Physical properties of oil rapeseed kernels at different moisture content and varietes

Abstract

The physical properties of the three common cultivars were evaluated as a function of seed moisture content, which varied from 6.04 - 21.17%, from 5.82 - 20.90% and from 5.98 - 20.46% in 'Banacanka', 'Jasna' and 'Slavica', respectively. Results of thousand-seed weight increased from 4.18 g to 4.94 g in 'Banacanka', from 4.74 g to 5.61 g in 'Jasna', and from 4.11 to 4.81 g in 'Slavica'. The seed volume of 'Jasna' ranged between 4.72 mm(3) and 5.49 mm(3), and it was significantly higher than that of 'Banacanka' and 'Slavica' (4.07 - 4.93 mm(3) and 4.12 - 4.81 mm(3), respectively). The bulk density of 'Jasna' seeds was significantly lower than in other cultivars. Depending on seed moisture content, seed density decreased from 1023.18 kgm(-3) to 996.97 kgm(-3) in 'Banacanka', from 1009.31 to 992.70 kgm(-3) in 'Jasna', and from 1012.96-992 kgm(-3) in 'Slavica'. Porosity increased with increasing seed moisture content in all cultivars. The porosity of 'Jasna' seeds (35.97-38.43%) was higher than that of 'Banacanka' (35.42-38.23%) and 'Slavica' (35.19-37.07%) seeds. At different seed moisture levels, bulk density varied from 665.82 to 615.84 kgm(-3) in 'Banacanka', from 646.24 to 611.22 kgm(-3) in 'Jasna', and from 656.57 to 624.66 kgm(-3) in 'Slavica'. The static angle of repose in 'Banacanka', 'Jasna' and 'Slavica' ranged from 22.96 degrees to 28.05 degrees, from 24.64 degrees to 29.66 degrees and from 24.63 degrees to 29.61 degrees at moisture contents increasing. The dynamic angle of repose was highest in 'Jasna' (20.32-25.90 degrees), followed by 'Slavica' (21.03-25.58 degrees), and lowest in 'Banacanka' (19.22-24.66 degrees). Increasing seed moisture content was found to increase the friction coefficient. The static friction coefficient of cvs. 'Jasna' and 'Slavica' was higher than for 'Banacanka'.