INFLUENCE OF MOISTURE CONTENT ON MECHANICAL PROPERTIES OF RYE KERNELS

Ab s t r a c t. The results of investigation of mechanical properties of rye kernels (cv. Fernando and Ursus) of different moisture content (from 10 to 20%) are presented. The uniaxial compression test and shear test were used for determining single kernel properties. For both cultivars, as the kernel moisture increased from 10 to 14 % the kernel deformation up to the rapture point increased, too. When the kernel moisture was 16 % and higher, the rapture point during compression test was not observed. For both cultivars, increase of moisture content from 10 to 16 % caused increase of specific work of kernel deformation up to the end of compression (average from 5.8 to 8.0 J g-1). When kernel moisture was 18 and 20%, a decrease of this work was observed (average up to 7.2 J g-1). The shearing force of single kernels decreased as the moisture increased, and similar levels of values for both cultivars were obtained (average from 60.8 to 31.4 N). Increase of kernel water content caused decrease of shear strength, too (from 7.9 to 3.8 N mm2 for Ursus and from 7.6 to 3.6 N mm2 for Fernando). K e y wo r d s: rye, kernel, compression, shear, moistur