Performance Evaluation of Improved Motorised Dry Locust Bean (Parkia biglobosa) Seed Depulping Machine

Abstract

African locust bean (Parkia biglobosa) seed processing involves the removal of pulp before further handling for traditional condiments such as iru and dawadawa. Conventional wet depulping is labour-intensive and requires considerable quantities of water, creating practical and hygienic limitations for small-scale processors. This study evaluated the performance of an improved motorised dry locust bean seed depulping machine designed to remove pulp without water use. The machine comprises a feed hopper, depulping chamber, cleaning chamber, rotating shaft fitted with a wire wheel brush, pulley-belt transmission system, and a 1.5 hp petrol engine. Performance evaluation was conducted using dried locust bean seeds with an average moisture content of 9.29%. The measured parameters were depulping efficiency, cleaning efficiency, throughput capacity, depulping time, cleaning time, and operating speed. The machine was tested at sample masses of 0.5, 0.6, and 0.7 kg, with operating speeds ranging from 594 to 1290 rpm. The results showed a depulping efficiency of 100% for all test runs, while cleaning efficiency ranged from 91.63% to 94.36%. The throughput capacity ranged from 12.28 to 14.29 kg/hr, with an average value of 13.13 kg/hr. No seed breakage was reported during depulping. These results indicate that the machine can support water-free depulping with reduced processing time and labour demand for small- and medium-scale locust bean processing.