Development and Performance Analysis of a Pedal-Operated Wadi (Nuggets) Making Machine

This study presents development and performance evaluation of a pedal-operated wadi (nuggets) making machine, designed to improve productivity, hygiene and product uniformity compared with traditional hand-forming methods. Conventional wadi preparation is highly labour intensive and often produces inconsistent products, whereas the proposed system reduces direct manual handling, enhances hygienic conditions and increases throughput. The machine consists of a hopper, a pair of grooved rollers, a pedal driven transmission system, and a manual cutting unit. During operation, the pedaling action of the operator is converted into continuous rotary motion via a pedal–wheel and pulley arrangement. This motion drives the synchronized grooved rollers, which control the flow of the batter, while a manually operated cutting blade periodically cuts the extruded batter into uniform wadis. Process parameters were optimized using Response Surface Methodology (RSM) with a Central Composite Design (CCD). Roller speed (18–30 rpm), batter moisture content [45%–70% wet basis (wb)], and cutting speed (20–30 strokes min^-1) were taken as independent variables, and throughput was used as the response variable. The optimum conditions of roller speed of 19.9 rpm, batter moisture content of 63.4% (wet basis), and cutting speed of 28 strokes min^-1 yielded a predicted throughput of 10.62 kg h^-1, which was in good agreement with experimental results, with a desirability value of 1.0. The cost–economic analysis indicated a payback period of about 1–2 months, suggesting that the machine is well suited for small scale and rural food processing enterprises.