Volume Expansion Ratio
The volume expansion was measured by sand replacement
method (Chinnaswamy and Bhattacharya 1983a;
Joshi et al. 2013). Initial volume of 50g unpuffed
parboiled milled rice was taken in a 500-ml cylinder
and filled it with fine sand, and the volume was noted.
The same sample was then puffed in a microwave oven
with the process described in the earlier section. Volume
expansion ratio was calculated using following expression: