Production of structured lipids via batch and continuous acidolysis of triglycerides using the hydration–aggregation-pretreated lipase loaded onto surface-modified glass bead supports

Abstract

A commercial lipase from Rhizopus japonicus was activated and utilized for triglyceride (TG) modification for producing structured lipids via acidolysis of TGs and fatty acids. To activate the lipase, lipase powder was mixed with glass beads (GBs) in 1-dodecanol and then a buffer solution were added dropwise to form hydrated lipase aggregates. After removal of liquid phase in the mixuture, the residue consisting of hydrated lipases and GBs was lyophilized and then the hydration–aggregation-pretreated lipase loaded onto GBs was recovered. The acidolytic activity of the lipase was significantly enhanced after hydration–aggregation pretreatment, whereas untreated lipase exhibited little activity. The effects of the surface hydrophobicity, diameter, and amount of lipase loading on GBs on the acidolytic activity of the lipase were investigated. The optimal GBs and lipase loadings were 0.428 mm in diameter with a hydrophobic surface and 89.2 U/g-GB, respectively. Under these conditions, the lipase exhibited an 8-fold higher catalytic activity than that of the hydration–aggregation-pretreated lipase without GBs. Furthermore, continuous modification of olive oil with palmitic acid via acidolysis using the hydration–aggregation-pretreated lipase packed in a column reactor was achieved for 116 h. The half-life of the packed-bed reactor was 149 h.