共查询到20条相似文献,搜索用时 15 毫秒
1.
Peter W. Parodi 《Lipids》1982,17(6):437-442
Milk triglycerides from the echidna, koala, Tammar wallaby, guinea pig, dog, cat, Weddell seal, horse, pig and cow were subjected
to fatty acid and stereospecific analysis to determine the positional distribution of the fatty acids in the triglycerides.
The samples presented a wide range of fatty acids, most of which varied in content among species. The compositions of the
acids at the 3 positions also varied among species, reflecting the content of these acids in the triglycerides. However, there
was a general similarity in fatty acid positional distribution patterns for all the species with the exception of the echidna.
The echidna exhibited a completely different fatty acid positional distribution pattern. The saturated acids were preferentially
esterified at thesn-1-position whereas the unsaturated acids were selectively esterified at thesn-2-position. The triglyceride carbon number distribution of milk from the above species (with the exception of the Weddell
seal) was determined by gas liquid chromatography and compared to that predicted by the 1-random-2-random-3-random fatty acid
distribution hypothesis. Agreement was excellent between observed and predicted composition for echidna, koala, Tammar wallaby,
guinea pig and pig milk, and agreement was reasonable for dog, cat, horse and cow milk. Results are discussed in relation
to biochemical mechanisms. 相似文献
2.
Freshly isolated rat hepatocytes were incubated for 20 min with [U-14C]glycerol in the presence or absence of unlabeled linoleic (18∶2n-6), arachidonic (20∶4n-6), or docosahexaenoic (22∶6n-3)
acid, added as albumin complex in 10% ethanol. Most of the radioactivity (≈95%) recovered in hepatocyte lipids was present
in phosphatidylcholine (PC), phosphatidylethanolamine (PF), and triacylglycerol (TAG). The presence of exogenous fatty acids
resulted in (i) higher incorporation of [U-14C]glycerol, (ii) higher percentage of label in TAG, and (iii) enhanced formation of PC and PE molecular species bearing the
exogenous fatty acid at both the sn-1 and sn-2 positions of glycerol. In each case, these molecular species contained 60 to 70% of the label in that lipid class. Further
incubation of the cells for 40 and 80 min in the absence of labeled substrate and exogenous fatty acids resulted in a redistribution
of label among PC and PE molecular species due to deacylation-reacylation at the sn-1 position of glycerol. 相似文献
3.
Tong Wang Earl G. Hammond Walter R. Fehr 《Journal of the American Oil Chemists' Society》1997,74(12):1587-1594
Phospholipid (PL) fatty acid composition and stereospecific distribution of 25 genetically modified soybean lines with a wide
range of compositions were determined by gas chromatography and phospholipase A2 hydrolysis. Pl contained an average of 55.3% phosphatidylcholine, 26.3% phosphatidylethanolamine, and 18.4% phosphatidylinositol.
PL class proportions were affected by changes in overall fatty acid composition. PL fatty acid composition changed with oil
fatty acid modification, especially for palmitate, stearate, and linolenate. Stereospecific analysis showed that saturated
fatty acids were primarily located at the sn-1 position of all PL, and changes of the saturates in PL were largely reflected on this position. Oleate was distributed
relatively equally between the sn-1 and sn-2 positions. Linoleate was much more concentrated on sn-2 than on sn-1 position for all PL. Linolenate was distributed relatively equally at low concentration but preferred sn-2 position at high concentration. 相似文献
4.
J. E. Kinsella 《Lipids》1972,7(3):165-170
The microsomes isolated from lactating bovine mammary tissue contained 4.3 mg lipid per milligram nitrogen. Phospholipids
comprised 83% of the lipids. The neutral lipids were composed of triglycerides (20–30%), diglycerides (5–10%), free fatty
acids (15–30%, cholesterol (35–40% and cholesterol esters (10–12%, respectively. Phosphatidylcholine was the predominant phospholipid
component (>50%), and the remainder consisted of phosphatidylethanolamine (21–13%), phosphatidylserine (4–6%), phosphatidylinositol
(8%), sphingomyelin (9%) and lysophosphatidylcholine (2%) respectively. The composition of the microsomal phospholipids was
similar to that of isolated mammary cells and tissue homogenates but quite different from milk and fat globule membrane phospholipids.
The triglycerides contained short chain fatty acids but their relative concentrations were lower than in milk triglycerides.
The various lipid fractions had a variable proportion of saturated fatty acids, i.e., triglycerides (47.7%), diglycerides
(86.7%), free fatty acids (70.6%), phosphatidylcholine (50.6%), phosphatidylethanolamine (50.8%), phosphatidylserine (35.3%),
phosphatidylinositol (40.5%) and sphingomyelin (82.3%), respectively. The molecular distribution of fatty acids in the microsomal
triglycerides and phosphatidylcholine was similar to that occurring in milk, i.e., the short chain and unsaturated fatty acids
were concentrated in the primary positions (sn1 andsn3) of the triglycerides, and the unsaturated acids were preferentially located in positionsn2 of the phosphatidylcholine. The compositional data indicate that mammary microsomes are not the direct source of the phospholipids
of the milk fat globule. 相似文献
5.
Roberta Claro da Silva Fabiana Andreia Schaffer De Martini Soares Thaís Gonzaga Fernandes Anna Laura Donadi Castells Kelly Caroline Guimarães da Silva Maria Inês Almeida Gonçalves Chiu Chih Ming Lireny Aparecida Guaraldo Gonçalves Luiz Antonio Gioielli 《Journal of the American Oil Chemists' Society》2011,88(12):1925-1933
Structured lipids (SL), formulated by blends of lard and soybean oil in different ratios, were subjected to continuous enzymatic
interesterification catalyzed by an immobilized lipase from Thermomyces lanuginosus (Lipozyme TL IM) in a continuous packed bed reactor. The original and interesterified blends were examined for fatty acid
and triacylglycerol composition, regiospecific distribution, and solid fat content. Blends of lard and soybean oil in the
proportions 80:20 and 70:30 (w/w), respectively, demonstrated a fatty acid composition, and proportions of polyunsaturated/saturated
fatty acids (PUFA/SFA) and monounsaturated/polyunsaturated fatty acids (MUFA/PUFA), that are appropriate for the formulation
of pediatric products. These same blends were suited for this purpose after interesterification because their sn-2 positions were occupied by saturated fatty acids (52.5 and 45.4%, respectively), while unsaturated fatty acids predominantly
occupied sn-1,3 positions, akin to human milk fat. Interesterification caused rearrangement of triacylglycerol species. 相似文献
6.
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
7.
Laura J. Pham Edmar P. Casa Myla A. Gregorio Dae Young Kwon 《Journal of the American Oil Chemists' Society》1998,75(7):807-811
Three Philippine seed oils, namely coconut (Cocos nucifera Linn.), pilinut (Canarium ovatum Engl.), and cashew (Anacardium occidentale Linn.), which were selected for their local abundance and availability, were examined for their triacylglycerol profiles
and fatty acid compositions. Triacylglycerol molecular species in terms of carbon number and partition number were determined
by gas chromatography and liquid chromatography, respectively. The distribution of fatty acids in the primary and secondary
positions of the glycerol backbones for the three oils were examined by regiospecific analysis by using pancreatic lipase.
Coconut oil had high concentrations of lauric and myristic acids, while the other two oils did not have such fatty acids.
Lauric acid in coconut oil and linoleic acid in pilinut oil were distributed mainly in the primary positions (sn-1,3) of the glycerol backbone. Trilaurin and dioleylpalmitoylglycerol were the major triglycerides in coconut and pilinut
oils, respectively. 相似文献
8.
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
9.
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
10.
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
11.
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
12.
The distribution of C14–C22 fatty acids in the phosphatidylethanolamines isolated from the spongesAgelas sp. andSpongia tampa was investigated. Selective changes with phospholipase A2 (fromAgkistrodon halys blomhoffii) followed by thin-layer chromatographic separation of the resulting lysophosphatidylethanolamines and free fatty acids and
subsequent methylation with HCl/MeOH and diazomethane, respectively, revealed that the 5,9-octadecadienoic acid and the 9,12-octadecadienoic
acid present showed no preference for either positionsn-1 orsn-2 in these phosphatidylethanolamines. The other saturated and unsaturated fatty acids with chains between 14 and 22 carbons
long were also found to be equally distributed between positionssn-1 andsn-2 in the phosphatidylethanolamines in these sponges. The results contrast with what is known about the distribution in most
mammalian phospholipids, such as the phosphatidylcholines from human erythrocytes, where octadecadienoic acid typically occupies
thesn-2 position. 相似文献
13.
Julia Svensson Patrick Adlercreutz 《European Journal of Lipid Science and Technology》2008,110(11):1007-1013
A blend of rapeseed and butter oil was transesterified using immobilized Thermomyces lanuginosus lipase (Lipozyme® TL IM) as catalyst. The reaction was followed by reversed-phase HPLC and the triacylglycerol peaks were tentatively identified from their elution times by calculating equivalent carbon numbers. Further identification was made using HPLC-electrospray tandem mass spectrometry. A few of the triacylglycerols detected were typical combinations of fatty acids originating from rapeseed oil, such as α-linolenic acid, and short-chain fatty acids from butter oil. Due to the regioselectivity of the lipase, the transesterification reaction involved mainly fatty acids in the sn-1 and sn-3 positions. However, significant changes in the fatty acid composition in the sn-2 position were detected after 6 h. 相似文献
14.
Hiromi Yoshida Yuka Tomiyama Naoko Yoshida Yoshiyuki Mizushina 《European Journal of Lipid Science and Technology》2009,111(4):386-391
Regiospecific distributions of fatty acids of triacylglycerols (TAG) and phospholipids (PL) separated from broad beans (Vicia faba) of four cultivars (Minpo, Sanuki, Nintoku and Sanren) were investigated. The major lipid components were PL (47.5–50.5 wt‐%) and TAG (47.7–50.1 wt‐%), while steryl esters, hydrocarbons, free fatty acids, diacylglycerols and monoacylglycerols were present in minor proportions (1.6–2.4 wt‐%). The PL components isolated from the four cultivars were phosphatidylcholine (56.4–58.4 wt‐%), phosphatidylethanolamine (20.3–21.7 wt‐%) and phosphatidylinositol (16.6–18.6 wt‐%). Phosphatidylinositol was unique in that it had the highest saturated fatty acid content among these PL. The principal characteristics of the fatty acid distribution in the TAG and PL were evident in the beans: Unsaturated fatty acids were predominantly concentrated in the sn‐2 position while saturated fatty acids primarily occupied the sn‐1 or sn‐3 position in these lipids. The lipid components and fatty acid distributions were almost the same in the four cultivars and were not influenced by genetic variability and planting location. These results could be useful information to both consumers and producers for the manufacture of traditional broad bean foods in Japan. 相似文献
15.
Matthew R. Miller Nigel B. Perry Elaine J. Burgess Susan N. Marshall 《Journal of the American Oil Chemists' Society》2011,88(4):509-516
The lipid profiles of the two most important New Zealand marine oil sources were investigated, with particular attention to
the regioisomeric compositions of triacylglycerides (TAG), using 13C-nuclear magnetic resonance analysis. Oils from hoki (Macruronus novaezelandiae) and Greenshell™ mussel (Perna canaliculus) (GSM) were analyzed for their lipid content, lipid class and fatty acid profile. The regiospecific distribution of long
chain (C ≥ 20) polyunsaturated fatty acids (LC-PUFA) between the sn-1,3 and sn-2 glycerol positions was calculated from 13C responses in the carbonyl region in the triacylglycerol fraction. Rendered hoki oil (RHO) produced from the viscera and
filleting discards, had a similar lipid profile to that of hoki liver oil (HLO) confirming that the liver is the major source
of oil in RHO. The regioisomeric distribution of fatty acids showed differences between the two oil sources. Docosahexaenoic
acid (DHA) had a regioisomeric distributional preference to the sn-2 position in TAG from all the oils (59.2% HLO, 54.3% RHO and 63.4% GSM). Eicosapentaenoic acid (EPA) had a more even distribution
along the triacylglycerol backbone in hoki TAG (29.1% HLO, 33.6% RHO) while there was a slight sn-2 positional preference in the GSM TAG (37.6%). This regioisomeric information is vital to distinguish LC-PUFA-rich marine
oils from other marine sources for authentication purposes. 相似文献
16.
Marie‐Caroline Michalski 《European Journal of Lipid Science and Technology》2009,111(5):413-431
In milk fat, fatty acids are located at specific positions on the triacylglycerol backbone. The sn‐2 position contains most saturated long‐chain fatty acids, while the sn‐3 position contains short‐chain fatty acids. Moreover, these triacylglycerols are structured as milk fat globules surrounded by their native membrane containing phospholipids. This native structure can be modified by the dairy processes to generate various possible colloidal structures with milk fat. The structure of triacylglycerols and the milk fat ultrastructure can impact on fatty acid digestion and absorption, which has a potential effect on cardiovascular risk factors linked to postprandial hypertriglyceridemia. The review points out the impact of the triacylglycerol structure and the ultrastructure of milk fat on these risk factors. 相似文献
17.
Hiromi Yoshida Masayuki Saiki Yuka Tomiyama Yoshiyuki Mizushina 《European Journal of Lipid Science and Technology》2008,110(2):158-163
The fatty acid distributions of triacylglycerols (TAG) and major phospholipids (PL) obtained from adzuki beans (Vigna angularis) were investigated. The total lipids extracted from the beans were separated by thin‐layer chromatography (TLC) into eight fractions. The major lipid components were PL (63.5 wt‐%), TAG (21.2 wt‐%), steryl esters (7.5 wt‐%) and hydrocarbons (5.1 wt‐%), while free fatty acids, diacylglycerols (1,3‐DAG and 1,2‐DAG) and monoacylglycerols were also present in minor proportions (0.2–1.1 wt‐%). The major PL components isolated from the beans were phosphatidylcholine (45.3 wt‐%), phosphatidylethanolamine (25.8 wt‐%) and phosphatidylinositol (21.5 wt‐%). Phosphatidylinositol was unique in that it had the highest saturated fatty acid content among the three PL. With a few exceptions, however, the principal characteristics of the fatty acid distribution in the TAG and three PL were evident in the beans: Unsaturated fatty acids were predominantly concentrated in the sn‐2 position while saturated fatty acids primary occupied the sn‐1 or sn‐3 position in the oils of the adzuki beans. In general, these results could be useful to both consumers and producers for the manufacture of traditional adzuki foods in Japan. 相似文献
18.
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
19.
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
20.
Carlos F. Torres Hugo S. Garcia Jason J. Ries Charles G. Hill Jr. 《Journal of the American Oil Chemists' Society》2001,78(11):1093-1098
Free fatty acids from fish oil were prepared by saponification of menhaden oil. The resulting mixture of fatty acids contained
ca. 15% eicosapentaenoic acid (EPA) and 10% docosahexaenoic acid (DHA), together with other saturated and monounsaturated fatty
acids. Four commercial lipases (PS from Pseudomonas cepacia, G from Penicillium camemberti, L2 from Candida antarctica fraction B, and L9 from Mucor miehei) were tested for their ability to catalyze the esterification of glycerol with a mixture of free fatty acids derived from
saponified menhaden oil, to which 20% (w/w) conjugated linoleic acid had been added. The mixtures were incubated at 40°C for
48h. The ultimate extent of the esterification reaction (60%) was similar for three of the four lipases studied. Lipase PS
produced triacylglycerols at the fastest rate. Lipase G differed from the other three lipases in terms of effecting a much
slower reaction rate. In addition, the rate of incorporation of omega-3 fatty acids when mediated by lipase G was slower than
the rates of incorporation of other fatty acids present in the reaction mixture. With respect to fatty acid specificities,
lipases PS and L9 showed appreciable discrimination against esterification of EPA and DHA, respectively, while lipase L2 exhibited
similar activity for all fatty acids present in the reaction mixture. The positional distribution of the various fatty acids
between the sn-1,3 and sn-2 positions on the glycerol backbone was also determined. 相似文献