The invention relates to a process for manufacturing soluble and functional plant proteins, characterized in that it comprises at least one functionalizing step that consists of a treatment of 0.01 s to 1 s constituted of a step of heating plant proteins at a temperature of 100° C. to 160° C. and a step of cooling the heated plant proteins. The invention also relates to a process for converting non-functional plant proteins to functional proteins. Another subject of the invention is a plant protein, characterized in that it has a solubility in water of greater than 50% (with the exception of a potato protein for which the solubility in water is 25%), an emulsifying capacity between 700,000 mPa·s and 1,200,000 mPa·s for a sample directly placed at 4° C. for 24 h (with the exception of a potato protein for which the emulsifying capacity for a sample directly placed at 4° C. for 24 h is between 400,000 mPa·s and 600,000 mPa·s) and between 500,000 mPa·s and 1,100,000 mPa·s for a sample treated at 75° C. then placed at 4° C. for 24 h and an emulsifying capacity between 70% and 95%. A further subject of the invention is the use of said plant protein in the manufacture of food.
