Lipase-Catalyzed Synthesis of Ferulyl Oleins and their Inhibition Effects on Nitrosamine

Abstract

Ferulyl oleins were synthesized from ethyl ferulate and triolein with Lipopan lipase. The influence of reaction parameters, such as reaction system and water activity were evaluated. Among the tested lipases in different reaction system, Lipopan S BG appeared to be the most appropriate resulting in a overall yield of ferulyl oleins 28.31% within 120h in toluene system, whereas transesterification degree with other lipases did not exceed 20% in any condition. Similarly, the Lipopan lipase expressed the highest transesterification yield at aw = 0.33. The inhibition of nitrosamine by ferulyl oleins in vitro experiments were performed. The results showed that ferulyl oleins had a greater ability to inhibit the N-nitrosodimethylamine formation than ferulic acid and ethyl ferulate did. Ferulyl oleins showed an inhibition rate as high as 76.9%. In the case of nitrite, the extent of the inhibition by ferulyl oleins was slightly lower than EF. They all exhibited the highest inhibition rate at the concentration of 1.5mg/mL. The results suggest that ferulyl oleins can inhibite nitrosamine formation efficiently.