Construction of magnetic switchable Pickering interfacial catalysis system and its application in the hydrolysis of crude rice bran oil

SUMMARY The high refining cost of traditional rice bran oil with high acid value and its large environmental impact have limited its further application. In this study, a lipase-catalysed hydrolysis reaction of crude rice bran oil at the oil–water interface was performed using a Pickering emulsion system stabilised by modified magnetic microcrystalline cellulose (MMC) particles. The results revealed that the modified MMC particles exhibited a rod-like structure, and a contact angle of 84.8°. In addition, the stability of the Pickering emulsion can be enhanced when the modified MMC was used as an emulsifier, and at an optimal addition amount of 2.0wt.%. The saturation magnetisation value of the emulsifier decreased from 38.8 to 8.9 emu g −1 after 12 reuses. Furthermore, the hydrolysis rates of crude rice bran oil in the Pickering emulsion system and a two-phase system at a Candida antarctica lipase B (CALB) content of 2mg mL −1 were 92.8% and 58.8%, respectively. In addition, the relative activity of CALB after 10 reuses was 71.8%. These findings provide a sustainable interface biocatalysis method and provide ideas for the rational development of high acid value oils.