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1.
Daniel Alberto Sánchez Gabriela Marta Tonetto María Luján Ferreira 《Journal of the American Oil Chemists' Society》2014,91(2):261-270
New avenues to add value to glycerol are currently being explored. One of them is the synthesis of structured lipids through glycerol esterification. In this work we have analyzed the recovery and purification of dicaprin obtained by esterification of glycerol with capric acid (C) in heptane, mediated by Lipozyme RM IM. This is an intermediate step to obtain lipids MLM. In the first stage, the diglyceride synthesis MGM (being G a central HC–OH) was carried out. When M = C, the diglyceride is CGC. Recovery of the diglyceride CGC is required to carry out the esterification of the sn-2 position with palmitic acid (P), thus obtaining the triglyceride CPC. Different solvents were evaluated using Ecofac 1.0 (a molecular design software solvent) through a theoretical approach to explore the best solvents for the acylglycerides separation. Then, the performance of the selected solvents to separate dicaprin from mono and tricaprin was experimentally studied in a liquid–liquid extraction process. Previously, the remaining fatty acid had been neutralized. With liquid–liquid extraction in three simple steps, using ethanol/water, 94 % of the dicaprin obtained by enzymatic esterification was recovered with a purity of 89 % (wt%). It was also possible to obtain dicaprin with a purity of 97 % but with a yield of 56 %. 相似文献
2.
Dae Young Kwon Hyo Nam Song Suk Hoo Yoon 《Journal of the American Oil Chemists' Society》1996,73(11):1521-1525
Using commercial lipases from various microbial origins, medium-chain glycerides, such as mono-, di-, and tricaprin, were
synthesized in isooctane from glycerol and capric acid. The enzyme reaction was performed with 0.35 M capric acid, 0.025 M
glycerol, and 0.46 g silica gel to remove water in 5 mL of isooctane with 30 mg lyophilized lipase. Of the 21 kinds of lipases,
11 showed good synthetic activities. Lipases fromPseudomonas aeruginosa (Lipase PS),Rhizomucor miehei lipase andChromobacterium viscosum lipase (Lipase CV) showed high activities for the production of tricaprin, while lipase OF-360 (fromCandida rugosa) and lipase D (Rhizopus delemar) were good for dicaprin production. Lipases CC and MY fromC. rugosa (C. cylindracea) and lipase D (Rhizopus delemar) were good for dicaprin production. Lipases CC and MY fromC. rugosa (C. cylindracea) also showed high activities for dicaprin and tricaprin. Some lipases, especially lipase PS, had high thermal stability over
60°C. The optimal lyophilization pH to dehydrate the lipase coincides with the optimal buffer solution pH for hydrolysis. 相似文献
3.
Scott Bloomer Patrick Adlercreutz Bo Mattiasson 《Journal of the American Oil Chemists' Society》1992,69(10):966-973
Scaling up of Lipozyme-catalyzed ester synthesis with >99% conversion and a reflux trap to remove product water from the reaction
mixture is reported. Ethyl stearate was synthesized in 2000-g batch reactions from technical stearic acid. The ethyl stearate
was purified to 97% by crystallization and interesterified with sunflower seed oil by means of a lipase catalyst to investigate
reaction parameters of temperature, substrate ratio, enzyme content and catalyst water activity. The endpoint of the reaction
was defined as the incorporation of stearate into sunflower seed oil corresponding to the amount of stearate necessary to
be incorporated into palm oil mid-fraction to produce a cocoa butter substitute. No tristearate was formed at the reaction
endpoint in any of the reactions conducted. Reaction times decreased and levels of free fatty acids and diglycerides increased
with increasing temperature and with increasing ratio of acyl donor to triglyceride. Increasing the enzyme content of the
reaction mixture reduced reaction times but caused higher levels of free fatty acids and diglycerides. In reactions catalyzed
by Lipozyme of defined water activity, the shortest reaction times were obtained at intermediate water activity, while free
fatty acid and diglyceride levels increased with water activity. When the interesterification reaction was carried out in
refluxing pentane with the condensed solvent dried by passage through a reflux trap, the free fatty acid and diglyceride levels
were reduced to 6 and 3.3%, respectively. 相似文献
4.
W. C. Wong M. Basri C. N. A. Razak A. B. Salleh 《Journal of the American Oil Chemists' Society》2000,77(1):85-88
Enzymatic synthesis of medium-chain glycerides (MCG) from capric acid and glycerol was studied using lipase from Candida rugosa. The effects of various reaction parameters such as time, molar ratio of substrates (mmol capric acid/mmol glycerol), amount
of lipase, type of organic solvents, and initial water activity (a
w
) were studied. The best conditions tested for MCG synthesis at 37°C were, respectively, time, 24 h; molar ratio of substrates,
2.5; and amount of lipase, 100.0 mg. The use of organic solvents greatly influenced the activity of lipase in the synthesis
of MCG. Generally, activity of lipase was high in nonpolar solvents with log P values from 3.50 to 4.50, where P is the partition coefficient between water and 1-octanol. The enzymatic synthesis of MCG was preferably carried out at an
initial a
w
of 0.328, which resulted in maximal yield. Analysis of the products of reaction using gas chromatography showed that lipase
from Candida rugosa seemed to produce more dicaprin and tricaprin than monocaprin. 相似文献
5.
Esterification patterns of lipases for synthesizing tricaproylglycerols in organic solvent 总被引:1,自引:0,他引:1
Dae Young Kwon Hyo Nam Song Suk Hoo Yoon 《Journal of the American Oil Chemists' Society》1997,74(10):1287-1290
To investigate the synthetic patterns of triglyceride (triacylglycerol) by lipases in organic solvent, esterification patterns
of triglyceride, diglyceride, and monoglyceride were monitored at various reaction times with 10 lipases. As a model study,
tricaprin was synthesized from glycerol and capric acids (C10:0) in isooctane. Lipases that were known to give nonspecific hydrolysis in aqueous solvent, such as lipase from Candida cylindracea, Lipase OF-360 (from C. rugosa), and Lipase MY (C. rugosa) showed nonspecific synthesis of tricaprin in organic solvent (Group I). There are two groups for esterifying trigly cerides
in organic solvent with 1,3-specific lipases: one consists of the lipases from Rhizomucor miehei, Pseudomonas aeruginosa (Lipase PS), and Chromobacterium viscosum (Lipase CV) (Group II), and another (Group III) is represented by Lipase AP (Aspergillus niger), Lipase FAP-15 (Rhizopus javanicus), and Lipase D (R. delemar). Although both groups showed 1,3-specific hydrolysis in aqueous solvent, Group III has stricter 1,3-specificity for the
synthesis of tricaprin from dicaprin. 相似文献
6.
Kuan-hsiang Huang Casimir C. Akoh 《Journal of the American Oil Chemists' Society》1994,71(11):1277-1280
The ability of immobilized lipases IM60 fromMucor miehei and SP435 fromCandida antarctica to modify the fatty acid composition of selected vegetable oils by incorporation of n−3 polyunsaturated fatty acids into
the vegetable oils was studied. The transesterification was carried out in organic solvent with free acid and ethyl esters
of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) as acyl donors. With free EPA as acyl donor, IM60 gave higher
incorporation of EPA than SP435. However, when ethyl esters of EPA and DHA were the acyl donors, SP435 gave higher incorporation
of EPA and DHA than IM60. When IM60 and free acid were used, the addition of 5 μL water increased EPA incorporation into soybean
oil by 4.9%. With ethyl ester of EPA as acyl donor, addition of 2 μL water increased EPA incorporation by 3.9%. For SP435,
addition of water up to 2μL resulted in increased EPA incorporation, but the incorporation declined when the added water exceeded
this amount. The addition of water increased the EPA incorporation into Trisun 90 after 24 h reaction but not the reaction
rate at early stages of the reaction. 相似文献
7.
Phosphatidylkojibiosyl diglyceride: Metabolism and function as an anchor in bacterial cell membranes
The recently discovered phosphoglycolipid, phosphatidylkojibiosyl diglyceride (PKD), was first observed as a biosynthetic by-product of glucosyl diglyceride metabolism inStreptococcus faecalis (faecium) ATCC 9790. Its structure is 1,2-diacyl-3-O(2′-O-α-D-glucopyranosyl-6′-O-phosphoryl-[1″,2″-diacyl-3″-O-sn-glycerol]-α-D-glucopyranosyl)-sn-glycerol. The biosynthesis of phosphatidylkojibiosyl diglyceride occurs by a novel transphosphatidylation reaction in which a phosphatidyl group is transferred from diphosphatidyl glycerol to the primary alcohol function at the 6 position of the internal glucose of kojibiosyl diglyceride. The reaction is catalyzed by a membrane-derived enzyme. Phosphatidylkojibiosyl diglyceride is bound covalently through a phosphodiester bond to the polyglycerol phosphate moiety of membrane lipoteichoic acid fromS. faecalis. Phosphatidylkojibosyl diglyceride has four nonpolar long chain fatty acyl groups and appears to have the necessary physico-chemical properties to anchor the long hydrophilic glycerol phosphate polymer of lipoteichoic acid to the hydrophobic environment of the membrane ofS. faecalis and probably other gram-positive bacteria as well. 相似文献
8.
以玉米油、甘油为原料,在无溶剂体系中用固定化脂肪酶Lipozyme TL IM催化合成甘油二酯,通过单因素试验和响应面试验研究底物摩尔比(亚油酸/甘油)、反应温度、反应时间、酶质量分数和初始水质量分数等因素对亚油酸转化率的影响。得出:反应温度、底物摩尔比、反应时间、酶质量分数对亚油酸转化率影响较大;影响酯化反应中亚油酸转化率的主次因素依次为反应温度、底物摩尔比、反应时间、酶质量分数;最佳工艺条件为亚油酸和甘油的摩尔比为2.10∶1,反应温度为61.16℃,反应时间为12.17 h,酶质量分数为20.09%,亚油酸转化率达到75.69%。Lipozyme TL IM连续反应3批次,其相对酶活仍有65.7%。 相似文献
9.
Casimir C. Akoh Brenda H. Jennings Dorris A. Lillard 《Journal of the American Oil Chemists' Society》1996,73(8):1059-1062
Immobilized lipase SP435 fromCandida antaractica was used as a biocatalyst for the modification of the fatty acid composition of evening primrose oil by incorporating n−3
polyunsaturated fatty acid (PUFA) and eicosapentaenoic acid (EPA). Transesterification (ester-ester interchange) was conducted
in organic solvent or without solvent, with EPA ethyl ester (EEPA) as the acyl donor. Products were analyzed by gas-liquid
chromatography (GLC). After 24-h incubation in hexane, the fatty acid composition of evening primrose oil was markedly changed
to contain up to 43% EPA. The amount of 18:2n−6 PUFA was reduced by 32%, and the saturated fatty acid content was also reduced.
The effects of incubation time, molar ratio, enzyme load, and reaction medium on mol% EPA incorporation were also studied.
Generally, as the incubation time (up to 24 h), molar ratio, and enzyme load increased, EPA incorporation also increased.
Evening primrose oil, containing EPA and γ-linolenic acid (18:3n−6) in the same glycerol backbone, was successfully produced
and may be more beneficial for certain applications than unmodified oil. 相似文献
10.
Substrate preferences for lipase-mediated acyl-exchange reactions with butteroil are concentration-dependent 总被引:1,自引:0,他引:1
Substrate preferences for pancreatic lipase-mediated acyl-exchange reactions with butteroil were concentration-dependent for
the series of acyl donors and alcohol acceptors evaluated. For acidolysis reactions, the initial reaction rates and percent
reaction yields after 18 h at 50 μmol acyl donor per gram substrate mixture were similar forn-fatty acids and their methyl and glycerol esters. At 400–500 μmol g−1 (and greater), order of initial reaction rates and percent reaction yield was fatty acid glycerol esters > fatty acid methyl
esters > fatty acids. At concentrations above 300–500 μmol g−1, reaction inhibition was observed for fatty acid substrates, and inhibition took place at lower concentrations for the shorter-chainlength
fatty acids of those evaluated (5–17 carbons). Inhibition was primarily attributed to acidification of the microaqueous environment
of the lipase. Desorption of water by the fatty acid substrate may be a secondary mode of inhibition. The concentration dependence
of initial reaction rates and percent reaction yield was similar for then-alcohol substrates evaluated (2–15 carbons) for alcoholysis reactions with butteroil. Optimum alcohol concentration was 375–500
μmol g−1 (except for butanol, which was 1 mmol g−1, above which reaction inhibition was observed. Inhibition was attributed to desorption of water from the enzyme by the alcohol
substrate. Relative reactivity of classes of alcohols for this reaction system was primary alcohols > secondary alcohols >
tertiary alcohols. Generally, alcoholysis reactions were faster than acidolysis reactions, and triacylglycerols were the best
substrates for acidolysis reactions with butteroil at high levels (up to 2 mmol g−1) of acyl donor substrate. 相似文献
11.
12.
C. P. Singh Peter Skagerlind Krister Holmberg D. O. Shah 《Journal of the American Oil Chemists' Society》1994,71(12):1405-1409
Lipase-catalyzed synthesis-esterification of oleic acid with glycerol-was carried out in L2 microemulsions and in monolayers.
The microemulsions were based on isooctane as a nonpolar component and various water-glycerol mixtures as polar component.
The substrate, oleic acid/sodium oleate, constituted the microemulsion surfactant. The lipase resides mainly in the water
pools. Monolayers of oleic acid/sodium oleate were formed on subsolutions of glycerol and water, and the enzyme solution was
injected under the compressed monolayers. Thus, the arrangement of the reactants at the oil-water interface of the microemulsion
can be regarded as analogous to that at the airwater interface of the monolayer. The microemulsion structure was characterized
by self-diffusion nuclear magnetic resonance. It was found that the higher the glycerol-to-water ratio, the lower are the
water D-values. The reactions in microemulsions generally gave a low degree of oleic acid conversion. The yield increased
with increasing glycerolto-water ratio. Monoglycerides were the main product, and no triglyceride could be detected. The monolayer
experiments gave a somewhat higher degree of conversion, with tri- and diglycerides being the major reaction products. The
reason why triglycerides are formed in monolayer experiments but not in microemulsions is believed to be due to an unfavorable
partitioning of the diglyceride in the microemulsion systems. Once formed, the diglyceride will partition into the hydrocarbon
domain and become inaccessible for reaction with the enzyme-O-acyl intermediate at the oil-water interface. In addition, the
interfaces in the two systems are different. The monolayer interface is static, whereas the microemulsion interface is highly
dynamic, and this difference may also influence the product patterns. 相似文献
13.
Reactions of olive oil and glycerol over immobilized lipases 总被引:1,自引:0,他引:1
The reaction of olive oil and glycerol over immobilized lipases was studied. For oil samples with free fatty acid (FFA) contents
larger than 2%, FFA esterification and glycerolysis took place simultaneously, but the esterification reaction was faster
than glycerolysis. Similar product distributions were obtained for glycerol/oil mole ratios of 3:1 and 6:1. Therefore, an
excess of glycerol does not result in a significant increase in monoglyceride yield within the experimental range tested.
The main reaction product at 80°C was diglyceride. No increase in monoglyceride yield was observed by lowering the reaction
temperature to 10°C. 相似文献
14.
Optimization of reaction conditions for the production of DAG using immobilized 1,3-regiospecific lipase lipozyme RM IM 总被引:9,自引:3,他引:9
Oils with a high DAG (1,3-DAG) content have attracted considerable attention as a healthful food oil component. In this study,
we report on the synthesis of 1,3-DAG from a mixture of FA, constituted largely of oleic and linoleic acids, using an immobilized
1,3-regioselective lipase from Rhizomucor miehei in a solvent-free system. The kinetics of 1,3-DAG production from FA and glycerol were investigated on the basis of a simplified
model, taking into consideration the acyl migration reaction, the removal of water, and glycerol dissolution in the oil phase
in addition to the esterification reactions. Both the yield of 1,3-DAG and the purity of DAG were evaluated under a variety
of experimental conditions, including reaction temperature, pressure, and amount of enzyme present. When either the reaction
temperature or the amount of enzyme used was increased, the 1,3-DAG production rate increased, but yield remained relatively
constant. The 1,3-DAG yield as well as the purity of DAG gradually decreased because of the enhancement of acyl migration
at later stages of the reaction after the 1,3-DAG concentration reached a maximum. Vacuum was important for attaining high
yields of 1,3-DAG. Under conditions of a high vacuum (1 mm Hg) at 50°C, 1.09 M 1,3-DAG was produced from 1.29 M glycerol and
2.59 MFA in an 84% yield and in 90% purity. 相似文献
15.
High-yield diacylglycerol formation by solid-phase enzymatic glycerolysis of hydrogenated beef tallow 总被引:5,自引:0,他引:5
Tsuneo Yamane Sung Tae Kang Katsuyoshi Kawahara Yoshito Koizumi 《Journal of the American Oil Chemists' Society》1994,71(3):339-342
Diglyceride (DG) was prepared by reaction of hydrogenated beef tallow and glycerol in the presence of aPsesudomonas lipase. The yield of DG depended strongly on the reaction temperature. After initial incubation at 60°C for 2 h, followed
by the first temperature shift down to 55°C for 4 h and then the second shift down to 48°C for up to 3 d, the reaction mixture
became solid and a yield of approximately 90% DG was obtained. About 95% of total DG was 1,3-DG. The yield of DG was also
dependent on the glycerol (GL) to triglyceride (TG) molar ratio. At the molar ratio of 1∶2 (GL/TG), the enzyme-catalyzed reaction
was highly efficient and utilized essentially all of the glycerol. The free fatty acid (FFA) content at equilibrium depended
on the water concentration in the glycerol phase. The initial rate of FFA formation was low and was hardly affected by the
moisture content between 0.5 and 4%, but, at higher water content (4–6.7%), there was a small increase in the rate. 相似文献
16.
Parameters affecting diacylglycerol formation during the production of specific-structured lipids by lipase-catalyzed interesterification 总被引:2,自引:0,他引:2
X. Xu H. Mu A. R. H. Skands C. E. Høy J. Adler-Nissen 《Journal of the American Oil Chemists' Society》1999,76(2):175-181
Diacylglycerols (DAG) are important intermediates in lipase-catalyzed interesterification, but a high DAG concentration in
the reaction mixture results in a high DAG content in the final product. We have previously shown that a high DAG concentration
in the reaction mixture increases the degree of acyl migration, thus adding to the formation of by-products. In the present
study we examined the influence of water content, reaction temperature, enzyme load, substrate molar ratio (oil/capric acid),
and reaction time on the formation of DAG in batch reactors. We used response surface methodology (RSM) to minimize the numbers
of experiments. The DAG content of the product was dependent on all parameters examined except reaction time. DAG formation
increased with increasing water content, enzyme load, reaction temperature, and substrate ratio. The content of sn-1,3-DAG was higher than that of sn-1,2-DAG under all conditions tested, and the ratio between the contents of the former compounds and the latter increased
with increasing temperature and reaction time. The water content, enzyme load, and substrate ratio had no significant effect
on this ratio. The DAG content was positively correlated with both the incorporation of acyl donors and the degree of acyl
migration. 相似文献
17.
Synthesis of Fatty Acid Ethyl Ester from Acid Oil in a Continuous Reactor via an Enzymatic Transesterification 下载免费PDF全文
Nakyung Choi Yangha Kim Jeom-Sig Lee Jieun Kwak Junsoo Lee In-Hwan Kim 《Journal of the American Oil Chemists' Society》2016,93(3):311-318
Synthesis of a fatty acid ethyl ester via the lipase‐catalyzed transesterification of acid oil and ethanol was investigated in a continuous reactor. Lipozyme TL IM was employed as the immobilized lipase. This immobilized lipase derived from Thermomyces lanuginosus was purchased from Novozymes (Seoul, Korea). The acid oil was prepared by the acidification of soapstock formed as a by‐product during the refining of rice bran oil. The parameters investigated were water content, temperature, and molar ratio of substrates. The relative activity of Lipozyme TL IM was assessed during the repeated use of the immobilized lipase. The water content of the substrate had a considerable effect on the yield and the optimum water content was 4 %. The optimum temperature and molar ratio of acid oil to ethanol were 20 °C and 1:4, respectively. The maximum yield of approximately 92 % was achieved under the optimum conditions. The corresponding compositions were 92 % fatty acid ethyl esters, 3 % fatty acids, and 5 % acylglycerols. When glycerol formed during the reaction was removed by intermittent washing with ethanol, the relative activity of lipase was maintained over 82 % for a total usage of 27 cycles. For a mean residence time of 4 h, the half‐life times of Lipozyme TL IM on the control (unwashed) and treatment (washed) were 39 and 45 cycles, respectively. 相似文献
18.
Enzymatic Synthesis of Tyrosol-Based Phenolipids: Characterization and Effect of Alkyl Chain Unsaturation on the Antioxidant Activities in Bulk Oil and Oil-in-Water Emulsion 下载免费PDF全文
Oxidative stability of lipids is one of the most important parameters affecting their quality. Lipase‐catalyzed lipophilic tyrosyl esters with an equivalent carbon alkyl chain but different degrees of unsaturation (C18:0 to C18:4n3) were prepared, characterized, and used as antioxidants. Free fatty acids and fatty acid ethyl esters (substrate molar ratio tyrosol: acyl donor, 1:10) were used as acyl donors and immobilized lipase from Candida antarctica was the biocatalyst (10 %). The phenolipids were isolated and characterized using ESI–MS, 1H‐NMR, and 13C‐NMR. Peroxide value (PV) and para‐anisidine value (p‐AV) were measured to evaluate their antioxidant activities in bulk oil structured lipid (SL) and in an oil‐in‐water emulsion (SL‐based infant formula). No significant difference was found in yield and reaction time between the two types of acyl donors. However, as the unsaturation of the fatty acids increased the reaction time also increased. In SL, tyrosyl esters exhibited lower antioxidant activity than tyrosol whereas the addition of an alkyl chain enhanced the antioxidant efficiency of tyrosol in infant formula. Tyrosyl oleate was the most efficient antioxidant in the emulsion system followed by tyrosyl stearate and tyrosyl linoleate. These results suggest that the synthesized phenolipids may be used as potential antioxidants in lipid‐based products. 相似文献
19.
The possibilities of producing structured phospholipids between soybean phospholipids and caprylic acid by lipase-catalyzed
acidolysis were examined in continuous packedbed enzyme reactors. Acidolysis reactions were performed in both a solvent system
and a solvent-free system with the commercially immobilized lipase from Thermomyces lanuginosa (Lipozyme TL IM) as catalyst. In the packed bed reactors, different parameters for the lipase-catalyzed acidolysis were elucidated,
such as solvent ratio (solvent system), temperature, substrate ratio, residence time, water content, and operation stability.
The water content was observed to be very crucial for the acidolysis reaction in packed bed reactors. If no water was added
to the substrate during reactions under the solvent-free system, very low incorporation corporation of caprylic acid was observed.
In both solvent and solvent-free systems, acyl incorporation was favored by a high substrate ratio between acyl donor and
phospholipids, a longer residence time, and a higher reaction temperature. Under certain conditions, the incorporation of
around 30% caprylic acid can be obtained in continuous operation with hexane as the solvent.
Presented at the 95th American Oil Chemists' Society Annual Meeting and Expo in Cincinnati, Ohio, May 10, 2004. 相似文献
20.
Anders F. Vikbjerg Huiling Mu Xuebing Xu 《Journal of the American Oil Chemists' Society》2006,83(7):609-614
Elucidation of acyl migration was carried out in the Lipozyme RM IM (Rhizomucor miehei)-catalyzed transesterification between soybean phosphatidylcholine (PC) and caprylic acid in solvent-free media. A five-factor
response surface design was used to evaluate the influence of five major factors and their relationships. The five factors—enzyme
dosage, reaction temperature, water addition, reaction time, and substrate ratio—were varied on three levels together with
two star points. Enzyme dosage, reaction temperature, and reaction time showed increased effect on the acyl migration into
the sn-2 position of PC, whereas increased water addition and substrate ratio had no significant effect in the ranges tested. The
best-fitting quadratic response surface model was determined by regression and backward elimination. The coefficient of determination
(R
2) was 0.84, which indicates that the fitted quadratic model has acceptable qualities in expressing acyl migration for the
enzymatic transesterification. Correlation was observed between acyl donor in the sn-2 position of PC and incorporation of acyl donor into the intermediate lysophosphatidylcholine. Furthermore, acyl migration
into the sn-2 position of PC was confirmed by TLC-FID, as PC with caprylic acid was observed on both positions. Under certain conditions,
up to 18% incorporation could be observed in the sn-2 position during the lipase-catalyzed transesterification. 相似文献