Abstract:
Kidney beans are more susceptible to breakage under impact loading during
harvesting and processing. This problem limited the mechanical harvesting. Mechanical
damage decreased the commercial values of seeds. It also decreased the biological values of
seeds. Improper harvesting of beans during harvesting may also result in severe seed vigour
loss. The objective of this study was to study the effect of impact velocity (at 5, 7.5, 10, and 12
m/s) and beans moisture content (at 5, 10, 15 and 20% wet basis) on percentage of physically
damaged beans. The device of assessing the impact damage was used to conduct the tests. All
the tests were conducted in laboratory conditions at about 25 oC and 50% relative humidity.
The results showed that impact velocity and moisture content significantly influenced the
physical damages of kidney beans at 1% and 5% significant level, respectively. Increasing the
impact velocity from 5 to 12 m/s caused an increase in the mean percent of physical damages
from 3.25 to 37.5%. The corresponding data for beans at the moisture content of 5% were from
3.7% to 45.7%. With increasing the moisture content from 5 to 15%, the mean values of
percentage of damaged beans decreased by 1.4 times. However, with higher increase in the
moisture content from 15 to 20%, the mean values of physically damaged beans showed a nonsignificant
increasing trend. The relationship between the percent of physical damage with
impact velocity and beans moisture content was expressed mathematically. It was found that
the model has provided satisfactory results over the whole set of values for the dependent
variable.
