D-Tagatose 3-epimerase (D-TE) from Pseudomonas sp. ST-24 immobilized on Chitopearl beads of BCW 2503 was used in the preparation of D-psicose from D-fructose. When D-fructose solution (10%) was passed through a column packed with immobilized D-TE about 20% of the D-fructose was converted to D-psicose. This column was continuously used for 10 d at 45 degrees C and about 90 g of D-psicose were obtained from D-fructose (500 g). Through the coupling with immobilized D-TE and D-xylose isomerase, D-psicose could be prepared directly from D-glucose.