Abstract:
Cassava is an important tuber crop in the tropics owing to its economic potentials and its enormous uses as a staple food. Cassava tubers require peeling before it can serve its numerous industrial and domestic uses as this highly affects the quality and safety of the end product(s). There is need for improved peeling methods because cassava toxicity is highly concentrated in the peels. However, mechanization of cassava peeling process is still receiving attention from engineers especially in developing nations like Nigeria. Therefore this project investigated the efficiency of an already developed cassava peeling machine using three selected peeling tools. Comparative analysis of the performance of the machine with each of the peeling tools was also carried out. Freshly harvested TME 419 cassava tuber was used for the evaluation. The evaluation was performed with five (5) different speeds (75,100, 125, 150,175 rpm) at three different feed rates (5kg, 10kg and 15kg) with the three (3) selected peeling tools (A, B, and C) and three (3) tuber sizes (Large tubers, medium tubers and small tubers). The relationship between independent variables (tool speed, feed rate and tuber size) and dependent parameters (peeling efficiency, quality performance efficiency, mechanical damage, peel retention and throughput capacity) were graphically presented and statistically determined. The result revealed that peeling efficiency of the machine shows a slightly decreasing trend with increase in tool speed and mass of cassava tuber fed into the machine. However, the highest peeling efficiency (72.07 ± 2.58, 87.33 ±3.43 and 88.53 ± 2.36 %) were recorded for tuber size A, B and C respectively. Quality performance efficiency of the machine also followed the same trend. Conversely, mechanical damage and peel retention slightly increase with increase in tool speed and mass of fed for all categories of tuber sizes. However, the least mechanical damage (5.07 ± 1.07, 2.71 ± 0.70 and 2.69 ± 0.67 %) were recorded for tuber size A, B and C respectively. This was observed when tool C was used. The highest peeling efficiencies was recorded for tool C followed by tool B while the highest mechanical damage (14.63 ± 3.85, 6.15 ± 1.29 and 5.37 ± 1.45%) for tuber size A, B and C respectively were equally recorded for all the selected sizes of cassava tubers when peeling tool A was used. However, the least percentage of peel retained on the tubers (27.92 ± 5.47, 12.67 ± 0.9 and 11.47 ± 0.55% for tuber size A, B and C respectively) was observed when peeling tool C was used at constant tool speed and mass feed to the machine. Highest percentage of peel retention (41.85 ± 7.42, 32.00 ± 2.20 and 30.85 ± 1.90% for tuber size A, B and C respectively) were recorded for peeling tool A for all the selected size of cassava tuber, mass feed to the machine and constant machine speed. The results obtained from the study, tool C was found to have the best performance from the analysis due to the followings: highest peeling efficiency, highest quality performance efficiency, least mechanical damage and least peel retention, at all speed levels and mass of feed for all categories tuber size.