Development, Testing and Optimization of a Moringa (Moringa oleifera) Seed Dehuller

A moringa dehuller which adopted impact principle for dehulling was developed, and the performance was evaluated in terms of the dehulling efficiency. Central composite rotatable design consisting of three factors and five levels was adopted for the experiments, and the experimental factors were moisture content, feed rate and operational speed, while dehulling efficiency was the dependent variable. Data analyses were performed using multiple linear regression at 5% significant level, and the processing factors were related to dehulling efficiency using developed mathematical models. Experimental results were used to validate predicted optimum conditions. Maximum dehulling efficiency of 87.41% was obtained at moisture content of 9.00% wet basis, feed rate of 2.17 kg/min and an operating speed of 900 rpm. The coefficient of determination (R2) for the dehulling efficiency was 0.86. In the range of 8–12% wet basis for moisture content, 1.17–2.5 kg/min for feed rate and 600–1000 rpm for operational speed, where the goal for dehulling efficiency was maximum, the predicted optimal value was 90.20% at 8.00% wet basis moisture content, 2.50 kg/min feed rate and 902.36 rpm operational speed with a desirability of 0.92. Under these optimal conditions, the experimental value was 89.63%. The deviation between the experimental and predicted values was low and statistically insignificant, which implies that the selected model could efficiently predict the dehulling efficiency.