Abstract:

Dietary fiber was prepared from wheat bran and the effects of ultrafine comminution and freeze-grinding on its physicochemical properties were studied. The results showed that the average particle sizes of ultrafine and freeze-ground dietary fibers were 20.861 and 13.382 μm, respectively. Ultrafine comminution and freeze-grinding both were able to increase content of soluble dietary fiber, swelling capacity and adsorption capacity of heavy metal ions while the ultrafine and freezeground dietary fibers displayed lower water- and oil-holding capacities. The cholesterol adsorption capacity was slightly reduced in while a slight increase in cation exchange capacity was observed. The freeze-ground fiber had better physicochemical properties than the ultrafine. X-ray diffraction patterns showed that ultrafine comminution and freeze-grinding did not alter the polymeric crystalline state of dietary fiber.

Key words: ultrafine comminution, freeze-grinding, wheat bran, dietary fiber