Thermal properties and paste and gel behaviors of starches recovered from accessions used in the Germplasm Enhancement of Maize project

The objective of this study was to screen starches recovered from the corn accessions used in the Germplasm Enhancement of Maize (GEM) project for unu sual thermal properties and paste and gel behaviors, so that they could be exploited in corn breeding programs to enhance traits important to corn uti lization. In general, the values for gelatinization temperatures and peak h eight indices were greater, but heat of gelatinization values were less for the starches recovered from the GEM accessions (particularly BRA 052051 (S E 32)) than for starches from commercial Dent corn hybrids (11.3 vs. 13.6 J /g). Generally, retrogradation properties were similar among the GEM access ions, although there were specific accessions (particularly Lima 13) that p ossessed modestly lower percentage retrogradation (34 vs. 42%). Generally, peak viscosities, cold paste viscosities, and viscosity breakdowns were gre ater for the starches of the GEM accessions (particularly ARZM 01150, Antiq ua 3, and URZM 01089, respectively) than for the starches of commercial hyb rids. Pasting temperatures were about the same for all starches. Both 1-day and 7-day gel strengths were considerably greater for the starches recover ed from the GEM accessions (particularly BRA 052051 (SE 32), 21.0 g for i-d ay and FS8A(T), 66.2 g for 7-day). Although the differences in starch prope rties were statistically different only the higher gel strengths of the sta rches recovered from the GEM accessions were of practical significance to t he starch industry.