Effects of selected harvest moistures and frozen storage times on selected yellow dent corn: wet-milling yields and starch pasting properties.

摘要

Effects of harvest moistures and frozen storage times on corn wet-milling yields and pasting properties of the resulting starch were studied. Pioneer hybrid P-0916-XR harvested at 3 moisture contents (49, 35 and 21% wb) were stored frozen for 3 days or for 5 months, followed by wet-milling. Pasting properties of the resulting starch were evaluated with a rapid visco analyser. Yields of starch and germ increased by 1.2 and 1.9%, respectively, when harvest moisture decreased from 49 to 21% wb, whereas yields of steep water solids, total fibre and gluten decreased by 2.1, 0.7 and 0.6%, respectively. Frozen corn had lower coarse fibre yields but higher cellular fibre yields. Starch pasting properties showed that peak and breakdown viscosities decreased by 8% (3824 +or- 36 vs. 3520 +or- 38 cP) and 13% (2336 +or- 47 vs. 2029 +or- 60 cP), respectively, when harvest moisture decreased from 49 to 21% wb, whereas peak time increased by 5% (6.32 +or- 0.06 vs. 6.62 +or- 0.07 min). Setback and final viscosities of starch from long-term frozen storage (5 months) were 14% (1574 +or- 65 vs. 1828 +or- 79 cP) and 8% (3063 +or- 27 vs. 3317 +or- 101 cP) lower, respectively, than that from control (unfrozen) corn.