This application relates to the field of
bioactive peptide preparation technology, and discloses a method for preparing a
blood pressure-lowering
protein active
peptide composition. The raw materials for this composition include a
protein substrate, deionized water,
alkaline protease, a complex solubilizing buffer, and a cross-linked
aqueous solution containing
sodium hexametaphosphate. The preparation method includes: isothermal
enzymatic hydrolysis of the
protein substrate; adding the complex solubilizing buffer to the
hydrolysate and instantaneously heating it to construct a steric hindrance protective layer for the short peptides; subsequently injecting the cross-linked
aqueous solution for high-shear cross-linking, allowing large molecular impurities to target and bind; and then directly spraying it into a vacuum flash
evaporator for rapid cooling, causing the cross-
linked protein network to shrink and densify; finally,
centrifugation,
ultrafiltration, concentration, and
drying are performed to obtain the finished product. This invention prevents the active short peptides from co-precipitating with impurities under heat, effectively maintaining the
blood pressure-lowering activity of the peptides, and densifying the
impurity flocs, thereby improving the separation and
sludge removal efficiency and the anti-
fouling ability of the
ultrafiltration membrane.