A pharmaceutical grade hydrolyzed casein and its preparation method:
(1) Mix casein and concentrated hydrochloric acid in an autoclave at a mass/volume ratio (g/mL) of 1:0.6~1:1;
(2) Adjust the pressure of the kettle to 200-300kPa, the temperature to 100-120°C, heat and hydrolyze for 2-6 hours, and steam condenses and refluxes during the hydrolysis process;
(3) Release the pressure after hydrolysis, change the reflux device to a distillation device, raise the temperature to 180~220°C, and heat
(4) After cooling the reactor, open it, add activated carbon at a mass ratio of activated carbon to casein of 1-2:1, add water at a mass ratio of water to casein of 8-16:1, adjust the pressure of the kettle to 150-250kPa, the temperature to 100-120°C, heat for 2-4 hours for decolorization, and condense and reflux the steam during the decolorization process;
(5) After cooling down to room temperature after depressurization, perform suction filtration operation on the mixture in the kettle, and collect the filtrate;
(6) Weigh the anion exchange resin according to the ratio of casein to resin mass ratio of 1:10 to 1:20, fill it in an ion exchange column, rinse with distilled water to remove impurities; add 0.5 mol/L HCl solution 4 times the mass of the resin to soak for 2 hours, wash with distilled water until neutral; then add 0.5 mol/L NaOH solution 4 times the mass of the resin to soak for 2 hours, wash with distilled water until neutral, and set aside;
(7) Use a peristaltic pump to transport the filtrate to the upper end of the ion exchange column at a flow rate of 2.0-6.0 mL/min, and collect the effluent at the lower end of the column;
(8) Place the effluent in a steel tray for freeze-drying at a temperature of -50°C, a pressure of 500-600Pa, and a time of 24 hours. The obtained powdery product is pharmaceutical grade hydrolyzed casein.
