Lipase biocatalysis in the production of esters

Lipase biocatalysis was investigated as a tool for the production of butyl oleate and rapeseed oil 2-ethyl-1-hexyl ester by esterification and transesterification, respectively. We screened 25 commercially available lipases and found that butyl oleate was produced at high yields from oleic acid and 1-butanol by lipases fromCandida rugosa, Chromobacterium viscosum, Rhizomucor miehei, and Pseudomonas fluorescens. The initial water content of the system, lipase quantity, and the molar ratio of 1-butanol to oleic acid were important factors in influencing the ester yield. In general, no ester was formed without the addition of water. The exception wasCh. viscosum lipase, which yielded 98% of ester in 12 h with 1-butanol excess without additional water. The addition of 3.2% water increased the initial rate of reaction. With an oleic acid excess and only 0.3% lipase,C. rugosa andR. miehei lipases yielded 94 and 100% esters with initial water contents of 3.2 and 14%, respectively. Lipase-catalyzed alcoholysis of low-erucic acid rapeseed oil and 2-ethyl-1-hexanol without additional organic solvent also was studied in stirred batch reactors. In this case,C. rugosa lipase was the best biocatalyst with an optimal 2-ethyl-1-hexanol to rapeseed oil molar ratio of 2.8, a minimum of 1.0% added water, and 37°C. An increase in temperature up to 55°C increased the rate of reaction but did not affect the final ester yield. The enzyme was inactivated at 60°C. Under optimal conditions, the ester yield increased from 88% in 7 h to nearly complete conversion in 1 h when the lipase content was increased from 0.3 to 14.6%. In a 2-kg small pilot scale, up to 90% conversion (97% of theoretical) was obtained in 8 h at 37°C with 3.4% lipase in the presence of Amberlite XAD-7 resin with 3% added water.     

Lipase-Catalyzed Irreversible Transesterification of <Emphasis Type="Italic">Jatropha Curcas</Emphasis> L. Seed Oil to Fatty Acid Esters: An Optimization Study

In this work, fatty acid ethyl esters were produced from the lipase-catalyzed irreversible transesterification reaction between Jatropha oil and diethyl carbonate (DEC). Response surface methodology (RSM) based on central composite design (CCD) was used to optimize the five important reaction variables for the irreversible transesterification of Jatropha oil in a solvent-free system. The optimum conditions for the transesterification were a reaction time of 13.3 h, a temperature of 44.5 °C, a lipase amount of 13.7% (w/w), a DEC to Jatropha oil molar ratio of 3.75:1 and no need for adding water. The optimal predicted yield of fatty acid esters was 97.7% and the actual value was 96.2%. The results showed that the RSM based on CCD was adaptable for a fatty acid esters yield study for the current transesterification system.     

Parameter optimization for the enzymatic hydrolysis of sunflower oil in high-pressure reactors

This study is concerned with the hydrolysis of sunflower oil in the presence of lipase preparation Lipolase 100T (Aspergillus niger lipase). Supercritical carbon dioxide was used as a solvent for this reaction. In a high-pressure stirred tank reactor operated in a batch mode, the effects of various process parameters (temperature, pressure, enzyme/substrate ratio, pH, and oil/buffer ratio) were investigated to determine the optimal reaction rate and conversion for the hydrolysis process. The optimal concentration of lipase was 0.0714 g/mL of CO₂-free reaction mixture, and the highest conversions of oleic acid (0.193 g/g of oil phase) and linoleic acid (0.586 g/g of oil phase) were obtained at 50°C, 200 bar, pH=7, and an oil/buffer ratio of 1∶1 (w/w).     

Transesterification of trimethylolpropane and rapeseed oil methyl ester to environmentally acceptable lubricants

Biodegradable trimethylolpropane [2-ethyl-2-(hydroxymethyl)-1,3-propanediol] esters of rapeseed oil fatty acids were synthesized by transesterification with rapeseed oil methyl ester both by enzymatic and chemical means, both in bench and pilot scales. Nearly complete conversions were obtained with both techniques. A reduced pressure of about 2 to 5 kPa, to remove the methanol formed during transesterification, was critical for a high product yield. The quantity of added water was also critical in the biocatalysis. Candida rugosa lipase was used as biocatalyst and an alkaline catalyst in chemical transesterifications. In biocatalysis the maximum total conversion to trimethylolpropane esters of up to 98% was obtained at 42°C, 5.3 kPa, and 15% added water. The maximum conversion of about 70% to the tri-ester was obtained at the slightly higher temperature of 47°C. The reaction time was longer in the biocatalysis, but considerably higher temperatures were required in chemical synthesis. In the chemical synthesis tri-ester yields increased when the temperature was first held at 85 to 110°C for 2.5 h and subsequently increased to up to 120°C for 8 h. The trimethylolpropane esters obtained were tested as biodegradable hydraulic fluids and compared to commercially available hydraulic oils. The hydraulic fluids based on trimethylolpropane esters of rapeseed oil had good cold stability, friction and wear characteristics, and resistance against oxidation at elevated temperatures.     

Immobilization and stabilization of <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> SRT9 lipase on tri(4-formyl phenoxy) cyanurate

Lipase was extracted and purified from Pseudomonas aeruginosa SRT9. Culture conditions were optimized and highest lipase production amounting to 147.36 U/ml was obtained after 20 h incubation. The extracellular lipase was purified on Mono QHR5/5 column, resulting in a purification factor of 98-fold with specific activity of 12307.81 U/mg. Lipase was immobilized on tri (4-formyl phenoxy) cyanurate to form Schiff’s base. An immobilization yield of 85% was obtained. The native and immobilized lipases were used for catalyzing the hydrolysis of olive oil in aqueous medium. Comparative study revealed that immobilized lipase exhibited a shift in optimal pH from 6.9 (free lipase) to 7.5 and shift in optimal temperature from 55 °C to 70 °C. The immobilized lipase showed 20–25% increase in thermal stability and retained 75% of its initial activity after 7 cycles. It showed good stability in organic solvents especially in 30% acetone and methanol. Enzyme activity was decreased by ∼60% when incubated with 30% butanol. The kinetic studies revealed increase in K _M value from 0.043 mM (native) to 0.10 mM for immobilized lipase. It showed decrease in the V _max of immobilized enzyme (142.8 μmol min⁻¹ mg⁻¹), suggesting enzyme activity decrease in the course of covalent binding. The immobilized lipase retained its initial activity for more than 30 days when stored at 4 °C in Tris-HCl buffer pH 7.0 without any significant loss in enzyme activity.     

Transesterification of waste cooking oil with a commercial liquid biocatalyst: Key information revised and new insights

The transesterification of the waste cooking oil (WCO) with various linear alcohols (C1 to C4) using the commercial biocatalyst Eversa® Transform in its liquid form is addressed in this investigation. The influence of the amount of the liquid formulation of lipase Eversa® Transform, nature of alcohol, oil to alcohol molar ratio and water addition in the transesterification of fresh sunflower oil and WCO was investigated. In addition, an innovative combination of that fungal based biocatalyst with a native vegetable lipase, known as Araujia sericifera (ASL), in a liquid formulation fashion was investigated. The assays carried out at 35°C for 24 h, an oil: alcohol molar ratio of 1:6.8, 2% v/w water added and 1% v/w of biocatalyst allowed to obtain up to 90% conversion and yield towards fatty acid methyl, ethyl and propyl esters. In the particular case of 1-butanol (C4) a 79% conversion and 72% yield to the esters was obtained. The biocatalyst maintains about 60% of its activity in the conversion of glycerides and yield towards the esters. The combination of process using Eversa® Transform and then the ASL lipase in the transesterification of the WCO probed efficient in the conversion of triglycerides using 1-butanol. A shift from 73 wt % of fatty acid butyl esters (FABE) towards 90 wt % was achieved.     

Enzymatic fatty ester synthesis

Fatty ester synthesis with immobilized 1,3-specific lipase fromMucor miehei is described. 1,2-Isopropylidene glycerol produced by condensation of glycerol with acetone was esterified with oleic acid in the presence of aMucor miehei lipase (Lipozyme™) to obtain 1,2-isopropylidene-3-oleoyl glycerol. The effects of various process parameters (temperature and pressure) and various ratios (enzyme/substrate) have been investigated to determine optimal conditions for the esterification process. The highest conversion of oleic acid (80% w/w) was obtained at 55°C and 0.057 bar, while the optimal addition of lipase to substrate was determined to be 0.096 g per gram of reaction mixture. The esterification can be modeled successfully as a reverse second-order reaction. Thermodynamic properties of the reaction system at 55°C and 0.057 bar also were determined. Activation energy was 20.82 kJ/mole, entropy of activation −0,26 kJ/(K mole) and free energy of activation was 103.32 kJ/mole.     

Fatty Acid Alkyl Esters as Feedstocks for the Enzymatic Synthesis of Alkyl Methacrylates and Polystyrene-<Emphasis Type="Italic">co</Emphasis>-alkyl Methacrylates for use as Cold Flow Improvers in Diesel Fuels

The enzymatic transesterifications of fatty acid methyl esters (FAME) with hydroxyethyl methacrylate (HEMA) were carried out using the Candida antarctica lipase B immobilized within a porous polymethacrylate resin. The enzymatic activity in the transesterification reaction of FAME with HEMA depended on the polarity of the solvent and the highest yield was obtained in toluene (non-polar). The molar ratio of 1:4 (for methyl laurate:HEMA) and 1:2 (for methyl oleate:HEMA) was most favorable for the transesterification yield. The reaction condition (at 60 °C/24 h), and the enzyme concentration of 5% (w/w) for methyl laurate with HEMA, 2% (w/w) for methyl oleate with HEMA resulted in the highest final yield. Under these conditions, the maximum yields for the transesterification of methyl laurate with HEMA, methyl oleate with HEMA were 97 ± 5.4% and 91 ± 4.7%, respectively. After ten batches of transesterification of FAME with HEMA, enzyme activity was retained at the level of 88 ± 2.6% and 76 ± 2.3%, respectively, compared with their initial activity. Also, alkyl methacrylate/styrene copolymers were synthesized by radical polymerization of HEMA-LMA (or HEMA-OMA) and styrene. The prepared copolymers have average molecular weights from 2.6 × 10⁴ to 5.5 × 10⁴. Especially, the poly(styrene-co-alkyl methacrylate)s (PStmHAMAn) led to a reduction in the pour point in ultra low sulfur diesel (ULSD) treated with 200–1,000 ppm of poly(styrene-co-alkyl methacrylate). Diesel fuel containing 1,000 ppm of the copolymer (PSt2HLMA8) showed a 15 ± 1.25 °C reduction in its pour point.     

Enzymatic synthesis of geranyl acetate by transesterification with acetic anhydride as acyl donor

Pseudomonas sp. lipase (PS) was immobilized by adsorption technique onto glass beads and tested for its ability to synthesize geranyl acetate by transesterification with acetic anhydride as the acyl donor. Reactions were carried out inn-hexane containing 0.1 M geraniol, 0.1 M acetic anhydride, and 200 units of lipase PS. Enzyme load, effect of substrate concentration, added water, temperature, time course, organic solvent, pH memory, and enzyme reuse were studied. Yields of up to 96% were obtained with 200 units (approximately 11% w/w of reactants) of enzyme. Increasing amounts of geraniol inhibited lipase activity, while excess acyl donor concentration enhanced ester production. Yields as high as 97% were obtained at 50°C, 24 h incubation, with no added water. Solvents with logP values ≥3.0 showed the highest conversion yields. Solvent-free samples also performed well. The pH range of 4–9 gave good yields (92–98.4%). Enzyme reuse studies showed the lipase remained active after 15 runs.     

Purification of steryl esters from soybean oil deodorizer distillate

Soybean oil deodorizer distillate (SODD) contains steryl esters in addition to tocopherols and sterols. Tocopherols and sterols have been industrially purified from SODD but no purification process for steryl esters has been developed. SODD was efficiently separated to low b.p. substances (including tocopherols and sterols) and high b.p. substances (including 11.2 wt% DAG, 32.1 wt% TAG, and 45.4 wt% steryl esters) by molecular distillation. The high b.p. fraction is referred to as soybean oil deodorizer distillate steryl ester concentrate (SODDSEC). We attempted to purify steryl esters after a lipase-catalyzed hydrolysis of acylglycerols in SODDSEC. Screening of industrially available lipases indicated that Candida rugosa lipase was most effective. Based on the study of several factors affecting hydrolysis, the reaction conditions were determined as follows: ratio of SODDSEC/water, 1∶1 (w/w); lipase amount, 15 U/g reaction mixture; temperature, 30°C. When SODDSEC was agitated for 24 h under these conditions, acylglycerols were almost completely hydrolyzed and the content of steryl esters did not change. However, study with a mixture of steryl oleate/trilinolein (1∶1, w/w) indicated that about 20% of constituent FA in steryl esters were exchanged with constituent FA in acylglycerols. Steryl esters in the oil layer obtained by the SODDSEC treatment with lipase were successfully purified by molecular distillation (purity, 97.3%; recovery, 87.7%).     

Lipase PS-catalyzed transesterification of citronellyl butyrate and geranyl caproate: Effect of reaction parameters

Pseudomonas sp. lipase PS was immobilized by adsorption and tested for its ability to catalyze the synthesis of citronellyl butyrate and geranyl caproate by transesterification in n-hexane. The reaction parameters investigated were: enzyme load, effect of substrate concentration, added water, temperature, time course, organic solvent, pH memory, and enzyme reuse. Yields as high as 96 and 99% were obtained for citronellyl butyrate and geranyl caproate, respectively, with 300 units (approx. 15% w/w of reactants) of lipase PS. Increasing amounts of terpene alcohol inhibited lipase activity, while excess acyl donor (triacylglycerol) concentration enhanced ester production. Optimal yields were obtained at temperatures from 30–50°C after 24-h incubation time. Yields of 90 and 99% were obtained for citronellyl and geranyl esters, respectively, with 2% added water. Solvents with log P values ≥ 2.5 showed the highest conversion yields. pH 7 and 6–8 seemed to be ideal for citronellyl butyrate and geraniol caproate, respectively. The lipase remained active after reusing 12 times.     

Lipase‐mediated methanolysis of soybean oils for biodiesel production

BACKGROUND: Biodiesel is increasingly perceived as an important component of solutions to the important current issues of fossil fuel shortages and environmental pollution. Biocatalysis of soybean oils using soluble lipase offers an alternative approach to lipase‐catalyzed biodiesel production using immobilized enzyme or whole‐cell catalysis. The central composite design (CCD) of response surface methodology (RSM) was used here to evaluate the effects of enzyme concentration, temperature, molar ratio of methanol to oil and stirring rate on the yield of fatty methyl ester. RESULTS: Lipase NS81006 from a genetically modified Aspergillus oryzae was utilized as the catalyst for the transesterification of soybean oil for biodiesel production. The experimental data showed that enzyme concentration, molar ratio of methanol to oil and stirring rate had the most significant impact on the yield of fatty methyl ester; a quadratic polynomial equation was obtained for methyl ester yield by multiple regression analysis. The predicted biodiesel yield was 0.928 (w/w) under the optimal conditions and the subsequent verification experiments with biodiesel yield of 0.936 ± 0.014 (w/w) confirmed the validity of the predicted model. CONCLUSION: RSM and CCD were suitable techniques to optimize the transesterification of soybean oil for biodiesel production by soluble lipase NS81006. The related lipase NS81006 reuse stability, chemical or genetic modification, and transesterification mechanism should be taken into consideration. Copyright © 2007 Society of Chemical Industry     

Regiospecific analysis by ethanolysis of oil with immobilized <Emphasis Type="Italic">Candida antarctica</Emphasis> lipase

A mixture of oil/ethanol (1∶3, w/w) was shaken at 30°C with 4% immobilized Candida antarctica lipase by weight of the reaction mixture. The reaction regiospecifically converted FA at the 1- and 3-positions to FA ethyl esters, and the lipase acted on C₁₄−C₂₄ FA to a similar degree. The content of 2-MAG reached a maximum after 4 h; the content was 28–29 mol% based on the total amount of FA in the reaction mixture at 59–69% ethanolysis. Only 2-MAG were present in the reaction mixture during the first 4 h, and 1(3)-MAG were detected after 7 h. After removal of ethanol from the 4-h reaction mixture by evaporation, 2-MAG were fractionated by silica gel column chromatography. The contents of FA in the 2-MAG obtained by ethanolysis of several oils coincided well with FA compositions at the 2-position, which was analyzed by Grignard degradation. It was shown that ethanolysis of oil with C. antarctica lipase can be applied to analysis of FA composition at the 2-position in TAG.     

Production of biodiesel from palm oil using liquid core lipase encapsulated in κ-carrageenan

This work deals with the enzymatic transesterification of palm oil with methanol in a solvent-free system. Among the five lipases tested in the initial screening, lipase PS from Burkholderia cepacia resulted in the highest triglyceride conversion. Lipase PS was further investigated in a novel immobilized form by encapsulating within a biopolymer, κ-carrageenan. Using the immobilized lipase the production parameters of biodiesel from palm oil were optimized. The optimal conditions for processing 10 g of palm oil was: 30 °C, 1:7 oil/methanol molar ratio, 1 g water, 5.25 g immobilized lipase, 72 h reaction time and 23.7g relative centrifugal force. At the optimal conditions, triglyceride conversion of up to 100% could be obtained. The immobilized lipase was stable and retained 82% relative transesterification activity after five cycles. Liquid core lipase encapsulated in κ-carrageenan could be a potential immobilized catalyst for eco-friendly production of biodiesel.     

Production of a very low saturate oil based on the specificity of Geotrichum candidum lipase

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.     

Characterization of Terebinth Fruit Oil and Optimization of Acidolysis Reaction with Caprylic and Stearic Acids

Characterization of the fatty acid and triacylglycerol composition of terebinth fruit oil and the synthesis of structured lipids (SL) were performed in this study. Interesterification reaction of terebinth fruits oil (Pistacia terebinthus L.) with caprylic acid (CA) and stearic acid (SA) to produce a SL was performed in n-hexane using immobilized sn-1,3 specific lipase from Mucor miehei. The effect of reaction conditions and relationship among them were analyzed by response surface methodology (RSM) with a four-factors five-level central composite rotatable experimental design. The four major factors chosen were enzyme load (10–30 wt% based on substrates), reaction time (7–18 h), reaction temperature (40–60 °C) and substrate mole ratio (terebinth oil:SA:CA 1:1:1–1:1:3). The best fitting quadratic model was determined by regression and backward elimination. Based on the fitted model, the optimal reaction conditions for the incorporation of CA and SA were found to be temperature 50 °C; time 18 h; enzyme load 30 wt%; substrate ratio 1:1:3. Under these optimum conditions, the incorporation of SA and CA could be obtained as 19 and 14%, respectively.     

Use of thermostable Fusarium heterosporum lipase for production of structured lipid containing oleic and palmitic acids in organic solvent-free system

A newly developed 1,3-positionally specific thermostable lipase from Fusarium heterosporum (named R275A lipase) was immobilized on Dowex WBA for the production of structured lipid by acidolysis of tripalmitin (PPP) with oleic acid (OA). The immobilized catalyst was fully activated by pretreatment at 50°C in a PPP/OA mixture containing 2% water. The pretreatment caused concomitant hydrolysis, but the hydrolysis was repressed using a substrate without water in the subsequent reactions. The optimal reaction conditions were determined as follows: A mixture of PPP/OA (1∶2, w/w) and 8% immobilized lipase catalyst was incubated at 50°C for 24 h with shaking at 130 oscillations/min. The acidolysis reached 50% under these conditions, and the contents of triolein, 1,3-dioleoyl-2-palmitoyl-glycerol, 1(3),2-dioleoyl-3(1)-palmitoyl-glycerol, 1(3),2-palmitoyl-3(1)-oleoyl-glycerol, 1,3-dipalmitoyl-2-oleoyl-glycerol, and PPP in the reaction mixture were 8, 36, 4, 28, 1, and 6 mol%, respectively. The stabilities of immobilized R275A lipase catalyst and two immobilized catalysts containing Rhizopus delemar or Rhizomucor miehei lipases were compared under the conditions mentioned above, with the catalysts being transferred to fresh substrate every 24 h. The half-life of the R275A lipase catalyst was 370 d, which was significantly longer than those of Rhizopus and Rhizomucor lipase catalysts.     

Production of structured lipids containing essential fatty acids by immobilizedRhizopus delemar lipase

An attempt was made to produce structured lipids containing essential fatty acid by acidolysis with 1,3-positional specificRhizopus delemar lipase. The lipase was immobilized on a ceramic carrier by coprecipitation with acetone and then was activated by shaking for 2 d at 30°C in a mixture of 5 g safflower or linseed oil, 10 g caprylic acid, 0.3 g water and 0.6 g of the immobilized enzyme. The activated enzyme was transferred into the same amount of oil/caprylic acid mixture without water, and the mixture was shaken under the same conditions as for the activation. By this reaction, 45–50 mol% of the fatty acids in oils were exchanged for caprylic acid, and the immobilized enzyme could be reused 45 and 55 times for safflower and linseed oils, respectively, without any significant loss of activity. The triglycerides were extracted withn-hexane after the acidolysis and then were allowed to react again with caprylic acid under the same conditions as mentioned above. When acidolysis was repeated three times with safflower oil as a starting material, the only products obtained were 1,3-capryloyl-2-linoleoylglycerol and 1,3-capryloyl-2-oleoyl-glycerol, with a ratio of 86∶14 (w/w). Equally, the products from linseed oil were 1,3-capryloyl-2-α-linolenoyl-glycerol, 1,3-caprylol-2-linoleoyl-glycerol, and 1,3-capryloyl-2-oleoly-glycerol (60∶22∶18, w/w/w). All fatty acids at the 1,3-positions in the original oils were exchanged for caprylic acid by the repeated acidolyses, and the positional specificity ofRhizopus lipase was also confirmed to be strict.     

Biodiesel (FAME) Productivity,Catalytic Efficiency and Thermal Stability of Lipozyme TL IM for Crude Palm Oil Transesterification with Methanol

Crude palm oil (CPO) transesterification with methanol at room temperature is an important factor for optimizing biodiesel processing costs with respect to energy input; in addition, good stability of expensive lipase activity was ensured and is reported in this study. The enzyme loading, agitation speed and reaction time at a constant operating temperature of 30 °C were studied to find favourable operational conditions using a factorial design. Statistical analysis was used to assist the enzymatic transesterification so that a reduced mass transfer effect was achieved to obtain high FAME yields. The combination of optimum enzyme loading of 6.67 wt% and 150 rpm agitation speed for the system at 30 °C gave 81.73% FAME yield at 4 h and a production rate of 85.86% FAME yield/h. The high viscosity of CPO observed at 30 °C compared to 40 °C hindered the achievement of 96.15% FAME yield at room temperature. It was found that an increase of 10 °C invariably deactivated the lipase, but was compensated by the enhanced FAME production rate with 96.15% FAME yield after only 4 h reaction time. Thus, 40 °C was considered the most suitable operating temperature for lipozyme TL IM to catalyze CPO transesterification.     

Enrichment of salmon oil with n‐3 PUFA by lipolysis,filtration and enzymatic re‐esterification

Selective enzymatic hydrolysis of salmon oil extracted without solvent from by‐products was carried out under mild conditions, using a stereospecific sn‐1, sn‐3 lipase Novozyme^®. A modification of the lipid class composition was obtained by controlling the degree of hydrolysis (40%, 24 h). The mixture of acylglycerols and free fatty acids was submitted to a filtration step to retain in the retentate most of the saturated fatty acids, with melting peaks ranging from ‐31.9 °C to +14.7 °C obtained by differential scanning calorimetry. This step allowed a significant increase of polyunsaturated fatty acids (PUFA) from 39.2 mol‐% in the crude oil to 43.3% in the permeate. The remaining free fatty acids in the permeate (20.2 wt‐%) was re‐esterified with an immobilized 1, 3‐specific lipase IM60. Acylglycerols synthesis reached 90% in optimized conditions. After 48 h of reaction, the distribution of monoacylglycerols, diacylglycerols and triacylglycerols was 22.1, 28.7, 43.4 (w/w), respectively. The re‐esterification step did not modify the PUFA content obtained after membrane filtration.