Separation of regioisomers and enantiomers of underivatized saturated and unsaturated fatty acid monoacylglycerols using enantioselective HPLC

The challenging separation of regioisomers and enantiomers of monoacylglycerols (MAGs) of fatty acids has been achieved using a single chiral HPLC column (Chiralpak^® IC or Chiralpak^® IA) and hexane/2‐propanol eluent mixtures, without previous derivatization of the samples. The efficacy of the method is independent of the chain length and the degree of unsaturation of the fatty acids of the MAG. In addition, the separation method allows monitoring the time course for the loss of enantiomeric purity of the fatty acid‐derived MAGs in polar hydroxylic solvents.     

Vapour liquid equilibria of monocaprylin plus palmitic acid or methyl stearate at P = (1.20 and 2.50) kPa by using DSC technique

The Differential Scanning Calorimetry (DSC) technique is used for measuring isobaric (vapour + liquid) equilibria for two binary mixtures: {monocaprylin + palmitic acid (system 1) or methyl stearate (system 2)} at two different pressures P = (1.20 and 2.50) kPa. The obtained PTx data are correlated by Wilson, NRTL and UNIQUAC models. The original UNIFAC group contribution method is also considered and new binary interaction parameters for the main groups CH₂, CCOO, OH and COOH are regressed, to account for the non-idealities found in these lipid systems. Established thermodynamic consistency tests are applied and attest the quality of the measured data. In terms of relevance of the selected components, system 1 can be found in the purification and deodorization steps during the production of edible oils, while, system 2 can be found in the purification steps of biodiesel. It should be noted that no such data could be found in the open literature, not only for the specific components selected but also for the combination of the classes of components considered; that is, acylglycerol plus fatty acid or fatty ester.