Physical properties of kernels from modern maize hybrids used in Croatia

Abstract

The physical properties of maize are a result of kernel structure, they indicate chemical properties of the kernel, and hence, its nutritive value. This research aimed to explore the physical traits of kernels of 80 commercial maize hybrids from nine seed companies. The grain from investigated hybrids was produced during the same season on the same field under the same agricultural conditions. Moisture content, bulk and real density, Stenvert hardness (time to grind 17mL of grits, height of freshly ground grain, and coarse-to-fine particles ratio, C/F), flotation index, breakage susceptibility, kernel dimensions, and sphericity were determined in maize samples. Test weight was in a range from 70.2 to 82.1 kg/hL, with the majority of hybrids of high nutritive value (>72 kg/hL). Density ranged from 1.159 to 1.301 kg/L and similarly as test weight increased with increasing hardness (C/F; r=0.52 and 0.68, respectively; P<0.001); a trait that is related to breakage and insect resistance, and to decreased starch digestibility. Flotation index was from 8 to 100%, and its value decreased with increasing hardness (r=-0.65; P<0.001). A wide range of values in physical traits of investigated hybrids implies different behavior of grain during postharvest handling and processing and thus variable nutritive value.