Method for preparing dietary fiber through solid-gas explosion

The invention belongs to the technical field of preparation of dietary fibers, and particularly relates to a method for preparing the dietary fibers by using grain seed husks, such as corn husks and the like as raw materials and utilizing a solid-gas explosion technology, which comprises the following steps of: regulating the water content of the grain seed husks to 50-300 percent, and then placing into a sealed gas explosion device; raising the pressure of the gas explosion device to 0.4-1.2Mpa within 5-25 minutes, and retaining the pressure for 10-120 seconds and then instantaneously depressurizing; and adding water into the processed grain seed husks for extraction, removing the starch and the protein therein, modifying, separating and removing impurities to obtain the dietary fibers. The method has the advantages of simple operation, convenient and rapid extraction, abundant raw material sources and low production cost and can simultaneously obtain two types of high-quality corn-husk dietary fiber products with high purity and large yield, and both the yield and the physiological activity of the products are markedly improved.