The invention relates to a preparation process of functional
soybean protein concentrate. The preparation process comprises the following steps: (1) putting
soybean protein concentrate curd which is prepared by an
alcohol extraction process or
soybean protein concentrate which is sold on markets and screened by a 80-mesh screen in a dissolving tank; adding 6-15 times of water to mix and stir for 10-20 minutes while controlling
water temperature at 50-60 DEG C; (2) using
sodium hydroxide to adjust the pH value of the
protein liquid to 7.0-8.0 and stirring the
protein liquid for 10-20 minutes; (3) using a feeding pump to pump the
protein liquid in an ultra-high temperature sterilizer so that the temperature reaches 120-155 DEG C,
processing the protein liquid for 1-240 seconds and setting the temperature of a liquid outlet at 40-80 DEG C; (4) pumping the protein liquid in a
spray drying tower for spraying and
drying; (5) heating
phospholipid at different
processing stages, wherein the addition of the
phospholipid is 0.1-1 percent of the
dry weight of protein, and the HLB value of the
phospholipid is 4-10; and (6) together adding
sucrose ester and / or amber acid direactive
glyceride and the phospholipid to the protein liquid, wherein the additions are respectively 0.1-0.5 percent of the
dry weight of the protein. The invention remarkably improves the dissolvability of products, achieves the NSI of 50-80 percent and the haloduric index of 30-80 and has light color, mild
flavor and good oil and
moisture retention.