Acyl Migration Kinetics of Vegetable Oil 1,2-Diacylglycerols

• Published in: Journal of the American Oil Chemists' Society Vol. 85; no. 4; pp. 307 - 312
• Main Authors: Laszlo, Joseph A., Compton, David L., Vermillion, Karl E.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01-04-2008; Springer-Verlag; Springer; Springer Nature B.V
• Subjects: 1,2‐Diacylglycerol; Acyl migration; Agriculture; Alcoholysis; Biological and medical sciences; Biomaterials; Biotechnology; Carbon dioxide; Chemicals; Chemistry; Chemistry and Materials Science; diacylglycerols; Equilibrium; Fat industries; Fatty acids; Food industries; Food Science; Fundamental and applied biological sciences. Psychology; Industrial Chemistry/Chemical Engineering; Kinetics; Lipase; NMR; Original Paper; Potential energy; Protons; Solvent extraction; solvents; soybean oil; Structured lipids; Sunflower oil; vegetable oil; Vegetable oils; 1,2-Diacylglycerol; Acyl migration; Alcoholysis; Structured lipids; NMR; Lipase; Structured lipid; NMR Lipase; Enzyme; Migration; Diacylglycerol; Triacylglycerol lipase; Esterases; Vegetable oil; Carboxylic ester hydrolases; Oils and fats industry; Hydrolases; Kinetics
• ISSN: 0003-021X; 1558-9331
• DOI: 10.1007/s11746-008-1202-5

The acyl migration kinetics of long-chain 1,2-diacylglycerol (1,2-DAG) to form 1,3-diacylglycerol (1,3-DAG) over the temperature range of 25-80 °C were examined using ¹H-NMR spectroscopy. Lipase-catalyzed ethanolysis of high-oleic sunflower oil, followed by a series of solvent extraction steps, generated high purity 1,2-DAG (0.93 mol fraction of the DAG content). The 1,2-DAG mole fraction of 0.32 at equilibrium was found to be insensitive to temperature, indicating that long-chain acyl group migration is neither endothermic nor exothermic. Determination of the temperature-dependent, first-order reaction kinetic parameters revealed a 1,2-DAG half life (t ₁/₂) of 3,425 h and 15.8 h at 25 and 80 °C, respectively. A comparison of 1,2-DAG with 2-monoacylglycerol indicated that there is no difference between the two in the potential energy state (ΔG [double dagger]) of their respective transitions states or cyclic intermediates.