The invention discloses a method for preparing
microorganism-dedicated
soybean protein isolate. The method comprises the following steps: soaking low-temperature degreased
soybean meal in an alkali solution with a pH value of 9.5 to 10.0 at a temperature of 50 to 55 DEG C, adjusting the pH value to 6.8 to 7.4, the
sugar content to 8.0 to 9.0, stirring for 40 to 60min, and performing
solid-liquid separation to obtain a crude
protein extracting solution; adding an acid solution into the crude
protein extracting solution at
room temperature, stirring for 10 to 50min, and centrifuging to obtain acid-precipitated
protein; dissolving the acid-precipitated protein in water at
room temperature, adjusting the pH value to 6.00 to 6.30 and the
sugar content to 18.0 to 19.5 to obtain an acid-precipitated
protein solution; adding
neutral protease and
alkaline protease, reacting at 50 to 60 DEG C for 0.5 to 3h to obtain enzymatic
hydrolysate; performing sterilization, flash treatment and
spray drying to obtain the
microorganism-dedicated
soybean protein isolate. The
soybean protein isolate prepared according to the invention has good dispersibility, low
viscosity and suitable
amino acid nitrogen, and has the advantages of simple process, easy operation, strong protein practicability, wide application in
fermentation industry and better popularization value.