An Efficient Strategy for the Production of Epoxidized Oils: Natural Deep Eutectic Solvent‐Based Enzymatic Epoxidation

Abstract

AbstractPoor H2O2‐resistance by enzymes is a key bottleneck in the epoxidation process of oil by enzymatic methods. In this study, the stability of three lipases, from Aspergillus oryzae lipase (AOL), Aspergillus fumigatus lipase B (AflB), and marine Janibacter (MAJ1), in the presence of H2O2 was evaluated in different types of natural deep eutectic solvents (NADES). This stability was strengthened significantly in the NADES compared to the buffer. Specifically, AOL retained 84.7% of its initial activity in the presence of choline chloride/sorbitol (1:1 M ratio) and 3 mol L−1 H2O2 after 24 h incubation at 40°C. In addition, the two‐phase epoxidation process was optimized with AOL in ChCl/sorbitol to reach up to 96.8% conversion under the optimized conditions (molar ratio of octanoic acid/H2O2/C=C‐bonds = 0.3:1.5:1, enzyme loading of 15 U g−1 of soybean oil, ChCl/sorbitol content of 70.0% of the weight of hydrophilic phase, and reaction temperature of 50°C). Moreover, the lipase dispersed in NADES retained approximately 66% of its initial activity after being used for seven batch cycles. Overall, NADES‐based enzymatic epoxidation is a feasible and promising strategy for the synthesis of epoxidized oils.