The invention relates to a preparation method of
rice bran dietary fiber, which comprises the following steps that: (1) rice
bran is crushed, passes through a screen which is more than or equal to 30mesh, is added with water to be stirred uniformly, and stays still for 30 to 50min; (2) the prepared water-absorbing swelling rice
bran material is added with dilute
hydrochloric acid, the pH value is adjusted to be 4.5 to 5.5, and then 1.0 to 1.5 percent of
hot temperature resistant
amylase is added to be heated to 85 to 100DEG C, and the temperature is maintained for 30 to 40min; (3) dilute
sodium hydroxide or
potassium hydroxide solution is added, the pH value is adjusted to be 7.5 to 8.5, 1.0 to 1.5 percent of
protease with the
enzyme activity more than or equal to 500U / g to be heated to 45 to 55 DEG C, and the temperature is maintained for 60 to 90min; (4) the
intermediate product is pressed, filtered and washed by water; (5) diluted
phosphoric acid is added in to adjust the pH value to be 5.0 to 5.5, 0.1 to 0.2 percent of
cellulose is added in to be heated to 45 to 55DEG C, and the temperature is maintained for 50 to 70min; (6) 2 to 5 percent of
hydrogen peroxide is added into a sealed container to be stirred for 20 to 30min; and (7) and the product is dried and crushed. The
dietary fiber prepared by the invention has delicate taste without roughness, and can serve as the additive in
medicine,
health food, bread, biscuits, drinks and the like.