Pickering emulsion stabilized by immobilized lipase for OPO synthesis and acyl migration inhibition

This study employed chitosan (CS) for the electrostatic immobilization of Rhizomucor miehei lipase (RML). The immobilized lipase exhibited an activity retention of 95.43% and formed a stable oil-in-water (O/W) Pickering emulsion with a particle size of 400 nm. With tripalmitin (PPP) as the substrate, ethanol was introduced to react with the enzymatically hydrolyzed palmitic acid (PA), forming ethyl palmitate and consequently enhancing 2-MAG generation. Furthermore, Al(OH)₃ was incorporated into the aqueous phase effectively inhibiting acyl migration. Following separation and purification, a high 2-MAG content of 96.24% was achieved. Subsequently, using 2-MAG and oleic acid (OA) as substrates for esterification, the yield of 1,3-dioleoyl-2-palmitoylglycerol (OPO) reached 82.53%. Notably, the enzyme maintained 80.91% of its activity after 17 reuse cycles in the esterification reaction. This method offers a novel approach for the efficient synthesis of OPO.