title: Solvent-free enzymatic synthesis of 1, 3-diacylglycerols by direct esterification of glycerol with saturated fatty acids.
abstract: BACKGROUND
  Pure 1, 3-diacylglycerols (1, 3-DAG) have been considered to be significant surfactants in food, cosmetics and pharmaceutical industries, as well as the effect on obesity prevention.
  
  
  METHODS
  In this study, a vacuum-driven air bubbling operation mode was developed and evaluated for the enzymatic synthesis of 1, 3-DAG of saturated fatty acids, by direct esterification of glycerol with fatty acids in a solvent-free system. The employed vacuum-driven air bubbling operation mode was comparable to vacuum-driven N2 bubbling protocol, in terms of lauric acid conversion and 1, 3-dilaurin content.
  
  
  RESULTS
  Some operation parameters were optimized, and 95.3% of lauric acid conversion and 80.3% of 1, 3-dilaurin content was obtained after 3-h reaction at 50°C, with 5 wt% of Lipozyme RM IM (based on reactants) amount. Of the lipases studied, both Lipozyme RM IM and Novozym 435 exhibited good performance in terms of lauric acid conversion. Lipozyme TL IM, however, showed low activity. Lipozyme RM IM showed good operational stability in this operation protocol, 80.2% of the original catalytic activity remained after 10 consecutive batch applications. Some other 1, 3-DAG were prepared and high content was obtained after purification: 98.5% for 1, 3-dicaprylin, 99.2% for 1, 3-dicaprin, 99.1% for 1, 3-dilaurin, 99.5 for 1, 3-dipalmitin and 99.4% for 1, 3-disterin.
  
  
  CONCLUSIONS
  The established vacuum-driven air bubbling operation protocol had been demonstrated to be a simple-operating, cost-effective, application practical and efficient methodology for 1, 3-DAG preparation.
authors: Nanjing
authors: N
authors: Zhong
authors: Zhongyu
authors: Z
authors: Gui
authors: Li
authors: L
authors: Xu
authors: Jianrong
authors: J
authors: Huang
authors: Kun
authors: K
authors: Hu
authors: Yongqing
authors: Y
authors: Gao
authors: Xia
authors: X
authors: Zhang
authors: Zhenbo
authors: Z
authors: Xu
authors: Jianyu
authors: J
authors: Su
authors: Bing
authors: B
authors: Li
mesh_terms: D000388:Air; D060326:Chemistry Techniques, Synthetic; D004075:Diglycerides / Q000138:chemical synthesis* / Q000737:chemistry; D004800:Enzymes, Immobilized; D004951:Esterification; D005227:Fatty Acids / Q000737:chemistry*; D005656:Fungal Proteins; D005990:Glycerol / Q000737:chemistry*; D007850:Lauric Acids / Q000737:chemistry; D008049:Lipase / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry; D012997:Solvents
chemical_list: D004075:Diglycerides; D004800:Enzymes, Immobilized; D005227:Fatty Acids; D005656:Fungal Proteins; D007850:Lauric Acids; D012997:Solvents; C030358:lauric acid; C005071:dipalmitin; C093666:Lipozyme; C093667:Novozyme 435; D008049:Lipase; D009584:Nitrogen; D005990:Glycerol
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