• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.367-375
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• 2013

The enzymatic interesterification was performed to produce structured lipids (SLs) with palm mid fraction (PMF) and stearic ethyl ester (STEE) for 1, 3, 6, 9, 12 and 15 hr at $80^{\circ}C$. The reaction was catalyzed by Lipozyme TLIM (immobilized lipase from Thermomyces lanuginosus, amount of 20% by weight of total substrates) in a shaking water bath set at 180 rpm. The optimum condition for synthesis of asymmetric SLs were: substrate molar ratio 1:0.5 (PMF:STEE, by weight), reaction time 6 hr, enzyme 20% (wt%, water activity=0.085) of total substrate and reaction temperature $80^{\circ}C$. After reaction at optimized condition, triacylglycerols (symmetrical and asymmetrical TAGs) from reactants were isolated. POP/PPO (1,3-palmitoyl-2-oleoyl glycerol or 1,2-palmitoyl-3-oleoyl glycerol), POS/PSO (palmitoyl-oleoyl-stearoyl glycerol or palmitoyl-stearoyl-oleoyl glycerol), SOS/SSO (1,3-stearoyl-2-oleoyl glycerol or 1,2-stearoyl-3-oleoyl glycerol) were obtained by solvent fractionation. Finally, refined SLs contained stearic acid of 16.91%. Solid fat index and thermogram of the refined SLs were obtained using differential scanning calorimetry. The degree of asymmetric triacylglycerol in the refined SLs was analyzed by Ag-HPLC equipped with evaporated light scattering detector (ELSD). The refined SLs consisted of symmetric TAG of 41.15 area% and asymmetric TAG of 58.85 area%.

• Korean Journal of Agricultural Science
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• v.40 no.1
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• pp.35-45
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• 2013

The fat content, fatty acid composition, trans fatty acid content and triacylglycerol (TAG) composition of 22 chocolates (domestics 8, foreigns 14) collected from the Korea distribution markets were investigated. The crude fat was extracted by acid hydrolysis method and analyzed by gas chromatography (GC) and reversed-phase HPLC for fatty acid and TAG compositions, respectively. The crude fat content of all chocolates varied between 30.11% and 49.59%. The major fatty acids in most of the chocolates were palmitic acid (19.36~31.15 wt%), stearic acid (5.11~36.32 wt%) and oleic acid (18.77~36.68 wt%). Whereas lauric acid (approximately 35.43 wt%) was detected in chocolate fat of sample No. 18. High oleic acid content was observed for the sn-2 position fatty acid with a range from 64.91% to 86.93%. Trans fatty acid contents in domestic chocolates (sample No. 1~8) and foreign chocolates (sample No. 9~22) were 0.03~0.59 wt% (0.01~0.19 g/100g chocolate) and 0.05~6.32 wt% (0.02~1.99 g/100g chocolate), respectively. In TAG composition, TAGs such as POP/PPO(1,3(2)-palmitoyl-2(3)-oleoyl glycerol, PN=48), POS/PSO(palmitoyl-oleoyl-stearoyl glycerol or palmitoyl-stearoyl-oleoyl glycerol, PN=50), SOS/SSO(1,3(2)-stearoyl-2(3)-oleoyl glycerol, PN=50) were mainly detected in most of the chocolates. The peaks of TAG with low PN (ex, 32-34, 36-38, and 40-42) were detected in No. 18 chocolate fat because of containing short chain fatty acid such as lauric acid.

• Food Science and Preservation
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• v.18 no.5
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• pp.721-728
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• 2011

1(3)-palmitoyl-2-oleoyl-3(1)-stearoyl-(POS)-glycerol-enriched reaction products were synthesized from camellia oil, palmitic ethyl ester, and stearic ethyl ester via lipase-catalyzed interesterification. Response surface methodology (RSM) was employed to optimize the production of the POS-enriched reaction product (Y1, %) and the stearicand palmitic-acid contents at the sn-2 position due to acyl migration (Y2, %). The reaction factors were the enzyme amount (X1, 2-6%), reaction time (X2, 60-360 min), and substrate molar ratio of camellia oil to palmitic ethyl ester and stearic ethyl ester (X3, 1-3 mol). The predictive models for Y1 and Y2 were adequate and reproducible as no lack of fit was signified (0.128 and 0.237) and as there were satisfactory levels of R2 (0.968 and 0.990, respectively). The optimal conditions for the reaction product for maximizing Y1 while minimizing Y2 were predicted at the reaction combination of 5.86% enzyme amount, 60 min reaction time, and 1:3 substrate molar ratio (3 moles of palmitic ethyl ester and 3 moles of stearic ethyl ester). Actual reaction was performed under the same conditions as above, and the resulting product contained 20.19% TAG-P/O/S and 12.71% saturated fatty acids at the sn-2 position.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.8
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• pp.1113-1120
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• 2011

Enzymatic interesterification was conducted with the palm mid fraction (PMF) and stearic ethyl ester for 1, 5, and 9 hr at 46$^{\circ}C$. The reaction was catalyzed by Lipozyme TLIM (2, 3, and 4% by weight of total substrates) in a shaking water bath at 180 rpm. As the reaction continued, oleic acid (C18:1) content at the sn-2 position decreased, whereas saturated fatty acid (C16:0 and C18:0) content increased. In the high performance chromatography analysis, 1,3-dipalmitoyl-2-oleoyl glycerol content decreased, whereas 1(3)-palmitoyl-2-oleoyl-3(1)-stearoyl glycerol (POS) content increased up to the reaction equilibrium. The rate of acyl migration increased with increasing molar ratio and enzyme load as well as reaction time. The optimal reaction conditions for maximizing POS content (53.5 area%) and minimizing acyl migration (23.1 area%) were obtained with a PMF : stearic ethyl ester=1:2 (molar ratio), Lipozyme TLIM 3 wt%, and a reaction time of 5 hr.

• Korean Journal of Food Science and Technology
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• v.24 no.2
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• pp.111-116
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• 1992

Production of cocoa butter equivalent fat (CBE) from palm oil and stearic acid by reverse micelle lipase reaction system was studied. Qualitative and quantitative analyses of triglycerides were performed by HPLC. The reaction conditions for maximum conversion from triolein and stearic acid to 1-stearoyl-2,3-dioleoyl glycerol(SOO) and 1,3-distearoyl-2-oleoyl glycerol(SOS) were as follows: a molar ratio of water/Aerosol OT, 10; triolein, 30 mM; stearic acid, 90 mM; pH, 7.5; and temperature, $50^{\circ}C$. By lipase in reverse micellar system containing palm oil and stearic acid, 1,3-dipalmitoyl-2-oleoyl glycerol(POP), 1-palmitoyl-2,3-dioleoyl glycerol(POO) and SOO decreased, but large amounts of 1-palmitoyl-2-oleoyl-3-stearoyl glycerol(POS) and SOS was formed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.10
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• pp.1430-1437
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• 2011

Synthesis conditions of cocoa butter equivalents were optimized using the response surface method (RSM) by interesterification of canola oil (Ca), palmitic ethyl ester (PEE), and stearic ethyl ester (StEE). The reaction was catalyzed by immobilized lipase (Lipozyme TLIM) from Thermomyces lanuginosa to produce structured lipids containing a composition of triacylglycerols similar to cocoa butter. Reaction conditions were optimized using D-optimal design with the three reaction factors of the substrate molar ratio of canola oil to palmitic ethyl ester and stearic ethyl ester (Ca : PEE : StEE=1:1:3, 1:1.66:5, 1:2:6, 1:2.33:7, 1:3:9, $X_1$), enzyme ratio (2~6%, $X_2$), and reaction time (30~270 min, $X_3$). The optimal conditions that minimized acyl-migration while maximizing 1-palmitoyl-2-oleoyl-3-stearoyl glycerol (POS), 1,3-distearoyl-2-oleoyl glycerol (SOS), and 1,3-dipalmitoyl-2-oleoyl glycerol (POP) were predicted, resulting in Ca : PEE : StEE=1:3:9, 6% of enzyme ratio, and 40 min of reaction time. The reaction product of structured lipids was synthesized again under the same conditions, showing 10.43 area% of acyl-migration, 25.31 area% of POS/PSO, 19.79 area% of SOS, and 11.22 area% of POP.