Preparation method of soybean peptide

The invention discloses a preparation method of soybean peptide, and relates to the technical field of preparation of soybean peptide. The invention relates to a preparation method of soybean peptide. The preparation method comprises the following steps: S1, soaking cleaned soybeans at normal temperature for 12 hours; s2, adding the soybeans soaked in the step S1 into water which is 5-8 times of the weight of the dry soybeans, performing grinding, and performing separation in a slurry-residue separator with the fineness of 200 meshes so as to extract protein liquid; and S3, performing complete decoloration, odor removal and fishy smell removal treatment on the protein liquid obtained in the step S2. According to the preparation method of the soybean peptide, trypsin is used as zymogen for enzymatic hydrolysis of vegetable protein, especially soybean protein isolate, other enzymes do not need to be added for auxiliary hydrolysis, the hydrolysis efficiency is high, and macroporous resin is added in the preparat