Mechanical Behaviour of Common Bean (cv. Butter) Seeds as Affected by Maturation

In this study, the effects of maturation of bean seeds on some mechanical behaviours of common bean (cv. Butter) were investigated. The bean seeds were harvested at three maturity stages (15 DAPA, 22 DAPA and 29 DAPA), and their rupture force, rupture energy, specific deformation, toughness and rupture power were test. The bean seeds were quasi-statically loaded in along their three main axes (X-axis, Y-axis and Z-axis), at a loading speed of 25 mm/min. The results obtained revealed that the maturity stage and loading orientation had significant (p ≤0.05) effect on all the mechanical parameters investigated in this study. According to the results, all the parameters investigated increased linearly as the bean seeds matured from 15 DAPA to 29 DAPA. For all the mechanical parameters, the highest values were obtained when the seeds were compressed along the Z-axis, while the least values were obtained when the seeds were compressed along the Y-axis. The highest rupture energy (0.064 Nm) was obtained for bean seeds (harvested at 29 DAPA) loaded along the Z-axis, while the bean seeds harvested at 15 DAPA and loaded along the Y-axis required the least energy to rupture (0.028 Nm). From the results, at 29 DAPA, the mean rupture power of 0.277 W, 0.212 W, and 0.314 W were recorded, when the seeds were compressed along the X-axis, Y-axis and Z-axis respectively. These results will be useful in the design and development of bean seeds processing and handling equipment.