Method for modifying gliadin and application thereof

A method for modifying a gliadin, comprising the following steps:

• completely dissolving gliadin in a solvent with stirring to obtain a first gliadin solution;
• adding the first gliadin solution to ultrapure water then stirring to provide a uniformly mixed gliadin solution;
• evaporating liquid from the uniformly mixed gliadin solution and adding pure water to a predetermined volume to obtain a second gliadin solution having a mass concentration of gliadin of 5-25 mg/mL;
• adding a proline endoprotease to the second gliadin solution at a volume ratio of 1:5-15 and to provide a mass concentration of proline endoprotease of 0.5-2.5 mg/mL to obtain a third gliadin solution for a reaction, and adjusting a pH value of the third gliadin solution during the reaction to neutral according to a gradient comprising:
• adjusting the pH value of the third gliadin solution to 5.0±0.2 after adding the proline endoprotease then reacting for 1-1.5 h, then
• adjusting the pH value of the third gliadin solution to 6.0±0.2 then continuing to react for 1-1.5 h, then
• adjusting the pH value of the third gliadin solution to 7.0±0.2 and then continuing to react for 1-1.5 h;
• and
• thereby obtaining modified gliadin, wherein the modified gliadin has uniform and stable dispersion in water after heating to 85° C. for 10 min or after 15 minutes in a 1.5 M NaCl solution.