Purification of Barley Starch by Protein Extraction

Preparation of pure starch samples requires gentle extraction from the endosperm matrix, followed by removal of contaminating endosperm proteins. Published techniques for removal of these proteins include protease treatment or centrifugation through CsCI. We present a simple method to remove proteins from starch, exploiting the solubility of the major groups of endosperm proteins in aqueous, saline, and alcoholic solvents. The data show that the purity of the starch and retention of B‐granules is similar to conventional techniques. Denaturing polyacry‐lamide gel electrophoresis reveals very few proteins retained with the starch. One major protein has an apparent MW of 54000 and probably corresponds to the “waxy” protein, granule‐bound starch synthase.