Cereal Chem 54:230 - 237. | VIEW
Comparative Susceptibility to Amylases of Starches from Different Plant Species and Several Single Endosperm Mutants and Their Double-Mutant Combinations with Opaque-2 Inbred Oh43 Maize.
H. Fuwa, M. Nakajima, A. Hamada, and D. V. Glover. Copyright 1977 by the American Association of Cereal Chemists, Inc.
We confirmed that starch granules of potato, yamanoimo (tubers of Dioscorea batatas DECNE), and sweet potato were respectively in decreasing order more resistant to the attack of Rhizopus glucoamylase, pancreatin, and crystalline alpha-amylase of Bacillus subtilis than were those of maize and rice. Several endosperm mutants, each nearly isogenic in the maize inbred Oh43 (Zea mays L.), their double-mutant combinations with opaque-2, and the normal counterpart, were studied for the relative susceptibility of their granular and gelatinized starches to amylases. When opaque-2 was combined with each of the ten endosperm mutants, namely, amylose-extender, brittle-1, brittle-2, dull, soft-starch, shrunken-1, shrunken-2, sugary-1, sugary-2, and waxy, it was observed that the starch granules of these double mutants were digested by Rhizopus glucoamylase, pancreatin, and B. subtilis alpha-amylase to an extent very comparable to their respective nonopaque single-mutant counterpart. Starch granules of the amylose-extender mutant and its double combination with the opaque-2 were much more resistant to the action of amylases than were those of the normal counterpart. Starch granules of the sugary-2 mutuant and its double combination with opaque-2 were digested much faster than those of the normal counterpart by amylases. These differences among the endosperm mutants and their double-mutant combinations in susceptibility of starch granules to the action of amylases disappeared following gelatinization of starches with alkali.