Detachment of coffee fruits by oscillation

This research studied the effects of the frequency and amplitude of oscillation as well as the effect of coffee branch length on the detachment of coffee cherries at various maturation stages, i.e. green, ripe (red cherries), and over-ripe cherries.Coffee branches were collected at two lengths (100 and 400 mm). The tests were accomplished under three oscillation amplitudes (11, 22 and 33 mm). For each oscillation amplitude, four vibration frequencies were tested (13.3, 15.0, 18.3, and 20.0 Hz). Thetests were performed every 10 seconds. The oscillation amplitudes of 22 and 33 mm and the vibration frequencies of 18 to 20 Hz provided higher efficiency in detaching the coffee cherries. The detachment of coffee cherries decreased with the increase in coffee branch length. Ripe and over-ripe cherries were more easily detached than cherries at the green stage.