Vikash Kumar, Raushan Kumar, Dinesh Rajak, Vishal Kumar and Anjani Kumar
Makhana (Euryale ferox Salisb.) is one of the most common dry fruits utilized by the people due to low fat content, high contents of carbohydrates, protein, minerals and other medicinal significance. For the purpose of developing any kind of mechanized system for sorting, grading and manual processing, different engineering properties like test weight, bulk density, true density, porosity, angle of repose and coefficient of friction of different grades of makhana were determined using standard techniques at moisture contents ranging from 20 to 60% (dry basis). Increase in moisture content was found to increase the linear dimensions, mass of 100 seeds, bulk density, true density, angle of repose, and coefficient of friction while porosity decreased with increase in moisture content. Coefficient of friction was found to increase as moisture content increased from 0.298–0.414, 0.420–0.517 and 0.524–0.639 respectively on glass, wooden and mild steel sheet structural surfaces. Angle of repose showed an increasing trend with increase in moisture content. The study concludes that grade and changes in moisture content significantly (P<0.05) affected most of the engineering properties determined.