Makhana is a popped kernel of gorgon nut (Euryale ferox) and is consid
ered a delicious food item in India. It is, presently, sorted, graded
and processed manually. To develop any kind of mechanized system for t
hese purposes, physical data are required and thus, test weight, bulk
density, true density, porosity, angle of repose and coefficient of fr
iction of different grades of makhana were determined using standard t
echniques at moisture contents ranging from 5 to 20% (dry basis). The
data were used to develop correlation equations that predict these phy
sical properties as a function of moisture content of makhana. The spa
tial dimensions and aerodynamic properties were also determined. The a
verage diameter of makhana varied between 18.4 mm to 12.4 mm with the
sphericity between 0.581 to 0.967; and other physical properties varie
d quadratically with moisture content. The terminal velocity and drag
coefficient of makhana at 8% moisture content (dw basis) varied betwee
n 4.48 to 6.10 m/s and 0.62 to 1.06, respectively.