Modifying Wheat Dietary Fiber with Double-Screw Extrusion

Modification of wheat dietary fiber(WDF)was studied by using a double-screw extruder.Results indicate that the optimal extrusion condition are as follows: material moisture 15%,extrusion temperature 140 ℃,screw rotation speed 100 r/min.At the condition,the water holding capacity of the WDF is 4.18 g/g,the swelling capacity is 3.45 mL/g,compare to the WDF before extrusion,0.7 g/g and 1.25 mL/g increased separately.After extrusion,the content of water and soluble dietary fiber were higher;starch,the content of protein and insoluble dietary fiber were lower;and the content of other basic ingredients didn’t have much change.With microscopic observation,the extruded WDF was looser in weave construction,uniformer in size.