Method for preparing high-absorptivity silica as lutein carrier

A method for preparing high-absorptivity silica as lutein carrier, comprising the steps of:

• (1) adding sodium silicate into a synthesis kettle, introducing steam for heating while stirring, adding water, stirring for reaction to obtain a reaction substrate A, and adding sulfuric acid for pre-acidification until the solution pH is 8.5-10.5 to obtain reaction solution B;
• (2) simultaneously adding sulfuric acid and sodium silicate into the reaction solution B, and performing synthesis reaction to obtain reaction solution C;
• (3) adding sulfuric acid only into the reaction solution C, for post-acidification, until the solution pH reaches 3.5-4.0, and aging to obtain dilute slurry D;
• (4) filtering the dilute slurry D, washing to obtain a filter cake E, transferring to a slurrying machine, and adding a slurry viscosity reducer to obtain slurry F;
• and
• (5) drying the slurry F and packaging to obtain high-absorptivity silica microspheres as lutein carrier, wherein:
• the sodium silicate is water solution of sodium silicate with a concentration of 30-40 Baume;
• the sodium silicate has a modulus of 3.30-3.60;
• the slurry viscosity reducer is food-grade organic acid;
• and
• the organic acid is citric acid.