A method for preparing alkaline hydrolysates of plant proteins, which includes the following steps: 1) preparing a suspension of proteins selected from the group consisting of pea proteins, potato proteins and maize proteins, at a dry matter content of between 10 and 15%； 2) adjusting the pH, with stirring, to a value between 9.5 and 10.5 using, as the only alkaline agent, one or more alkali metal hydroxides selected from the group consisting of sodium hydroxide and potassium hydroxide； 3) heating the resulting suspension at a temperature between 70 and 80° C., for 4 to 6 hours； 4) neutralizing said heated suspension using an inorganic acid, preferably hydrochloric acid； 5) drying the neutralized suspension so as to obtain the alkaline hydrolysate.
