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1.
Thomas A. Foglia Kerby C. Jones Philip E. Sonnet 《European Journal of Lipid Science and Technology》2000,102(10):612-617
The lipase‐catalyzed hydrolysis of castor, coriander, and meadowfoam oils was studied in a two‐phase water/oil system. The lipases from Candida rugosa and Pseudomonas cepacia released all fatty acids from the triglycerides randomly, with the exception of castor oil. In the latter case, the P. cepacia lipase discriminated against ricinoleic acid. The lipase from Geotrichum candidum discriminated against unsaturated acids having the double bond located at the Δ‐6 (petroselinic acid in coriander oil) and Δ‐5 (meadowfoam oil) position or with a hydroxy substituent (ricinoleic acid). The expression of the selectivities of the G. candidum lipase was most pronounced in lipase‐catalyzed esterification reactions, which was exploited as part of a two‐step process to prepare highly concentrated fractions of the acids. In the first step the oils were hydrolyzed to their respective free fatty acids, in the second step a selective lipase was used to catalyze esterification of the acids with 1‐butanol. This resulted in an enrichment of the targeted acids to approximately 95—98% in the unesterified acid fractions compared to the 70—90% content in the starting acid fractions. 相似文献
2.
The purpose of this study was to investigate the hydrolysis of saturated and unsaturated triglycerides by lung lipoprotein
lipase and to measure the incorporation of triglyceride fatty acids into lung tissue lipids. Lipolytic activity was studied
in the isolated ventilated rat lung, perfused for 100 min in a recycling system with Krebs Ringer bicarbonate containing bovine
serum albumin, 5.6 mM glucose, and 1.5 or 10 mM triglyceride. Saturated triglycerides were hydrolyzed at significantly (p<0.05)
lower rates than unsaturated triglycerides; tricaprylin, trimyristin and tripalmitin were hydrolyzed at 8.1+1.8, 5.4+1.5 and
9.5+1.8 μmol free fatty acids/g dry wt/100 min, respectively, whereas triolein and trilinolein were hydrolyzed at 20.2+1.8
and 20.6+0.3 μmol free fatty acids/g dry wt/100 min, respectively. The polyunsaturated triglycerides, trilinolein and triarachidonin
were hydrolyzed at even higher rates (44.3+3.0 and 50.9+5.4 μmol free fatty acids/g dry wt/100 min, respectively). Intralipid
infused at a concentration of 10 mM triglyceride was hydrolyzed at a significantly higher rate than at 1.5 mM triglyceride
(58+6.3 μmol free fatty acids/g dry wt/100 min vs 16.6+1.7 μmol free fatty acids/g dry wt/100 min, respectively). Labeled
unsaturated triglycerides were broken down at significantly higher rates than labeled saturated triglycerides. Incorporation
of triglyceride-fatty acid into lung lipid was greater into neutral lipids than into phospholipids. The data suggest that
(a) the factors that appear to affect lung lipoprotein lipase activity are composition and concentration of circulating triglyceride,
(b) uptake of fatty acids into the tissue was proportional to the rate of hydrolysis of the emulsion, and (c) triglyceride-fatty
acids could therefore be used by the lung for metabolic needs.
The data presented in part at the Annual Meetings of the American Physiological Society, Atlanta, GA, April 1981, and the
American Thoracic Society, Detroit, MI, May 1981, and published in abstract form-Fed. Proc. 40, 621 (1981), andAm. Rev. Respir. Dis. 123, 219 (1981). 相似文献
3.
To improve the economic feasibility of hydrolyzing fats and oils with moist oat caryopses, various factors affecting the efficiency
of the process were studied. Caryopses produced with an impact-type dehuller exhibited greater lipase activity than those
produced by a wringer-type dehuller. Abrasion of oat caryopses against each other in a fluidized bed released particles rich
in lipase. Such lipase concentrates could be added to moist caryopsis reactors to speed fat hydrolysis. Beef tallow, lard,
soybean oil and crambe oil were hydrolyzed more efficiently than corn oil, castor oil and milk fat. The poor hydrolysis of
castor oil was attributed to the formation of esters with the hydroxy group of ricinoleic acid, and the hydrolysis of castor
oil was increased by dilution of the substrate with hexane. Diglycerides inhibited the hydrolysis and accounted for the slower
hydrolysis of corn oil. Hydrolysis of milk fat by moist oat caryopses resulted in preferential hydrolysis of C6 to C10 acids. Erucic acid was released from crambe oil at significantly slower rates than the other acyl groups. High conversions
of fats and oils to free fatty acids could be attained by (i) exposing the fats and oils to two to three lots of moist caryopses,
(ii) the use of special oat varieties with elevated lipase content, (iii) the addition of oat lipase concentrates to moist
caryopsis reactors, and (iv) dilution of the substrate with hexane. Estimates of the cost of producing free fatty acids with
these processes indicated that the first three should be profitable. Growth ofClostridium sporogenes spores could not be demonstrated in caryopsis reactors. During the incubation of moist oat caryopses immersed in oil, the
free fatty acid content of the internal caryopsis lipid increased only slightly, but there were changes in its fatty acid
composition. 相似文献
4.
Douglas G. Hayes Robert Kleiman Bliss S. Phillips 《Journal of the American Oil Chemists' Society》1995,72(5):559-569
Members of the genusLesquerella, native to North America, have oils containing large amounts of hydroxy fatty acids and are under investigation as potential
new crops. The triglyceride structure of oils from twenty-fiveLesquerella species in the seed collection at our research center has been examined after being hydrolysis-catalyzed by reverse micellar-encapsulated
lipase and alcoholysis-catalyzed by immobilized lipase. These reactions, when coupled with supercritical-fluid chromatographic
analysis, provide a powerful, labor-saving method for oil triglyceride analysis. A comprehensive analysis of overall fatty
acid composition of these oils has been conducted as well.Lesquerella oils (along with oils from two other Brassicaceae:Physaria floribunda andHeliophilia amplexicaulis) have been grouped into five categories: densipolic acid-rich (Class I); auricolic acid-rich (Class II); lesquerolic acid-rich
(Class III); an oil containing a mixture of hydroxy acids (Class IV); and lesquerolic and erucic acid-rich (Class V). The
majority of Class I and II triglycerides contain one or two monoestolides at the 1- and 3-glycerol positions and a C18 polyunsaturated acyl group at the 2-position. Most Class III and IV oil triglycerides contain one or two hydroxy acids at
the 1- and 3-positions and C18 unsaturated acid at the 2-position. A few of the Class III oils have trace amounts of estolides. The Class V oil triglycerides
are mostly pentaacyl triglycerides and contain monestolide and small amounts of diestolide. Our triglyceride structure assignments
were supported by1H nuclear magnetic resonance data and mass balances. 相似文献
5.
Fish oils containing different levels of polymers of triacylglycerols formed during autoxidation were incubated with pancreatic
lipase to establish whether these polymers are substrates for lipase hydrolysis. With oils containing low amounts (less than
4%) of triacylglycerol polymers as substrates, both triacylglycerols and polymers of triacylglycerols were almost completely
hydrolyzed, and fatty acid monomers and monoacylglycerols were the major lipid products. Under the same incubation conditions,
some triacylglycerols remained intact when highly oxidized oils containing 20 or 30% triacylglycerol polymers were the substrate.
The fatty acid composition of these residual triacylglycerols was almost identical to that of triacylglycerols present at
the start of the assay. When fish oil containing 30% triacylglycerol polymers was incubated with the lipase, the component
triacylglycerols and polymers of triacylglycerols were hydrolyzed at similar rates, and fatty acid dimers were detected as
a product. It is concluded that the high molecular weight polymers of triacylglycerols present in oxidized fish oils can be
hydrolyzed by pancreatic lipasein vitro. 相似文献
6.
Alexander Bilyk Raymond G. Bistline Michael J. Haas Stephen H. Feairheller 《Journal of the American Oil Chemists' Society》1991,68(5):320-323
An investigation of lipases fromRhizomucor miehei,Candida rug osa and porcine pancreas revealed that these enzymes hydrolyzed triglycerides in an organic solvent system. The presence of secondary
amines,i.e., diethylamine,N-methylbutylamine, or the tertiary amine, Methylamine, greatly increased the extent of hydrolysis. The lipolysis of tallow
took place under mild conditions,e.g., room temperature, moderate shaking and within 20 hr. At 45°C, complete hydrolysis of tallow was obtained in 6 hr. Vegetable
oils and a fish oil (cod liver oil) were also hydrolyzed at 20°C byR. miehei lipase in the presence of iV-methylbutylamine for 20 hr. The lipases were recovered for reuse with some loss of activity.
Optimum yields of free fatty acids were obtained by usingR. miehei lipase as catalyst.
Mention of brand or firm names does not constitute an endorsement by the U.S. Department of Agriculture over others of a similar
nature not mentioned. 相似文献
7.
Microbial lipase-catalyzed hydrolysis, esterification, and alcoholysis reactions were carried out on acid oils of commerce
such as coconut, soybean, mustard, sunflower, and rice bran for the purpose of making fatty acids and various monohydric alcohol
esters of fatty acids of the acid oils. Neutral glycerides of the acid oils were hydrolyzed byCanadida cylindracea lipase almost completely within 48 h. Acid oils were converted into fatty acid esters of short- and long-chain alcohols like
C4, C8, C10, C12, C16, and C18 in high yields by simultaneous esterification and alcoholysis reactions withMucor miehei lipase as catalyst. Acid oils of commerce can be utilized as raw materials in making fatty acids and fatty acid esters using
lipase-catalyzed methodologies. 相似文献
8.
Acid lipase of the castor bean 总被引:1,自引:0,他引:1
Robert L. Ory 《Lipids》1969,4(3):177-185
The acid lipase of the castor bean is present in the dormant seed. It is extracted from the fat pad obtained by centrifuging
a macerate of the seed in pH 7.0 buffer containing cysteine and ethylene diaminetetraacetic acid. The pH optimum of the enzyme
is 4.2; it is rather heat-stable, and is inhibited by mercurials and sulfhydryl reagents. Maximum hydrolysis of saturated
triglycerides occurs with fatty acids of chain length C4 to C8; unsaturated C18 triglycerides are hydrolyzed at a slightly lower rate.
This lipase is a three-component system consisting of the apoenzyme, a lipid cofactor (a cyclic tetramer of ricinoleic acid),
and a protein activator (a small, heat-stable glycoprotein which appears to be related to some of the castor allergens). Maximum
lipolysis requires all three components. Lipase activity is associated with the spherosomes, the subcellular site of oil storage
in the endosperm.
Presented at the AOCS-AACC Joint Meeting, Washington, D.C., April 1968.
So. Utiliz. Res. Dev. Div., ARS, USDA. 相似文献
9.
G. Üstun L. Kent N. Çekin H. Civelekoglu 《Journal of the American Oil Chemists' Society》1990,67(12):958-960
Three commercially cultivatedNigella sativa seed varieties of Turkish origin were analyzed, and the characteristics and constituents of the seed oils were reported.
Presence of lipase enzyme in seed results in enzymatic hydrolysis at ordinary temperature; the free acid content of oil may
increase up to 40% or higher. Black cumin seed oil might serve as a source of semi-drying oil and fatty acids of technical
grade, and the removal of free fatty acids from oil and the recovery of fatty acids were investigated. 相似文献
10.
Acetone powders prepared fromVernonia anthelmintica seed catalyzed the release of 6.4 to 9.6 μ-moles of free fatty acids per milligram of protein when blended with olive oil
and phosphate buffer and shaken for 20 min at 43 C. A 20 fold purification was achieved by differential centrifugation of
an ammonium hydroxide extract of the acetone powder. Results from Sephadex G-200 chromatography and polyacrylamide gel electrophoresis
suggested that the lipase activity was associated with a molecule of molecular weight greater than 200,000. Free fatty acids,
1,2- and 1,3-diglycerides, monoglycerides and glycerol were found in the digestion products. With most substrates the 1,2-to
1,3-diglyceride ratio was approximately 2∶1 and monoglycerides tended to accumulate. Analysis of the digestion products from
synthetic triglycerides of known structure indicated that both primary and secondary ester positions of the triglyceride molecule
were hydrolyzed and that considerable isomerization of 1,2-diglyceride to 1,3-diglyceride occurred. The monoglyceride was
consistently lower than the 1,2-diglyceride and in the majority of cases also lower than the 1,3-diglyceride in the fatty
acid originally present in the 2 position of the triglyceride. No fatty acid preference was observed.
Scientific contribution No. 316.
Presented in part at the AOCS Meeting, Philadelphia, October 1966. 相似文献
11.
H.-J. Fiebig 《European Journal of Lipid Science and Technology》1985,87(2):53-57
HPLC Separation of Triglycerides The high performance liquid chromatography on reversed phases represents an effective method for qualitative separation of triglycerides. First the chromatographic system was optimized by investigations concerning the influence of the column material, of the eluent and the temperature on qualitative separation of complex triglyceride mixtures. Then conditions of quantitative analysis could be established. On the one hand model mixtures of known composition were used, and on the other hand triglycerides, isolated from vegetable oils by column chromatography, whose composition was calculated by analysis of fatty acids and lipase hydrolysis. The results, obtained by high performance liquid chromatography, provide more detailed knowledge about the triglyceride composition of fats and oils than gaschromatography. 相似文献
12.
The acid lipase of castor bean endosperm catalyzed the hydrolysis of fatty acids from the 1 and 3 positions of synthetic glycerides
immediately after achieving proper reaction conditions, but fatty acids from the 2 position were not detected in the reaction
products until 7 to 10 min later. Results obtained with 2,3-butane dioleate, n-hexyl oleate and 2-hexyl oleate showed that
the castor lipase does not cleave secondary ester linkages. These findings suggest that the acid lipase of the castor bean
may catalyze hydrolysis of fatty acids from the 1 and 3 positions of triglycerides only; the steady appearance of 2 position
fatty acids in the reaction products during lipolysis is probably the result of an apparent isomerization reaction.
So. Utiliz. Res. Dev. Div., ARS, USDA. 相似文献
13.
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
14.
Uptake of blood triglyceride by various tissues 总被引:3,自引:0,他引:3
Triglycerides are transported in the blood in chylomicrons and very low density lipoproteins. Electron microscopic studies
indicate that these particles, which range in diameter from 0.03–0.6 μ, cannot cross the capillary endothelium in most tissues.
There is now considerable evidence that the triglycerides are hydrolyzed to free fatty acids (FFA) during uptake and that
this process is catalyzed by lipoprotein lipase. The enzyme is found in nearly all tissues that utilize circulating triglyceride,
and the level of activity, in individual tissues, varies with nutritional and physiological states that affect triglyceride
uptake, such as fasting, diabetes and pregnancy. Studies in perfused adipose tissue with doubly labeled chylomicrons showed
that hydrolysis occurs outside of the blood stream. Two-thirds of the fatty acids are incorporated into tissue triglyceride
and the rest are release as FFA, with glycerol, to the blood. Infusion of heparin causes immediate release of lipoprotein
lipase activity to the blood and decreases the amount of chylomicron-triglyceride hydrolyzed by the tissue. Electron microscopic
cytochemical studies showed that hydrolysis of blood glycerides by lipoprotein lipase in adipose tissue occurs within the
capillary endothelial cells and in the subendothelial space near the pericytes, but not in the capillary lumen or near the
fat cells. The results indicate that the fatty acids of chylomicrons cross the capillary endothelium as glycerides and FFA,
within a membrane-bounded system, and cross the extravascular space to the fat cells as FFA.
Presented at the AOCS Meeting, Atlantic City, October 1971. 相似文献
15.
The hydrolysis by lipoprotein lipase of a very low density lipoprotein/chylomicron fraction, obtained from the intestinal
lymph of sheep, has been studied in vitro. Rapid hydrolysis of triacylglycerols, with an accumulation of free fatty acids,
was observed. After an initial lag period, phosphatidylcholine also was hydrolyzed. No specificity for particular fatty acids
in the triacylglycerols (or phosphatidylcholines) was observed. 相似文献
16.
Two hydroxy acids, lesquerolic (53 wt%) and auricolic (4%), are present at significant quantities inLesquerella fendleri seed oil. Results reported here indicate the selective release of hydroxy fatty acids during hydrolysis of this oil catalyzed
byRhizopus arrhizus lipase. For example, hydroxy acids composed 85–90 wt% of the free fatty acids released during lipolysis, as compared to 54%
present overall in the oil. In addition, over 80% of the lesquerolic acid is released from the triglycerides. The reason for
this lipase’s success was determined to be its 1,3-positional specificity. The vast majority of lesquerella oil’s hydroxy
acids is at the 1- and 3-positions of its triglycerides, as confirmed by the compositional analysis of partial glycerides
formed during lipolysis. 相似文献
17.
Lipase B (GCB) produced by the fungus Geotrichum candidum CMICC 335426 is known for its high specificity towards cis-Δ9 unsaturated fatty acids. The wild-type lipase (not genetically modified) as well as the lipase obtained by heterologous
expression of the corresponding gene in Pichia pastoris (genetically modified) were studied in a process aiming to produce an oil containing very little saturated fatty acids (SAFA).
The approach described in this paper is based on the selective hydrolysis of sunflower oil (12% SAFA) using the G. candidum type B (GCB) lipases. Depending on the lipase input, up to 60% w/w degree of hydrolysis was obtained within 6–8 h. Because
of the high specificity of the GCB lipases (specificity factor ∼30), the level of unsaturates in the free fatty acid fraction
was >99% w/w. In contrast with literature data, no loss of specificity was observed, even at the highest degree of hydrolysis
obtained. Though both GCB lipases are stable at 30°C, the rate of hydrolysis decreased considerably during the process. Product
inhibition as well as time-dependent deactivation (half-life ≈2 h) were shown to be involved. After separation of the oil
phase, the unsaturated free fatty acids were recovered from the mixture by evaporation and reconverted to triglycerides by
enzymatic esterification with glycerol. Because the GCB lipases have a very low efficiency for esterification, this reaction
was carried out with immobilized Rhizomucor miehei lipase. Under continuous removal of the water generated during the process, >95% triglycerides were obtained in less than
24 h. Standard deodorization resulted in an odorless, colorless, and tasteless oil with less than 1% SAFA. 相似文献
18.
Bjørnar Myrnes Harald Barstad Ragnar L. Olsen Edel O. Elvevoll 《Journal of the American Oil Chemists' Society》1995,72(11):1339-1344
Marine triglyceride oils (cod liver oil and oils from blubber of harp seal and minke whale) were reacted with glycerol using
lipase as a catalyst at low temperature. A solvent-free batch system with magnetic stirring was used. Solidification of the
reaction mixture occurred, and a mixture of mono-, di-, and triglycerides was obtained in all cases. The recovered glyceride
mixtures were solid at room temperature. The yield of monoglyceride (MG) and the fatty acid profile of the MG fractions were
dependent on oil and the type of lipase used as a catalyst. Of the commercially-available lipases investigated, lipase AK
fromPseudomonas sp. synthesized the highest yield of MG (42–53%) at 5°C. These MG fractions were low in saturated fatty acids (4–11%) and
high in long-chain monounsaturated fatty acids (52–69%). The concentration of n-3 polyunsaturated fatty acids was 12–20%. 相似文献
19.
The physiological specificity of fat digestion in several species of marine fish was studied by incubating a variety of synthetic and natural lipid substrates in fish intestinal fluid. Wax ester and triglyceride hydrolyses were studied in vivo and in vitro. In vivo feeding studies showed triglyceride hydrolysis and reesterification in the gut occurred 4 times faster than wax ester metabolism. In vitro comparisons of wax and triglyceride lipolysis always showed triglycerides to be hydrolyzed faster than wax esters; however, wide variation in the ratio occurred among different batches of intestinal juice. Ca. 50% of the 2 monoglycerides formed in the lipolytic sequence were hydrolyzed. Esters of lipase resistent fatty acids (20:4 and 20:5) were cleaved faster than normal fatty acid esters (18:2 and 18:3). Two of the species studied, the northern anchovy, Engraulis mordax and the jack mackerel, Trachurus symmetricus, empty lipase(s) into their gall bladders and produce-phospholipid free bile. 相似文献
20.
Thomas A. Foglia Edith J. Conkerton Philip E. Sonnet 《Journal of the American Oil Chemists' Society》1995,72(11):1275-1279
A modified procedure for the regiospecific analysis of triacylglycerols (TAG) with a 1,3-specific lipase is described. After
partial lipase hydrolysis of the triacylglycerol, the released free fatty acids (FFA) and 1,2(2,3)-diacylglycerols (DAG) were
isolated by thin-layer chromatography (TLC) and converted to fatty acid methyl esters (FAME). The FAME were analyzed by gas-liquid
chromatography (GLC). The 1,3-specific lipases used in this study included supported preparations from strains ofMucor miehei andRhizopus oryzae. The method also was applied to the regiospecific analyses of tung nut and Chinese melon seed oil triacyglycerols, both of
which contain high proportions of α-elaeostearic acid. The TAG composition of the oils was substantiated in parallel analysis
of the oils by highperformance liquid chromatography with chemical ionization mass spectrometric detection of intact TAG. 相似文献