• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.8
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• pp.1062-1068
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• 2009

Diacylglycerol (DAG) were synthesized by enzymatic esterification of glyceryl monooleate (GMO) and conjugated linoleic acid (CLA) in a shaking water bath. The reaction was catalyzed by Lipozyme TLIM (immobilized lipase from Thermomyces lanuginosa). Effects of reaction time, molar ratio, enzyme road and molecular sieves were studied. Results of normal-phase high performance liquid chromatography (NP-HPLC) analysis were performed. At 1:1, 2:1 and 3:1 (GMO : CLA) molar ratio and Lipozyme TLIM of 20% amount, DAG were produced in 42.6, 54.4 and 54.6 area% in 1 hr, respectively. When different Lipozyme TLIM amounts (2, 5, 10, 20%) were used with 2:1 (GMO : CLA) molar ratio, DAG were produced 21.4 (24 hr), 51.7 (12 hr), 56.2 (6 hr) and 54.4 (1 hr) area%, respectively. The reaction in the absence of molecular sieves increased DAG contents. The maximum DAG concentration conditions were obtained with molar ratio of 2:1 (GMO : CLA), lipase concentration of 10% (of substrate), 10% molecular sieves and reaction time of 6 hours at 55$^{\circ}C$. Under this reaction condition, produced DAG-rich oil was composed of 69 area% DAG, 7.9 area% TAG, 2 area% FFA, and 21.1 area% MAG.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.717-722
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• 2004

Response surface methodology was used to optimize production conditions of monoacylglycerol (MAG) and diacylglycerols (DAG) from corn oil by enzymic glycerolysis. Contents of $1,3-DAG\;(Y_1),\;1,2-DAG\;(Y_2),\;total\;DAG\;(Y_3),\;MAG\;(Y_4)$, and total $DAG+MAG\;(Y_5)$ were obtained. Conditions were optimized using central composite design with incubation temperature $(35-75^{\circ}C,\;X_1)$, incubation time (1-11 hr, $X_2$), and amount of hexane added (0-2 mL, $X_3$) as three variables. Content of 1,3-DAG was maximized by 20.43 area% at incubation temperature of $44.92^{\circ}C$, incubation time of 10.24 hr, and hexane content of 1.16 mL, whereas that of 1,2-DAG (26.78 area%) was maximized at $56.32^{\circ}C$, 6.95 hr, and 1.04 mL, respectively. Predicted maximum total DAG content was 45.09 area% at $53.82^{\circ}C$, 8.03 hr, and 1.08 mL, while production conditions of MAG (9.57 arae%) were $64.14^{\circ}C$, 7.00 hr, and 0.13 mL. At variables of $54.07^{\circ}C$, 7.98 hr, and 1.02 mL, maximum content of total DAG+MAG predicted by RSM was 53.54 area%.

• Food Science and Preservation
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• v.16 no.2
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• pp.246-252
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• 2009

Diacylglycerol(DAG) was produced by enzymatic esterification of glyceryl mono-oleate(GMO) and conjugated linoleic acid(CLA) in a stirred-batch type reactor. The reaction was catalyzed by lipozyme RMIM(an immobilized lipase from Rizomucor miehei). DAG was isolated by a short-path distillation process and decolorized. DAG oil was composed of 87.3% DAG, 11.4% triacylglycerol(TAG), and 1.5% monoacylglycerol(MAG)(all w/w). Major fatty acids in DAG oil were oleic acid(54%), CLA(31.1%), and linoleic acid(7%). DAG oil iodine,and acid values were 108.8, 2.57, and 1, respectively. The DAG oil solid fat index(SFI) and thermograms were obtained using differential scanning calorimetry.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.246-249
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• 2010

Diacylglycerol (DAG) was produced from lipase by the catalyzed synthesis of soybean oil (SBO) and glyceryl monooleate (GMO) with Lipozyme TLIM (Thermomyces lanuginosa). Effects of reaction time, molar ratio and enzyme road were studied. When 2:1, 1:1 and 1:2 (SBO:GMO) molar ratios with 20% Lipozyme TLIM were applied in a 1-hr reaction, the concentrations of DAG produced were 17.8, 20.0 and 20.4 g/100 g oil, respectively. Different amounts (2, 5, 10 and 20%) of Lipozyme TLIM were used at a 1:2 (SBO:GMO) molar ratio, and the concentrations of DAG produced in a 1-hr reaction were 10.8, 14.0, 16.9 and 20.4 g/100 g oil, respectively. During a 72-hr reaction, 10.8-22.7 g/100 g oil of DAG were produced under the reaction conditions in this study.

• Korean Journal of Agricultural Science
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• v.41 no.1
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• pp.47-58
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• 2014

The effect of conjugated linoleic acid (CLA) isomers esterified in diacylglycerol (DAG)-rich oil on lipid metabolism was investigated. Since dietary DAG has been known to induce the regression of atherosclerosis, CLA-DAG and olive-DAG oils containing similar levels of DAG (51.4~54.2%) were synthesized from olive oil. Hyperlipidemic C57BL/6J mice were then fed high-fat high-cholesterol diets supplemented with these oils (5% each) for 7 wk. The CLA-DAG diet containing 2.1% CLA isomers (0.78% c9,t11-CLA; 1.18% t10,c12-CLA) remarkably increased the levels of total plasma cholesterol and glutamic oxaloacetic transaminase (GOT) along with hepatic cholesterol and triacylglycerol (TAG) contents. Furthermore, the CLA-DAG diet inhibited fat uptake into adipose tissue whereas fat deposition (especially in the liver) was increased, resulting in the development of fatty livers. Hepatic fatty acid composition in the CLA-DAG mice was different from that of the olive-DAG mice, showing higher ratios of C16:1/C16:0 and C18:1/C18:0 in the liver. The activity of hepatic acyl-CoA:cholesterol acyltransferase (ACAT) was higher in CLA-DAG mice while plasma lecithin:cholesterol acyltransferase (LCAT) activity and the ferric reducing ability of plasma (FRAP) were lower in CLA-DAG mice compared to the olive-DAG animals. Results of the present study suggest that CLA incorporation into DAG oil could induce atherosclerosis in mice.

• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.272-277
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• 2019

The effects of medium-chain enriched diacylglycerol (MCE-DAG) oil on hepatic cholesterol homeostasis were investigated. HepG2 hepatocytes were treated with either 0.5, 1.0, or $1.5{\mu}g/mL$ of MCE-DAG for 48 h. There was no evidence of cytotoxicity by MCE-DAG up to $1.5{\mu}g/mL$. The level of proteins for cholesterol uptake including CLATHRIN and LDL receptor increased by MCE-DAG in a dose-dependent manner (p<0.05). Furthermore, proprotein convertase subtilisin/kexin type 9, an inhibitor of LDLR, was dose-dependently diminished (p<0.05), indicating cholesterol clearance raised. MCE-DAG significantly increased 3-hydroxy-3-methylglutaryl-coenzyme A reductase and acetyl-CoA acetyltransferase2 (p<0.05), required for cholesterol synthesis, and their transcriptional regulator sterol regulatory element-binding protein2 (p<0.05). These findings suggest that given conditions of prolonged sterol fasting in the current study activated both hepatic cholesterol synthesis and clearance by MCE-DAG. However, total intracellular level of cholesterol was not altered by MCE-DAG. Taken together, MCE-DAG has the potential to prevent hypercholesterolemia by increasing hepatic cholesterol uptake without affecting intracellular cholesterol level.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.584-589
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• 2005

Structured triacylglycerol (SL-TAG) was synthesized by enzymatic interesterification with algae oil and soybean oil in solvent-free system. Structured di- and monoacylglycerol (SL-DAG/MAG) were produced by glycerolysis with SL-TAG and glycerol catalyzed by lipase. Reactions were performed by sn-1.3 specific Lipozyme RM IM lipase from Rhizomucor miehei (interesterification, 11%; glycerolysis 5% by weight of total substrates) in solvent-free system using stirred-batch type reactor. SL-DAG/MAG contained TAG (42,3 area%), 1,3-DAG (19.2 area%), 1,2-DAG (22.2 area%), MAG (16.0 area%), and free fatty acid (0.2 area%). Iodine and saponification values of SL-DAG/MAG were 208.8 and 179.6, respectively. SL-DAG/MAG appeared yellowish in color.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.8
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• pp.1091-1097
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• 2002

Capacitated goat spermatozoa generated diacyl glycerol (DAG) when suspended in Krebs-Ringer bicarbonate medium and induced by progesterone or $Ca^{2+}$ ionophore A23187. We have added Sn-1-oleoyl-2-acetyl glycerol externally, to study the effect of DAG in goat sperm acrosomal exocytosis. Addition of neomycin abolished the DAG generating capacity of progesterone in a dose dependent manner, suggesting the involvement of a phosphoinositidase C activated phospholipase C system in the process. The level of increase in phosphatidic acid was considerably low and was produced well after the DAG generation thereby suggesting the involvement of a DAG kinase which phosphorylates DAG to produce PA. The inhibition of progesterone mediated effect by inhibitors of $GABA_A/Cl^{-}$ channel and $Ca^{2+}$ channels further supports the evidence that the events of binding of agonist to the receptor(s), opening of $Ca^{2+}$ channels and the activation of phospholipase C are reconciled to perform the function of acrosome reaction in capacitated goat spermatozoa.

• Korean Journal of Agricultural Science
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• v.41 no.2
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• pp.141-147
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• 2014

Diacylglycerol-oil (DAG oil) and four kinds of fatty acids [C16:0, C18:0, perillar oil-hydrolyzate(C18:3, 59.7%) and docosahexaenoic acid(DHA, C22:6, 63.7%)] were enzymatically esterified with 1:0.5, 1:1 and 1:1.5 molar ratio (DAG oil: fatty acids) to produce structured DAG. The reaction mixture were catalyzed by addition of sn-1,3 specific Lipozyme RMIM with 10 wt% of total substrates, and reacted for 1, 3, 6 and 24 hr at $62^{\circ}C$ with 220 rpm on the shaking water bath. The produced DAG were analyzed by TLC. In the result, the proportion of each fatty acid [(C16:0, C18:0, perilla oil-hydrolysate(C18:3, 59.7%) and DHA(C22:6, 63.7%)] on DAG products were increased as molar ratios of substrate increased. Among them, DHA showed the least reaction rate in which 24.2 % of DHA was found in the structured DAG molecules after 24 hr reaction with 1:1.5 molar substrate amount ratio.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.11
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• pp.1559-1563
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• 2009

Scaled-up production of oil containing diacylglycerol (DAG), so called diacylglycerol-oil, was produced by lipase-catalyzed reaction. Mixture of soybean oil and glyceryl monooleate with 1:2 molar ratio was esterified with Lipozyme RMIM in a batch-type reactor at 55$^{\circ}C$ and 300 rpm during 6 hr. After short-path distillation for removal of monoacylglycerol and free fatty acid as reaction by-products, diacylglycerol-oil mainly consisted of DAG (29 area%) and TAG (71 area%). The major compositional fatty acids in diacylglycerol-oil were oleic (44.36 wt%), and linoleic acids (37.36 wt%). Acid value and iodine value of diacylglycerol-oil were 0.13 and 112.6, respectively. Solid fat content (SFC) of diacylglycerol-oil was observed after differential scanning calorimetry (DSC) analysis in which three melting peaks at -25.0, 0.1, and 11.2$^{\circ}C$ were shown.