Stability of immobilized Rhizomucor miehei lipase for the synthesis of pentyl octanoate in a continuous packed bed bioreactor

Enzymatic Glycerolysis of Palm Kernel Olein-Stearin Blend for Monolaurin Synthesis as an Emulsifier and Antibacterial

Monolaurin is a monoacylglycerol, which can act as an emulsifier and antibacterial. Palm kernel oil is a monolaurin raw material that can be fractionated into palm kernel olein (PKOo) and palm kernel stearin (PKS). Therefore, this study prepares monolaurin through enzymatic glycerolysis of the PKOo-PKS blend. The effects of enzyme concentration, molar ratio of oil to glycerol, solvent to oil ratio, and reaction temperature on the products of glycerolysis were investigated. The best conditions were selected for further production, purification, and characterization of the monolaurin. The results showed that the best glycerolysis condition was obtained with an enzyme concentration of 10% w/w, an oil–glycerol molar ratio of 1:4, a solvent–oil ratio of 2:1 v/w, and a glycerolysis temperature of 40 °C with a stirring speed of 600 rpm based on the monoacylglycerol (MAG) concentration. The identification of the sample with FTIR and NMR indicated that the purified glycerolysis product is the monolaurin. The thermal analysis showed a large endothermic peak with a melting point of 35.56 °C. The purified monolaurin has a HLB value of 5.92, and an emulsion capacity and stability of 93.66 ± 1.85% and 89.54 ± 3.36%, respectively. The minimum inhibitory concentration (MIC) of the monolaurin for Escherichia coli FNCC 0091 and Staphylococcus aureus FNCC 0047 were at 500 ppm, and 100 ppm for Bacillus subtilis FNCC 0060.

Lipase Catalyzed Acidolysis for Efficient Synthesis of Phospholipids Enriched with Isomerically Pure cis-9,trans-11 and trans-10,cis-12 Conjugated Linoleic Acid

The production of phospholipid (PL) conjugates with biologically active compounds is nowadays an extensively employed approach. This type of phospholipids conjugates could improve bioavailability of many poorly absorbed active compounds such as isomers of conjugated linoleic acid (CLA), which exhibit versatile biological effects. The studies were carried out to elaborate an efficient enzymatic method for the synthesis of phospholipids with pure (>90%) cis-9,trans-11 and trans-10,cis-12 CLA isomers. For this purpose, three commercially available immobilized lipases were examined in respect to specificity towards CLA isomers in acidolysis of egg-yolk phosphatidylcholine (PC). Different incorporation rates were observed for the individual CLA isomers. Under optimal conditions: PC/CLA molar ratio 1:6; Rhizomucor miehei lipase loading 24% wt. based on substrates; heptane; DMF, 5% (v/v); water activity (aw), 0.11; 45 °C; magnetic stirring, 300 rpm; 48 h., effective incorporation (EINC) of CLA isomers into PC reached ca. 50%. The EINC of CLA isomers was elevated for 25–30% only by adding a water mimic (DMF) and reducing aw to 0.11 comparing to the reaction system performed at aw = 0.23. The developed method of phosphatidylcholine acidolysis is the first described in the literature dealing with isometrically pure CLA and allow to obtain very high effective incorporation.