Design and Development of Low-Cost Makhana Grading and Roasting Machine

The currently available technology of Makhana processing is not only indigenous and manual but also cumbersome and painstaking. The process involves handling of hot roasted seeds which require two to three laborers to process 8-9 kg of popped Makhana per day. With the view to mechanize the unit operation involved in Makhana processing, grading and roasting machine were designed and developed. Grader was developed based on engineering properties of Makhana while the roaster was designed based on preliminary experiments for Makhana, i.e. shell breaking force at different temperatures and for varying residence time. The grader performed best at feed rate of 20 kg/h with grading effectiveness of 0.99, 0.955 and 0.95 for grade 1, grade 2 and grade 3 Makhana seeds respectively. The developed roasting machine worked satisfactorily with 100% popping efficiency at machine capacity around 23.0 kg/h. The residence time of seeds in the roaster was 2.6 min and the average temperature of roasted seeds of grade 1, grade 2, grade 3 was found to be 271.33 degrees C, 281.1 degrees C and 280.7 degrees C respectively.