Preparation of Hydrophobic Starch Through Lipase-Catalyzed Reaction in Ionic Liquids

Abstract:

In order to improve the hydrophobilicity of starch，lauric acid was grafted on starch through lipase-catalyzed reaction in ionic liquids. Firstly，the DS values of modified starch and their structure obtained in different solvent systems was detailed studied. Results showed that lauric acid could be successfully grafted on starch by Novozym 435 in all the selected systems. And therein，DS value of modified starch obtained in ionic liquids was much higher than the others. Secondly，the properties of modified starch were tested through water contact angle，DSC，viscosity and SEM. Results showed that the hydrophobicity of modified starch was significantly improved. DSC showed that melting temperature of modified starch was improved. In addition，viscosity and transmittance of the modified starch was slightly reduced accordingly. SEM showed that the surface morphology of starch particles was destroyed and became irregularly sheet structure during modification.