Lipase-catalyzed production of solid fat stock from fractionated rice bran oil,palm stearin,and conjugated linoleic acid by response surface methodology

Solid fat stock was produced from the fractionated rice bran oil (solid phase, S-RBO) and palm stearin (PS) through lipase-catalyzed reaction, in which conjugated linoleic acid (CLA) was intentionally incorporated. For optimizing the reaction, response surface methodology (RSM) was employed with four reaction variables such as water activity, reaction temperature, reaction time, and mole ratio of S-RBO to PS. The predictive model was adequate due to no significant lack of fit and satisfactory level of coefficient of determination (R² = 0.95). The melting point of solid fat stock was affected by reaction time and substrate mole ratio, whereas water activity and reaction temperature had no significant effect. Based on ridge analysis, the combination of A_w (X₁; 0.32), reaction temperature (X₂; 65.3 °C), reaction time (X₃; 28.9 h), and substrate mole ratio (X₄; 1:1.1) was optimized for producing solid fat stock with target melting point of 43.8 °C. The solid fat stock (SFS) contained 39.9% palmitic, 31.3% oleic, 13.2% linoleic acid, and 10.9% CLA isomers. Solid fat contents were 23.4, 10.9, and 2.5% at 20, 30, and 40 °C, respectively. These results suggested that RSM can be used to optimize the lipase-catalyzed production of a solid fat stock.     

Enzymatic Production of Trans-Free Hard Fat Stock from Fractionated Rice Bran Oil, Fully Hydrogenated Soybean Oil, and Conjugated Linoleic Acid

ABSTRACT:  Rice bran oil (RBO) was fractionated into 2 phases, solid (S-RBO) and liquid (L-RBO), using acetone at –18 °C and the weight yield of each S-RBO and L-RBO was 45.5% and 54.5%, respectively. Then, trans -free hard fat was synthesized from trans -free substrate of S-RBO and fully hydrogenated soybean oil (FHSBO) at different molar ratios (S-RBO : FHSBO; 1 : 1, 1 : 1.5, 1 : 2, and 1 : 3) with Lipozyme TL IM lipase (10% of total substrate). Conjugated linoleic acid (CLA, 20% of total substrate) was used as functional fatty acids for the production of trans- free hard fat. After fatty acid analysis, CLA (12.2% to 14.2%) was found on the triacylglycerol (TAG) backbone of the interesterified products along with stearic (37.6% to 49%), palmitic (15% to 17.9%), and oleic acids (13.3% to 19.2%). The interesterified product contained higher level of saturated fatty acid (62.6% to 70.1%) at sn -2 position. Total tocopherols (α-, γ-, and δ-; 1.4 to 2.6 mg/100 g) and phytosterols (campesterol, stigmasterol, and β-sitosterol; 220.5 to 362.7 mg/100 g) were found in the interesterified products. From DSC results, solid fat contents of the interesterified products (S-RBO : FHSBO 1 : 1, 1 : 1.5, 1 : 2, and 1 : 3) at 25 °C were 23.1%, 27%, 30.1%, and 44.9%. The interesterified products consisted mostly of β' form crystal with a small portion of β form. The interesterified product (S-RBO : FHSBO 1 : 1.5) was softer than the physical blend but slightly harder than commercial shortenings as measured by texture analyzer. Thus, trans- free hard fat stock, which may have a potential functionality could be produced with various physical properties.     

响应面优化脂肪酶催化酸解合成共轭亚油酸磷脂

采用商业化脂肪酶Lipozyme RM IM作为生物催化剂,催化共轭亚油酸(CLA,80％)和大豆磷脂( PC90)酸解反应合成富含CLA的结构磷脂.利用响应面分析方法研究了在正己烷溶剂体系中,底物摩尔比、酶用量、反应温度和反应时间对产物中CLA含量的影响.通过分析验证得到最佳反应条件为∶CLA与大豆磷脂的摩尔比6∶1,酶用量30％(以底物总质量计),反应温度48℃,反应时间64 h.在最佳反应条件下,产物中CLA的含量为24.18％.     

响应面试验优化Lipozyme TLIM催化制备共轭亚油酸结构脂工艺

以Lipozyme TLIM催化茶油和共轭亚油酸乙酯制备共轭亚油酸(conjugated linoleic acid,CLA)结构脂,并调控酰基迁移反应以制备Sn-2位含CLA的结构脂。通过响应面法研究反应温度、水分活度、反应时间和底物物质的量比对总CLA键入量和酰基迁移的影响,并优化反应条件。本实验得到的结构脂中含有36.97%的总CLA,其中12.54%的CLA分布在Sn-2位,所得总CLA及Sn-2位的CLA键入量均高于文献报道。     

无溶剂体系酶法催化酸解合成共轭亚油酸甘油酯

采用商业化固定化酶Novozym 435作为生物催化剂,催化共轭亚油酸(CLA)和葵花籽油的酸解反应合成富含CLA的结构脂质(CLA-SL).研究了在无溶剂体系中,底物摩尔比、酶用量、体系含水量、反应温度和反应时间对产物中CLA含量和Sn-2位CLA含量的影响.结果表明,最佳反应条件为:CLA与葵花籽油摩尔比3 :1,酶用量10%,体系含水量1%,反应温度55 ℃,反应时间36 h.在最佳反应条件下,产物中的CLA含量和Sn-2位CLA含量分别为15.7%和2.73%.     

Response surface modelling of the production of structured lipids from soybean oil using Rhizomucor miehei lipase

The production of structured lipids (SLs) by the acidolysis of soybean oil (SO) with a free fatty acid (FFA) mixture obtained from Brazilian sardine oil, catalysed by Rhizomucor miehei lipase (Lipozyme RM IM) in a solvent-free medium, was optimised by response surface methodology (RSM) using a three-factor central composite rotatable design. The best reaction conditions to achieve an adequate n-6/n-3 FA ratio were: sardine-FFA:SO mole ratio of 3:1, initial water content of the enzyme of 0.87% w/w, reaction time of 12 h, reaction temperature of 40 °C and 10% by weight of the enzyme (% w/w). Under these conditions, the incorporation of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) into the soybean oil reached 9.2% (% of the total FAs), leading to a significant reduction in the n-6/n-3 FA ratio from 11:1 to 3:1. Analysis of variance (ANOVA) showed that 95% (R² = 0.95) of the observed variation was explained by the model. Lack of fit analysis revealed a non-significant value for the model equation, indicating that the regression equation was adequate for predicting the degree of EPA + DHA incorporation under any combination of values of the variables. Easy ambient sonic-spray ionisation mass spectrometry (EASI-MS) was used for instantaneous characterisation of TAGs. After the enzymatic reaction, a great variety of new TAGs were formed containing EPA, DHA or both in the same molecule.     

Transesterification of conjugated linoleic acid and tricaprylin by lipases in organic solvents

Lipase-catalyzed transesterification of tricaprylin with conjugated linoleic acid (CLA) ethyl ester was performed to produce triacylglycerols containing conjugated linoleic acid. Six commercially available lipases, and seven solvents were screened for their ability to incorporate CLA into tricaprylin. The transesterification reaction was performed by incubating a 1:2 mole ratio of tricaprylin and CLA ethyl ester in 3 ml solvents at 55°C, and the products were analyzed by gas chromatography. Three lipases, Novozym 435, Lipozym IM and lipase PS-C were chosen to allow a comparison of transesterification activity in our model reaction. The highest CLA incorporation with Novozym 435 and Lipozym IM was achieved in hexane while isooctane produced the highest CLA incorporation with lipase PS-C. Lipase PS-C gave higher CLA incorporation into tricaprylin when fatty acid was used as the acyl donor than other lipases did. Lipozym IM and lipase PS-C had not restrict specificity to sn-1, 3 positions, even though they had high specificity at sn-1, 3 positions. Novozym 435 among lipases tested was the most effective on the incorporation of CLA into tricaprylin.     

Enzymatic synthesis of lysophosphatidylcholine containing CLA from sn-glycero-3-phosphatidylcholine (GPC) under vacuum

Lysophosphatidylcholine (LPC) was successfully synthesised by enzyme-catalysed esterification of sn-glycero-3-phosphatidylcholine (GPC) with the acid form of conjugated linoleic acid (CLA), using a vacuum system. GPC was prepared from phosphatidylcholine (PC) by alkaline deacylation using a methanolic tetra-butylammonium hydroxide solution. Five enzymes were tested as biocatalysts for direct esterification, and lipases were found to be more effective than phospholipases for production of LPC. Amongst the enzymes tested, Novozym 435, from Candida antarctica, gave the highest yield of LPC. The optimal temperature, molar ratio of substrate, and vacuum were 40 °C, 1:50 (GPC to CLA), and 1 mm Hg, respectively. The maximum yield (70 mol%) of LPC was obtained under optimal conditions after a 48 h reaction time.     

Conjugated linoleic acid production by cells and enzyme extract of Lactobacillus delbrueckii ssp. bulgaricus with additions of different fatty acids

The objective of the study was to determine the effect of fatty acid additions to the cells and enzyme extract of Lactobacillus delbrueckii ssp. bulgaricus (CCRC14009) on CLA production. Washed cells of L. delbrueckii ssp. bulgaricus, obtained by cultivation in a MRS broth, were mixed with BSA and each of the three fatty acids: linoleic, oleic, and linolenic acids in sodium phosphate buffer at pH 6.5. After incubation at 37 °C for 108 h, CLA concentration was analyzed by HPLC. Enzyme extract from the culture was also reacted with each fatty acid at 50 °C for 10 min at pH 5 to test for CLA production. Results showed that linoleic acid addition to the culture improved CLA production, indicating the presence of linoleic acid isomerase activity in the culture. The crude enzyme extract from the culture was observed to be capable of oleic and linolenic acid conversions into CLA, demonstrating the possible presence of desaturase activity in the enzyme extract.     

Optimisation of lipase-catalysed interesterification reaction for modulating rheological and heat transfer properties of frying oil

The present work reports the optimisation of enzyme interesterification reaction of rice bran oil (RBO) and refined, bleached, deodorized, palm olein (RBDPO) blend using immobilized 1,3-specific lipase, to improve the kinematic viscosity and heat transfer coefficient of oil, important for characterising heat transfer during the frying process. Four variables, namely RBO (20–80%) in RBO–RBDPO blend, reaction temperature (25–65 °C), enzyme concentration (1–13%, w/w) and reaction time (1–13 h) were selected and optimised using response surface methodology (RSM) coupled with central composite rotatable design (CCRD). The optimisation results predicted that optimum reaction conditions for preparing enzyme interesterified oil, having minimum kinematic viscosity (2.63 × 10⁻⁶ m² s⁻¹) and maximum heat transfer coefficient (262.0 Wm⁻² °C⁻¹) were at 62% RBO, temperature 65 °C, enzyme concentration 10% (w/w) and time 6.4 h. The predicted values were validated experimentally and corroborated with DSC melting profile and triacylglycerol molecular species data. This investigation could help snack food industries to develop suitable oils for frying operations.     

Effects of dietary replacement of fish oil by conjugated linoleic acid on some meat quality traits of Pacific white shrimp Litopenaeus vannamei

This experiment was conducted to evaluate the effects of fish oil replacement by conjugated linoleic acid (CLA) on body proximate analysis and thiobarbituric acid-reactive substances, fat content, shear force and fatty acid composition in musculature of Pacific white shrimp (Litopenaeus vannamei). Graded levels of CLA (0%, 0.5%, 1% and 2%) were added to the basic diet of shrimp at the expense of fish oil. Results showed that fat content (p = 0.036) and shear force (p = 0.001) in shrimp musculature were enhanced with increasing dietary CLA inclusion. Fish oil replacement by CLA significantly promoted the incorporation of cis-9, trans-11 CLA (p = 0.0001) and trans-10, cis-12 CLA (p < 0.0001) into shrimp musculature; moreover, the polyunsaturated fatty acid was elevated (p = 0.020) and monounsaturated fatty acid was reduced by CLA inclusion (p = 0.024). It was concluded that replacement of fish oil by CLA could improve some meat quality traits of shrimp and 1% CLA was an appropriate amount.     

Chemoenzymatic synthesis of structured triacylglycerols with conjugated linoleic acids (CLA) in central position

A chemoenzymatic process for the production of structured triacylglycerols (TAG) containing CLA at sn2 position and lauric acid at external ones is proposed. First, castor bean oil was chemically dehydrated and isomerised to obtain a new modified oil with very high proportion of CLA (>95%). Then, this new oil was used for enzymatic transesterification allowing the grafting of lauric acid at external positions of the TAG backbone by using 1,3 regioselective enzymes. Among these, Aspergillus niger lipase was not satisfactory giving very low lauroyl incorporation (<5%) On the contrary, lipases from Thermomyces lanuginosa (Lipozyme TL IM) and from Carica papaya latex allowed good reaction yields. The effect of the type of acyl donor was studied. With alkyl esters T. lanuginosa lipase provided a final incorporation of 58.9% after 72 h corresponding to 88.4% transesterification yield. Concerning C. papaya lipase, incorporation of lauroyl residues was lower than Lipozyme TL IM. This lipase exhibited higher performance with lauric acid accounting for 44.7% lauroyl incorporation at the end of reaction for a 67.1% transesterification yield. The effect of the substrates mole ratio was also evaluated. It was observed that a 1:3 TAG/acyl donor mole ratio was the most efficient for both lipases. Finally, fatty acids regiodistribution of the newly formed structured TAG was determined. With Lipozyme TL IM, the proportion of lauric acid incorporated at the sn2 position did not exceed 5.4% after 72 h while with C. papaya lipase a more pronounced incorporation of lauroyl residues at the central position (8.8%) was observed.     

A study on parameters of potential cocoa butter analogue synthesis from camel hump by lipase-catalysed interesterification in supercritical CO2 using response surface methodology

A potential cocoa butter analogue was prepared from camel hump fat and tristearin by enzymatic interesterification in supercritical carbon dioxide (SC–CO₂) using immobilised Thermomyces lanuginosus lipase (Lipozyme TL IM) as a biocatalyst. Response surface methodology (RSM) was used to investigate the effects of pressure, temperature, tristearin/camel hump fat ratio, water content, and incubation time on TAG distribution of cocoa butter analogue. The process conditions were optimised by conducting experiments at five different levels. A second order polynomial response surface equation was developed to indicate the effect of variables on TAG distribution of cocoa butter analogue. Overlaid contour plots generated using the response surface equations showed that all TAG components of cocoa butter analogue are significantly affected by the experimental independent variables. The pressure of 10 MPa; temperature of 42 °C; SSS/CHF ratio of 1.15:1; water content of 10% (w/w); and incubation time of 3 h were found to be the optimum conditions to achieve the most similar cocoa butter analogue to the corresponding cocoa butter.     

Enzymatic preparation of chitooligosaccharides by commercial lipase

The effect of a commercial lipase on chitosan degradation was investigated. When four chitosans with various degrees of deacetylation were used as substrates, the lipase showed higher optimal pH toward chitosan with higher DD (degree of deacetylation). The optimal temperature of the lipase was 55 °C for all chitosans. The enzyme exhibited higher activity to chitosans which were 82.8% and 73.2% deacetylated. Kinetics experiments show that chitosans with DD of 82.8% and 73.2% which resulted in lower K_m values had stronger affinity for the lipase. The chitosan hydrolysis carried out at 37 °C produced larger quantity of COS (chitooligosaccharides) than that at 55 °C when the reaction time was longer than 6 h, and COS yield of 24 h hydrolysis at 37 °C was 93.8%. Products analysis results demonstrate that the enzyme produced glucosamine and chitooligosaccharides with DP (degree of polymerization) of 2–6 and above, and it acted on chitosan in both exo- and endo-hydrolytic manner.     

Production of a diacylglycerol-enriched palm olein using lipase-catalyzed partial hydrolysis: Optimization using response surface methodology

Partial hydrolysis using Lipozyme RMIM lipase in a solvent-free system was used to produce a diacylglycerol (DAG)-enriched palm olein. Response surface methodology (RSM) was applied to model and optimize the reaction conditions namely water content (30–70 wt% of enzyme mass), enzyme load (5–15 wt% of oil mass), reaction temperature (45–85 °C) and reaction time (6–16 h). Well fitting models were successfully established for both DAG yield (R² = 0.8788) and unhydrolysed triacylglycerol (TAG) (R² = 0.8653) through multiple linear regressions with backward elimination. Chi-square test indicated that there were no significant (P > 0.05) differences between the observed and predicted values for both models. All reaction conditions had positive effects on DAG yield and negative effects on unhydrolysed TAG. Optimal reaction conditions were: 50 wt% water content, 10 wt% enzyme load, 65°C of reaction temperature and 12 h of reaction time. The process was further up-scaled to a 9 kg production in a continuous packed bed bioreactor. Results indicated that upscaling was possible with a similar DAG yield (32 wt%) as in lab scale. Purification of the DAG oil using short path distillation yielded a DAG-enriched palm olein with 60 wt% DAG and 40 wt% TAG which is suitable for margarine, spread or shortening applications.     

Influence of binding conjugated linoleic acid and myristic acid on the heat- and high-pressure-induced unfolding and aggregation of β-lactoglobulin B

Heat and pressure treatment of β-lactoglobulin B (β-LG) causes it to partially unfold and aggregate. β-LG solutions at pH 7.2 were heat treated at temperatures between 40 and 93 °C for 12 min or were pressure treated at pressures between 50 and 800 MPa for 30 min. Another set of samples also contained myristic acid (MA) or conjugated linoleic acid (CLA) in a molar ratio of 1:1.1 protein:ligand. All the treated samples were analysed using polyacrylamide gel electrophoresis (PAGE) and near- and far-UV circular dichroism (CD) spectroscopy. Native- and sodium dodecyl sulfate (SDS)-PAGE showed that, at temperatures above about 63 °C, bands of lower mobility were produced. As the treatment temperature increased, the quantity of native protein decreased steadily and the quantity of higher molecular weight aggregates increased. Thus β-LG could be native (Stage I T) or non-native disulfide-bonded monomers and polymers (and their stable hydrophobic adducts) (Stage II T). Pressure treatments of 50 and 100 MPa had no discernible effect. At pressures between 150 and 350 MPa, PAGE analysis showed that only non-native and dimer β-LG were produced but that hydrophobic adducts were apparent in the native-PAGE patterns. At pressures above 500 MPa, the whole range of polymers (higher molecular weight aggregates) was discernible. Therefore three stages have been proposed for the pressure denaturation of β-LG. Thus β-LG could be native (Stage I P), non-native disulfide-bonded monomers, intermediates in the aggregation process and dimers (and their stable hydrophobic adducts) (Stage II P) or larger polymers (Stage III P). This model is consistent with the near- and far-UV CD data and with reported 8-anilino-1-naphthalenesulfonate probe data. The addition of MA or CLA to β-LG followed by heat or pressure treatment shifted the transition of native β-LG to non-native monomer or dimer by stabilizing the native structure (Stage I T or Stage I P). Pressurizing similar samples at higher pressures showed that only CLA had the ability to inhibit the transition from Stage II P to Stage III P.     

Solvent-free production of 1,3-diglyceride of CLA: Strategy consideration and protocol design

Enzymatic production of a homogeneous 1,3-diglyceride of polyunsaturated fatty acids (PUFAs) was carried out using Novozym 435 as biocatalyst and conjugated linoleic acid (CLA) as a model fatty acid. Three different operation modes, namely, magnetic stirring under vacuum, vacuum-driven N₂ bubbling and incubation with molecular sieves, were examined to find an efficient protocol for the enzymatic production. Studies on the effects of mass transfer showed that the occurrence of mass transfer limitation was strongly dependent on the operational modes. Vacuum-driven N₂ bubbling proved to be capable of eliminating mass transfer resistance, creating effective interaction for a multiple-phase reaction system and yielding an efficient water removal and a faster reaction rate. Hence, vacuum-driven N₂ stirring was considered as the best choice among the tested strategies for the production of pure 1,3-diglyceride of PUFAs with industrial interests, because it gave a higher yield of the desired product, higher productivity and lower impurity content due to its suppression of the acylmigration of 1,3-diglyceride to 1,2-diglyceride. The yield of 92–96% 1,3-dCLG could be obtained when 5 mmol of glycerol were incubated with 10–12 mmol CLA for about 3 h at 45–55 °C and a pressure less than 10 mbar, with enzyme loading of 40–70 g l⁻¹. Among the operational parameters, temperature and reaction time were found to have profound effects on the acylmigration and yield of 1,3-diglyceride. Moreover, the enzyme showed excellent operational stability in this protocol under the optimized conditions (little activity loss of enzyme was observed after 10 consecutive batch reactions), indicating the potential of this technology for industrial application.     

Enzymatic production of infant milk fat analogs containing palmitic acid: optimization of reactions by response surface methodology

Infant milk fat analogs resembling human milk fat were synthesized by an enzymatic interesterification between tripalmitin, coconut oil, safflower oil, and soybean oil in hexane. A commercially immobilized 1,3-specific lipase, Lipozyme RM IM, obtained from Rhizomucor miehei was used as a biocatalyst. The effects of substrate molar ratio, reaction time, and incubation temperature on the incorporation of palmitic acid at the sn-2 position of the triacylglycerols were investigated. A central composite design with 5 levels and 3 factors consisting of substrate ratio, reaction temperature, and incubation time was used to model and optimize the reaction conditions using response surface methodology. A quadratic model using multiple regressions was then obtained for the incorporation of palmitic acid at the sn-2 positions of glycerols as the response. The coefficient of determination (R²) value for the model was 0.845. The incorporation of palmitic acid appeared to increase with the decrease in substrate molar ratio and increase in reaction temperature, and optimum incubation time occurred at 18 h. The optimal conditions generated from the model for the targeted 40% palmitic acid incorporation at the sn-2 position were 3 mol/mol, 14.4 h, and 55°C; and 2.8 mol/mol, 19.6 h, and 55°C for substrate ratio (moles of total fatty acid/moles of tripalmitin), time, and temperature, respectively. Infant milk fat containing fatty acid composition and sn-2 fatty acid profile similar to human milk fat was successfully produced. The fat analogs produced under optimal conditions had total and sn-2 positional palmitic acid levels comparable to that of human milk fat.     

Effect of trans-10, cis-12 conjugated linoleic acid on performance, adipose depot weights, and liver weight in early-lactation dairy cows

In feeding practice, conjugated linoleic acid (CLA) supplements are used to decrease milk fat excretion in early-lactation dairy cows to save energy to counteract the physiological negative energy balance. The present study was conducted to examine the effects of CLA on energy metabolism, changes in liver weight, and the weight of different adipose depots during early lactation. Primiparous lactating German Holstein cows (n = 25) were divided into 5 groups and each group contained 5 animals. The experiment started 21 d prepartum and continued until 105 d in milk (DIM). Cows were slaughtered at 1, 42, and 105 DIM. The experiment was divided into a prepartum period (21 d prepartum until calving), period 1 (1 until 42 DIM), and period 2 (>42 until 105 DIM). In the prepartum period, all animals were housed together and fed the same diet with no CLA supplementation. At 1 DIM, an initial group, with no CLA supplementation, was slaughtered. The 20 remaining cows were assigned to 2 diets. One group received 100 g/d of a control fat supplement (CON; n = 10) and the other group 100 g/d of a CLA supplement (CLA; n = 10) from 1 DIM until slaughter. Five cows of each feeding group were slaughtered after 42 DIM and the remaining animals after 105 DIM. The CLA supplement contained approximately 10% each of trans-10, cis-12 CLA and cis-9, trans-11 CLA. During the slaughter process the empty body weight was recorded and the omental, mesenteric, retroperitoneal, and s.c. adipose depots, as well as the liver, were dissected and weighed. The CLA treatment decreased milk fat content in period 1 (14.1%). In period 2, milk fat content (25.4%) and yield (17.1%) were lower in the CLA group. No effect of CLA on milk yield was observed. The net energy intake, milk energy output, and the calculated energy balance remained unchanged by CLA supplementation. No effect of CLA on the weights of liver, omental, mesenteric, or s.c. adipose depots was observed when related to empty body weight. Liver weight increased with DIM, whereas the retroperitoneal adipose depot weight decreased at the same time. Compared with the initial group, the retroperitoneal adipose depot weight for control animals slaughtered after 42 DIM was decreased (47.7%); however, for the CLA group slaughtered after 42 DIM, a trend to a lower retroperitoneal adipose depot weight (34.0%) was observed. This suggests a CLA-induced deceleration of mobilization of the retroperitoneal adipose depot during the first 42 DIM.     

Incorporation of selected long-chain fatty acids into trilinolein and trilinolenin

The effect of chain length, number of double bonds, the location and geometry of double bonds, the reaction conditions, and reactivity of different lipases on the incorporation of selected long-chain fatty acids (LCFA) into triacylglcerols, such as trilinolein (tri C18:2) and trilinolenin (tri C18:3) is examined. This study also discusses reasons behind different degrees of incorporation of selected LCFA into tri C18:2 or tri C18:3 on a molecular basis. Five lipases, namely Candida antarctica (Novozyme-435), Mucor miehei (Lipozyme-1M), Pseudomonas sp. (PS-30), Aspergillus niger (AP-12), and Candida rugosa (AY-30) were screened for their effect on catalyzing the acidolysis of trilinolein (tri C18:2) or trilinolenin (tri C18:3) with selected C18, C20 and C22 fatty acids (FA). Incorporation of a mixture of C18 FA into trilinolein, using Pseudomonas sp., the most effective lipase, was in the order of SA > OA > GLA > ALA > CLA. Meanwhile, the degree of n-6 FA incorporation into tri C18:2 with Pseudomonas sp. was in the order of GLA > AA > CLA. The order of incorporation of n-3 FA into trilinolein using lipases from C. antarctica and M. miehei was ALA > EPA > DPA > DHA.