Physical and stress-strain properties of wheat (Triticum aestivum) kernel

BACKGROUND: Two hard wheat varieties and one soft variety grown under the same agroecological conditions were analyzed for their physical and uniaxial stress-strain compression properties. RESULTS: The physical properties of wheat kernel were determined at a moisture content of 0.13 kg kg(-1) (wet basis), whereas the stress-strain compression test was conducted at a kernel moisture content from 0.082 to 0.433 kg kg(-1). Mean kernel lengths were 5.46 (5.37 and 5.38) mm, widths were 2.56 (2.47 and 2.62) mm and thicknesses were 2.12 (2.18 and 2.43) mm for Simonida, Dragana and NS 40S cultivars, respectively. Bulk densities were 791.34 (Simonida), 788.51 (Dragana) and 731.77 kg m(-3) (NS 40S). The force at the yield point was 241.46 N for Dragana (moisture content 0.133 kg kg(-1)), 244.30 N for Simonida (0.136 kg kg(-1)) and 164.90 N for NS 40S (0.433 kg kg(-1)). CONCLUSION: The width and thickness of the analyzed kernels were small compared with the length, and bulk densities were also moderate. The yield point force values of the two hard varieties were 2.2 times higher than the values of the soft variety, at amoisture content of 0.136 kg kg(-1) for Simonida, 0.133 kg kg(-1) for Dragana and 0.141 kg kg(-1) for NS 40S. (C) 2011 Society of Chemical Industry