Design, Fabrication and Evaluation of Electrically-operated Groundnut Roasting Machine

摘要

Groundnut is a valuable crop with an excellent source of protein that can be used to fight hunger and malnutrition especially in underdeveloped and developing countries. Products such as oil, peanut butter, soups, roasted groundnuts among others can be obtained from groundnuts However, in developing nations especially Nigeria, roasting of groundnut, a means of moisture removal and food processing, has been associated with drudgery and bad hygiene (that is, use of sand, ashes as means of heat transfer). This can be a source of physical and microbial contamination to the product. Hence, the need for development and evaluation of a peanut processor that alleviate the problems associated with the process. Design, fabrication and performance evaluation of groundnut roasting machine were carried out at the AGE Workshop, Federal University of Technology, Akure, Nigeria. The factors considered for the design were; the volume of product to be roasted, reduction of heat loss, inclusion of stirrer and stable roasting temperature. Raw groundnuts were roasted with the fabricated machine and parameters such as weight of raw groundnuts, weight of roasted groundnuts, weight of seeds damaged were used to evaluate the efficiency of the machine. The effect of sand on the roasted groundnuts was also determined through microbial analysis, free fatty acids, peroxide value, tannin, flavonoid, phytate and phenol. The average percentage losses were 16.15% and 5.89% for traditional and mechanical methods, respectively. The traditional and mechanical methods recorded an average roasting efficiency of 83.85% and 94.11%, respectively. Both processing methods produced a product with considerable low moisture content. Processing time was reduced by 18 minutes when processed mechanically with significantly (p < 0.05) lower antinutrients and reduced microbial load. Mechanical processing of groundnuts is more efficient than traditional roasting in terms of time and overall quality of the roasted groundnut.