SUCRALOSE PURIFICATION METHOD

Disclosed is a method for purifying sucralose, sequentially including: adding sucralose to ultrapure water, heating the resulting mixture for dissolution to obtain a dissolved solution, filtering the dissolved solution to obtain a filtrate, and then extracting the filtrate with an extraction solvent to remove non-polar impurities; subjecting the extracted recrystallization solution to concentration by evaporation to obtain a concentrated recrystallization solution with a preset concentration, and leaving the concentrated recrystallization solution to stand at a preset temperature for a preset time to produce a sucralose crystal nucleus in the concentrated recrystallization solution; subjecting the concentrated recrystallization solution containing the sucralose crystal nucleus to programmed cooling to obtain a recrystallization solution with a large amount of a sucralose crystal; and centrifuging the recrystallization solution with a large amount of a sucralose crystal to obtain a solid, and subjecting the solid to water-washing and drying to obtain a sucralose crystal. In the method, a sucralose crystal is prepared by removing impurities through extraction, then promoting nucleation, and promoting the rapid growth of a crystal through a second-time nucleation procedure to ensure full crystallization. The prepared sucralose crystal has a single crystal form, a regular crystal morphology, an extremely-high purity, an excellent color, a high bulk density, and long shelf time, and could meet the requirements of high-end products for sugar substitutes.