2001 AACC Annual Meeting Charlotte, North Carolina October 14-18, 2001 Charlotte Convention Center

Starch yields play an important role in the economics of the corn wet milling industry. They seem to be affected by the harvest moisture and drying conditions. This study was designed to investigate the effect of harvest moistures and drying temperatures on extractable starch yields and characteristics affecting starch yields. Fifteen commercial hybrids including 3 waxy varieties were used in this study. They were grown on the Agricultural Engineering Farm at the University of Illinois. They were harvested at three harvest moistures of about 30, 25, and 14% wet basis. The two higher moisture samples were dried at temperatures of 50, 70, 85 and 100°C, using a convection drier at ISU Bloomington to a target moisture of about 14% wet basis. Samples harvested at 14% were not dried further. Stress cracks in the samples were measured as an index of the effect of drying severity. The dried samples were scanned with an Infratec 1229, it uses near infrared transmittance. Extractable starch yields were predicted using an equation with an R2 of 0.81, and SECV of 1.33. The starch was studied for the effects of high drying temperature on gelatinization using a differential scanning calorimeter (DSC 2920), an electron microscope, and with water activity measurements. The results indicated that the two harvest moistures were significantly different, with the 25% harvest moisture having higher starch yields, than the 30% corn. Corn dried at temperatures of 50 and 70°C had significantly higher starch yields than those dried at 85 and 100°C.