A liquid composition which has, in an aqueous medium, one or more protein(s) and one or more solubilizing agent(s) chosen from anionic compounds of non-saccharide structure, the structure of which contains at least one aromatic nucleus having at least 6 ring members and at least one carboxylic acid group in salified form, and which has, in its acid form, a molar mass between 130 and 500 g/mol. A process for solubilizing one or more protein(s), wherein at least one solubilizing agent chosen from anionic compounds of non-saccharide structure, the structure of which contains at least one aromatic nucleus having at least 6 ring members and at least one carboxylic acid group in salified form, and which has, in its acid form, a molar mass between 130 and 500 g/mol, is added to an aqueous protein preparation in order to solubilize the protein is also provided.