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1.
Positional isomers (1-butyryl-2X-3Y-rac-glycerol and 2-butyryl-1X-3Y-rac-glycerol;X,Y=long-chain acyls) of saturated triacylglycerols (TAG) with 34 and 40 acyl carbons were shown to separate in two chromatographic
peaks on immobilized phenyl(65%) methylsilicone column by gas-liquid chromatography, and on reversed-phase ODS-1 column by
high-performance liquid chromatography. The analysis of 500-MHz1H nuclear magnetic resonance (NMR) spectra showed distinct differences between 2-butyryl-1X-3Y-rac-glycerol and 1-butyryl-2X-3Y-rac-glycerol isomers in the resonance signals of methylene and methine protons of glycerol backbone, and carbon-2 methylene of
acyl groups, and methyl protons of butyryl group. The1H NMR spectra of three interesterified mixtures of three monoacid TAG containing saturated butyrate and caproate TAG and unsaturated
butyrate TAG showed that triplets of methyl protons of butyryl groups atsn-1(3)- andsn-2-positions in saturated and unsaturated TAG had similar chemical shifts and that the chemical shift of caproyl methyl protons
was different from those of butyryl methyl protons. The positional distribution of butyryl groups in isolated positional isomers
of butyrate TAG, interesterified TAG mixtures, and natural and interesterified butteroil can be determined by integration
of these signals. 相似文献
2.
Johanna Reske Jodi Siebrecht Jan Hazebroek 《Journal of the American Oil Chemists' Society》1997,74(8):989-998
Changes in composition were examined in oils extracted from genetically modified sunflower and soybean seeds. Improvements
were made to the analytical methods to accomplish these analyses successfully. Triacylglycerols (TAG) were separated on two
300 mm × 3.9 mm 4μ Novapak C18 high-performance liquid chromatography (HPLC) columns and detected with a Varex MKIII evaporative
light-scattering detector. Peaks were identified by coelution with known standards or by determining fatty acid composition
of eluted TAG by capillary gas chromatography (GC). Stereospecific analysis (fatty acid position) was accomplished by partially
hydrolyzing TAG with ethyl magnesium bromide and immediately derivatizing the resulting diacylglycerols (DAG) with (S)-(+)-1-(1-naphthyl)ethyl isocyanate. The derivatized sn-1,2-DAG were completely resolved from the sn-2,3-DAG on two 25 mm × 4.6 mm 3 μ silica HPLC columns. The columns were chilled to −20°C to obtain baseline resolution of
collected peaks. The distribution of fatty acids on each position of the glycerol backbone was derived from the fatty acid
compositions of the two DAG groups and the unhydrolyzed oil. Results for the sn-2 position were verified by hydrolyzing oils with porcine pancreatic lipase, isolating the resulting sn-2 monoacylglycerols by TLC, and determining the fatty acid compositions by GC. Results demonstrated that alterations in the
total fatty acid composition of these seed oils are determined by the concentration of TAG species that contain at least one
of the modified acyl groups. As expected, no differences were found in TAG with fatty acid quantities unaffected by the specific
mutation. In lieu of direct metabolic or enzymatic assay evidence, the authors’ positional data are nevertheless consistent
with TAG biosynthesis in these lines being driven by the mass action of available acyl groups and not by altered specificity
of the acyltransferases, the compounds responsible for incorporating fatty acids into TAG. 相似文献
3.
F. C. Phillips W. L. Erdahl J. D. Nadenicek L. J. Nutter J. A. Schmit O. S. Privett 《Lipids》1984,19(2):142-150
The analysis of triglyceride species by high performance liquid chromatography (HPLC) with a flame ionization detector (FID)
and reversed-phase chromatography using chemically bonded octadecyl silane (ODS) Zorbax columns and gradient or isocratic
solvent elution with methylene chloride/acetonitrile is described. Triglycerides containing acyl groups of critical pairs,trans and positional isomers, as well as mixtures of even and odd chain lengths are separated. Identification of triglycerides
is made on the basis of retention times compared with equivalent and theoretical carbon numbers, and comparison with chromatograms
of reference triglyceride mixtures. The methodology is demonstrated by fractionizing the triglycerides of olive oil under
different chromatographic conditions using single and coupled conventional 250×4.6 mm columns and a short 80×6.2 mm column
for fast separations. 相似文献
4.
J. J. Rios M. C. Pérez-Camino G. Márquez-Ruiz M. C. Dobarganes 《Journal of the American Oil Chemists' Society》1994,71(4):385-390
Various chromatographic techniques for isolation and separation of highly esterified sucrose polyesters (SPE) of olive oil
are described. High-performance size-exclusion chromatography was used to check the purity of the samples, particularly to
show that SPE were free from unreacted fatty acid methyl esters. Thin-layer chromatography (TLC), Iatroscan TLC flame-ionization
detection (FID) and highperformance liquid chromatography (HPLC) on reversed-phase were applied for separation of octa-, hepta-
and hexaesters of sucrose. Pure fractions from the total mixture, obtained by column chromatography, were identified by infrared
and nuclear magnetic resonance spectroscopy. When necessary, specific reactions were applied; particularly, silylation and
lead acetate-dichlorofluorescein (in toluene) spray were used to ascertain the degee of esterification of sucrose. Finally,
octa-, hepta- and hexaesters of sucrose were quantitated by silica column chromatography, TLC/FID and HPLC on reversed-phase. 相似文献
5.
J. M. Bland E. J. Conkerton G. Abraham 《Journal of the American Oil Chemists' Society》1991,68(11):840-843
The triacylglyceride components of cottonseed oil were isolated and positively identified by a combination of high performance
liquid chromatography (HPLC) and gas chromatography (GC). Both reversed-phase HPLC and capillary GC were capable of separating
the oil into triacylglyceride peaks. These peaks were isolated by HPLC and their component acyl groups were converted to fatty
acid methyl ester derivatives. The acyl constituents for each triacylglyceride were determined by GC analysis, thus positively
identifying the triacylglyceride associated with each HPLC peak. The triacylglyceride elution order agreed with predictive
methods. HPLC and capillary GC peaks were correlated by peak area, thus identifying the GC peaks. The corresponding GC elution
order of triacylglycerides also agreed with predictive methods. 相似文献
6.
Fani Mantzouridou Maria Z. Tsimidou 《European Journal of Lipid Science and Technology》2007,109(1):3-10
The carotenoid pattern in Blakeslea trispora grown on oil‐enriched substrates was investigated with regard to triacylglycerol (TAG) species accumulation, to assess the interrelationship between these two processes. Analysis of individual carotenoids and TAG was carried out by HPLC. β‐Carotene production was at the expense of lycopene and γ‐carotene formation in cells grown on crude olive pomace oil (COPO) and crude soybean oil (CSO) at two levels of addition (10.0 and 30.0 g/L culture medium). A shift to γ‐carotene synthesis was observed at increased oil level. Cellular lipids produced at the low COPO or CSO levels contained more unsaturated TAG compared with those obtained on glucose as the sole carbon source. With regard to the typical soybean or olive oil TAG profile, cellular TAG had profiles dependent on the type and the amount of the co‐substrates used. In the presence of CSO, the cellular TAG profile was similar to that of the respective oil for both levels of addition. A notable desaturase activity was observed only in the presence of low COPO addition. The present study can serve as a basis for a better understanding of TAG accumulation with regard to β‐carotene production in oil‐enriched substrates. 相似文献
7.
Triacylglycerols of Finnish winter butterfat containing one saturated and two monoenoic fatty acyl residues were studied.
With silver ion high-performance liquid chromatography (HPLC), molecules were separated according to the difference in the
configuration of one fatty acyl moiety. The distribution of the saturatedcis,trans-dimonoenoic and saturatedcis,cis-dimonoenoic triacylglycerols according to their acyl carbon numbers was compared by means of reversed-phase HPLC and tandem
mass spectrometry. Furthermore, two examples of the fatty acid composition of a specified molecular weight species were shown.
The fatty acid compositions of corresponding saturatedcis,trans-dimonoenoic and saturatedcis,cis-dimonoenoic triacylglycerols were similar; however, there may be differences in the proportions of different fatty acid combinations
or in the distribution of fatty acids between primary and secondary glycerol positions. 相似文献
8.
Lu Jiang He Huang Mingliu Lei Hongbo Zheng Jingrui Liang Hongman Zhang 《Journal of the American Oil Chemists' Society》2013,90(8):1213-1221
Column chromatography and reversed-phase HPLC using a Sepax BR-C18 column were applied for the analysis of glycerides in the docosahexaenoic acid (DHA) oil by Schizochytrium sp. The oil was detected under UV light after isocratic elution with 20 % 2-propanol/hexane (5:4, v/v) + 80 % acetonitrile. The correlation coefficients for the calibration of HPLC for DHA glycerides were in the range of 0.9958–0.9998. The accuracy was confirmed with recoveries of 93.47–102.25 %. DHA oil samples under different aeration rates were successfully analyzed and the content of the binding of DHA on the acylglycerol backbone was very low (1.81–4.21 %). However, the content of glycerides (tri-, di-, mono-) separated by column chromatography was more than 87.22 %. The glycerides were largely composed of triacylglycerides (TAG) (82.29–89.54 %), where higher content of TAG correlated to higher contents of DHA and TAG of DHA (TriDHA). In addition, the optimal aeration rate of 250 m3/h was obtained for TAG, DHA, and TriDHA production by Schizochytrium sp. with the temperature 30 ± 0.5 °C, impeller speed 85 ± 5 rpm and pressure 0.04 Mpa. 相似文献
9.
Menhaden oil (MO) and partially hydrogenated menhaden oil (PHMO) were dry-fractionated and solvent-fractionated from acetone.
After conversion to fatty acid methyl esters, the compositional distribution of saturated, monounsaturated, trans, and n−3 polyunsaturated fatty acids (PUFA) in the isolated fractions was determined by gas chromatography. Acetone fractionation
of MO at −38°C significantly increased the n−3 PUFA content in the liquid fractions over that of starting MO (P<0.05). For PHMO, liquid fractions obtained by low-temperature crystallization (−38, −18, and 0°C) from acetone showed significant
increases (P<0.05) in monounsaturated fatty acid (MUFA) content over that of the starting PHMO. For selected MUFA-enriched fractions,
reversed-phase high-performance liquid chromatography (HPLC) was used to separate, isolate, and characterize the major triacylglycerol
(TAG) molecular species present. Thermal crystallization patterns for these fractions also were determined by differential
scanning calorimetry (DSC). The results demonstrated that under the appropriate conditions it is possible to dry-fractionate
or solvent-fractionate MO and PHMO into various solid and liquid fractions that are enriched in either saturated, monounsaturated,
polyunsaturated, or the n−3 classes of fatty acids. Moreover, characterization of these TAG fractions by reversed-phase HPLC
gives insight into the compositional nature of the TAG that are concentrated into the various fractions produced by these
fractionation processes. Finally, the DSC crystallization patterns for the fractions in conjunction with their fatty acid
compositional data allow for the optimization of the fractionation schemes developed in this study. This information allows
for the production of specific TAG fractions from MO and PHMO that are potentially useful as functional lipid products. 相似文献
10.
Separation of Triacylglycerols from Edible Oil Using a Liquid Chromatography–Mass Spectrometry System with a Porous Graphitic Carbon Column and a Toluene–Isopropanol Gradient Mobile Phase 下载免费PDF全文
Shi‐Ding Zhang Can Gong Yan Lu Xu Xu 《Journal of the American Oil Chemists' Society》2018,95(10):1253-1266
This study presented a rapid and practical method of separating triacylglycerol (TAG) from edible oil using high‐performance liquid chromatography (LC) coupled with atmospheric‐pressure chemical ionization (APCI)/mass spectrometry (MS) system with a porous graphitic carbon column (150 mm × 2.1 mm, 5 μm) and a toluene–isopropanol–formic acid mobile phase. After investigating the experimental conditions, the gradient toluene–isopropanol mobile phase containing 0.1% formic acid was changed from 50:50 to 80:20 in 30 min; the column temperature was set to 35 °C, and APCI/MS was used in the positive‐ion acquisition mode. The TAG retention displayed a special order and was summarized to fit as follows: S‐ECN (special equivalent carbon number) = 2CN (carbon number) ? 3dB (double bond number) – 5uFA (unsaturated fatty‐acid number). Then, the LC–MS method was applied to separate TAG in 6 vegetable oils, resulting in the recognition of 27 TAG in corn oil, 21 TAGs in olive oil, 22 TAG in sunflower seed oil, 28 TAG in soybean oil, 25 TAG in sesame oil, and 31 TAG in peanut oil. The TAG separation through the LC–MS method was rapid, reproducible, and durable. 相似文献
11.
P. M. Kris-Etherton 《European Journal of Lipid Science and Technology》1993,95(12):448-452
We conducted two clinical studies to examine the effects of diets high in stearic acid and lauric + myristic acid on plasma lipids and lipoproteins of healthy young men. In the first study subjects (n = 15) were fed whole food diets high in cocoa butter, butter, olive oil and soybean oil. In the second study, subjects were fed diets very high in saturated fatty acids (> 20% of calories) that were high in either stearic acid (from cocoa butter or milk chocolate) or lauric + myristic acid (from butter). In the first study, cocoa butter elicited a neutral cholesterolemic effect, whereas the butter diet was hypercholesterolemic and the olive oil and soybean oil diets were hypocholesterolemic. In the second study, the diets high in stearic acid did not raise plasma total and LDL-cholesterol levels, whereas, as in the first study, butter was markedly hypercholesterolemic. Regression analyses performed on the individual data from these two clinical studies were conducted to establish the cholesterolemic effects of individual fatty acids. The bestfitting linear regression equations relating ΔTC (change in plasma total cholesterol) was: ΔTC = 2.3 ΔC14:0 + 3.0 ΔC16:0-0.8 ΔC18:0-1.0 ΔPUFA, where Δ fatty acid = change in intake expressed as percent of calories. This predictive equation separates stearic acid from the other long-chain saturated fatty acids and suggests that it has an independent cholesterol-lowering effect. In conclusion, stearic acid is a unique long-chain saturated fatty acid. 相似文献
12.
Tomohisa Kinami Naoto Horii Bhaskar Narayan Shingo Arato Masashi Hosokawa Kazuo Miyashita Hironori Negishi Junichi Ikuina Ryuji Noda Seiichi Shirasawa 《Journal of the American Oil Chemists' Society》2007,84(1):23-29
A high-performance liquid chromatographic (HPLC) method is described for the determination of conjugated linoleic acids (CLA)
and conjugated linolenic acids (CLN). Methyl esters prepared from purified lipid fractions of soybean oil were analyzed using
an HPLC system equipped with photodiode-array detector to detect peaks having maximum absorption around 233 and 275 nm. These
peaks were concentrated by AgNO3-silicic acid column chromatography and reversed-phase HPLC. The structural analysis, of dimethyloxazoline (DMOX) derivatized
methyl esters, using gas chromatography–mass spectrometry (GC–MS) showed the occurrence of 9,11- and 10,12-CLA and 8,10,13-,
8,10,12-, and 9,11,13-CLN. The comparison of these conjugated fatty acids with authentic isomers by HPLC revealed the presence
of isomeric mixtures of CLA [cis (c),trans(t) or t,c and t,t] and CLN (c,t,t or t,t,c and t,t,t). Traces of 9,11- and 10,12-CLA (c,t or t,c) were found in crude oil.
CLN isomers (8,10,12-18:3 and 9,11,13-18:3) were found to be forming during the bleaching phase of soybean oil processing.
8,10,13-CLN and 9,11- and 10,12-CLA (t,t) were only found in soybean oil after the deodorization step. CLN contents in commercial
soybean oil varied from 387 to 1,316 mg/kg oil. A decreased level of bleaching earth and temperature resulted in a reduced
CLN content. It is possible that CLN would be derived from the linoleate hydroperoxides formed during the processing and storage
of soybean oil. 相似文献
13.
Chemical structure of long-chain esters from “sansa” olive oil 总被引:1,自引:0,他引:1
Giorgio Bianchi Aldo Tava Giovanna Vlahov Nicoletta Pozzi 《Journal of the American Oil Chemists' Society》1994,71(4):365-369
The major objective of this study was to determine the chemical structure of long-chain esters present in lower-grade olive
oil. The classes of esters composing the hexanediethyl ether (99∶1) extract of the wax fraction from a pomace olive oil were:
(i) esters of oleic acid with C1−C6 alcohols, (ii) esters of oleic acid with long-chain aliphatic alcohols in the range C22−C28 and (iii) benzyl alcohol esters of the very long-chain saturated fatty acids C26 and C28. The analysis and the structure assignments were carried out by gas chromatography coupled with mass spectrometry and by
comparison with synthetic authentic model compounds. This work provided precise data on the chemical nature of the wax esters
present in olive oil and should represent a means to detect adulteration of higher-grade olive oil with less expensive pomace
olive oil and seed oils. 相似文献
14.
Identification of the less common isologous short-chain triacylglycerols in the most volatile 2.5% molecular distillate of butter oil 总被引:6,自引:0,他引:6
The isologous short-chain triacylglycerols of the most volatile 2.5% distillate of butter oil were resolved by reversed-phase
high-performance liquid chromatography (HPLC) with mass spectrometry. The molecular species were identified by means of the
[MH]+ and the [MH-RCOOH]+ ions in positive chemical ionization mode. A set of empirically determined incremental elution factors was found that could
be used to calculate the accurate elution order of natural butterfat triacylglycerols when analyzed by reversed-phase HPLC.
The triacylglycerols were also resolved by temperature-programmed gas-liquid chromatography on capillary columns coated with
polar liquid phases. The high polarity of the columns provided separation of triacylglycerols on the basis of the degree of
unsaturation, as well as on the nature of the shortest acyl chain, with the isologous species having the shortest chainlength
eluting last. Both saturated and unsaturated triacylglycerols containing normal and branched-chain odd-carbon fatty acids
in combination with short-chain acids were identified, and over 150 molecular species were quantitated. 相似文献
15.
Identification and quantification of feruloylated mono-, di-, and triacylglycerols from vegetable oils 总被引:1,自引:0,他引:1
David L. Compton Joseph A. Laszlo Mark A. Berhow 《Journal of the American Oil Chemists' Society》2006,83(9):753-758
The use of HPLC-MS to separate and identify the feruloylated acylglycerols formed during the transesterification of ethyl
ferulate with TAG was examined. Novozym 435 (Candida antarctica lipase B)-catalyzed transesterifications of ethyl ferulate and soybean oil resulted in a mixture of feruloylated MAG, DAG,
and TAG and diferuloylated DAG and TAG. These feruloylated acylglycerols have recently garnered much interest as cosmeceutical
ingredients. The ratio of the various feruloylated acylglycerol species in the resultant oils is presumed to affect the oil's
cosmetic efficacy as well as its physical (formulation) properties. Thus, it was desirable to develop an analytical method
to separate, identify, and quantify the individual feruloylated acylglycerols to determine their relative ratios. The feruloylated
acylglycerols were successfully separated and identified by HPLC-MS using a phenyl-hexyl reversed-phase column developed with
a water/methanol/1-butanol gradient. The chromatograms of the feruloylated acylglycerols from soybean oil were convoluted
by myriad fatty acids; therefore, feruloylated acylglycerols from triolein were studied as a model reaction. Hydrolysis of
the feruloylated acylglycerols from triolein catalyzed by Lipase PS-C “Amano” I (Burkholderia cepacia), which showed no hydrolysis reactivity toward ethyl ferulate, allowed for the chromatographic assignment of the feruloyl
acylglycerol positional isomers. 相似文献
16.
A. B. Imbs N. V. Nevshupova L. Q. Pham 《Journal of the American Oil Chemists' Society》1998,75(7):865-870
The triacylglycerol (TG) composition of Pinus koraiensis seed oil, which contains Δ5 nonmethylene-interrupted (NMI) fatty acids (FA) (the main acid is pinolenic, 18:3 Δ5, 9, 12),
was determined. TG were preliminarily separated by argentation thin-layer chromatography (TLC), and the obtained fractions
were analyzed by high-temperature gas chromatography (GC) on a capillary column with methyl phenyl silicone phase. Additionally,
high-performance liquid chromatography (HPLC) of TG was applied. The FA composition of all TG fractions was identified. The
identification of TG was carried out by combining TLC, GC, HPLC, and calculated equivalent carbon numbers of TG standards.
The TG species identification was confirmed by comparison of the theoretical recalculated and directly analyzed FA compositions
of all TLC fractions of TG. Species of TG with unsaturation degrees of 1 to 7 and trace amounts of saturated and octaenoic
TG species were found. Except for minor compounds, 26 TG molecular species of 32 main components were quantitatively determined.
The main species were oleoyl dilinoleoylglycerol (14.7%), dilinoleoyl pinolenoylglycerol (10.7%), palmitoyl oleoyl linoleoylglycerol
(8.3%), triolein (7.6%), and dioleoyl, linoleoylglycerol (7.4%). Seven TG species contained Δ5 NMI acyl groups. Of these,
the major were dilinoleoyl pinolenoyglycerol (10.7%), stearoyl linoleoyl pinolenoylglycerol (6.5%) dioleoyl, pinolenoylglycerol
(5.4%), and palmitoyl linoleoyl pinolenoyl-glycerol (5.5%). TG species with two or three NMI acyl groups were not detected. 相似文献
17.
The changes in the triacylglycerol (TAG) composition of colostrum fat of three cows were studied. In addition to the determination
of fatty acid composition by gas chromatography, the distribution of TAG according to the acyl carbon number (ACN) and molecular
weight was analyzed utilizing both supercritical fluid chromatography (SFC) and ammonia negative-ion chemical ionization mass
spectrometry (MS). Colostrum TAG contained substantially less stearic and oleic acids and more myristic and palmitic acids
than the normal Finnish milk fat. The major trends in the changes of fatty acids and TAG were similar for each cow, although
clear differences between individuals were found. During the first week of parturition, the proportions of short-chain fatty
acids (C4–C10) typically increased as well as those of stearic and oleic acids, whereas the relative amounts of C12–C16 acids decreased, especially those of myristic and palmitic acids. Distinct changes occurred also in TAG distributions: the
proportions of molecules with ACN 38–40 increased and those with ACN 44–48 decreased. Although there were distinct differences
between individuals shortly after delivery, both the fatty acid compositions and TAG distributions of the milk samples of
the cows started to resemble each other after one week. The theoretical profiles of colostrum TAG calculated based on the
fatty acid compositions differed clearly from the ACN distributions analyzed by SFC and MS. Thus, the analysis of TAG is essential,
because the changes in molecular species composition of colostrum TAG cannot be estimated according to the fatty acid analysis
alone. 相似文献
18.
Teimoor Mohammadi Jamshid Farmani Zahra Piravi-Vanak 《Journal of the American Oil Chemists' Society》2019,96(5):555-569
The simplest and the most cost-effective way of human milk fat substitute (HMFS) production is formulating of suitable vegetable oils at proper ratios. To do this, the D-optimal mixture design was used to optimize the HMFS formulation. The design included 25 formulations made from refined palm olein (35–55%), soybean oil (5–25%), olive oil (5–20%), virgin coconut oil (5–15%), and fish oil (0–10%). Samples were produced in laboratory and characterized in terms of fatty acid and triacylglycerol (TAG) compositions, free fatty acid content, peroxide value, iodine value, and oxidative stability index (OSI). HMFS samples were also compared with Codex Alimentarius (CA) and Iran National Standards Organization (INSO) standards. Each characteristic of HMFS samples was then expressed as a function of ingredient ratio using regression models. Finally, using numerical optimization, four optimized blends (PB1-PB4) were selected, made in the laboratory (HMFS1-HMFS4), characterized, and compared with CA and INSO standards. The properties of all the optimized blends (except the palmitic acid content of HMFS2 and the monounsaturated fatty acid [MUFA] content of HMFS3) met the standards. HMFS4 showed the highest OSI in Rancimat and the lowest oxidation rate in Schaal oven tests. POL (19.53–21.73%), PPO (20.77–21.73%), OOO (9.11–11.16%), and OPO (8.84–9.46%) were the main (totally about 60%) TAG species found in HMFS samples. In conclusion, the HMFS4 formula (55% palm olein, 13.5% soybean oil, 16% refined olive oil, 15% virgin coconut oil, and 0.5% fish oil) was suggested as the best formula for HMFS production. 相似文献
19.
The triacylglycerols of winter butterfat were fractionated according to the type and degree of unsaturation into six fractions
by silver ion high-performance liquid chromatography (Ag-HPLC). The acyl carbon number distribution of the triacylglycerols
in each fraction was elucidated by reversed-phase HPLC and mass spectrometry (MS). The MS analysis of each fraction gave deprotonated
triacylglycerol [M - H]− ions which were produced by chemical ionization with ammonia. The daughter spectrum of each of the [M - H]− ions provided information on its fatty acid constituents. Successful fractionation of triacylglycerols differing in the configuration
of one fatty acyl residue by Ag-HPLC was important because geometrical isomers could not be distinguished by the MS system
used. In addition to the fatty acid compositions, reversed-phase HPLC analysis demonstrated the purity of the collected fractions:
molecules having acis-trans difference were separated nearly to the baseline. Triacylglycerols differing in the configuration of one fatty acyl residue
were not equally distributed in relation to their acyl carbon numbers. This indicates that during the biosynthesis of triacylglycerols,cis- andtrans-fatty acids are processed differently. Although the fatty acid compositions of the corresponding molecular weight species
of disaturatedtrans- and disaturatedcis-monoenoic triacylglycerols were similar, there may be differences in the amounts of different fatty acid combinations or
in the distribution of fatty acids between the primary and secondary glycerol positions. In addition to the main components,
it was possible to analyze minor triacylglycerols, such as molecules containing one odd-chain fatty acid, by the MS system
used. 相似文献
20.
Koji Masuda Kosuke Abe Yoshihiro Murano 《Journal of the American Oil Chemists' Society》2021,98(1):21-29
Triacylglycerol (TAG) isomers have been reported to have differing physical and nutritional properties. The analysis of TAG isomers is therefore important for understanding the physical properties of lipids as well as their digestion and absorption. However, methods for the quantitative analysis of TAG regioisomers and enantiomers in vegetable oils and biological samples are still under development. Recently, methods using recycle high-performance liquid chromatography (HPLC) and silver ion column-HPLC have been reported. However the recycle HPLC method requires more than 1 hour, in general, for each sample that is analyzed. Furthermore, existing methods are unable to quantify regioisomers and enantiomers simultaneously. Thus, we aimed to develop a practical method to simultaneously quantify regioisomers and enantiomers of TAG. Three isomers of sn-POO, OPO, and OOP were separated by supercritical fluid chromatography coupled with triple quadrupole mass spectrometer (SFC/MS/MS) using a CHIRALPAK® IG-U column with acetonitrile and methanol as mobile phase. The separation was completed in 40 min, which is a shorter run time than the conventional techniques published to date. Linear calibration curves with standards were obtained and used to quantify sn-OPO, sn-POO, and sn-OOP in extra virgin olive oil, refined olive oil, palm oil, palm olein, and interesterified palm olein. 相似文献