Antioxidant and antibacterial activity of fatty acid vanillyl ester produced by Proteus vulgaris K80 lipase-mediated transesterification

Vanillyl alcohol (VA) is a good antioxidant compound, but its widespread use is impeded due to its low solubility in emulsion or organic solvent systems. Furthermore, several fatty acids have antimicrobial activity, but their broad spread is limited by their susceptibility to oxidation. In this study, we carried out a Proteus vulgaris K80 lipase-mediated transesterification reaction using VA and menhaden oil (MO) to produce fatty acid vanillyl ester (FAVE) and achieved a conversion yield of 75.3%. FAVE purified by prep-HPLC showed 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and the scavenging activity increased significantly in non-polar solvent. FAVE also inhibited the formation of conjugated diene and triene in MO-in-water emulsion stabilized by Tween 20. Furthermore, FAVE showed evident antibacterial activity against typical food spoilage bacteria by interacting with cell membrane and releasing cell constituent. These results demonstrated that FAVE is a bi-functional compound showing both antioxidant and antibacterial activities and it can be used as an essential component in food and cosmetic products.