Design and construction of a multipurpose pineapple processing machine.

Abstract

Pineapple fruit (Ananas comosus) is highly perishable in its natural state after harvest and is vulnerable to spoilage by mechanical damage, chemical deterioration and environmental effects. Thus, it is highly essential to process the freshly harvested fruit into juice which can be consumed freshly or processed further into healthful beverages. Design considerations included: high processing capacity and efficiency, quality of juice quality, availability and cost of construction materials. The main design features involved pulley and belt design, worm shaft design, design for capacity, power requirements and prime mover selection. The major components of the machine were peeling table, chopping unit, extraction unit, juice outlet, waste outlet, frame, prime mover (electric motor) and motor stand. The chopping unit consists of a shaft attached with spikes which chop whale pineapple fruit into smaller pieces and convey the chopped product to the position where it enters the extraction unit through a lower hopper. The extraction chamber houses a shaft which conveys crushes, grinds and presses the product from the chopping unit. The juice extracted is drained through the juice sieve into the juice outlet from where it is collected while the residual waste is collected at the Waste outlet. The machine was tested using freshly. harvested whole pineapple fruits and result revealed a juice yield, extraction efficiency and extraction loss of 57.8, 77.9 and 51.2 % respectively. Powered by a 2 hp single-phase electric motor, the machine has a production cost of UGX (1,033,000 OR 1.563.000) when the motor is hired or bought with the construction materials being locally available at affordable costs. A cottage pineapple juice extraction plant based on this technology can provide employment for at least two persons at the same time providing fresh juice at low Costs and residual waste as an ingredient for livestock feed manufacturing.