Immobilisation of lecitase® ultra for production of diacylglycerols by glycerolysis of soybean oil

Immobilisation of lecitase® ultra and production of diacylglycerols (DAG) through glycerolysis of soybean oil catalysed by immobilised lecitase® ultra (IM-LU) were investigated in this study. This enzyme was immobilised by macroporous resin adsorption, and IM-LU with an enzyme activity of 1682 U/g, achieved under selected conditions. The results showed that the solvent-free system was preferred for the IM-LU-catalysed glycerolysis reaction as compared with the organic solvent systems. In a solvent-free system, with a reaction of 12 h under the optimum conditions, an upper lipid layer of the reaction mixture with 53.7 wt.% DAG content was obtained. IM-LU exhibited a remarkable reusability in recycling experiments by reusing the recovered IM-LU for 28 consecutive batches. Furthermore, IM-LU was observed to have sn-1, 3-specificity towards triacylglycerols in the glycerolysis reaction and a tendency to enrich saturated fatty acids in DAG with respect to the original oil.