The invention relates to the
deep processing field of
soy bean protein. Specifically, the present invention relates to an acid soluble
soy protein preparation method which includes the following steps: alkali dissolving, acid precipitating and centrifugating a defatted
soy bean residue to obtain
soybean protein isolate
precipitation which is dissolved in water to form a
slurry, adjusting the pH of the
slurry to 1.0 to 4.0 using an
acidity regulator, stirring and completely dissolving the
soybean protein isolate
precipitation to obtain a
protein liquid a;
microwave digesting the
protein liquid a and separating the protein liquid a through
centrifugation; treating supernatants obtained by
centrifugation at a temperature of 100-180 DEG C and subsequently cooling the treated supernatants; and at last, obtaining the acid soluble
soy protein through
spray drying. The acid soluble
soy protein preparation method has the following advantages of high production efficiency, simple process, low production cost, and high product safety; and produced acid soluble soy protein has a relatively high
solubility in the
acidic region, and thus acidic beverage containing the acid soluble soy protein has less
precipitation, a good taste and a high nutritional value.