The mode of action on Granular Wheat Starch by Bacterial α‐Amylase

Large (A) and small (B) granules from wheat starch were subjected to α‐amylolysis. The B granules were solubilised faster than the A granules. The solubilised dextrins we separated from the enzyme before a secondary hydrolysis of the products occurred and then characterized. The size‐distribution of the hydrolysis products ranged between a degree of polymerization of 2–500. The dextrins solubilised from the B granules contained somewhat more linear fragments and had smaller average chain length than the corresponding dextrins from the A granules. The composition of the residues of the A granules remained practically unchanged, whereas the B granules contained somewhat less amylose. Both granule types possessed extensive fragmentation of some granules, whereas other granules were virtually untouched by the enzyme.