Relationships Between Kernel Physical Properties and Zein Content in Corn Hybrids

Abstract

Previous research documented that physical properties of corn kernel are related to total zein content, but limited information exists for specific hybrid responses. Therefore, the objective of this research was to determine the relationships between kernel physical properties and zein content in various corn hybrids. Eight commercial corn hybrids (Bc 244, Bc 354, Bc 394, Bc 462, Bc 572, Bc 572, Bc 678 and Pajdaš) were grown under intensive production management in the growing season of 2009. Kernel physical properties determined were the 1000-kernel weight, bulk density, kernel density, Stenvert hardness parameters (grinding time, total column volume, ratio of coarse to fine particles) and flotation index. For tested hybrids, physical properties ranged 342.6- 446.2 g for 1000-kernel weight, 0.861 - 0.909 kg/L for bulk density, 1.051 - 1.243 g/mL for kernel density, 0 - 30.40 % for flotation index and 1.20 - 2.03 for coarse-to-fine particles ratio. Total zein content ranged from 51.62 to 65.15 g/kg in the whole kernel and from 59.64 to 73.81 % in the crude protein. Hybrid with the lowest zein content in the whole kernel had the highest zein content in crude protein. The total zein content in the crude protein positively correlated with bulk density (r=0.39*) and 1000-kernel weight (0.29*). Positive correlation (r= 0.47**) was found for total zein content and Stenvert coarse-to-fine ratio. However, two hybrids (Bc 678 and Bc 462) that significantly varied for zein content achieved similar kernel hardness properties indicating that factors other than zein content influenced kernel hardness.