Grapefruit dietary fiber as well as preparation method and application thereof

The invention discloses pomelo fruit dietary fiber as well as a preparation method and application thereof. The preparation method of the pomelo fruit dietary fiber comprises the following steps: (1) selecting pomelo fruits, cleaning the selected pomelo fruits, cutting the cleaned pomelo fruits into blocks, adding water, and pulping the blocks to obtain pomelo fruit pulp; (2) firstly adding alpha-amylase into the small pomelo fruit pulp for enzymolysis, then adding protease for enzymolysis, and after the enzymolysis is finished, inactivating the enzyme to obtain an enzymolysis product; (3) filtering the enzymolysis product to obtain filter residues and filtrate; and (4) taking filter residues, washing and drying to obtain the insoluble small pomelo dietary fiber, namely the small pomelo dietary fiber. According to the method, the pomelo dietary fibers obtained by performing enzymolysis on the pomelo fruits through the alpha-amylase and the protease have a relatively good blood sugar reducing effect. Therefore