A highly efficient and recoverable enzymatic method for removing phospholipids from soybean oil via an ionic liquid-based three-liquid-phase

A three-liquid-phase system (TLPS) with the ionic liquid (IL) constituting one of the phases was developed and used as a novel enzymatic reaction and separation system to remove phospholipids from crude soybean oils. Among the TLPSs tested, the oil/[BMIM]BF4/sodium citrate TLPS was considered to be the optimal system. In this system, a novel emulsion containing two different emulsion structures (W-1/W-2 and W-2/O/W-2 emulsion, W-1 and W-2 represent the IL-enriched and salt-enriched phase, respectively) could be formed, giving rise to its high catalytic efficiency. In this emulsion, not only could the phospholipids at the top/middle interface be hydrolyzed, but the hydrolysis of phospholipids also occurred at a higher efficiency at the middle/bottom interface where the interface area was much larger than the top/middle interface. As a result, the enzymatic treatment time in the TLPS (3 min) could be shortened by 60-fold relative to the conventional O/W system (3 h). Furthermore, the phospholipase in the salt-enriched phase could be reused for at least 8 batches without a significant loss in catalytic efficiency. This TLPS could offer a cost-effective, easily scaled up, and low-energy cost system for the reaction of weak polar substrate catalyzed by an interfacial enzyme.

Automated summary

A three-liquid-phase system containing an ionic liquid was developed for efficient removal of phospholipids from crude soybean oils, significantly reducing enzymatic treatment time and allowing for multiple reuses of the enzyme. This system offers a cost-effective and energy-efficient solution for catalyzing weak polar substrates using interfacial enzymes.