Plant proteins from industrial crops (cereals, oilseeds, legume seeds) are a reservoir for functional macromolecules. Those extracted from wheat, soybean and pea are more and more used for their texturizing, gelling, emulsifying and foaming properties not only in food formulation but also for non-food applications. These properties, which are related to the structure and physicochemical properties of the proteins, are very different depending on the botanical origin of the proteins and on their polymorphism, but also according to their biological function (storage proteins or small metabolic or defense proteins). This large diversity is poorly exploited. Functional properties of proteins are also influenced by technological treatments. They could be modified by tailoring proteins either by physical, chemical or enzymatic treatments.