The invention relates to an aqueous enzymatic method for preparing
protein peptide powder from soybean
hydrolysate and belongs to the technical field of
soybean product processing. The method comprises the steps as follows: (1) soybeans are peeled and crushed,
extrusion treatment is performed, and an extruded product is obtained; (2) water is injected into an
enzymatic hydrolysis reaction tank,
steam heating is performed, the extruded product is added, a
mixed solution is obtained, the pH value of the
mixed solution is adjusted, and
alkaline protease is added for enzymolysis; (3)
centrifugal separation is performed with a horizontal
centrifuge after enzymolysis, and
emulsified oil, a
hydrolysate I and residues I are obtained; (4)
isolated soy protein is added to the
hydrolysate I, the pH value is adjusted,
pepsin is added for enzymolysis,
centrifugal separation is performed after enzymolysis,
soybean oil, a hydrolysate II and residues II are obtained, alkali is added to the hydrolysate II for
neutralization until the pH is neutral, and
desalination is performed with an
ultrafiltration membrane; (5) malt syrup,
maltodextrin and other auxiliary materials are added to desalinated hydrolysate for blending, uniform mixing is performed, a
protein emulsion is formed, homogenization, vacuum concentration and
spray drying are performed, and
protein peptide powder is obtained. The method adopts a simple process and is low in cost, the prepared protein
peptide powder has high nutritional value, has strong milk
aroma, tastes fine and has good digestibility, besides, the instant
solubility of the protein peptide powder is significantly improved, and the protein peptide powder is suitable for industrial
continuous production.