Development of a Modular Bitter Leaf Washing and Juice Extraction Machine

Abstract

Bitter leaf (Vernonia amygdalina) is one of the leafy vegetables that can be used to alleviate the problem of micronutrient malnutrition, prominent in tropical Africa. To ensure availability in non-growing areas, the vegetable needs to be preserved. Processing and preservation methods influence the nutrient content of the vegetables. This research work is therefore focused on the development of a modular bitter leaf washing and juice extraction machine. The machine is an electrically powered bitter leaf juice extractor that washes bitter leaf fed into it and at the same time squeezes out the juice. It uses stainless steel beaters inclined to angle of 0o to wash and squeeze the leaves against the cylindrical hopper incorporated with a perforated plate that drained juice while pulp is expelled. The beater is designed to work with the principle of oscillatory motion. The designed and fabricated bitter leaf juice washing and extraction machine was evaluated to determine the power, torque, force, etc., that are required to wash and extract the juice. The results obtained showed that the speed reduction, angular velocity, centrifugal force, torque, and power of 0.0127 m3, 480 rpm, 50.285 rad/sec, 303.430 N, 3.03 Nm, 0.75 hp are required. Also, a minimum bitter leaf extraction time of 398.28 seconds was required by the machine in comparison to manual extraction time of 724.13 seconds. Besides, the result of volume of bitter leaf juice extracted manually and mechanically from 407.54 g of bitter leaf were 3.60 litre and 3.63 litre respectively. The efficiency of the machine and the machine throughput capacity were obtained as 55.00 % and 1.032 g/sec respectively. This simply implies that the developed machine is 55.00 % efficient than manual method of washing bitter leaf.