The starch granule associated proteomes of commercially purified starch reference materials from rice and maize

► C3 and C4 metabolism plants both sequester 23% amylose into starch granules. ► These ancient and recent granule surface proteomes are contrasted. ► Starch granule associated proteins (SGAPs) are trypsinized and analyzed by direct sequencing mass spectrometry. ► Proteomes comprise carbohydrate metabolism, mobilization, storage proteins, markers of seed maturity and industrial traits. ► Commercially available rice and maize starch samples are documented to aid in their development as reference materials.