The invention discloses a method of separating D-
fructose and D-
psicose by using a
simulated moving bed. The method comprises the following steps of: step (1) converting D-
psicose, to be specific, converting the D-
fructose into the D-
psicose by using immobilized D-psicose epimerase nanoparticles, thereby obtaining a mixed
sugar solution; step (2) pretreating the mixed
sugar solution, to be specific, carrying out decolorizing pretreatment on the mixed
sugar solution; and step (3) separating by using the sequential
simulated moving bed, to be specific, separating the pretreated mixed sugar solution according to the specific separation parameters of the sequential
simulated moving bed to obtain the D-psicose solution and the D-
fructose solution, wherein the purity of the D-psicose solution isgreater than or equal to 99%, the
recovery rate of the D-psicose solution is greater than or equal to 95%, the purity of the D-fructose solution is greater than or equal to 99%, and the
recovery rateof the D-psicose solution is greater than or equal to 90%. In summary, the method has the beneficial effects that the purity and
recovery rate of the separated products are high, the sequential simulated
moving bed is used for replacing a traditional simulated
bed, and the number of chromatographic columns used and the production cost are reduced.