Methods of recovering plant-derived proteins or suprastructure proteins, are provided. The method may comprise obtaining a plant, or plant matter comprising apoplast-localized proteins, or suprastructure proteins, loosening the cell wall to produce a plant or plant matter having a loosened cell wall, thus allowing the release of apoplastic content through the cell wall to produce an apoplastic content fraction from the plant or plant matter, and recovering the apoplastic content fraction. The apoplastic content fraction comprises plant-derived proteins or suprastructure proteins.