The variability in thermal properties among 62 S3 lines derived from a high-yielding exotic corn (Zea mays) population, Antigua 1 (PI 484990), was evaluated by differential scanning calorimetry (DSC). The S3 lines were grown in Puerto Rico (1990–1991) and Georgia (1994). Separate single-kernel starch extractions for five kernels (five replicates) from each line grown in each location were performed, and the starch was analyzed. The DSC values reported included gelatinization onset (ToG), range (RG), enthalpy (ΔHG), and peak height index (PHI) and retrogradation onset (ToR), range (RR), enthalpy (ΔHR), and percent retrogradation (%R) (an indication of the stability of gelatinized starch after storing at 4°C for 7 days). Significant differences (P< 0.05) were found among the 62 lines of Antigua 1 for ToG, RG, and PHI and highly significant differences (P < 0.01) were found for ΔHG. The starches from plants grown in Georgia (1994) had significantly (P < 0.05) greater ToG, ΔHG, and PHI but a significantly lower RG than those from Puerto Rico (1990–1991). These data suggest that the starch from plants grown in Georgia (1994) might have a greater degree of crystallinity than that from Puerto Rico (1990–1991). None of the retrogradation values were significantly different among starches of the 62 lines of Antigua 1 and the starches from plants grown in the two locations.
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