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1.
Yuji Shimada Akio Sugihara Yumi Minamigawa Kenichi Higashiyama Kengo Akimoto Shigeaki Fujikawa Sadao Komemushi Yoshio Tominaga 《Journal of the American Oil Chemists' Society》1998,75(12):1213-1217
An attempt was made to enrich arachidonic acid (AA) from Mortierella single-cell oil, which had an AA content of 25%. The first step involved the hydrolysis of the oil with Pseudomonas sp. lipase. A mixture of 2.5 g oil, 2.5 g water, and 4000 units (U) Pseudomonas lipase was incubated at 40°C for 40 h with stirring at 500 rpm. The hydrolysis was 90% complete after 40 h, and the resulting
free fatty acids (FFA) were extracted with n-hexane (AA content, 25%; recovery of AA, 91%). The second step involved the selective esterification of the fatty acids with
lauryl alcohol and Candida rugosa lipase. A mixture of 3.5 g fatty acids/lauryl alcohol (1:1, mol/mol), 1.5 g water, and 1000 U Candida lipase was incubated at 30°C for 16 h with stirring at 500 rpm. Under these conditions, 55% of the fatty acids were esterified,
and the AA content in the FFA fraction was raised to 51% with a 92% yield. The long-chain saturated fatty acids in the FFA
fraction were eliminated as urea adducts. This procedure raised the AA content to 63%. To further elevate the AA content,
the fatty acids were esterified again in the same manner with Candida lipase. The repeated esterification raised the AA content to 75% with a recovery of 71% of its initial content. 相似文献
2.
Yuji Shimada Akio Sugihara Masahiro Shibahiraki Hiroyuki Fujita Hirofumi Nakano Toshihiro Nagao Tadamasa Terai Yoshio Tominaga 《Journal of the American Oil Chemists' Society》1997,74(11):1465-1470
γ-Linolenic acid (GLA) was purified from borage oil by a two-step enzymatic method. The first step involved hydrolysis of
borage oil (GLA content, 22.2 wt%) with lipase, Pseudomonas sp. enzyme (LIPOSAM). A mixture of 3 g borage oil, 2 g water, and 5000 units (U) LIPOSAM was incubated at 35°C with stirring
at 500 rpm. The reaction was 91.5% complete after 24 h. The resulting free fatty acids (FFA) were extracted from the reaction
mixture with n-hexane (GLA content, 22.5 wt%; recovery of GLA, 92.7%). The second step involved selective esterification of borage-FFA with
lauryl alcohol by using Rhizopus delemar lipase. A mixture containing 4 g borage-FFA/lauryl alcohol (1:2, mol/mol), 1 g water, and 1000 U lipase was incubated at
30°C for 20 h with stirring at 500 rpm. Under these conditions, 74.4% of borage-FFA was esterified, and the GLA content in
the FFA fraction was enriched from 22.5 to 70.2 wt% with a recovery of 75.1% of the initial content. To further elevate the
GLA content, unesterified fatty acids were extracted, and esterified again in the same manner. By this repeated esterification,
GLA was purified to 93.7 wt% with a recovery of 67.5% of its initial content. 相似文献
3.
Purification of docosahexaenoic acid from tuna oil by a two-step enzymatic method: Hydrolysis and selective esterification 总被引:3,自引:0,他引:3
Yuji Shimada Kazuaki Maruyama Akio Sugihara Shigeru Moriyama Yoshio Tominaga 《Journal of the American Oil Chemists' Society》1997,74(11):1441-1446
Purification of docosahexaenoic acid (DHA) was attempted by a two-step enzymatic method that consisted of hydrolysis of tuna
oil and selective esterification of the resulting free fatty acids (FFA). When more than 60% of tuna oil was hydrolyzed with
Pseudomonas sp. lipase (Lipase-AK), the DHA content in the FFA fraction coincided with its content in the original tuna oil. This lipase
showed stronger activity on the DHA ester than on the eicosapentaenoic acid ester and was suitable for preparation of FFA
rich in DHA. When a mixture of 2.5 g tuna oil, 2.5 g water, and 500 units (U) of Lipase-AK per 1 g of the reaction mixture
was stirred at 40°C for 48 h, 83% of DHA in tuna oil was recovered in the FFA fraction at 79% hydrolysis. These fatty acids
were named tuna-FFA-Ps. Selective esterification was then conducted at 30°C for 20 h by stirring a mixture of 4.0 g of tuna-FFA-Ps/lauryl alcohol (1:2, mol/mol), 1.0 g water, and 1,000 U of Rhizopus delemar lipase. As a result, the DHA content in the unesterified FFA fraction could be raised from 24 to 72 wt% in an 83% yield.
To elevate the DHA content further, the FFA were extracted from the reaction mixture with n-hexane and esterified again under the same conditions. The DHA content was raised to 91 wt% in 88% yield by the repeated
esterification. Because selective esterification of fatty acids with lauryl alcohol proceeded most efficiently in a mixture
that contained 20% water, simultaneous reactions during the esterification were analyzed qualitatively. The fatty acid lauryl
esters (L-FA) generated by the esterification were not hydrolyzed. In addition, L-FA were acidolyzed with linoleic acid, but
not with DHA. These results suggest that lauryl DHA was generated only by esterification. 相似文献
4.
Yuji Shimada Norihito Sakai Akio Sugihara Hiroyuki Fujita Yo Honda Yoshio Tominaga 《Journal of the American Oil Chemists' Society》1998,75(11):1539-1544
γ-Linolenic acid (GLA) is a physiologically valuable fatty acid, and is desired as a medicine, but a useful method available
for industrial purification has not been established. Thus, large-scale purification was attempted by a combination of enzymatic
reactions and distillation. An oil containing 45% GLA (GLA45 oil) produced by selective hydrolysis of borage oil was used
as a starting material. GLA45 oil was hydrolyzed at 35°C in a mixture containing 33% water and 250 U/g-reaction mixture of
Pseudomonas sp. lipase; 91.5% hydrolysis was attained after 24 h. Film distillation of the dehydrated reaction mixture separated free
fatty acids (FFA; acid value 199) with a recovery of 94.5%. The FFA were selectively esterified at 30°C for 16 h with two
molar equivalents of lauryl alcohol and 50 U/g of Rhizopus delemar lipase in a mixture containing 20% water. The esterification extent was 52%, and the GLA content in the FFA fraction was
raised to 89.5%. FFA and lauryl esters were not separated by film distillation, but the FFA-rich fraction contaminated with
18% lauryl esters was recovered by simple distillation. To further increase the GLA content, the FFA-rich fraction was selectively
esterified again under similar conditions. As a result, the GLA content in the FFA fraction was raised to 97.3% at 15.2% esterification.
After simple distillation of the reaction mixture, lauryl esters contaminating the FFA-rich fraction were completely eliminated
by urea adduct fractionation. When 10 kg of GLA45 oil was used as a starting material, 2.07 kg of FFA with 98.6% GLA was obtained
with a recovery of 49.4% of the initial content. 相似文献
5.
Yuji Shimada Akio Sugihara Hirofumi Nakano Takashi Kuramoto Toshihiro Nagao Munekazu Gemba Yoshio Tominaga 《Journal of the American Oil Chemists' Society》1997,74(2):97-101
To purify docosahexaenoic acid (DHA), we attempted the selective esterification of fatty acids originating from tuna oil with
lipases. Tuna oil was hydrolyzed in NaOH-ethanol solution, and the resulting fatty acid mixture [DHA, 23.2%; named tuna-free
fatty acid (FFA)] was used as a starting material. Rhizopus delemar which acted lightly on DHA, was a suitable catalyst for the selective esterification of tuna-FFA, and lauryl alcohol was
the best substrate. The reaction proceeded most effectively when a mixture of 2.4 g lauryl alcohol/tuna-FFA (2:1, mol/mol),
0.6 g water, and 600 U Rhizopus lipase was incubated at 30°C for 20 h with stirring at 500 rpm. Under these conditions 72% of tuna-FFA was esterified, and
84% of DHA was recovered in the unesterified fatty acid fraction. The DHA content in the fatty acid fraction rose from 23
to 73% with this reaction. To further elevate the DHA content, the unesterified fatty acids were extracted, and then esterified
again under the same conditions. By this repeated esterification, DHA was purified to 89% with a recovery of 71% of its initial
content. 相似文献
6.
Purification of arachidonic acid (AA) from Mortierella alpina single-cell oil was attempted. The process comprised three steps: (i) preparation of FFA by nonselective hydrolysis of the
oil with Alcaligenes sp. lipase; (ii) elimination of long-chain saturated FA from the resulting FFA by urea adduct fractionation; and (iii) enrichment
of AA through lipase-catalyzed selective esterification with lauryl alcohol (LauOH). In the third step, screening of industrially
available lipases indicated that Burkholderia cepacia lipase (Lipase-PS, Amano Enzyme Inc., Aichi, Japan) acted on AA more weakly than on other FA and was the most effective for
enrichment of AA in the FFA fraction. When the FFA obtained by urea adduct fractionation were esterified with 2 molar equivalents
of LauOH at 30°C for 16 h in a mixture with 20% water and 20 units (U)/g-mixture of Lipase-PS, the esterification reached
39% and the content of AA in the FFA fraction was raised from 61 to 86 wt%. To further increase the content of AA, unesterified
FFA were allowed to react again under the same conditions as those in the first selective esterification except for the use
of 50 U/g Lipase-PS. A series of procedures raised the content of AA to 97 wt% with a 49% recovery based on the initial content
in the single-cell oil. These results indicated that the three-step process for selective esterification with Lipase-PS was
effective for purifying AA from the single-cell oil. 相似文献
7.
Isolation of tocopherol and sterol concentrate from sunflower oil deodorizer distillate 总被引:10,自引:0,他引:10
The isolation of tocopherols and sterols together as a concentrate from sunflower oil deodorizer distillate was investigated.
The sunflower oil deodorizer distillate was composed of 24.9% unsaponifiable matter with 4.8% tocopherols and 9.7% sterols,
28.8% free fatty acid (FFA) and 46.3% neutral glycerides. The isolation technology included process steps such as biohydrolysis,
bioesterification and fractional distillation. The neutral glycerides of the deodorizer distillates were hydrolyzed byCandida cylindracea lipase. The total fatty acids (initial FFA plus FFA from neutral glycerides) were converted into butyl esters withMucor miehei lipase. The esterified product was then fractionally distilled in a Claisen-vigreux flask. The first fraction, which was
collected at 180–230°C at 1.00 mm of Hg for 45 min, contained mainly butyl esters, hydrocarbons, oxidized products and some
amount of free fatty acids. The fraction collected at 230–260°C at 1.00 mm Hg for 15 min was rich in tocopherols (about 30%)
and sterols (about 36%). The overall recovery of tocopherols and sterols after hydrolysis, esterification and distillation
were around 70% and 42%, respectively, of the original content in sunflower oil deodorizer distillate. 相似文献
8.
Facile purification of tocopherols from soybean oil deodorizer distillate in high yield using lipase 总被引:16,自引:0,他引:16
Yuji Shimada Seiichi Nakai Masaharu Suenaga Akio Sugihara Motohiro Kitano Yoshio Tominaga 《Journal of the American Oil Chemists' Society》2000,77(10):1009-1013
Tocopherols have been purified from deodorizer distillate produced in the final deodorization step of vegetable oil refining
by a process including molecular distillation. Deodorizer distillate contains mainly tocopherols, sterols, and free fatty
acids (FFA); the presence of sterols hinders tocopherol purification in good yield. We found that Candida rugosa lipase recognized sterols as substrates but not tocopherols, and that esterification of sterols with FFA could be effected
with negligible influence of water content. Enzymatic esterification of sterols with FFA was thus used as a step in tocopherol
purification. High boiling point substances including steryl esters were removed from soybean oil deodorizer distillate by
distillation, and the resulting distillate (soybean oil deodorizer distillate tocopherol concentrate; SODDTC) was used as
a starting material for tocopherol purification. Several factors affecting esterification of sterols were investigated, and
the reaction conditions were determined as follows: A mixture of SODDTC and water (4∶1, w/w) was stirred at 35°C for 24 h
with 200 U of Candida lipase per 1 g of the reaction mixture. Under these conditions, approximately 80% of sterols was esterified, but tocopherols
were not esterified. After the reaction, tocopherols and FFA were recovered as a distillate by molecular distillation of the
oil layer. To enhance further removal of the remaining sterols, the lipase-catalyzed reaction was repeated on the distillate
under the same reaction conditions. As a result, more than 95% of the sterols was esterified in total. The resulting reaction
mixture was fractionated to four distillates and one residue. The main distillate fraction contained 65 wt% tocopherols with
low contents of FFA and sterols. In addition, the residue fraction contained high-purity steryl esters. Because the process
presented in this study includes only organic solvent-free enzymatic reaction and molecular distillation, it is feasible as
a new industrial purification method of tocopherols.
This work was presented at the Biocatalysis symposium in April 2000, held at the 91st Annual Meeting and Expo of the American
Oil Chemists Society, San Diego, CA. 相似文献
9.
An efficient method for the purification of arachidonic acid from fungal single-cell oil (ARASCO) 总被引:3,自引:0,他引:3
PUFA, such as arachidonic acid (AA), have several pharmaceutical applications. An efficient method was developed to obtain
high-purity arachidonic acid (AA) from ARASCO, a single-cell oil from Martek (Columbia, MD). The method comprises three steps.
In the first step, AA was enriched from saponified ARASCO oil by low-temperature solvent crystallization using a polar, aprotic
solvent, which gave a FA fraction containing 75.7% AA with 97.3% yield. The second step involved enriching AA content via lipase-catalyzed selective esterification of FA with lauryl alcohol. When a mixture of 1 g FA/lauryl alcohol (2∶1 mol/mol),
50 mg Candida rugosa lipase, and 0.33 g water was incubated at 50°C for 24 h with stirring at 400 rpm, the AA content in the unesterified FA fraction
was as much as 89.3%, with ca. 90% yield. Finally, a solvent extraction procedure, in which acetonitrile was the extracting solvent, was used to enrich
AA from FA fraction dissolved in n-hexane. The best results were obtained when 2 g FA was dissolved in 80 mL hexane and extracted twice, each time with 20 mL
acetonitrile at −20°C, by allowing 2 h storage. This step gave a FA fraction containing 95.3% AA with 81.2% yield. By using
this three-step process the AA content in the saponified single-cell oil (ARASCO) was increased from 38.8 to 95.3% with a
total yield of ca. 71%. 相似文献
10.
Yuji Shimada Nobuhiro Fukushima Hiroyuki Fujita Yo Honda Akio Sugihara Yoshio Tominaga 《Journal of the American Oil Chemists' Society》1998,75(11):1581-1586
A 46% γ-linolenic acid (GLA)-containing oil was produced by selective hydrolysis of borage oil (GLA content, 22%) at 35°C
for 15 h in a mixture containing 50% water and 20 units (U)/g reaction mixture of Candida rugosa lipase. The GLA content was not raised over 46%, even though the hydrolysis extent was increased by extending the reaction
time and by using a larger amount of the lipase. However, 49% GLA-containing oil was produced by hydrolysis in a reaction
mixture with 90% water. This result suggested that free fatty acids (FFA) that accumulated in the mixture affected the apparent
fatty acid specificity of the lipase in the selective hydrolysis and interfered with the increase of the GLA content. To investigate
the kinetics of the selective hydrolysis in a mixture without FFA, glycerides containing 22, 35, and 46% GLA were hydrolyzed
with Candida lipase. The result showed that the hydrolysis rate decreased with increasing GLA content of glycerides, but that the release
rate of GLA did not change. Thus, it was found that the apparent fatty acid specificity of the lipase in the selective hydrolysis
was also affected by glyceride structure. When 46% GLA-containing oil was hydrolyzed at 35°C for 15 h in a mixture containing
50% water and 20 U/g of the lipase, GLA content in glycerides was raised to 54% at 20% hydrolysis. Furthermore, GLA content
in glycerides was raised to 59% when the hydrolysis extent reached 60% using 200 U/g of the lipase. These results showed that
repeated hydrolysis was effective to produce the higher concentration of GLA oil. Because film distillation was found to be
extremely effective for separating FFA and glycerides, large-scale hydrolysis of borage oil was attempted. As a result, 1.5
kg of 56% GLA-containing oil was obtained from 7 kg borage oil by repeated reaction. 相似文献
11.
Toshihiro Nagao Yuji Shimada Yoshie Yamauchi-Sato Takaya Yamamoto Masaaki Kasai Kentaro Tsutsumi Akio Sugihara Yoshio Tominaga 《Journal of the American Oil Chemists' Society》2002,79(3):303-308
A commercial product of CLA contains almost equal amounts of cis-9,trans-11 (c9,t11)-CLA and trans-10,cis-12 (t10,c12)-CLA. We attempted to enrich the two isomers by a two-step selective esterification using Candida rugosa lipase that acted on c9,t11-CLA more strongly than on t10,c12-CLA. An FFA mixture containing CLA isomers was esterified with an equimolar amount of lauryl alcohol in a mixture of 20%
water and the lipase. When the esterification of total FA reached 50%, two isomers were fractionated in a good yield: t10,c12-CLA was enriched in FFA, and c9,t11-CLA was recovered in lauryl esters. The FFA were esterified again to enrich t10,c12-CLA. At 27.3% esterification of total FA, the t10,c12-CLA content in FFA increased to 64.8 wt% with 89.3% recovery: The ratio of the content of t10,c12-CLA to that of two isomers was 95.9%. Lauryl esters obtained by the single esterification were employed for enrichment
of c9,t11-CLA. After the esters were hydrolyzed, the resulting FFA were esterified again with lauryl alcohol. At 62.0% esterification
of total FA, the c9,t11-CLA content in lauryl esters increased to 73.3 wt% with 79.4% recovery: The ratio of the content of c9,t11-CLA to that of two isomers was 95.6%. In a 600-g-scale purification, molecular distillation was effective in separating
the reaction mixture into lauryl alcohol, FFA, and lauryl ester fractions. 相似文献
12.
Yuji Shimada Yoshinori Hirota Takashi Baba Akio Sugihara Shigeru Moriyama Yoshio Tominaga Tadamasa Terai 《Journal of the American Oil Chemists' Society》1999,76(6):713-716
Steryl esters of long-chain fatty acids have water-holding properties, and polyunsaturated fatty acids (PUFA) have various
physiological functions. Because steryl ester of PUFA can be expected to have both features, we attempted to synthesize steryl
esters of PUFA by enzymatic methods. Among lipases used, Pseudomonas lipase was the most effective for the synthesis of cholesteryl docosahexaenoate. When a mixture of cholesterol/docosahexaenoic
acid (3:1, mol/mol), 30% water, and 3000 units/g of lipase was stirred at 40°C for 24 h, the esterification extent attained
89.5%. Under the same reaction conditions, cholesterol, cholestanol, and sitosterol were also esterified efficiently with
docosahexaenoic, eicosapentaenoic, arachidonic, and γ-linolenic acids. 相似文献
13.
A. Ramírez Fajardo L. Esteban Cerdán A. Robles Medina M. M. Muñío Martínez E. Hita Peña E. Molina Grima 《Journal of the American Oil Chemists' Society》2006,83(3):215-221
The aim of this work was to increase the content of EPA in FFA extracts from a commercial oil (43.1% EPA) and from Phaeodactylum tricornutum oil, a single-cell oil, by selective enzymatic esterification. Initially, the FFA extract was esterified with lauryl alcohol
using nine lipases. All the lipases concentrated EPA in the unesterified FFA fraction. The criterion used to choose the best
lipase was maximization of the dimensionless effectiveness factor (FAE). This factor grouped the concentration factor (ratio between the EPA concentrations in the FFA fractions before and after
esterification) with EPA recovery in the final FFA fraction. Experiments were carried out to correlate FAE and the degree of esterification (ED, percentage of initial FA converted to lauryl esters). Lipase AK from Pseudomonas fluorescens was the most effective for concentrating EPA. Studies, of the optimal temperature, substrate molar ratio, solvent/substrate
ratio, and treatment intensity (product of the lipase mass and the reaction time) were also carried out using the lipase.
The maximum FAE was obtained when the ED was 60%: EPA concentration was 72%, and recovery was 73%. Finally, this lipase was used to concentrate
EPA from a FFA extract from P. tricornutum (23% EPA). The content of EPA in the unesterified FFA fraction increased to 71% at 78% ED (recovery of EPA, 75.5%). Comparison
of the results of obtained with the two FFA extracts seemed to indicate that the selectivity of Lipase AK for EPA depended
on the content of EPA, with higher contents of EPA in the initial FFA mixture reducing the selectivity for EPA. 相似文献
14.
Luis Vázquez Leslie Kleiner Casimir C. Akoh 《Journal of the American Oil Chemists' Society》2012,89(9):1655-1662
The concentration of stearidonic acid (SDA, 18:4 n-3) in free fatty acids (FFA) formed by selective esterification with dodecanol (lauryl alcohol) was studied. For this purpose, modified soybean oil (initial SDA content, ~23 %) was converted into its corresponding FFA by chemical hydrolysis. In a second step, the resulting FFA were esterified with dodecanol. Process variables such as the type of biocatalyst (lipase), substrate molar ratio and amount of lipase were evaluated. The best SDA concentration (58 %) and recovery (94 %) were attained by performing the esterification reaction for 4 h, with 1:1 molar ratio (dodecanol:FFA), and 5 % (w/w) Candida rugosa lipase as biocatalyst. It was observed that SDA was concentrated in the unesterified fraction. 相似文献
15.
Yomi Watanabe Toshihiro Nagao Yutaka Nishida Yoshiaki Takagi Yuji Shimada 《Journal of the American Oil Chemists' Society》2007,84(11):1015-1021
Acid oil, a by-product of vegetable oil refining, was enzymatically converted to fatty acid methyl esters (FAME). Acid oil
contained free fatty acids (FFA), acylglycerols, and lipophilic compounds. First, acylglycerols (11 wt%) were hydrolyzed at
30 °C by 20 units Candida rugosa lipase/g-mixture with 40 wt% water. The resulting oil layer containing 92 wt% FFA was used for the next reaction, methyl
esterification of FFA to FAME by immobilized Candida antarctica lipase. A mixture of 66 wt% oil layer and 34 wt% methanol (5 mol for FFA) were shaken at 30 °C with 1.0 wt% lipase. The degree
of esterification reached 96% after 24 h. The resulting reaction mixture was then dehydrated and subjected to the second esterification
that was conducted with 2.2 wt% methanol (5 mol for residual FFA) and 1.0 wt% immobilized lipase. The degree of esterification
of residual FFA reached 44%. The degree increased successfully to 72% (total degree of esterification 99%) by conducting the
reaction in the presence of 10 wt% glycerol, because water in the oil layer was attracted to the glycerol layer. Over 98%
of total esterification was maintained, even though the first and the second esterification reactions were repeated every
24 h for 40 days. The enzymatic process comprising hydrolysis and methyl esterification produced an oil containing 91 wt%
FAME, 1 wt% FFA, 1 wt% acylglycerols, and 7 wt% lipophilic compounds. 相似文献
16.
Yuji Shimada Yoshinori Hirota Takashi Baba Shinichiro Kato Akio Sugihara Shigeru Moriyama Yoshio Tominaga Tadamasa Terai 《Journal of the American Oil Chemists' Society》1999,76(10):1139-1142
l-Menthol has been widely used as a food additive and an ingredient of cosmetics, and it is esterified to moderate the strong
flavor. We attempted esterification of l-menthol with long-chain unsaturated fatty acid in an organic solvent-free enzymatic system. Commercially available lipases
were screened, and Candida rugosa lipase was selected as a catalyst. Several factors affecting the esterification were investigated, and the reaction conditions
were determined as follows: A reaction mixture of l-menthol/fatty acid (1:3, mol/mol), 30% water, and 700 units of the lipase per gram of reaction mixture was incubated at 30°C
with stirring. After 24 h under these conditions, the esterification extents of l-menthol with oleic, linoleic, and α-linolenic acids reached 96, 88, and 95%, respectively. The structure of the esterified
product was confirmed by mass, infrared, and nuclear magnetic resonance spectroscopies. Bacause Candida lipase acted strongly on l-menthol and very weakly on d-menthol, dl-menthol was esterified with oleic acid under the same conditions. The reaction showed high enantioselectivity; the enantiomeric
ratio (E) was 31, and enantiomeric excess (ee) of l-menthyl oleate reached 88% after 32 h. 相似文献
17.
A single-cell oil from a Mortierella alpina mutant (TGM17 oil) contains n−9 PUFA: 14.3 wt% 6,9-octadecadienoic acid (18∶2n−9; n−9 LnA) and 17.1 wt% Mead acid (20∶3n−9;
MA). Lipase screening indicated that Pseudomonas aeruginosa lipase acted strongly on n−9 LnA and weakly on MA, and Candida rugosa lipase acted weakly on the two PUFA. Hence, fractionation and enrichment of the two FA were conducted with the lipases. The
first step was selective hydrolysis of IGM17 oil with P. aeruginosa lipase. The hydrolysis fractionated the oil into FFA containing 20.4 wt% n−9 LnA and 6.3 wt% MA, and acylglycerols containing
10.7 wt% n−9 LnA and 23.7 wt% MA. The FFA fraction was used for preparation of n−9 LnA-rich FFA. After removal of saturated
FA, the FFA were esterified with lauryl alcohol (LauOH) using C. rugosa lipase. Two selective esterifications increased the n−9 LnA content to 54.0 wt% with 38.2% recovery of the initial content
of TGM17 oil. The acylglycerol fraction obtained in the hydrolysis with P. aeruginosa lipase was used for preparation of MA-rich FFA. The acylglycerol fraction was hydrolyzed under alkaline conditions, and saturated
FA were eliminated by urea adduct fractionation. Two selective esterifications of the FFA with LauOH increased the MA content
to 60.2 wt% with 53.5% recovery. Thus, the two-step enzymatic process was effective for fractionation and enrichment of n−9
LnA and MA. 相似文献
18.
Acid oil is a by-product in the neutralization step of vegetable oil refining and is an alternative source of biodiesel fuel.
A model substrate of acid oil, which is composed of TAG and FFA, was used in experiments on the conversion to FAME by immobilized
Candida antarctica lipase. FFA in the mixture of TAG/FFA were efficiently esterified with methanol (MeOH), but the water generated by the esterification
significantly inhibited methanolysis of TAG. We thus attempted to convert a mixture of TAG/FFA to FAME by a two-step process
comprising methyl esterification of FFA and methanolysis of TAG by immobilized C. antarctica lipase. The first reaction was conducted at 30°C in a mixture of TAG/FFA (1∶1, wt/wt) and 10 wt% MeOH using 0.5 wt% immobilized
lipase, resulting in efficient esterification of FFA. The reaction mixture after 24 h was composed of 49.1 wt% TAG, 1.3 wt%
FFA, 49.1 wt% FAME, and negligible amounts of DAG and MAG (<0.5 wt%). The reaction mixture was then dehydrated and used as
a substrate for the second reaction, which was conducted at 30°C in a solution of the dehydrated mixture and 5.5 wt% MeOH
using 6 wt% immobilized lipase. The activity of the lipase increased gradually when the reaction was repeated by transferring
the enzyme to a fresh substrate mixture. The activity reached a maximum after 6 cycles, and the content of FAME achieved was
>98.5 wt% after a 24-h reaction. The immobilized lipase was very stable in the first-and second-step reactions and could be
used for >100 d without significant loss of activity. 相似文献
19.
Yuji Shimada Toshihiro Nagao Yukiko Hamasaki Kengo Akimoto Akio Sugihara Shigeaki Fujikawa Sadao Komemushi Yoshio Tominaga 《Journal of the American Oil Chemists' Society》2000,77(1):89-93
Human milk fat contains 20–25% palmitic acid, and about 70% of the fatty acid is esterified to the 2-position of triglycerides.
It was also reported that arachidonic acid (AA) accelerated the growth of preterm infants. Thus, we attempted the synthesis
of 1,3-arachidonoyl-2-palmitoyl-glycerol by acidolysis of tripalmitin with AA using 1,3-specific Rhizopus delemar lipase. When a mixture of 10 g tripalmitin/AA (1∶5, w/w) and 0.7 g immobilized Rhizopus lipase was incubated at 40°C for 24 h with stirring, the AA content in glycerides reached 59 mol%. The immobilized lipase
could be used five times without a decrease in the extent of acidolysis. Glycerides were extracted from the reaction mixture
with n-hexane, and regiospecific analysis was performed. As a result, the AA contents at the 1,3- and 2-positions were 56.9 and
3.2 mol%, respectively. It was therefore confirmed that the fatty acids at the 1,3-positions of triglyceride were exchanged
for AA. High-performance liquid chromatography showed that the contents of triarachidonin, 1,3-arachidonoyl-2-palmitoyl-glycerol,
and 1(3)-arachidonoyl-2,3(1)-palmitoyl-glycerol were 7.3, 75.9, and 12.4 wt%, respectively. 相似文献
20.
Gerald P. McNeill Philip E. Sonnet 《Journal of the American Oil Chemists' Society》1995,72(2):213-218
Three lipases were compared for their ability to hydrolyze high erucic acid rapeseed oil, with the objective of concentrating
the erucic acid in a single glyceride fraction. Lipase fromPseudomonas cepacia released all fatty acids rapidly and did not result in selective distribution of erucic acid.Geotrichum candidum lipase released C20 and C22 fatty acids extremely slowly, resulting in their accumulation in the di- and triglyceride fractions.
Less than 2% of the total erucic acid was found in the free fatty acid (FFA) fraction. Lipase fromCandida rugosa released erucic acid more slowly than C20 and C18 fatty acids at 35°C but only resulted in a limited accumulation of the
erucic acid in the di- and triglyceride fractions. However, when hydrolysis catalyzed byC. rugosa lipase was carried out below 20°C, the reaction mixture solidified and was composed solely of FFAs and diglycerides. The
diglyceride fraction contained approximately 95% erucic acid while about 20% of the total erucic acid was found in the FFA
fraction. It is concluded that hydrolysis at low temperature withC. rugosa lipase results in a higher purity of erucic acid in the glyceride fraction than can be obtained withG. candidum lipase, but with considerable loss of erucic acid to the FFA fraction. 相似文献