A curable aqueous binder composition comprising one or more amine reactant selected from the group consisting of: a protein, a peptide, an amino acid, an ammonium salt of a polycarboxylic acid, an ammonium salt of a (poly)hydroxy-(poly)carboxylic acid; one or more carbohydrate; and one or more emulsion polymer; and the use thereof as thermosetting binders. Also described are composite materials comprising the curable binder composition, and methods of application.