Chromatographic methods in the monitoring of lipase-catalyzed interesterification

Structured lipids containing special fatty acids were produced via lipase-c atalyzed interesterification. Chromatographic methods were modified for the analysis of the acylglycerol content of the selected interesterified produ cts, resulting from different reacting substrate mixtures and reaction syst ems. A modified normal-phase high performance liquid chromatographic method with evaporative light-scattering detection was used in the analysis of th e diacylglycerols formed as intermediate products during interesterificatio n. One of the advantages of the method was the low solvent consumption thro ugh the use of a narrow-bore silica column. Another advantage was in the sp eed of the analysis. Using a suitable solvent gradient, both diacylglycerol and triacylglycerol components were separated by reversed-phase high perfo rmance liquid chromatography within 50 min, providing both the diacylglycer ol content and the triacylglycerol composition. High-temperature gas chroma tography was also used to separate both diacylglycerol and triacylglycerol molecular species after trimethylsilylation of the structured lipid samples . Good agreements in the values obtained for the concentrations of diacylgl ycerols and the triacylglycerol compositions were apparent with the differe nt chromatographic methods.