Enzymatic synthesis of phenolic lipids using flaxseed oil and ferulic acid in supercritical carbon dioxide media

Enzymatic synthesis of phenolic lipids from flaxseed oil and ferulic acid was studied in supercritical carbon dioxide (SCCO2) media using immobilized lipase from Candida antarctica. Response surface methodology based on central composite rotatable design at five levels and four factors, consisting of pressure (85–345 bar), temperature (40–80 °C), substrate molar ratio (2:1–10:1, flaxseed oil:ferulic acid), and time (2.5–52.5 h), was used to model and optimize the reaction conditions. Reactions at moderate pressures resulted in higher yields compared to lower and higher pressures. The highest yield was obtained at 80 °C. Increasing the substrate molar ratio decreased the yield. Optimum reaction conditions for the maximum yield were 215 bar, 80 °C, 6:1 substrate molar ratio and 27.5 h for the reaction. The optimum predicted yield was 57.6% whereas the experimental yield obtained was 58.0 ± 2%. SCCO2 is a promising green solvent for the enzymatic synthesis of phenolic lipids.