共查询到20条相似文献,搜索用时 24 毫秒
1.
Detailed investigation was made of the triacylglycerol structure of three varieties of peanut oils of varying atherogenic
activity. By means of chromatographic and stereospecific analyses, it was shown that all the oils had markedly nonrandom enantiomeric
structures with the long chain saturated fatty acids (C20−C24) confined exclusively to thesn-3-position, whereas the palmitic and oleic acids were distributed about equally between thesn-1-andsn-3-positions, with the linoleic acid being found preferentially in thesn-2-position. On the basis of detailed studies of the molecular species of the separatesn-1,2-,sn-2,3- andsn-1,3-diacylglycerol moieties, it was concluded that the fatty acids in the three positions of the glycerol molecule are combined
with each other solely on the basis of their relative molar concentrations. As a result, it was possible to calculate the
composition of the molecular species of the peanut oil triacylglycerols (including the content of the enantiomers and the
reverse isomers) by means of the 1-random 2-random 3-random distribution. In general, the three peanut oils possessed triacylglycerol
structures which where closely similar to that derived earlier for a commercial peanut oil of North American origin. Since
their oil has exhibited a high degree of atherogenic potential, it was anticipated that the present oils would likewise be
atherogenic, which has been confirmed by biological testing. However, there are certain differences in the triacylglycerol
structures among these oils, which can be correlated with the variations in their atherogenic activity. The major differences
reside in the linoleic/oleic acid ratios in the triacylglycerols, especially in thesn-2-position, and in the proportions in which these acids are combined with the long chain fatty acids. On the basis of the
characteristic structures identified in the earlier analyzed atherogenic peanut oil, the peanut oil of South American origin
would be judged to possess the greatest atherogenic potential and this has been borne out by biological testing. 相似文献
2.
Triacylglycerol structure of human colostrum and mature milk 总被引:2,自引:0,他引:2
Jean-Charles Martin Philippe Bougnoux Jean-Michel Antoine Monique Lanson Charles Couet 《Lipids》1993,28(7):637-643
Because triacylglycerol (TAG) structure influences the metabolic fate of its component fatty acids, we have examined human
colostrum and mature milk TAG with particular attention to the location of the very long chain polyunsaturated fatty acid
on the glycerol backbone. The analysis was based on the formation of various diacylglycerol species from human milk TAG upon
chemical (Grignard degradation) or enzymatic degradation. The structure of the TAG was subsequently deduced from data obtained
by gas chromatographic analysis of the fatty acid methyl esters in the diacylglycerol subfractions. The highly specific TAG
structure observed was identical in mature milk and colostrum. The three major fatty acids (oleic, palmitic and linoleic acids)
each showed a specific preference for a particular position within milk TAG: oleic acid for thesn-1 position, palmitic acid for thesn-2 position and linoleic acid for thesn-3 position. Linoleic and α-linolenic acids exhibited the same pattern of distribution and they were both found primarily
in thesn-3 (50%) andsn-1 (30%) positions. Their longer chain analogs, arachidonic and docosahexaenoic acids, were located in thesn-2 andsn-3 positions. These results show that polyunsaturated fatty acids are distributed within the TAG molecule of human milk in
a highly specific fashion, and that in the first month of lactation the maturation of the mammary gland does not affect the
milk TAG structure. 相似文献
3.
T. H. Sanders 《Lipids》1979,14(7):630-633
Stereospecific analysis of triacylglycerols from six peanut varieties showed diversity in percent fatty acid placement. Distribution
of the fatty acids among thesn-1,-2 and-3 positions was clearly nonrandom. The percentages of palmitic and stearic acids, generally very low at thesn-2 position, were more predominant at thesn-1 than thesn-3 position. Long chain fatty acids were located almost exclusively at thesn-3 position. Thesn-2 position of all varieties was high in unsaturated fatty acids. Triacyglycerols were sufficiently different to suggest that
concentrations of specific triacylglycerol species may vary with variety.
Mention of firm names or trade products does not imply that they are endorsed or recommended by the Department of Agriculture
over other firms or similar products not mentioned. 相似文献
4.
P. Damiani L. Cossignani M. S. Simonetti F. Santinelli M. Monotti 《Journal of the American Oil Chemists' Society》1997,74(8):927-933
Triacylglycerol stereospecific analysis of normal (NOS) and high-oleic sunflower (HOS) oils was carried out by two procedures
to study the influence of variety and growing conditions. Four cultural varieties, two NOS and two HOS, were grown in seven
different places of Italy. Three of the four varieties were grown both in dry conditions and with irrigation. Concerning the
triacylglycerol fatty acid compositions, the results showed no significant differences between irrigated and nonirrigated
samples (P>0.05), between the two NOS, and between the two HOS varieties. Between NOS and HOS varieties, only stearic acid showed no
significant differences (P>0.05). The fatty acid compositions of the sn-2 position of NOS and HOS samples showed different percentage abundances (P<0.01), especially for oleic and linoleic acids. Fatty acid distributions in the sn-1 and sn-3 positions indicated a certain asymmetry. The relationships between the percentage intrapositional content of each acid
(one sn-position at a time) and its percentage content in the original triacylglycerol matrix were studied. A general regression
model was used to verify if the content of each acid at the three stereospecific positions changed at the same rate as the
content in the intact triacylglycerols. The interpositional compositions of all varieties of NOS and HOS oils showed analogous
trends for each acid. 相似文献
5.
A tandem mass spectrometric method is described for the rapid analysis of fatty acid combinations in mixtures of triacylglycerols.
Triacylglycerols were introduced into a triple quadrupole mass spectrometervia a direct exposure probe and deprotonated using ammonia negative ion chemical ionization. Collisionally activated spectra
were obtained and the resulting fragments used to identify the fatty acid constituents, and the fatty acids preferentially
located at thesn-2 position of the triacylglycerols. Fourteen major molecular weight species of purified triacylglycerols of a supercritical
fluid extract of low erucic acid turnip rapeseed oil (Brassica campestris) were analyzed. The five major combinations of fatty acids comprised two thrids of the total triacylglycerols and contained
oleic, linoleic and α-linolenic acids with linoleic acid favoring thesn-2 position. 相似文献
6.
W. Van Pee L. Boni M. Foma M. Hoylaerts A. Hendrikx 《Journal of the American Oil Chemists' Society》1980,57(8):243-245
Triglycerides of mango seed kernel fat contain, depending on the variety, 32.4–44.0% of stearic acid and 43.7–54.5% of oleic
acid. Palmitic and linoleic acids represent, respectively, 5.9–9.1% and 3.6–6.7% of the fatty acids. The triglycerides also
contain minor amounts of arachidic and linolenic acids. Palmitic, stearic and arachidic acids were almost exclusively distributed
among thesn-1-andsn-3-positions. Oleic acid represented 85–89% of the fatty acids at thesn-2-position. Oleic acid at thesn-1- andsn-3-positions showed a preference for thesn-1-position. Linoleic acid was mainly esterified at thesn-2-position. The amounts of saturated fatty acids, i.e., palmitic and stearic acids, and of oleic acid, at thesn-1- and sn-3-positions, were linearly related to their respective contents in the total triglycerides. 相似文献
7.
Effects of selected substrate forms on the synthesis of structured lipids by two immobilized lipases
Two immobilized lipases, IM 60 from Rhizomucor miehei and SP 435 from Candida antarctica, were used to synthesize structured lipids (SL). Tricaprin and trilinolein were interesterified to produce SL that contained
one linoleic acid per triacylglycerol molecule (SL1) and SL with two linoleic acids (SL2). SL1 and SL2 were separated by silver
nitrate thin-layer chromatography according to their unsaturation, and the fatty acid at the sn-2 position was determined after pancreatic lipasecatalyzed hydrolysis of SL1 and SL2. With IM 60, 57.7 mol% capric acid and
42.3 mol% linoleic acid were found at the sn-2 position of SL1, while 43.3 mol% capric acid and 56.7 mol% linoleic acid were at the sn-2 position of SL2. The fatty acid at the sn-2 position of SL1 with SP 435 as biocatalyst was 43.6 mol% capric acid and 56.4 mol% linoleic acid, while SL2 contained 56.6
mol% capric acid and 43.4 mol% linoleic acid. Different structural forms of the capric acid-containing substrate (triacylglycerol
vs. ethyl ester) and different chainlengths of triacylglycerol were selected to study the substrate selectivity of lipases.
Results indicated that SP 435 had some degree of preference for the triacylglycerol form (tricaprin), and IM 60 produced SL
more rapidly and reached steady state faster with tricaprin as substrate than with capric acid ethyl ester. For chainlength
selectivity, mol% of synthesized SL from tricaprin + trilinolein and tristearin + trilinolein were compared. SP 435 exhibited
no apparent preference for either tricaprin or tristearin. However, IM 60 showed a more rapid reaction with tricaprin than
with tristearin. 相似文献
8.
Naturally occurring tetraalkylsubstituted furan fatty acids (F-acids) were tested as potential substrates for soybean lipoxygenase-1.
For this purpose, F-acid methyl ester and phosphatidylcholines containing F-acids at thesn-2 position of the glycerol residue wer incubated with the enzyme. Oxidation of F-acids only occurs in the presence of linoleic
acid as co-substrate. Linoleic acid is converted by lipoxygenase to the corresponding hydroperoxide that oxidizes the F-acid,
probably in a radical reaction, to form an unstable dioxoene compound. This intermediate the forms, dependent on pH, unsaturated
furanoid acids or isomers with cyclopentenolone structure that can be detected by gas chromatography/mass spectrometry (GC/MS).
F-acids located at thesn-2 position of a synthetic phosphadidylcholine (PC), containing linoleic acid in thesn-1 position, are co-oxidized to a greater extent by incubation with soybean lipoxygenase-1 than are F-acids bound to PC with
myristic acid in thesn-1 position when subjected to the enzyme in the presence of a great excess of linoleic acid. The results suggest that F-acids
may play a strategic role in antioxidative processes in plant cells. 相似文献
9.
Stereospecific analysis of soybeans and related species showed that there was little palmitic or stearic acid on thesn-2-position, and thesn-1-position is consistently richer in palmitic, stearic, and linolenic acids than thesn-3-position. Thesn-3-position is enriched in oleic acid and thesn-2-position with linoleic. Plots of the percentage of fatty acids on the glycerol positions vs. the percentage in the whole
oil revealed a soybean variety that had a deviant distribution that is probably genetically controlled.
Journal Paper No. J-8837 of the Iowa Agriculture and Home Economics Experiment Station, Ames IA. Project No. 2143. 相似文献
10.
The present study was carried out to examine if the positional distribution of medium-chain fatty acid (MCF) in dietary synthetic
fat influences lymphatic transport of dietary fat and the chemical composition of chylomicrons in rats with permanent cannulation
of thoracic duct. Four types of synthetic triacylglycerol were prepared: (i) sn-1(3) MCF-sn 2 linoleic acid, (ii) interesterified sn-1(3) MCF-sn 2 linoleic acid, (iii) sn-2 MCF-sn-1(3) linoleic acid, and (iv) interesterified sn-2 MCF-sn-1(3) linoleic acid. A purified diet composed of equal amounts of the synthetic fat and cocoa butter was given to rats with
permanent lymph duct cannulation. The positional distribution of MCF in the dietary fat had no significant effect on the lymph
flow, triacylglycerol output, phospholipid output, lipid composition of chylomicrons, or the particle size. The positional
distribution of MCF in the synthetic triacylglycerol was maintained in the chylomicron triacylglycerol. These results showed
that MCF in the dietary triacylglycerol is transported into lymphatics and the positional distribution is well preserved in
chylomicron triacylglycerol. 相似文献
11.
Detailed investigation was made of the triacylglycerol structure of native, simulated, and interesterified peanut oils, which
had previously been shown to differ markedly in their atherogenic potential. By means of chromatographic and stereospecific
analyses, it was shown that the more atherogenic native oil contains a significantly greater proportion of triacylglycerols
with linoleic insn-2-position and arachidic, behenic, and lignoceric acids insn-3-position than the synthetic oils. It is suggested that the atherogenicity may arise from a relative metabolic unavailability
of the linoleic acid from the native oil, which may be due in part to the presence of long chain saturated acids in the outer
position. This might render the oil metabolically more saturated than the interesterified oils of the same total fatty acid
composition, which contain a much greater proportion of the linoleic acid in the primary positions of the triacylglycerol
molecule. The identification of specific triacylglycerols may allow the experimental testing of this hypothesis by feeding
synthetic triacylglycerols incorporating the potentially atherogenic features. 相似文献
12.
The pattern of accumulation of triacylglycerols, their fatty acid compositions and the positional distribution of the fatty
acids at thesn-2- andsn-1,3-positions of the triacylglycerol molecules at progressive stages of oil palm fruit development were determined. There
was an exponential rate of increase of triacylglycerols and their fatty acids toward the end of fruit development. The fatty
acid composition of the triacylglycerols in the early stages of development, prior to active accumulation, was more or less
similar, but differed appreciably from the later stages, and the transition of fatty acid composition toward that of normal
palm oil occurred at around 16 wk after anthesis (WAA) and stabilized at 20 WAA. All fatty acids increased in terms of absolute
quantity. There was an overall consistency in fatty acid positional distribution, irrespective of development stage. More
saturated fatty acids were found to be esterified at thesn-1,3-positions and more unsaturated fatty acids at thesn-2-position of triacylglycerol. Higher rate of incorporation of 16:0 at the 1,3-positions during the active phase of triacylglycerol
synthesis was observed, while 18:1 acid exhibited a reverse trend. 相似文献
13.
The distribution of individual molecular species of the main wheat flour glycolipids, digalactosyldiglyceride (DGDG), monogalactosyldiglyceride
(MGDG), digalactosylmonoglyceride (DGMG) and monogalactosylmonoglyceride (MGMG) has been investigated by reversed phase high-performance
liquid chromatography of their benzoate derivatives after the respective galactosylglyceride classes were obtained by semi-preparative
high-performance liquid chromatography. Combinations of linoleic acid at thesn-2 position with linoleic, oleic and palmitic acids at thesn-1 position predominated as major common molecular species of MGDG and DGDG. The pairs 16:0/20:4, 18:3/20:1, 18:0/18:3, 18:0/18:1
and 20:0/18:2 were determined only among MGDG molecular species. Five common molecular species containing 16:0, 18:0, 18:1,
18:2 and 18:3 fatty acids, respectively, were determined in MGMG and DGMG, with 18:2 being the most predominant form, and
18:1 (MGMG) and 16:0 (DGMG) as the next major fatty acids. 相似文献
14.
Mohamed M. Soumanou Uwe T. Bornscheuer Rolf D. Schmid 《Journal of the American Oil Chemists' Society》1998,75(6):703-710
Structured triacylglycerides with medium-chain fatty acids (caprylic acid) in sn1- and sn3-positions and a long-chain unsaturated fatty acid (oleic or linoleic acid) in the sn2-position of glycerol (MLM) were synthesized by lipase catalysis in a two-step process. First, pure 2-monoacylglycerides
(2-MG) were synthesized by alcoholysis of triacylglycerides (triolein, trilinolein, or peanut oil) in organic solvents with
1,3-regiospecific lipases (from Rhizomucor miehei, Rhizopus delemar, and Rhizopus javanicus). The 2-MG were purified by crystallization and obtained in up to 71.8% yield. These 2-MG were esterified in a second reaction
with caprylic acid in n-hexane to form almost pure MLM. For 2-MG obtained from peanut oil, the final product contained more than 90% caprylic acid
in the sn1- and sn3-positions, whereas the sn2-position was composed of 98.5% unsaturated long-chain fatty acids. Reaction conditions for both steps were optimized with
respect to source and immobilization of lipase, water activity, and solvent. 相似文献
15.
Dibutyrate derivatives of monoacylglycerols of oleic, petroselinic, and cis-vaccenic acids were prepared by diesterification of monoacylglycerols with n-butyryl chloride. The resulting triacylglycerols were analyzed by gas chromatography (GC) with a 65% phenyl methyl silicone
capillary column and separated on the basis of both fatty acid composition and regiospecific position. The petroselinic acid
derivatives eluted first, followed sequentially by the oleic and cis-vaccenic acid derivatives, with the sn−2 positional isomer eluting before the sn−1(3) isomer in each case. Separation of the peaks was almost baseline between petroselinic and oleic acids as well as between
oleic and cis-vaccenic acids. To assess the accuracy of the method, mixtures of triolein, tripetroselinin, and tri-cis-vaccenin in various known proportions were partially deacylated with the use of ethyl magnesium bromide and derivatized and
analyzed as above. The results showed that this method compares favorably to the existing methods for analysis of oleic, petroselinic,
and cis-vaccenic fatty acids by GC with respect to peak separation and accuracy, and it also provides information on the regiospecific
distribution of the fatty acids. The method was applied to basil (Ocimum basilicum) and coriander (Coriandrum sativum) seed oils. cis-Vaccenic, oleic, and linoleic acids were mainly distributed at the sn−2 position in basil seed oil, and higher proportions of linolenic, palmitic, and stearic acids were distributed at the sn−1(3) position than at the sn−2 position. In coriander seed oil, petroselinic acid was mainly distributed at the sn−1(3) position, and both oleic and linoleic acids were mostly located at the sn−2 position, whereas palmitic, stearic, and cis-vaccenic acids were located only at the sn−1(3) position. 相似文献
16.
Bovine milk fat was fractionated using preparative reversed-phase high-performance liquid chromatography. The conditions consisted
of two successive linear gradients of acetonitrile and tert-butylmethylether, followed by a final isocratic mixture of the two eluants, leading to triacylglycerols grouped by their
partition number (PN). Fractions corresponding to partition numbers 32 to 50 were isolated and analyzed for fatty acid distribution
between sn-1,3 and sn-2 positions by Grignard degradation. Results showed that the fatty acid distribution in milk fat triacylglycerols is nonrandom.
The distribution of short-chain fatty acids, stearic (predominantly at sn-1,3 position) and palmitic (predominantly sn-2 position), did not change with triacylglycerol size. Medium-chain fatty acids were predominantly located at sn-2 position, but their proportion at this position decreased with triacylglycerol size. Oleic acid distribution was also size-dependent
in that it was located in high proportions at sn-2 position in smaller triacylglycerols and vice versa. Results also showed that the sn-2 position was more unsaturated than sn-1,3 position in the PN range from 32 to 40, but it was more saturated in triacylglycerols with higher PN. 相似文献
17.
Milk fatty acids consist of about 20–25% palmitic acid (16∶0), with about 70% of 16∶0 esterified to thesn-2 position of the milk triacylglycerols. Hydrolysis of dietary triacylglycerols by endogenous lipases producessn-2 monoacylglycerols and free fatty acids, which are absorbed, reesterified, and then secreted into plasma. Unesterified 16∶0
is not well absorbed and readily forms soaps with calcium in the intestine. The positioning of 16∶0 at thesn-2 position of milk triacylglycerols could explain the high coefficient of absorption of milk fat. However, the milk lipase,
bile salt-stimulated lipase, has been suggested to complete the hydrolysis of milk fat to free fatty acids and glycerol. These
studies determined whether 16∶0 is absorbed from human milk assn-2 monopalmitin by comparison of the plasma triacylglycerol total andsn-2 position fatty acid composition between breast-fed and formula-fed term gestation infants. The human milk and formula had
21.0 and 22.3% of 16∶0, respectively, with 54.2 and 4.8% 16∶0 in the fatty acids esterified to the 2 position. The plasma
triacylglycerol total fatty acids had 26.0±0.6 and 26.2±0.6% of 16∶0, and thesn-2 position fatty acids had 23.3±3.3 and 7.4±0.7% of 16∶0 in the three-month-old exclusively breast-fed (n=17) and formula-fed
(n=18) infants, respectively. Marked differences were found in the plasma total and the 2 position phospholipid percentage
of 20∶4ω6, i.e., 11.6±0.3 and 6.9±0.6 (total), 17.7±1.4 and 9.7±0.6 (sn-2 position) and percentage of 22∶6ω3, 4.6±0.3 and 2.1±0.3 (total), 5.6±0.6 and 2.0±0.2 (sn-2 position) for the breast-fed and formula-fed infants, respectively. These studies provide convincing evidence that 16∶0
is absorbed from human milk assn-2 monoacyl-glycerol. The metabolic significance of the differences in positional distribution of fatty acids in the plasma
lipids of breast-fed and formula-fed infants is not known. 相似文献
18.
Cam‐Chi Ngo‐Duy Frédéric Destaillats Marjo Keskitalo Joseph Arul Paul Angers 《European Journal of Lipid Science and Technology》2009,111(2):164-169
Oils from the seeds of caraway (Carum carvi), carrot (Daucus carota), celery (Apium graveolens) and parsley (Petroselinum crispum), all from the Apiaceae family, were analyzed by gas chromatography for their triacylglycerol (TAG) composition and fatty acid (FA) distribution between the sn‐1(3) and sn‐2 positions of TAG. Twenty‐two TAG species were quantified. Glyceryl tripetroselinate was the major TAG species in seed oils of carrot, celery and parsley, with levels ranging from 38.7 to 55.3%. In caraway seed oil, dipetroselinoyllinoleoylglycerol was the major TAG species at 21.2%, while the glyceryl tripetroselinate content was 11.4%. Other TAG species were linoleoyloleoylpetroselinoylglycerol and dipetroselinoyloleoylglycerol. Predominantly, TAG were triunsaturated (72.2–84.0%) with diunsaturates at 14.4–25.9%, and small amounts of monounsaturated TAG. Results for regiospecific analysis showed a non‐random FA distribution in Apiaceae for palmitic, petroselinic, linoleic and oleic acids. Petroselinic acid was predominantly located at the sn‐1(3) position in carrot, celery and parsley seed oils, while it was mainly at the sn‐2 position in caraway seed oil. The distribution of linoleic acid was opposite to that of petroselinic acid. Oleic acid was mostly located at the sn‐2 position, except for caraway, where it was evenly distributed between the sn‐1(3) and sn‐2 positions. Both the saturated FA, palmitic and stearic acid, were located mainly at the sn‐1(3) position. The presence of a high level of tripetroselinin in parsley seed oil (55.3%) makes it a potential source for the production of petroselinic acid. 相似文献
19.
Carlos A. Álvarez Casimir C. Akoh 《Journal of the American Oil Chemists' Society》2015,92(7):1003-1014
A structured lipid (SL) with a substantial amount of palmitic acid at the sn‐2 position and enriched with capric acid (C), was produced in two enzymatic interesterification stages by using immobilized lipase, Lipozyme® TL IM (Novozymes North America Inc., Franklinton, NC, USA). The substrates for the reactions were high melting point palm stearin, high oleic sunflower oil and tricaprin. The SL was characterized for total and positional fatty acid profiles, triacylglycerol (TAG) molecular species, free fatty acid content, melting and crystallization profiles. The final SL contained 20.13 mol% of total palmitic acid, of which nearly 40 % was located at the sn‐2 position. The total capric acid content was 21.22 mol%, mostly at the sn‐1 and sn‐3 positions. The predominant TAGs in the SL were oleic–palmitic–oleic, POP and CLC. The melting completion and crystallization onset temperatures of the SL were 27.7 and 6.1 °C, respectively. The yield for the overall reaction was 90 wt%. This SL might be totally or partially used in commercial fat blends for infant formula. 相似文献
20.
The objective of this study was to demonstrate that changing the fatty acid composition of bovine adipose tissue concurrently
changed (i) proportions of triacylglycerol species, (ii) fatty acid composition of triacylglycerol species, and (iii) positional
distribution of the component fatty acids of the triacylglycerol species. To achieve this, we took advantage of adipose tissue
lipids, from cattle fed in Australia and Japan, that varied widely in fatty acid composition and melting points. Treatment
groups produced in Australia were cattle fed: a cornbased diet (MUFA1); a grain-based diet containing whole cottonseed (SFA);
a grain-based diet containing protected cottonseed oil (PUFA); and a grain-based diet that resulted in high contents of trans fatty acids (TFA). Treatment groups produced in Japan (MUFA2 and MUFA3) were diets of unknown composition fed for over 300
d. The MUFA1, MUFA2, and MUFA3 samples all were rich in monounsaturated fatty acids, varying only in the proportions of the
individual monounsaturates. The SFA, PUFA, and TFA samples had relatively high concentrations 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, MUFA1, MUFA2, and MUFA3 groups, respectively (P<0.05). Triacylglycerols were separated by high-performance liquid chromatography on a silver nitrate-impregnated column into
sn-1,2,3-saturated fatty acid triacylglycerol (SSS); [triacylglycerols containing two saturated acids and one trans-monounsaturated fatty acid (SSMt sn-positions unknown)]; sn-1-saturated, 2-monounsaturated, 3-saturated triacylglycerol (SMS); sn-1-saturated, 2-monounsaturated, 3-trans-monounsaturated triacylglycerol (SMMt); sn-1-saturated, 2,3-monounsaturated fatty acid triacylglycerol (SMM); sn-1-saturated, 2-polyunsaturated, 3-trans-monounsaturated triacylglycerol; sn-1,2,3-monounsaturated fatty acid triacylglycerol (MMM); and sn-1-saturated, 2-polyunsaturated, 3-monounsaturated triacylglycerol. Fatty acid methyl esters of each triacylglycerol species
also were determined, and further analysis indicated sn-2, and sn-1/3 positions. As the percentage oleic acid increased in the total lipid extract, the proportions of SMM and MMM increased
(e.g., from 31.4 and 2.4% in the SFA group to 55.4 and 17.8% in the MUFA3 group). The elevated 18:0 in the SFA group (26%)
was reflected in increased percentages of SSS and SSM, and caused an increase in the proportion of 18:0 in all triacylglycerol
species relative to the other treatment groups. The percentage of 18:0 in the sn-1/3 positions was elevated markedly in the SMS fraction of the SFA group (to 44%); this would account for the high melting
point of the fat of these animals. We conclude that long-term feeding of cattle is sufficient to produce significant alterations
in fatty acid composition in bovine adipose tissue. Alterations in the fatty acid composition of bovine adipose tissue changed
both the distribution and the composition of the triacylglycerol species, which, in turn, accounted for marked differences
in melting points among treatment groups. 相似文献