, Spain.

We have developed cultures of smooth muscle cells (SMC) isolatedfrorn arterial hypercholesterolemic chicks (choJeslerol·SMC), These cut-tures are suitable for the study III the molecular level of the changes inarterial SMC induced by II cholesterol diet. By using II strong dose ofcholesterol (5%) for 10 d, we obtained very proliferative SMC whichbecame foam cells after 30 d in culture. On the other hand. SMC culturesisolated from control-fed chicks had II lower growth rate than the SMCones under the same culture conditions. DNA synthesis was fourfoldgreater in cholesterol-SMC than in conlrol-SMC cultures. lnlnlcellularcholesterol concentrations were the same in both cholesterol and controlSMC during the first 14 d of culture but afterward increased in differingways: after 20 d of culture the cholesterol-SMC increased their cholesterolcontent to double the control. We give here the results obtained fromtransmission electron microscopy. lipid analysis. proliferation studies,DNA, RNA and protein synthesis, and then discuss their implications.Upids33.181-190(l997).

ABSTRACTS FROM AOCS JOURNALS

of crx absorption was 16% while the efficiency of LYC absorption aver-aged only 6%. Efficiency of carotenoid absorption was not related 10 con-cenlnltiOll infused. Finally, to test whether LYC and crx interact duringabsorption both were added to a lipid emulsion at equal concentrations(20 ~moUL) and infused. 'The carotenoids did not significantly affect eachother's absorption. These results demonSlnlte the usefulness of the rat asan animal model to study the absorption of non-provitamin A carotenoids.Upids 33. 159-163 (1998).

Hepallc Cholesterol Metabolism In Experimental Nephrollc Syn-drome, Ayman AL-ShurbajiD,., Elisabet HumbleD, Mats RUdJingb. Bern-hard Lindenthelv. and Lars Berglun(]d. Departments of aMedical Labore-lory Sciences and Technology. Division of Clinical Chemistry. andbMedicine, Karolinska Institute! at Huddinge University Hospital, Hud-dinge. Sweden; cDepanment of Clinical Pharmacology, University ofBonn. Germany; and dDepanment of Medicine, College of Physiciansand Surgeons, Columbia University. New York. New York.

Hypercholesterolemia is a consistent feature of the nephrotic syn-drome. However. the mechanisms underlying this perturbation areunclear. In the present work, we have investigated different factors thatinfluence hepatic cholesterol metabolism using the nephrotic rat as amodel. The induction of nephrosis resulted in a severe and sustainedhypercholesterolemia. However, no effect on the rate-limiting enzymein cholesterol synthesis. 3-hydroxy-3-methylglutaryl CoA reductase.could be detected. Further, plasma lathosterol/cholesterol ratio, a mea-sure of cholesterol synthesis. was not altered. Also. plasma levels ofmevalonate, both a substrate for cnolesterogeoests beyond the rate-lim-iting step and a marker for cholesterol synthesis, did not differ betweencontrol rats and those with established hypercholesterolemia. Therewas no detectable change in the expression of low density lipoprotein(LDL) receptor between the two experimental groups. We conclude thatthe early increase in cholesterol synthesis reponed after the inductionof nephrosis is not necessary for the maintenance of hypercholes-terolemia. Established hypercholesterolemia of the nephrotic syndromeseems to represent a steady state in which neither enhanced hepaticcholesterol synthesis nor retarded LDL cholesterol clearance is ofmajor importance.lipids33,165-169(1998).

Elcosapentaenolc and Docesahexaenulc Acids Alter Rat SpleenLeukocyte Fatly Add Composition and Prostaglandin E:2 ProductionBut Have DilTerent ElTects on Lymphocyte Functions lind Cell·Medi·ated Immunity, L.D. Peterson". N.M. Jeffery", F. Thies", P. Sanderson",E.A. Newsholmes. and P.C. Calderl'··. "De~artment of Biochemistry.University of Oxford, Oxford OXI 3QU, and Institute of Human Nutri-tion. University of Southampton. Southampton SOl6 1PX. United King-dom.

Weanling rats were fed on high-fat (178 gllr::g)diets which contained4.4 g a-linolenic (ALA). j-tinclenic. arachidonic (ARA). eiccsapen-taenoic (EPA), or cocosahexeenotc acid (DHA)/loo g total fatty acids.The proportions of all other fatty acids. apart from linoleic acid. and theproponion of total polyunsaturated fatty acids (PUFA) (approximately 35glioo g total fatty acids) were constant, and the n-6 to n-3 PUFA reuc wasmaintained as close to 7 as possible. 'The fany acid compositions of theserum and of spleen leukocytes were markedly influenced by that of thediet. Prost.aglandin ~ production was enhanced from leukocytes fromrats fed the ARA-rich diet and was decreased from leukocytes from theEPA- or DHA-fed rats. Replacing dietary ALA with EPA resulted indiminished ex vivo lymphocyte proliferation and natural killer (NK) cellactivity and a reduced cell-mediated immune response in vivo. In contrast.replacing ALA with DHA reduced u vil'O lymphocyte proliferation butdid not affect u vivoNK cell activity or the cell-mediated immuneresponse in villO. Replacement of a proportion of linoleic acid with either"y-linolenic acid or ARA did not affect lymphocyte proliferation. NK cellactivity. or the cell-mediated immune response. Thus, this study showsthat different n-3 PUFA exert different Immunomodularory actions, thatEPA exerts more widespread andlor stronger lmmunomodulatory effectsthan DHA. that a low level of EPA is sufficient to influence the immuneresponse. and that the immunomooulatory effects of fish oil may be main-ly due to EPA.Upids33,171-180(1998).

Catalytic Properties of Allene Oxide Synthase from flaxseed (!inumusitatjssjmum L.). Claus Schneider and Peter Schreier'", Lehrsruht fUrLebensmittelchemie, Unlversitat werebcrg, D-91074 WOrzburg. Ger-many.

We investigated the catalytic and kinetic properties of allene oxidesynthase (AOS; E.C. 4.2.1.92) from flaxseed (Ullum USiUllissimum L.).Both Micltaelis constant and maximal initial velocity for the conversion of9(S}- and I 3(S)-hydropcroxides of linoleic and lioolenic acid were deter-mined by a photometric assay. 13(S)-Hydroperoxy-9(Z),II(.E}-octadeca-dienoic acid [13(S)-HPODJ as the most effective substrate was convenedat 116.9:1: 5.8 nkatlrng protein by the flax enzyme extract. The enzymewas also incubated with a series of variable conjugated hydroperoxydienyladlpates. Substrates with a shape similar to the naturalhydroperox-ides showed the best reactivity. Monoenoic substrates as oleic acidhydroperoxides were not converted by the enzyme. In contrast. 12-hydroperoxy-9(l),13(E}-oct.adecadienoic acid was a strong competitiveinhibitor for ADS catalyzed degradation of 13(S)-HPOD. The inhibitorconstant was detennined to be 0.09 ).1M.Based on these results. we con-eluded that allene oxide synthase requires conjugated diene hydropercx-ides for successful catalysis. Studying the enantiomeric preference of theenzyme, we found that ADS was also able to metabolize (R)..configuredIany acid hydrcperoxides. Conversion of these subsuares into labile alleneoxides was con finned by steric analysis of the stable n-ketol hydrolysisproducts.Upids 33. 191-196 (1998).

Positional Analysis or Triacylglycerols Irum Bovine Adipose TissneLipids Varying in negree of UnsaturaUon. Stephen B. Smith·. AijunYang. Tom W. Larsen. and Ron K. Tume, CSIRO, Division of Food Sci-ence and Technology, Brisbane Laboratory. Tlngalpa. Queensland. Aus-tralia 4173.

The objective of this study was to demonstrate that changing thefatty acid composition of bovine adipose tissue concurrently changed (i)proportions of triacylglycerol species. (ii) fatty acid composition of tria-cylglycerol species, and (iii) positional distribution of the component fattyacids of the macylglycerol species. To achieve this. we took advantage ofadipose tissue lipids. from cattle fed in AuslnIlia and Japan, that variedwidely in fatty acid composition and melting points. Treatment groupsproduced in Australia were cattle fed: a com-based diet (MUFA I); agrain-based diet containing whole cononseed (SFA); a grain-based dietcontaining protected OOItonseed oil (PUFA); and a grain-based diet thatresulted in high contents of trans fany acids (TFA). Treatment groups pro-duced in Japan (MUFA2 and MUFA3) were diets of unknown composi-tion fed for over 300 d. The MUFAI, MUFA2. and MUFA3 s.amples allwere rich in monounsaturated fany acids. varying only in tlte proponionsof the individual mOllounsaturates. The SFA, PUFA, and TFA sampleshad relatively high ccncencaucns of stearic acid (18:0), PUFA. and TFA.respectively. Slip points (indicative of melting points) were 45.1. 41.5,38.5,30.7,28.4. and 22.8"C, for the SFA. TFA. PUFA. MUFAI. MUFA2,and MUFA3 groups. respectively (P < 0.05). Triacylglycerols were sepa-

INFORM. Vol. 9. no. 3 (March 1998)

rated by high-performance liquid chromatography on a silver nitrate-impregnated column into sII-I.2.)-saturated fOlly acid triacylglycerol(SSS); [trlacylglycercls containing two saturated acids ond one trans-monounsaturated fany acid (SSMt III-positions unknown)!; In-l-salUrat-ed, 2-monounsalUrated. 3-salUrated triacylglycerol (SMS); sa-t-saturated.2-monounsaturated. 3-lrons-monoonsaturated triacylglycerol (SMMI); In-l-samrated. 2.3-monounsarurated fatty acid triacylglycerol (SMM); 111-1-saturated., 2-polyunsalUralOO. 3-lnl/I.f-monounsaturated triacylglycerol; In-1.2.3-monounsarurated fauy acid triacylglycerol (MMM): and sn-l-satu-rated, 2-polyunsaturated. Lmonounsaturated triacylglyceroL Fatty acidmethyl esters of each uiacylglycerol species also were determined. andfurtheT analysis indicated sn-2. and sn-113 positions. As the percentageoleic acid increased in the total lipid eJltract, the proportions of SMM andMMM increased (e.g .. from 31.4 and 2.4% in the SFA group to 55.4 and11.8% in the MUFA3 group). The elevated 18:0 in the SFA group (26%)was reflected in increased percentages of SSS and SSM. and caused anincrease in the proportion of 18:0 in aJltriacylglycerol species relative 10the other treatment groups. The percentage of 18:0 in the sn-l/3 positionswas elevated markedly in the SMS fraction of the SFA group (10 44%):this would account for the high melting point of the fat of these animals.We conclude that long-tenn feeding of carne is sufficient to produce sig-nificant alterations in fauy acid composition in bovine adipose tissue.Altenllions in the fatty acid composition of bovine adipose tissue changedboth the distribution and the composition of the triacylglycerol species,which, in tum. accounted for marked differences in melting points amongtreatment groups.lipidJ ss. 197-207 (1998)_

Stereospednc Analysis or Soybean TrilKylglycerols, Teresa K. Harpand Earl G. Hammood·, Department of Food Science and Human Nutri-tion and Center for Crops Utilization Research, Iowa SlIte University.Ames.lowa.

Thiny soybean germplasrn lines representing a wide distributionof fany acid compositions were analyzed stereospecifically by using achiral column to resolve the sll-I and sn-) positions of glycerol. Theamounts of each acyl group on each of the ~II positions were plotted V5.

the amount of that acyl group in the triacylglycerol5 (TAG), and theplOlli were fiued by linear regression. The deviation of individual datapoints from the linear regressions was much greater than observed inprevious studies. This could be attributed to the inclusion of a numberof gennplasm lines with elevated or reduced percentages of saturates.The stereospecific distributions could nor be fit with previously sug-gested mathematical models because the plots had intercepts that werenot allowed by the models. Statistical tests of the analytical procedureindicated that slight oxidation of or bias against the polyunsaturates hadoccurred and that the Grignard deacylation method gave ~lightly lessrepresentative analyses of the 911-2 position than pancreatic lipase dea-cylaucn on these TAG.UpidJ 33, 209-216 (1998)_

AOCS Mission StatementTo 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.

Declaration by the Gonming BoardThe American Oil Chemists' Society is organized for charitable, educa-tional and scientific purposes. It does not have as its purpose the promo-lion of any product. manufacturers. laboratory. or business. Members ofthe Society. and employees of the Society, do nOl and may not speak foror on behalf of the Society without the e~pressed permlsslon of the Gcv-

Silver-Ion High-Performance Liquid Chromatographic Separationand Identification or Conjugated Linoleic Acid Isomers. NajibullahSchar'. Martin P. YUllIwecza.·, John A,G. Roacha, Magdi M. MOS5Obaa,John K.G. Kramerb, and Youh KuD, aFood and Drug Administration,Center for Food Safety and Applied Nutrition, Washington, DC 20204,and bfood Processing Quality Improvement Prognun, Agriculture Cana-da. Guelph, Ontario. Nl H 8J7. Canada.

This is the first report of the application of silver-ion impregnatedhigh-performance liquid chromatography (Ag+-HPLC) 10 the separ1Itionof compleJl mixtures of conjugated linolenic acid (CLA) iSOfTJeBpresentin commacial CLA soun:es and foods and in biological specimens. Thismethod showed a clear separation ofCLA isomen into three groups relat-ed to their Irons,lrons, cis,lrons or lroru,cis. and cis.cis configuration ofthe conjugated double-hond system. In addition. this method separatedindividual positional iSOfTJeBof the conjugated diene system within eachgeometrical isomeric group. Following Ag+-HPLC isolation. gas chro-matography (GC)-eleclron impact mass spectrometry. and GC-directdeposition-Fourier transformed infrared spectroscopy were used to con-finn the identity of two major positional isomers in the cisllrons region.l.e.. ~8, 10- and t.11, 13-octadecadienoic acids, which had not been chro-matographically resolved previously. Furthermore, the potential of thismethod was demonstrated by showing different Ag+-HPLC profilesexhibiting patterns of isomeric distributions for biological specimens fromanimals fed a diet containing a commercial CLA preparntion. as well asfor a commercial cheese product.lipids 33, 217-221 (1998).

265

Phospholipase D Hydrol}"l:e5 Short·Chain Analogs or Pbosphatldyl-choline in the Absence of Detergent. tesree L. Davis. Jelfn:y J. Maglio.and Joel Horwitz·, MCP. Hahnemann School of Medicine, AlleghenyUniversity of the Health Sciences. Philadelphia. Pennsylvania 19129_

Phospholipase 0 is an important ellZyme in signal transduction inneuronal tissue. A variety of assays have been used 10 measure phospholi-pase 0 activity in ~itro.TIle most typical measure of phospholipase 0activity is the production of phosphatidylethanol in the presence ofethanol. Phosphatidylethanol is a product oftransphosphatidylation activi-ty !bat is considered a unique propeny of phospholipase D. To supportInU1sphosphatidylation activity, high concentrations of ethanol may berequired. Furthermore. most ass.ys in the literature utilize a detergent.These extreme conditions, detergent and ethanol. may alter phospholipaseo and hinder the study of its regulation. In this manuscript we describe lUI

assay that eliminates these potentially confounding conditions. It utilizeshigh specific activity [3Hlbutanol as a nucleophilic receptor. This elimi-nates the need for high concentrations of alcohol. The substrate is ananalog of phospbatidylcholine that contains short-chain fauy acids, 1.2-dioctanoyl-sII-glycero-3-phosphocholine. Phospholipase D readilyhydrolyzes this substrate in the absence of detergent. This novel assayshould be useful in the further characterization of phospholipase D.lipids 33. 22J-227 (1998).

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INFORM, Vol, 9, 00.3 (March 1998)