Modification of menhaden oil by enzymatic acidolysis to produce structured lipids: Optimization by response surface design in a packed bed reactor

Structured lipids from menhaden oil were produced by enzymatic acidolysis in a packed bed reactor. Response surface methodology was applied to optimize the reaction. Lipozyme IM from Rhizomucor miehei lipase was the biocatalyst, and caprylic acid was the acyl donor. Parameters such as residence time, substrate molar ratio, and reaction temperature were included for the optimization. High incorporation of acyl donor and retention of high levels of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids in the original menhaden oil were obtained. Good quadratic models were obtained for the incorporation of caprylic acid and for the content of EPA plus DHA retained, by multiple regression with backward elimination. The coefficients of determination (R ²) for the two models were 0.91 and 0.87, respectively. The regression probabilities (P) were below 0.003 for both models. Also, the predicted values from the two models had linear relationships with the observed responses. All parameters studied had positive effects on the incorporation of caprylic acid, but only residence time and substrate molar ratio had negative effects on the content of EPA plus DHA retained. The optimal conditions generated from models were temperature =65°C, substrate molar ratio=4–5, and residence time=180–220 min. Incorporated caprylic acid did not replace DHA, but the content of EPA decreased somewhat with an increase in caprylic acid incorporation.     

Strategies for lipase‐catalyzed production and the purification of structured phospholipids

This work provides different strategies for the enzymatic modification of the fatty acid composition in soybean phosphatidylcholine (PC) and the subsequent purification. Enzymatic transesterification reactions with caprylic acid as acyl donor were carried out in continuous enzyme bed reactors with a commercial immobilized lipase (Lipozyme RM IM) as catalyst. Operative stability of the immobilized lipase was examined under solvent and solvent‐free conditions. The long reaction time required to have a high incorporation, combined with rapid deactivation of the enzyme, makes the solvent‐free transesterification reaction unfavorable. Performing the reaction in the presence of solvent (hexane) makes it possible to have high incorporation into PC and deactivation of the lipase is less pronounced as compared to solvent‐free operations. For solvent‐free operation, it is suggested to recycle the reaction mixture through the packed bed reactor, as this would increase incorporation of the desired fatty acids, due to increased contact time between substrate and enzyme in the column. Removal of free fatty acids from the reaction mixture can be done by ultrafiltration; however, parameters need to be selected with care in order to have a feasible process. No changes are observed in the phospholipid (PL) distribution during ultrafiltration, and other techniques as column chromatography may be required if high purity of individual PL species is desired. LC/MS analysis of transesterified PC revealed the presence of 8:0/8:0‐PC, showing that acyl migration takes place during the acidolysis reaction.     

Lipase-catalyzed acidolysis of perilla oil with caprylic acid to produce structured lipids

Structured lipids were synthesized by acidolysis of perilla oil and caprylic acid using two lipases, Lipozyme RM IM from Rhizomucor miehei and Lipozyme TL IM from Thermomyces lanuginosa. Effects of molar ratio, reaction time, reaction temperature, enzyme load, and solvent content on acidolysis reactions were studied. The solvent content ranged from 0.0 (solvent-free) to 85.3%. The results showed that the incorporation increased in parallel with solvent content to 49.0% with Lipozyme RM IM and to 63.8% with Lipozyme TL IM. After 24 h incubation in n-hexane, caprylic acids were incorporated to 48.5 mol% with Lipozyme RM IM and to 51.4 mol% with Lipozyme TL IM, respectively, whereas linolenic acid content was reduced from 61.4 to 31.5 mol% with Lipozyme RM IM and to 28.4 mol% with Lipozyme TL IM, respectively. Lipozyme TL IM showed a higher acyl migration rate than Lipozyme RM IM when acidolysis was performed in the reaction system containing n-hexane as a solvent, whereas the difference in acyl migration between the two lipases in the solvent-free system was negligible.     

Lipase-catalyzed acidolysis of canola oil with caprylic acid to produce medium-, long- and medium-chain-type structured lipids

Lipase-catalyzed acidolysis of canola oil with caprylic acid was performed to produce structured lipids (SLs) containing medium-chain fatty acid (M) at position sn-1,3 and long-chain fatty acid (L) at the sn-2 position in a solvent-free system. Six commercial lipases from different sources were screened for their ability to incorporate caprylic acid into the canola oil. The sn-1,3 regiospecificity toward the glycerol backbone of canola oil of the lipases with relatively higher acidolysis activity was compared by investigating the fatty acid profiles of the products. The results showed that Lipozyme RM IM from Rhizomucor miehei resulted in the highest caprylic acid incorporation ability and the lowest acyl migration. The reaction parameters including substrate mole ratio, enzyme load, reaction time and temperature of Lipozyme RM IM were investigated. Incorporation of caprylic acid was higher when reactions were carried with 10% lipase of the total weight of substrates with a 1:4 mole ratio of oil and caprylic acid. The optimal time course and temperature for synthesis SLs were 15 h and 50–60 °C. Possible triacylglycerol species and physical properties of the SLs product obtained at relative optimal conditions were characterized.     

Production of structured lipids by lipase-catalyzed acidolysis in supercritical carbon dioxide: Effect on acyl migration

Structured lipids were synthesized by the acidolysis of corn oil by caprylic acid in supercritical carbon dioxide (SCCO₂) with Lipozyme RM IM from Rhizomucor miehei. The effects of pressure and temperature on the reaction were studied. To compare the degrees of acyl migration in the SCCO₂ and solvent-free reaction systems, the effects of reaction time on the degree of acyl migration were also studied. The highest mole percentage incorporation of caprylic acid (62.2 mol%) occurred at 24.13 MPa in SCCO₂. The overall incorporation of caprylic acid in the SCCO₂ system remained higher than that in the solvent-free system at every temperature tested. This trend was observed more clearly at lower temperatures (35–55°C) than at higher temperatures (65–75°C). Acyl migration with both reaction systems was low, with a negligible difference between them up to 12 h, after which the degree of acyl migration in the solvent-free system increased rapidly with time up to 24 h compared with the SCCO₂ system.     

Synthesis of Structured Lipids Containing Pinolenic Acid at the <Emphasis Type="Italic">sn</Emphasis>-2 Position via Lipase-Catalyzed Acidolysis

Lipase-catalyzed acidolysis of a modified pine nut oil (MPNO)—the pine nut oil was obtained from Pinus koraiensis Siebold &; Zucch.—with capric acid was studied in a continuous packed bed reactor (PBR) using Lipozyme RM IM from Rhizomucor miehei as a biocatalyst. The MPNO containing pinolenic acid (PLA) at the sn-2 position of the triacylglycerol (TAG) backbone was prepared by lipase-catalyzed redistribution of pine nut oil using Novozym 435 from Candida antarctica. The effects of the water content in the reaction mixture and the molar ratio of substrates on the extent of the acidolysis reaction as a function of residence time in a PBR were investigated. The water content of the reaction mixture significantly influenced both the rate of acidolysis and the degree of acyl migration, but the molar ratio of substrates affected only the rate of acidolysis. The optimum water content and molar ratio for synthesis of the structured lipid containing PLA at the sn-2 position and capric acid at the sn-1,3 positions of the TAG backbone were 0.04%, and 1:5 (MPNO to capric acid), respectively.     

Elucidation of acyl migration during lipase-catalyzed production of structured phospholipids

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.     

Production of specific-structured triacylglycerols by lipase-catalyzed interesterification in a laboratory-scale continuous reactor

A laboratory-scale continuous reactor was constructed for production of specific structured triacylglycerols containing essential fatty acids and medium-chain fatty acids (MCFA) in the sn-2 and sn-1,3 positions, respectively. Different parameters in the lipase-catalyzed interesterification were elucidated. The reaction time was the most critical factor. Longer reaction time resulted in higher yield, but was accompanied by increased acyl migration. The concentration of the desired triacylglycerol (TAG) in the interesterification product increased significantly with reaction time, even though there was only a slight increase in the incorporation of MCFA. Increased reactor temperature and content of MCFA in the initial reaction substrate improved the incorporation of MCFA and the yield of the desired TAG in the products. Little increase of acyl migration was observed. Increasing the water content from 0.03 to 0.11% (w/w substrate) in the reaction substrate had almost no effect on either the incorporation or the migration of MCFA, or on the resulting composition of TAG products and their free fatty acid content. Therefore, we conclude that the water in the original reaction substrate is sufficient to maintain the enzyme activity in this continuous reactor. Since the substrates were contacted with a large amount of lipase, the reaction time was shorter compared with a batch reactor, resulting in reduced acyl migration. Consequently, the purity of the specific structured TAG produced was improved. Interesterification of various vegetable oils and caprylic acid also demonstrated that the incorporation was affected by the reaction media. Reaction conditions for lipase-catalyzed synthesis of specific structured TAG should be optimized according to the oil in use. Presented in part at Food Science Conference, Copenhagen, Denmark, January 30–31, 1997.     

Production of specific-structured triacylglycerols by lipase-catalyzed interesterification in a laboratory-scale continuous reactor

A laboratory-scale continuous reactor was constructed for production of specific structured triacylglycerols containing essential fatty acids and medium-chain fatty acids (MCFA) in the sn-2 and sn-1,3 positions, respectively. Different parameters in the lipase-catalyzed interesterification were elucidated. The reaction time was the most critical factor. Longer reaction time resulted in higher yield, but was accompanied by increased acyl migration. The concentration of the desired triacylglycerol (TAG) in the interesterification product increased significantly with reaction time, even though there was only a slight increase in the incorporation of MCFA. Increased reactor temperature and content of MCFA in the initial reaction substrate improved the incorporation of MCFA and the yield of the desired TAG in the products. Little increase of acyl migration was observed. Increasing the water content from 0.03 to 0.11% (w/w substrate) in the reaction substrate had almost no effect on either the incorporation or the migration of MCFA, or on the resulting composition of TAG products and their free fatty acid content. Therefore, we conclude that the water in the original reaction substrate is sufficient to maintain the enzyme activity in this continuous reactor. Since the substrates were contacted with a large amount of lipase, the reaction time was shorter compared with a batch reactor, resulting in reduced acyl migration. Consequently, the purity of the specific structured TAG produced was improved. Interesterification of various vegetable oils and caprylic acid also demonstrated that the incorporation was affected by the reaction media. Reaction conditions for lipase-catalyzed synthesis of specific structured TAG should be optimized according to the oil in use. Presented in part at Food Science Conference, Copenhagen, Denmark, January 30–31, 1997.     

Parameters affecting diacylglycerol formation during the production of specific-structured lipids by lipase-catalyzed interesterification

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.     

Production of specifically structured lipids by enzymatic interesterification in a pilot enzyme bed reactor: process optimization by response surface methodology

Pilot production of specifically structured lipids by Lipozyme IM-catalyzed interesterification was carried out in a continuous enzyme bed reactor without the use of solvent. Medium-chain triacylglycerols and oleic acid were used as model substrates. Response-surface methodology was applied to optimize the reaction system with four process para-meters, these being volume flow rate, water content in the substrates, reaction temperature, and substrate ratio. The incorporation of acyl donors, product yields, and the content of diacylglycerols were measured as model responses. Enzyme activity was not identical for the sequential experiments in the same enzyme bed due to the deactivation of the Lipozyme IM. Therefore, the results were normalized based on enzyme deactivation models. Well-fitting quadratic models were obtained after normalizing the data for the incorporation of oleic acid and the production of mono-incorporated and di-incorporated structured lipids with multiple regression and backward elimination. The coefficient of determination (R²) for the incorporation was 0.93 and that for the diincorporated products was 0.94. The optimal conditions were flow rate, 2 ml/min; temperature, 65 °C; substrate ratio, 5.5; and water content, 0.1%. The production of diacylglycerols was not well correlated with any of the parameters, and the yield generally decreased with the experimental sequence. This was due to the stoichiometric water in the substrate mixture in the packed enzyme bed being complicated by the water binding and absorption of the immobilized lipase. The main effects of parameters were also examined, and conclusions in agreement with our previous results were made.     

Comparative Study of Sterol Ester Synthesis using <Emphasis Type="Italic">Thermomyces Lanuginosus</Emphasis> Lipase in Stirred Tank and Packed-Bed Bioreactors

A comparative study was done on the production of different sterol esters using a stirred tank batch reactor (STBR) and packed bed reactor (PBR) using Thermomyces lanuginosus (Lipozyme TLIM) enzyme, a commercially immobilized lipase. Different oils were used as the sources of particular fatty acids, e.g., fish oil for n-3 polyunsaturated fatty acids (n-3 PUFA), linseed oil for alpha linolenic acid (ALnA) and mustard oil for erucic acid. Reaction parameters, such as substrate molar ratio, reaction temperature and enzyme concentration, were standardized in the STBR and maintained in the PBR. To provide equal time of residence between the substrate and enzyme in both the reactors for the same amount of substrates, the substrate flow rate in the PBR was maintained at 0.27 ml/min. Thin layer chromatography was used to monitor the reaction, and column chromatography was used to determine the product yields. Fatty acid compositions of the esters were determined by gas chromatography. The study showed that the packed bed bioreactor was more efficient than the batch reactor in sterol-ester synthesis with less migration of acyl groups.     

Assessment of lipase- and chemically catalyzed lipid modification strategies for the production of structured lipids

The purpose of the present study was to devise a two-step reaction to produce partial glycerides, which would subsequently be used as substrates in both lipase-catalyzed and chemically catalyzed esterification reactions with caprylic acid. The yields and kinetics of these two-step reactions were compared to established lipase-catalyzed acidolysis and transesterification as well as to chemical transesterification reactions. Acyl migration did not occur during the hydrolysis or short-path distillation steps in the preparation of free fatty acid-free partial glycerides for esterification reactions. No significant differences in final yields (59.9% to 82.8% w/w of total triacylglycerols) of new structured lipids were detected among lipase-catalyzed (24 h) and chemically catalyzed (5 h) reactions; however, the yield of new structured triacylglycerols (TAG) after 2 h was lower for acidolysis than for the other lipase-catalyzed reactions (P≤0.05). Since no differences in final yields were detected among the reactions, chemical esterification using hydrolyzed oil could represent the best synthetic option, since it offers the advantage of positional distribution control associated with lipase-catalyzed reactions as well as rapid reaction times associated with chemically catalyzed reactions. Attempts to evaluate the positional distribution of caprylic acid using allyl magnesium bromide (Grignard reagent) were hampered by production of unknown species, which prevented accurate determination of the concentration of some key fatty acids.     

Synthesis, purification, and characterization of structured lipids produced from chicken fat

A structured lipid (SL) was synthesized enzymatically from chicken fat by incorporating a medium-chain length fatty acid (caprylic acid) into chicken fat triacylglycerols. Carica papaya latex was used as the biocatalyst. The optimal substrate mole ratio found was 1∶2 (chicken fat fatty acids/caprylic acid). At this ratio of reactants, the incorporation of caprylic acid (C_8∶0) at 65°C was 23.4 mol%, whereas at 55°C the incorporation of caprylic acid was 17.6 mol%. A packed-bed column bioreactor was designed for the synthesis of SL from chicken fat. In using ground crude C. papaya latex (a _w <0.1), 7.1 mol% of caprylic acid was incorporated into the chicken fat triacylglycerols after 117 min of reactor residence time. After purification of the SL, the acyl positional distribution of fatty acids on the glycerol backbone was determined by ¹³C nuclear magnetic resonance (NMR) spectroscopy. From the NMR spectrum of the SL, it was determined that saturated fatty acyl residues at the 1,3-positions of the SL triacylglycerols increased to 62% over that of the starting chicken fat triacylglycerols, suggesting that caprylic acid was preferentially incorporated at the 1,3-positions. In addition, differential scanning calorimetry thermograms were obtained to compare the crystallization characteristics of the starting chicken fat with the SL prepared from it. 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.     

甘油二酯的酶法合成工艺研究

以固定化脂肪酶为催化剂,研究无溶剂体系下甘油和辛酸直接酯化合成甘油二酯工艺。在选用的3种脂肪酶中,发现Novozym e 435催化效果最好。以Novozym e 435为催化剂,考察了底物摩尔比、温度、反应加酶量以及脱水方式等因素对辛酸转化率和甘油二酯含量的影响,并通过响应面法优化了工艺参数,获得酶法合成甘油二酯的最优工艺条件:酸油比1.99∶1,反应温度51.5℃,加酶量3.05%,反应时间6.29 h。在最优条件下,甘油二酯的含量达到71.9%。     

Production of specific-structured lipids by enzymatic interesterification in a pilot continuous enzyme bed reactor

Production of specific-structured lipids (interesterified lipids with a specific structure) by enzymatic interesterification was carried out in a continuous enzyme bed pilot scale reactor. Commercial immobilized lipase (Lipozyme IM) was used and investigations of acyl migration, pressure drop, water dependence, production efficiency, and other basic features of the process were performed. The extent of acyl migration (defined as a side reaction) occurring in the present enzyme bed reactor was compared to that in a pilot batch reactor. The continuous enzyme bed reactor was better than the batch reactor in minimizing acyl migration. Generally the former produced about one-fourth the acyl migration produced by the latter at a similar extent of incorporation. Pressure drop and production efficiency were evaluated in order to obtain a suitable yield in one reaction step. High incorporation was favored by high substrate ratios between acyl donors and oils, requiring long reaction times on the enzyme bed. Under these conditions, the pressure drop of the reactor was modeled statistically and theoretically. Residence time, water content, and effects of mass transfers were also investigated. Incorporation of medium-chain fatty acids increased with increased residence time. Approximately 40% of lipase activity was lost after a 4-wk run. External mass transfer was not a major problem in the linear flow range, but internal mass transfer did impose some transfer limitations.     

Lipase-Catalyzed Synthesis of Human Milk Fat Substitutes from Palm Stearin in a Continuous Packed Bed Reactor

Structured lipids (SL) with similar fatty acid (FA) composition and distribution to human milk fat (HMF) were synthesized by lipase-catalyzed acidolysis of chemically interesterified palm stearin (IV = 35.6) with mixed FA of stearic acid and myristic acid and FA from rapeseed oil, sunflower oil, and palm kernel oil in a continuous packed bed reactor. Response surface methodology (RSM) was used to optimize the reaction system with three selected parameters, namely residence time, temperature, and substrate molar ratio. The best-fitting quadratic models were obtained for the contents of palmitic acid (PA) and PA at the sn-2 position (sn-2 PA) by multiple regressions and the determination coefficient (R ²) values for the models were 0.9886 and 0.9799, respectively. The optimal conditions generated from the models were as follows: residence time, 2.7 h; temperature, 58 °C; substrate molar ratio, 9.5 mol/mol. Under these conditions, the contents of PA and sn-2 PA were 28.8 and 53.2%, respectively, and other FA observed in the experiments were all within the range of corresponding FA of HMF. The similarity of the product obtained to HMF was evaluated by the cited model. The scores for total and sn-2 FA of the product were 45.2 and 38.4, respectively, and the total score for the product was 83.6, which indicated a high degree of similarity of the product to HMF.     

Production of Structured Triacylglycerol via Enzymatic Interesterification of Medium-Chain Triacylglycerol and Soybean Oil Using a Pilot-Scale Solvent-Free Packed Bed Reactor

Oils rich in medium- and long-chain triacylglycerols (MLCT) serve as functional oils to help reduce body fat accumulation and weight gain. However, most of the MLCT-rich products on the market are physical blends of medium- and long-chain triacylglycerols (MCT and LCT, respectively) that are not structured triacylglycerols (TAG). In this study, an efficient pilot-scale packed bed reactor (PBR) of immobilized lipase from Thermomyces lanuginosus (Lipozyme® TL IM, Novozymes, Bagsvaerd, Denmark) was employed for producing structured MLCT via 1,3-specific interesterification of TAG enriched in caprylic and capric acyl groups and soybean oil (SBO). The PBR was operated under continuous recirculation mode in the absence of solvent. Optimal reaction conditions were determined to be: caprylic/capric TAG: SBO ratio (45:55 w/w), reaction temperature (75 °C) and residence time (16.0 min) on MLCT production were studied. When employing a pilot-scale PBR (100 kg day⁻¹) under optimal conditions, a product containing 76.61 wt% MLCT was produced. Lipozyme TL IM was reused for 25 successive batch reactions (125 kg substrates) with no significant reduction in catalytic efficiency. The light yellow MLCT-enriched product had a high level of saturated fatty acids (SFA, 82.74 wt%) in its sn-2 position as a result of the enzyme's 1,3-positional specificity. One-stage molecular distillation and methanol extraction were used to remove the free fatty acids, mono-, and diacylglycerols generated from hydrolysis. With distillation temperature of 150 °C and oil-to-methanol ratio of 1:3 v/v, MLCT content was further increased to 80.07 wt%. The enzymatic PBR was therefore effective in producing structured MLCT at a pilot-scale under solvent-free conditions.     

Continuous production of structured lipid containing γ-linolenic and caprylic acids by immobilized Rhizopus delemar lipase

Production of a structured lipid containing γ-linolenic acid (GLA) achieved by the continuous acidolysis of borage oil with caprylic acid (CA) using 1,3-specific Rhizopus delemar lipase as a catalyst. The lipase immobilized on a ceramic carrier was activated by feeding the borage oil/CA (1:2, w/w) mixture saturated with water into a column packed with the enzyme. However, the generation of partial glycerides (20%) in the reaction mixture showed that hydrolysis occurred concomitantly with acidolysis. The concomitant hydrolysis was completely repressed by feeding the oil/CA substrate mixture without adding additional water. When the substrate mixture was fed at 30°C and a flow rate of 4.5 mL/h into a column packed with 8 g of the carrier with immobilized lipase, the content of CA incorporated in glycerides was 50 to 55 mol%. The acidolysis activity scarcely changed even though the substrate mixture was continuously fed for 60 d; then it gradually decreased. The CA content in glycerides was decreased to 73% of the initial value after 100 d, but returned to the initial level when the flow rate was reduced to 3.1 mL/h. Molecular distillation was employed to separate the transesterified oil from the reaction mixture. No glycerides were detected in the distillate, and the transesterified oil was recovered as the residue (acid value, 2.6). Regiospecific analysis of the transesterified oil showed that only fatty acids at the 1- and 3-positions of borage oil were exchanged for CA. It was additionally found by high-performance liquid chromatography analysis that all the triglycerides contained one or two CA, and that the triglyceride with two GLA and one CA was also present, because the lipase acted on GLA very weakly.     

Modification of Stearidonic Acid Soybean Oil by Immobilized Rhizomucor miehei Lipase to Incorporate Caprylic Acid

Immobilized sn-1,3 specific Rhizomucor miehei lipase (RML) was used to catalyze the incorporation of caprylic acid (C8:0) into high stearidonic acid (SDA, C18:4ω3) soybean oil (SDASO) to form structured lipids (SL). The effects of type of biocatalyst (Celite-, octyl-Sepharose-, and Duolite-immobilized RML) and reaction temperature (30, 40, 50, and 60 °C) on acidolysis and acyl migration were studied. Celite-immobilized RML (C-RML) at 50 °C maximized C8:0 incorporation and minimized acyl migration compared to other treatments. Optimal levels of substrate molar ratio (C8:0 to SDASO), incubation time, and enzyme load for SL synthesis by C-RML at 50 °C was determined by response surface methodology to be 6:1, 24 h, and 20 % weight of substrates, respectively. This optimum treatment was scaled-up in hexane or solvent-free reaction media using SDASO or an SDA-enriched acylglycerol mixture as substrate. This yielded various SL with C8:0 contents ranging from 17.0 to 32.5 mol% and SDA contents ranging from 20.6 to 42.3 mol%. When digested, these SL may deliver C8:0 for quick energy and SDA for heart health making them potentially valuable for medical and nutraceutical applications.