DSC CHARACTERISTICS OF RETROGRADED STARCHES OF SINGLE-MUTANTS, DOUBLE-MUTANTS, AND TRIPLE-MUTANTS AND THEIR NORMAL COUNTERPART IN THE INBRED OH43-MAIZE (ZEA-MAYS L) BACKGROUND

Starch granules were isolated from mature kernels of single-, double-, and triple-mutants of starch modifying genes [waxy(wx), dull(du), amylose extender(ae), sugary-2(su2)] and their normal counterpart in the inbred Oh43 maize (Zea mays L.) background. Gelatinization characteristics of retrograded starches were investigated by means of differential scanning calorimetry (DSC), The thermograms of the retrograded starch shifted to lower temperature ranges and were broader compared with the native starch. The heat of gelatinization (DELTA-H) of the retrograded starch increased with increasing storage duration. The maximum value of the DELTA-H reached for each mutant and mutant combination was somewhat characteristic of the genotype and associated with duration of storage.