The invention discloses a method for synthetizing
starch octenylsuccinate with an enzymic method in ionic liquids and belongs to the technical field of
starch processing. The principle of the method is based on the fact that the
acetic acid typeionic liquids with high cation concentration are used as efficient
solvent environments for synthetizing the
starch octenylsuccinate with the enzymic method, so that starch
solubility is enhanced,
lipase activity is kept, and the synthetizing efficiency of the starch octenylsuccinate with the enzymic method is significantly improved. According to the method, the two ionic liquids, namely, an
ionic liquid 1 (Me(OEt)2-Al-Im)Ac and an
ionic liquid 2 (Me(OEt)3-Al-Im)Ac, are designed and synthetized, then one of the two ionic liquids is used as a reaction
solvent, 10% of common
corn starch is added, subjected to pregelatinization treatment at the temperature of 100 DEG C for 10 minand cooled to the subsequent enzymic
reaction temperature of 50 DEG C, octenyl succinic anhydrides accounting for 3% of the dry-basis
mass of the starch and a
lipase Novozym 435 accounting for 10% of the dry-basis
mass of the starch are added for an
esterification reaction for 30 min, a product is deposited and washed by 95% ethyl
alcohol until the concentration of theanhydrides in a washing liquid is lower than 0.3%, the product is dried at the temperature of 40 DEG C and crushed, and a starch octenylsuccinate product with the substitution degree
ranging from 0.014 to 0.019 is obtained.