Wet-Milling Characteristics of 10 Lines from Germplasm Enhancement of Maize Project Compared with Five Corn Belt Lines

The use of corn (Zea mays L.) hybrids with high grain yield and starch extractability has steadily increased in the processing industry. In light of widespread corn seed industry participation in the Germplasm Enhancement of Maize Project (GEM), which seeks to enhance exotic germplasm, future hybrids may contain more exotic sources in genetic backgrounds. It is necessary to establish and monitor physical, compositional, and milling characteristics of the new exotic breeding materials to determine the processing value. The present study was conducted to determine the wet-milling characteristics of a set of GEM lines compared with typical Corn Belt lines. Ten GEM lines introgressed with exotic materials from Argentina, Chile, Cuba, Florida, and Uruguay and previously identified as having different starch yields, three commercial inbred lines, and two public inbred lines (B73 and Mo17) were analyzed using both near-infrared transmittance (NIT) and a 100-g wet-milling procedure. There were statistical differences (P < 0.05) in the yield of wet-milled fractions (starch, fiber, gluten, and germ). The GEM lines AR16035:S19-227-1-B and CUBA117:S1520-562-1-B had similar or better starch yield and starch recovery than B73 and the other adapted inbred lines, indicating that they may be useful in improving the proportion of extractable starch present in kernels of hybrids. Residual protein levels in the starch and gluten fractions were 0.26-0.32% and 38-45%, respectively. The starch yield of GEM lines from wet milling correlated positively with starch content from NIT and was negatively correlated with protein content of the corn kernels. Oil content in the germ varied from 50 to 60%. Our results indicate that incorporating GEM lines in a breeding program can maintain or even improve wet-milling characteristics of Corn Belt materials if lines with appropriate traits are used.