Groundnut seed roasting is a critical step in the processing for oil extraction, snack nuts, confectionaries and peanuts for roasting. Roasting enhances oil extraction processes as it reduces the oil’s viscosity, releases oil from intact cells and reduces the moisture content. A comparative performance evaluation of an existing and a modified groundnut seed roasting machines was carried out and reported in this study. A Completely Randomized Design (CRD) was used where roasting efficiency, percentage of groundnut seed loss and fuel consumption rate were used as performance indicators, for the two machines investigated (existing and modified machines). Two groundnut seeds varieties (Manipintar and Ex-Dakar) and three turning speeds (30, 50 and 70 rpm) were used as independent variables. The combination of the independent variables resulted to a total of twelve (12) experimental treatments, thus with three replications carried out on each treatment a total of thirty-six (36) experiments were conducted. For the existing and modified roasting machine, results obtained revealed that 91.20% and 98.80%; 12.40% and 1.20%; and 1.90 kg/hr and 1.20 kg/hr were achieved as roasting efficiency; percentage of groundnut seed loss; and fuel consumption rate, respectively. It was established that the effects of using different roasting machine model and turning speeds are significant on roasting efficiency, while variety is not significant on roasting efficiency. For percentage of groundnut seed loss for the different machine models was highly significant, while variety and turning speed with their interaction are not significant. The interactions on the effects of using different machine model, variety of groundnut seed used and turning speed were highly significant on fuel consumption rate.
Keywords: Roasting efficiency, percentage of seed loss, turning speed, groundnut, performance