Development of environmental friendly multi-crop slicing machine to eradicate unhygienic manual processing for health safety

Abstract

Background: Human health safety is very important and considered as the number one criterion in the design and fabrication of any food processing machine. Manual slicing methods are unhygienic, risky, stressful and inefficient while the use of an internal combustion engine as prime mover in the food processing machine is not environmental friendly due to the emission of gases. Objectives: The aim of this study was to design, fabricate and evaluate for performance an environmental friendly and hygienic multi-crop slicing machine. Methods: The major components of the machine include the hopper, mainframe, driving pulley, belt, driven pulley, shaft, main bearings, crank plate, connecting rod, slicing unit, groove bearings, spacers, electric motor and outlet. The machine is powered by a variable speed, three-phase 0.75 kW electric motor with rotational speed ranging between 284 and 800 rpm. The performance of the machine was evaluated in slicing six different crops namely yam, carrot, sweet potato, onion, plantain and cucumber at three machine speeds of 190, 362 and 533 rpm while the slice thickness was also varied as 3, 5 and 8 mm. The parameters that were investigated include functional efficiency (FE), slicing efficiency (SE), percentage mechanical damage (MD), percentage materials lost (ML), percentage materials retained (MR), throughput (TP), slicing capacity (SC) and quality performance efficiency (QPE). Results: Major performance criteria obtained for yam were 90.4% FE, 93.7% SE, 156.7 kg/h TP, 84.8% QPE and 11899 slices per hour.  88% FE, 93.7% SE, 120.7 kg/h TP, 82.4% QPE and 9365 slices per hour were obtained for sweet potato. 85% FE, 95.8% SE, 138.5 kg/h TP, 81.5% QPE and 31300 slices per hour were obtained for the carrot. 78% FE, 98.3% SE, 68.4 kg/h TP and 77% QPE were obtained for onion. 89% FE, 92.5% SE, 83.5 kg/h TP, 82.5% QPE and 15876 slices per hour were obtained for plantain. 93.5% FE, 94% SE, 128 kg/h TP, 88% QPE and 13790 slices per hour were obtained for cucumber. The result of the study shows that the machine can slice any fruit as well as root and tuber crops satisfactorily. Conclusion: The performance evaluation revealed that any of the speed and thickness range can be used without a significant side effect. 

Keywords: multi-crop; functional efficiency; percentage materials retained; throughput; quality performance efficiency