Catalytic transesterification of corn oil and tristearin using immobilized lipases from Thermomyces lanuginosa

Thermomyces lanuginosa lipase was employed to catalyze the interesterification reaction between corn oil and tristearin at 45degreesC in a solvent-free system. HPLC and GC analyses were used to monitor both the distribution of TAG and the concentrations of MAG, DAG, and TAG as the reaction progressed. The positional distribution of the FA residues in the interesterified product was also determined for comparison to that of the original corn oil. Two different weight ratios of corn oil to tristearin were studied. Addition of molecular sieves to the reaction medium reduced the percentage of hydrolysis from 15 to 7. In order to improve the results obtained with Lipozyme TL IM, an immobilization of T. lanuginosa lipase was carried out. At a solids loading of 10% (w/w), the new immobilized lipase reduced the concentration of tristearin from 6 to 0.5% in only 30 min.