Glycerolysis of olive oil: batch operational stability of Candida rugosa lipase immobilized in hydrophilic polyurethane foams

The operational stability of the Candida rugosa lipase immobilized in a hydrophilic polyurethane foam was evaluated in consecutive batches for the glycerolysis of olive oil in n-hexane, aimed at the production of monoglycerides.Glycerol controlled the glycerolysis in the system under study, since it is both a substrate and a powerful water binder that reduces the water activity of the reaction medium and of the microenvironment. Two sets of experiments were carried out under different glycerol/triglyceride ratios. After 345 hours of consecutive 23 hours batches no lipase inactivation was observed.List of Symbols a_w thermodynamic activity of water - DG diglyceride (s) - FAME fatty acid methyl ester (s) - FFA free fatty acid (s) - FID flame ionization detector Gly glycerol - MG monoglyceride (s) - TG triglyceride (s) - TLC thin layer chromatography The authors are grateful to Profs. P. Adlercreutz, Technical University of Lund, Sweden, and J.M.S. Cabral, Instituto Superior Técnico, Lisbon, Portugal, for inspiring discussions and advice, to Prof. Helena Pereira, Instituto Superior de Agronomia (ISA), Lisbon, Portugal, for the use of GC equipment and to Mrs. Marlene Dionísio, ISA, for invaluable help with some of the experimental work.